Chapter 95. Torso Trauma

• Consideration of abdominal and thoracic injuries as one complex torso trauma is a useful treatment strategy.
• Prioritization of intervention in torso trauma is based on the relative threat to life from specific injuries.
• In managing torso trauma, the surgeon must be prepared to explore the chest and/or abdomen because the source of instability frequently is not obvious.
• The major decision in assessing the traumatized abdomen is to recognize the need for surgical exploration.
• In general, indications for surgical intervention in abdominal trauma are perforation, penetration, and hemorrhage.
• An organ-specific diagnosis is not necessary to establish the need for laparotomy in trauma.
• Ultrasound, peritoneal lavage, and computed tomographic (CT) scan are important tools in assessing the traumatized abdomen when physical examination alone is unreliable.
• Most thoracic injuries can be managed appropriately by simple measures aimed at correcting thoracic sources of hypoperfusion and hypoxemia.
• Emergency thoracotomy should be considered in the unstable patient who has a potentially correctable source of instability in the thorax.

Injuries involving the chest and abdomen may be considered as a single complex torso trauma. The rationale for this point of view is based on several factors. The configuration of the diaphragm and its attachment to the rib cage result in marked variability in its position with respiration and thus in demarcation of the thoracic and abdominal cavities. It is not unusual for the diaphragm to traverse distances of over 15 cm between the inspiratory and expiratory phases of respiration. The diaphragm may be at the level of the nipple line during full expiration and well below the costal margin during full inspiration, with corresponding shifts of the abdominal and thoracic contents (Fig. 95-1). This phenomenon, together with the variable trajectory of objects or forces after penetrating the torso, makes it virtually impossible in many instances to determine on the basis of the external point of impact or penetration whether intrathoracic or intraabdominal injury has been sustained. The concept of torso trauma ensures that injuries in one cavity will not be overlooked while injuries in the other are being managed.1,1a,1b

As outlined in Chap. 92, the initial approach in trauma management is to secure the airway, to maintain respiration, and to identify and control hemorrhage and institute immediate fluid resuscitation as required. Definitive management of intraabdominal or thoracic injury may be necessary as part of this resuscitative phase, particularly if the source of instability is major hemorrhage in the thoracic or abdominal cavity. Although it may be possible to identify a specific source in the thorax or abdomen for the abnormal hemodynamics in the trauma patient, it is frequently impossible to be absolutely certain of such a source. Therefore, a decision has to be made to approach the hemodynamically abnormal patient through either a laparotomy or a thoracotomy if a source outside the thorax or abdomen has been ruled out. With this approach, one must be prepared to stop exploration of one cavity when it becomes obvious that the source of the hemodynamic abnormality is in the other.

Generally, torso trauma may be classified into two broad groups: penetrating and blunt. As indicated earlier, any penetrating missile entering inferior to the nipple line can produce diaphragmatic, intrathoracic, or abdominal injuries. Similarly, blunt injuries may disrupt intrathoracic contents as well as intraabdominal contents either directly or indirectly through fractures of the lower ribs, which then puncture intraabdominal organs such as the spleen, liver, and stomach.

A more clinically applicable method of classifying torso trauma involves two categories. The first category consists of injuries that are immediately life threatening and thus require immediate intervention because of cardiorespiratory or hemodynamic compromise. The other category includes injuries in a relatively hemodynamically normal patient. These latter injuries are considered to be potentially life threatening because, if left unattended, they eventually may threaten the patient's survival.

Occasionally, neck injuries, particularly the penetrating type, may involve intrathoracic structures. In addition to causing vascular injury (which may present with hemorrhage or ischemic sequelae), injury to the thoracic duct (resulting in chylothorax), or violation of the pleura (resulting in pneumothorax), penetrating neck wounds may affect any of the intrathoracic structures, depending on the trajectory of the offending weapon.

The neck traditionally is divided into three anatomic regions for the purposes of categorizing penetrating wounds. Zone I extends from the cricoid to the clavicle, zone II from the cricoid to the angle of the mandible, and zone III lies between the angle of the mandible and the base of the skull.

Penetrating wounds of the neck should be explored in the operating room under sterile conditions with adequate anesthetic support. A preoperative plain x-ray of the neck if the patient is stable could provide information such as depth of penetration and the presence of air in the tissues, hematoma, airway deviation, etc. Impaling objects should be removed only in the operating room with vascular equipment available and a securely controlled airway in place. Although there is reasonably good agreement that zone III injuries should be investigated with angiography, the use of angiography and other diagnostic modalities in zone II injuries is controversial because this area can be assessed thoroughly and more easily through direct surgical exploration in the operating room. Diagnostic modalities include angiography, endoscopy, contrast radiography, and computed tomography (CT).2

A nasogastric tube should be inserted in the operating room, preferably after the airway is securely controlled by endotracheal intubation, because retching during the insertion of such a tube could lead to clot dislodgment, hemorrhage, and airway compromise. The possibility of intrathoracic injury always should be considered in patients with penetrating neck wounds. The chest therefore should be prepared and draped adequately in the event that thoracic exploration is necessary for repair of intrathoracic injury or possible vascular control for vascular injuries in the neck.

Although thoracic injury frequently is associated with trauma-related deaths, less than 10% of blunt chest injuries and only 15% to 30% of penetrating chest injuries require open thoracotomy.3 Lifesaving skills for dealing with thoracic trauma generally are within the scope of most practicing intensivists. Of the injuries that require open surgical intervention, most do not require the expertise of a trained thoracic surgeon. From the intensivist's standpoint, resuscitative measures are aimed at correcting hypoxemia and maintaining normal hemodynamic status. These two aims are achieved by techniques for establishing patency of the airway3,4 (see Chap. 35), chest decompression for evacuating fluid or air, pericardiocentesis, and vascular access for fluid administration.

In addition to upper airway obstruction, which is discussed in Chap. 34 and poses an immediate threat to life, the following thoracic injuries require immediate intervention4–6:

1. Tension pneumothorax

2. Open pneumothorax

3. Cardiac tamponade

4. Massive hemothorax

5. Massive pneumothorax

6. Traumatic air embolism

7. Flail chest

Since all of these conditions require immediate intervention, the intensivist who sees such patients must be prepared to institute therapy before any other physician is available. To guide appropriate intervention, a brief description of the pathophysiology, diagnosis, and treatment principles for each of these conditions follows. In all cases, the airway must be secured and adequate intravenous (IV) access established.

Tension Pneumothorax

This lesion arises when a one-way valve mechanism exists after chest wall or lung injury. Gas enters the pleural space but has no escape, and with each subsequent respiratory cycle, there is increased intrapleural pressure and gas accumulation. This increased tension causes the ipsilateral lung to be compressed and displaced to the opposite side. With the resulting mediastinal shift, there is not only compromise of ventilation and gas exchange but also kinking of the major veins at the thoracic inlet of the neck and at the diaphragmatic entrance of the inferior vena cava, thus compromising venous return to the heart. Continued shift of the mediastinum eventually compresses the contralateral lung as well, producing further ventilatory compromise. This combination of hypoperfusion and hypoxemia can be lethal, and immediate treatment is required. The diagnosis is suspected in a patient who presents with chest trauma, tachypnea, severe dyspnea, decreased air entry, and hyperresonance on the affected side and, sometimes, a clinically detectable shift of the trachea to the opposite side with hypotension.

The treatment is immediate decompression of the pleural space, which is accomplished initially by inserting a large-bore needle or incising with a scalpel down through the chest wall into the pleural space at the second intercostal space in the midclavicular line or the fourth to fifth intercostal space just anterior to the midaxillary line. If a plunger syringe is used with the needle, an immediate spontaneous rise of the plunger in the barrel will be seen. Similarly, when the scalpel enters the pleural space, there is a massive loud decompression of the pleural space, followed by immediate respiratory improvement. Either procedure should be followed by formal insertion of a chest tube. Briefly, the technique of chest tube insertion requires an incision down to the pleura in the fourth to fifth intercostal space just anterior to the midaxillary line. The large-bore chest tube (F32 to F36) is inserted directly with a clamp after verification with finger palpation that the pleural space has been entered and there are no pleural adhesions (Fig. 95-2). When needle decompression is performed prior to insertion of the chest tube, the needle may be inserted through the finger portion of a glove so that air may exit but not enter the pleural space from the atmosphere (Fig. 95-3). Once the chest tube is inserted, it is connected to an underwater seal system with the option of applying suction. Figure 95-4 illustrates the classic chest tube drainage system. However, commercially available prepackaged chest tube drainage systems are available that operate on the same principles.

Open Pneumothorax

In open pneumothorax, there is free communication through a chest wall wound between the pleural space and the atmosphere. Entry of air with each respiratory cycle results in progressive collapse of the ipsilateral lung. The larger the defect in the chest wall, the greater is the rate at which pleural air accumulates, and the more rapid is the collapse of the ipsilateral lung. This pathophysiology is similar to that in tension pneumothorax because collapse of the lung and shift of the mediastinum to the opposite side will cause hypoxemia and decreased venous return. The diagnosis usually is obvious, with a visible open wound in the chest wall and a characteristic loud noise created from atmospheric air entry into the pleural space.

The first principle in treating this injury is occlusion of the open wound. This usually can be accomplished with an occlusive gauze dressing (Fig. 95-5). Larger defects will require much larger dressings, and major defects that cannot be occluded readily by dressing technique will require support of the patient with endotracheal intubation and positive-pressure ventilation until formal surgical repair of the chest wall defect can be accomplished. After the opening in the chest wall is occluded, a chest tube should be inserted through a separate opening, as indicated earlier. Figure 95-5 shows a technique whereby an occlusive dressing can be applied that allows decompression of the pleural space as well as occlusion of the opening. The nonpermeable dressing is applied over the opening and secured on all but one side. This allows egress of air from the pleural space but prevents air from entering the pleural space.

Cardiac Tamponade

Cardiac tamponade occurs when fluid accumulation in the pericardial sac interferes with cardiac filling. Elevated pericardial pressure decreases transmural filling pressures of the cardiac chambers, resulting in diminished filling and stroke volume of the right and the left side of the heart. Cardiac output falls, with an attendant decrease in systolic blood pressure and pulse pressure.

The diagnosis of cardiac tamponade is one that requires a high index of suspicion and should be considered in any patient who has blunt or penetrating trauma to the chest and is hypotensive without any obvious signs of blood loss. The classic triad described by Beck of hypotension, elevated venous pressure, and muffled heart tones is not always present or easily discernible.7 The status of the neck veins is particularly important in distinguishing hypotension caused by hypovolemia from that caused by cardiac tamponade. In the former case, the neck veins are flat, whereas in the latter, they are distended. However, a struggling or straining patient may produce misleading bulging of the neck veins, which must be taken into consideration. An increase in pulsus paradoxus (the difference in systolic blood pressure between inspiration and expiration) above 10 mm Hg suggests the diagnosis of cardiac tamponade. However, in the emergency setting it may be difficult to quantitate the degree of pulsus paradoxus. During arterial pressure transduction in the ICU, it is possible to measure pulsus paradoxus accurately. The physician should note the difference between systolic blood pressure during inspiration and expiration. The pressure waveform will exhibit a lower peak level in inspiration, with higher peak levels in expiration. The difference between the two peaks is the pulsus paradoxus. The degree of pulsus paradoxus may be determined at the bedside by listening for the first set of sounds with the sphygmomanometer slowly deflating. The first set of sounds represents the systolic blood pressure on expiration. As the pressure in the cuff is slowly released, the gaps in systolic blood pressure sounds between inspiration and expiration disappear, and there is an increased frequency of sounds heard with the stethoscope. The difference between the initial pressure and the pressure when the gaps in sounds have disappeared is the degree of pulsus paradoxus. Since distended neck veins and hypotension are present in both tension pneumothorax and cardiac tamponade, differentiation between these two conditions is important but at times difficult. The physician must rely on evidence of hyperresonance and decreased breath sounds that will suggest tension pneumothorax. If a search for these signs still leaves doubt, the patient should be treated first for possible tension pneumothorax by insertion of a needle in the pleural space. This step can be performed quickly and will give the diagnosis as well as be therapeutic for a tension pneumothorax. Once tension pneumothorax is ruled out, one should proceed to treatment for cardiac tamponade if signs of circulatory compromise persist. If immediately available in the emergency setting, epigastric placement of an ultrasound probe is also helpful in diagnosing hemopericardium.8

Although performance of a subxiphoid pericardial window in the relatively stable patient is acceptable, the initial treatment of cardiac tamponade consists of prompt pericardiocentesis.9 This usually is performed with a 16- to 18-gauge needle that is at least 6 in long, incorporates a catheter, and is attached to a 50-mm empty syringe with a three-way stopcock. If time permits, the skin below the xiphoid process is anesthetized, and an electrocardiographic lead is attached to the hub of the needle as the needle is inserted below the skin at roughly a 45-degree angle and advanced cephalad toward the tip of the left scapula.3,9 Gentle aspiration is maintained as the needle is advanced. A sense of “give” may be noted as the needle enters the pericardial sac. Nonclotting blood aspirated at this time confirms a pericardial position of the needle. If the needle is advanced into the myocardium, an injury pattern is seen on the electrocardiogram (ECG) monitor. If this is noted, the needle should be withdrawn slightly and then aspirated coincident with return to the previous baseline ECG tracing. Other ECG patterns, including premature ventricular contractions, may occur when the needle contacts the myocardium.

Although the pericardial sac can accommodate large volumes of fluid when the fluid accumulates chronically, in acute pericardial tamponade, a volume as small as 100 mL can compromise cardiac function significantly. Similarly, withdrawal of as little as 20 to 50 mL of blood from the pericardial sac results in significant improvement in hemodynamic status.10 Apart from the signs noted earlier that suggest successful aspiration of the pericardial sac, recovery of blood that immediately clots in the syringe, particularly if the patient's hemodynamic status does not improve, should raise the concern that the needle has penetrated the heart and that intracardiac rather than pericardial blood is being aspirated. As pericardiocentesis is being conducted, the operating room (OR) should be prepared; whether pericardiocentesis fails or succeeds and results in stabilization of the hemodynamic status, it should be followed by formal thoracotomy and repair of the lacerated heart.10–13 This usually is conducted through an anterolateral thoracotomy incision in the fifth intercostal space. However, a median sternotomy is an alternate route. When the thoracic cavity is entered, the pericardium is identified, and a longitudinal incision is made in it, care being taken to avoid transection of the phrenic nerve. Blood is aspirated, and the laceration in the heart is identified and controlled quickly by digital pressure. With finger control of the bleeding point, interrupted sutures are placed and secured with Teflon pledgets to repair the laceration, and the pericardium is then resutured, with a small opening (approximately 1 cm) left to prevent reaccumulation of blood in the pericardial sac. Other reported techniques for repair of the cardiac laceration include temporary Foley catheter insertion into the cardiac wound, followed by inflation of the balloon of the catheter and repair of the laceration. Skin staples also may be used to close the cardiac wound. In very rare circumstances, the laceration involves the coronary arteries. Formal repair of the artery will require heart-lung bypass and may be accomplished in the acute setting if the resources are immediately available. If the patient's condition stabilizes and the bleeding and laceration have been controlled, then definitive therapy for the coronary artery laceration may be pursued subsequently on a semielective basis. In placing sutures for the cardiac repair, care should be taken to avoid incorporating and ligating coronary arteries.

Massive Hemothorax

Although most patients with traumatic hemothorax are relatively stable and do not require immediate surgical intervention, a few present with massive intrathoracic hemorrhage. This condition requires prompt diagnosis and immediate treatment to ensure survival. The mechanism of injury may be blunt or penetrating and generally involves disruption of a major central vascular structure or laceration of a systemic artery such as an intercostal artery or internal mammary artery. Intrathoracic hemorrhage usually arises from parenchymal lesions of the lung and stops spontaneously, particularly with reexpansion of the lung. The patient with massive intrathoracic hemorrhage presents initially with severe hypotension from blood loss and later with hypoxemia from collapse of the lung caused by the mass effect of the blood in the involved thoracic cavity.14 Apart from severe hypotension and tachycardia, these patients demonstrate dullness to percussion and decreased air entry on the involved side and a shift of the mediastinum to the opposite side. The central venous pressure or jugular venous pressure is usually low, but it may be elevated in the unusual circumstance that a mass effect from the blood contained in the thorax produces a mechanical obstruction to venous inflow into the chest.

The diagnosis is confirmed and treatment instituted by insertion of a large-bore chest tube, through which a large volume (frequently close to 2000 mL) of blood drains immediately, to be followed by a continuous drainage of blood at rates approximating 100 mL/h. If either of these conditions is present, the patient is considered to have a massive hemothorax requiring surgical intervention. These should not be considered absolute indications for thoracotomy but merely guidelines. The most important indicator of whether or not surgical intervention is necessary is whether the patient's hemodynamics improve significantly and remain so after chest decompression and with fluid resuscitation. If bleeding continues at a rapid rate, or if the patient's hemodynamic status cannot be normalized with rapid infusions of blood and crystalloid, surgical intervention is warranted. The involved chest is opened through a posterolateral incision. Once the blood has been evacuated from the pleural space, a search is made for the bleeding point. It is frequently necessary to clamp the hilum of the lung temporarily and to release it intermittently in order to identify the area of bleeding, which is repaired by direct suture. Occasionally, massive hemorrhage necessitates resection of the involved lung, which should be accomplished quickly using staple devices. Very occasionally, the bleeding is from a ruptured thoracic aorta. Usually patients with free bleeding into the thoracic cavity from a ruptured aorta exsanguinate at the scene or immediately thereafter. However, in certain instances, it is possible to salvage some of these patients by clamping the aorta proximal and distal to the laceration and expeditiously repairing the laceration or inserting an aortic graft prosthesis.4,15,16 If available, a preheparinized shunt may be of use in these circumstances to bypass the lacerated area of the aorta and maintain perfusion of the distal aorta and spinal cord while the repair is undertaken.17 Occasionally, access to the bleeding source will require extension of the unilateral thoracotomy incision into the opposite chest by transection of the sternum and ligation of the internal mammary arteries.

As indicated previously, it is not always possible to determine precisely whether massive bleeding arises from a thoracic or an abdominal source. Therefore, it is crucial that the entire abdomen and chest be prepared and draped for exposure in the OR. In these circumstances, if the bleeding is into the right chest and the apparent site of impact or penetrating injury is in the lower right chest below the nipple line, laparotomy through an upper midline incision should be conducted because the source of the hemorrhage is usually a liver injury with penetration of the right hemidiaphragm. Where ultrasound assessment is immediately available, this may allow more precise location of the source of the hemorrhage and thus guide the location of the incision in the abdomen or thorax. Failure to reveal an abdominal source of hemorrhage at laparotomy will necessitate an anterolateral thoracotomy on the right side, which usually will reveal lacerated intercostal arteries, which should be identified and ligated. As indicated earlier, injuries to the low-pressure pulmonary vasculature usually are not associated with massive hemorrhage, and the bleeding stops spontaneously, particularly with reexpansion of the lung and decompression of the pleural space. If the impact is to the right upper chest or to any portion of the left chest, then massive hemorrhage should be treated by anterolateral thoracotomy on the bleeding side, and the incision should be extended as necessary to obtain control of the bleeding site. Occasionally, bleeding into the chest arises from a penetrating injury to the base of the neck. In these circumstances, the chest should be opened through a median sternotomy, with the option of extending laterally into the chest as well as above the clavicle to convert the incision to a trapdoor type of exposure. The median sternotomy under these circumstances allows better exposure of the vascular structures of the base of the neck than would be available through an anterolateral thoracotomy.18

Massive Pneumothorax and Airway Injury

Most patients with traumatic pneumothoraces present with signs characteristic of a pneumothorax but without any major degree of hemodynamic compromise, and the pneumothorax responds very promptly to chest tube insertion. Occasionally, however, the pneumothorax persists despite adequately functioning large-bore chest tubes and is accompanied by massive subcutaneous emphysema and continued hypoxemia and respiratory instability. The patient usually also has some degree of hemoptysis, which may be evidenced by blood draining through the endotracheal tube if the patient has been intubated, as is often the case. This scenario suggests the presence of a large airway laceration and requires immediate surgical intervention.

The patient is immediately placed on 100% oxygen. If time allows, bronchoscopy should be performed to identify the level of the lacerated airway. However, thoracotomy is warranted even if the lesion is not identified or there is insufficient time to perform bronchoscopy. It is essential that one be certain that the chest tubes are functioning adequately in these circumstances, and if mechanical problems are ruled out, the patient should be taken to the OR promptly. Occasionally, for a right-sided bronchial leak, insertion of a balloon-tipped catheter down the right mainstem bronchus may allow ventilation of the normal left lung after the right bronchus is occluded by inflation of the balloon. This measure temporarily stabilizes the patient by decreasing the air leak on the involved side. It is technically very difficult to accomplish, however, and should not take priority over getting the patient to the operating room as quickly as possible. For a left-sided bronchial tear, the endotracheal tube may be directed into the right mainstem bronchus and the cuff of the endotracheal tube inflated. This would allow ventilation of the right lung until the left lung lesion has been repaired.19 In the OR, a double-lumen tube, if available, will allow selective ventilation of the normal lung. At surgery, the lesion is identified and repaired directly. If there is massive destruction of the airway with failure to achieve an anastomosis or a high risk of subsequent stenosis of the airway, lung resection should be considered.20

Traumatic Air Embolism

The exact incidence of this entity in patients with multiple injuries is not known. However, to make the diagnosis, a very high index of suspicion must be maintained, and this diagnosis should be suspected in any patient with sudden cardiovascular collapse who demonstrates a neurologic deficit after chest injury, especially if these signs occur with the initiation of positive-pressure ventilation.21 In most cases, the diagnosis of traumatic air embolism is made at thoracotomy that is conducted on the basis of sudden collapse of a patient who has sustained major chest trauma. Occasionally, these patients may be quite stable initially, only to develop a focal neurologic deficit suddenly with cardiovascular collapse immediately after being placed on positive-pressure ventilation. Another sign suggestive of the diagnosis is the presence of bubbles within arterial blood drawn by arterial puncture, usually for blood gas analysis. It must be recognized, however, that the most common cause of air bubbles in the syringe is a loosely fitting syringe connector; this must be ruled out prior to making the diagnosis. Occasionally, air may be seen in the retinal arteries on funduscopic examination as well.

An anterolateral thoracotomy should be performed on the side of the penetrating injury or on the left side if no penetration is apparent. On entry into the thoracic cavity, prevention of further embolization is accomplished by cross-clamping of the pulmonary hilum. An 18-gauge needle should be used for venting the most anterior surfaces of the left atrium, left ventricle, and ascending aorta. This maneuver is followed by compressing the root of the aorta between the thumb and index finger, which are placed in the transverse sinus. Massaging the heart should drive air bubbles out of the coronary microvasculature. Maintenance of a high systemic blood pressure, with α agonists if necessary, should help to force trapped air from the heart and brain through the microvasculature into the venous circulation. With reestablishment of cardiac activity, the left-sided chambers and the aorta should be vented once more. Attention is then directed to the pulmonary lesion, which will require repair by direct suture, lobectomy, or pneumonectomy as necessitated by the nature of the injury.

Flail Chest

This condition arises whenever a portion of the chest wall becomes completely discontinuous from the rest of the rib cage. It usually results from blunt chest trauma in which several adjacent ribs are fractured on both sides of the sternum or, at least, at two locations on each of the ribs involved. This leads to a free-floating segment of the chest wall that positions itself in response to changes in pleural pressure rather than to the mechanical positions of the rest of the chest wall. The result is paradoxical movement of this portion of the chest wall. During spontaneous breathing, the flail segment moves inward with the negative pleural pressure of inspiration and moves outward with expiration. The diagnosis frequently is missed initially if one relies entirely on the detection of paradoxical movement of the chest wall because muscle spasm and pain restrict movement of the chest wall and make it very difficult to detect the paradoxical movement. This is particularly true in injuries involving the posterior thorax, where the muscle mass makes it even more difficult to detect paradoxical movement. Also, if the patient has been intubated and positive-pressure ventilation is instituted, paradoxical movement of the chest wall will not be seen. The presence of multiple adjacent rib fractures involving the same rib in different segments on chest x-ray would suggest the presence of flail chest even if it is not apparent clinically. The degree of pulmonary and hemodynamic disability that arises is related to the extent of the flail, the degree of underlying lung contusion, and the restrictive effect of chest wall pain from the multiple fractures. There is, therefore, a wide spectrum of presentation of patients with flail chest.

In the severely hypoxemic patient with a large flail and/or hemodynamic instability, immediate endotracheal intubation and positive-pressure ventilation are indicated, with prompt chest tube insertion on the involved side to prevent a tension pneumothorax from developing on institution of positive-pressure ventilation. Patients who are able to maintain adequate oxygenation and ventilation with supplemental oxygen may be maintained without mechanical ventilation and endotracheal intubation, particularly if adequate pain control can be achieved. This may require frequent or continuous intravenous analgesia in the form of titrated fentanyl, morphine, or other agents. In other circumstances, epidural or, less preferably, intercostal blockade with long-acting local anesthetic agents may be used to control the pain. With adequate analgesia, it is possible to avoid endotracheal intubation and mechanical ventilation in most patients with flail chest.22

Emergency thoracotomy is not required for treating flail chest. Also, mechanical fixation of the rib fractures usually is not necessary. There is still controversy as to whether formal thoracotomy and mechanical fixation of the fractured ribs should be considered at all in these patients.23 However, in situations where thoracotomy is required for other reasons, it may be appropriate to reduce and plate the fractures involved.

If a decision is made to ventilate the patient with a flail chest, the timing of weaning will not necessarily depend on disappearance of the paradoxical movement of the chest wall. Rather, weaning from the respirator may be initiated when the gas exchange abnormality associated with the underlying lung contusion is resolved. In fact, frequently these patients are weaned completely off respiratory support (with adequate pain control) when the lung contusion clears, even when residual paradoxical movement remains apparent for several weeks. A potential disadvantage of the nonsurgical and conservative nonventilating approach to flail chest is the acceptance of a high degree of ultimate chest wall deformity. However, these chest wall abnormalities are of questionable significance in terms of producing a long-term restrictive defect in these patients.

Although the following chest injuries do not immediately threaten life, early diagnosis and treatment are essential to prevent significant morbidity and later mortality:

1. Lung contusion

2. Blunt cardiac injury

3. Aortic rupture

4. Esophageal disruption

5. Diaphragmatic rupture

6. Rib fractures

7. Simple hemopneumothorax

A very brief discussion of the pathophysiology, diagnosis, and treatment of these entities follows.

Lung Contusion

This lesion results from direct trauma to the lung parenchyma, usually by a blunt mechanism, although it can occur from penetrating injuries as well. There is a wide spectrum of severity, ranging from very minor localized hemorrhage into the lung parenchyma to complete obliteration of an entire lung or even bilateral involvement. This injury is missed often because the respiratory failure that develops is not immediately evident, and indeed, chest films may be completely normal initially. It is essential, therefore, that the diagnosis be considered whenever there is significant direct injury to the chest wall. Initially, there may be chest pain and minimal dyspnea or hypoxia. However, within hours there may be slow deterioration in gas exchange and a progressive development of radiologic densities on chest x-ray. As pointed out earlier, there may or may not be an associated flail chest.

The treatment is selective and is based on the degree of respiratory impairment.24 When the gas exchange abnormality is minimal and oxygenation and ventilation can be maintained without endotracheal intubation, close attention to fluid balance is required. However, fluid should not be restricted in a patient with lung contusion if fluid resuscitation is required in a hemodynamically abnormal patient. Close, continuous monitoring of the hemodynamic and respiratory status is essential; if there is no major hemodynamic or respiratory compromise, the patient will not require mechanical ventilation. The criteria for initiation of mechanical ventilation are outlined in earlier chapters, but certain associated disorders increase the likelihood that mechanical ventilation will be needed. These include preexisting chronic respiratory failure and associated abdominal, thoracic, or central nervous system injuries.

Blunt Cardiac Injury

This lesion probably occurs much more commonly than was suspected previously because of the subtle nature of its presentation among other associated injuries.4,25 It usually results from blunt trauma to the sternum, most commonly caused by steering wheel impact. In fact, whenever a fractured sternum is diagnosed in chest trauma, one must assume an underlying myocardial contusion. The patient's symptoms frequently are clouded by associated chest wall contusion and other causes for chest wall discomfort and cardiorespiratory dysfunction. The diagnosis is suggested by the presence of ECG abnormalities, serial elevations in the level of the creatine kinase MB isoenzyme, or abnormalities found by two-dimensional echocardiography. However, myocardial enzymes do not contribute significantly to the diagnosis or management in this injury.26 Although cardiac troponins usually are helpful in the diagnosis of myocardial infarction, the levels obtained following trauma are too inconclusive to allow a diagnosis of blunt cardiac injury and provide no additional information beyond that available by electrocardiography. ECG abnormalities may vary from few to multiple premature ventricular contractions, persistent tachycardia, dysrhythmias such as atrial fibrillation, bundle branch block, ST-segment changes, or even changes indistinguishable from those of acute myocardial infarction. None of these tests is specific for blunt cardiac injury.

Because of the nature of this entity and its propensity for certain life-threatening dysrhythmias, consideration should be given to monitoring these patients in an ICU environment. Oxygen should be administered, pain should be treated with parenteral analgesics, and the patient should be treated in the same way as for myocardial ischemia, as outlined in other chapters of this book. The indications for inotropic agents, vasoactive drugs, and other forms of cardiac support are comparable with those for any patient with myocardial ischemia. Most patients with minor degrees of contusion do not require ICU admission.

Aortic Rupture

Traumatic disruption of the thoracic aorta frequently is lethal.16 In patients who reach the hospital alive, the rupture tends to be located at the point of fixation of the aorta just distal to the origin of the left subclavian artery at the ligamentum arteriosum, which represents the junction between a relatively fixed and mobile portion of the vessel. Therefore, the mechanism is a shear force, commonly seen with acceleration-deceleration injuries, although a sudden increase in intraluminal hydrostatic pressure may play a role in its pathogenesis. Aortic rupture at other sites near the root of the aorta usually results in death at the scene. In patients who survive the initial injury, the hematoma is contained by an intact adventitial layer. Because of the possibility of free rupture and exsanguination whenever this diagnosis is suspected, investigations and treatment should be prompt. Although several radiologic signs are described (such as widened mediastinum, fractures of the first and second ribs, obliteration of the aortic knob, deviation of the trachea to the right, presence of a pleural cap, elevation and rightward shift of the right mainstem bronchus, depression of the left mainstem bronchus, and obliteration of the space between the pulmonary artery and the aorta), frequently the only suggestive sign is a widening of the mediastinum on the plain chest film (Fig. 95-6). Other suggestive signs are the presence of a thoracic bruit or a discrepancy in blood pressure between the upper and lower limbs or between the right and left upper limbs. Placement of a nasogastric tube may highlight the degree of esophageal deviation and hematoma size on the chest film. Since most chest x-rays in traumatized patients are done in the supine position, the size of the mediastinum is exaggerated, and consequently, this diagnosis is considered in a large percentage of patients who do not actually have a traumatic aortic rupture. However, because of the lethal nature of this disease, it seems justified to pursue further imaging whenever aortic rupture is seriously suspected.27

Spiral computed tomography (CT) is recommended in the presence of suspected mediastinal widening, and if this is totally normal, then further imaging is not warranted.28,29 If the CT scan is questionable or suspicious, then an aortogram should be obtained. In any event, most surgeons still insist that angiography be performed prior to surgery.

The use of transesophageal echocardiography30,31 also has given excellent results in the diagnosis of aortic rupture, and in some centers it has virtually replaced angiography because of its accuracy and relative noninvasiveness, but there still remains a worrisome incidence of false positivity with this diagnostic tool.

The approach to management of the patient with aortic rupture is early surgical repair unless contraindicated by significant associated life-threatening injuries such as major head injuries. Resection with placement of a prosthetic graft frequently is necessary, although direct repair without the use of a prosthetic graft is sometimes possible. As soon as immediate life-threatening injuries have been addressed, the aortic lesion should be treated surgically. If surgical treatment is delayed because of associated major injuries, then treatment and close monitoring in the ICU with afterload reduction, β blockade, and maintenance of borderline hypotension are appropriate.32

Esophageal Disruption

The most common cause of esophageal rupture is iatrogenic injury during endoscopic maneuvers. However, this injury may result from both penetrating and blunt injury. A severe blow to the upper abdomen in the presence of a closed glottis can result in a sudden increase in intraesophageal pressure with rupture. The resulting tear allows leakage of gastric contents into the mediastinum, causing severe mediastinitis.

The patient presents with severe retrosternal chest pain and very soon develops profound hypotension and tachycardia. Frequently, pneumothorax or hemothorax is evident without a rib fracture, and if a chest tube is inserted, particulate matter may appear in the drainage. The drainage of pleural fluid with a very low pH and a high amylase content also should suggest the diagnosis. Other radiologic signs include the presence of mediastinal air. The diagnosis may be confirmed by gastrograffin swallow or esophagoscopy.

Treatment consists of massive infusion of crystalloid to maintain euvolemeia, antibiotic coverage, and early thoracotomy with repair of the lesion. If the diagnosis is made late in the onset of the disease, direct repair of the laceration may not be possible, and esophageal diversion techniques may become necessary as part of the surgical therapy. This may require the formation of an esophagostomy in the neck, as well as a gastrostomy, pleural drainage through chest tubes, and parenteral nutrition and antibiotic therapy.33

Diaphragmatic Rupture

Lacerations of the diaphragm may occur from blunt and penetrating injuries, and the injury may originate from either the thorax or the abdomen. The injury is diagnosed most frequently on the left side but may occur with equal frequency on the right side. Penetrating injuries tend to be small and sharply demarcated, whereas blunt injuries often result in large, irregular lacerations with herniation of intraabdominal contents into the chest.34

The diagnosis is missed frequently because of misinterpretation of the chest film, often thought to represent an elevated left hemidiaphragm, gastric dilatation, or loculated hemopneumothorax or hematoma. The placement of a nasogastric tube with its location above the diaphragm after entry into the stomach suggests the diagnosis.

Depending on the degree to which abdominal contents herniate into the thoracic cavity, the symptoms may be very minimal or very significant.35–37 A patient with blunt chest or abdominal trauma who exhibits sudden deterioration in respiratory status when intraabdominal pressure is increased should be considered as having a ruptured diaphragm. This was noted frequently when the abdominal compartment of the pneumatic antishock garment was used in the past. During peritoneal lavage, drainage of lavage fluid through a chest tube that is in place also indicates that diaphragmatic rupture is present.

The urgency of treatment depends on the degree to which the patient's hemodynamic and respiratory status is compromised. In most instances, an isolated diaphragmatic hernia can be repaired within several hours of admission, after the patient is resuscitated. Repair is done through a midline upper abdominal incision. This approach allows complete examination of the abdominal cavity. The hernia can be reduced quite easily and the repair conducted from within the abdomen. Associated injuries, such as splenic rupture, also can be treated easily during the laparotomy. If the diagnosis is made several weeks after the injury, then it is preferable to approach the lesion through a thoracotomy because any intraabdominal injury would have declared itself already; also, it will be much easier to reduce the hernia from within the thoracic cavity. Although laparoscopy increases the risk of tension pneumothorax in the presence of a diaphragmatic rupture, recent reports have suggested that this technique may be employed cautiously in the diagnosis and treatment of diaphragmatic rupture when the laparoscope is used in assessment of the traumatized abdomen.38–40

Rib Fractures

Rib fractures are very common with chest injuries. Frequently they are missed on x-ray examination unless special rib views are taken. However, the diagnosis is suspected when there is localized chest wall pain. The diagnosis is also suggested when one is able to elicit crepitus over the fracture site or auscultate a “click” with inspiration over the fracture site. Tenderness on compression of the chest wall is also suggestive of rib fractures.

The treatment of rib fractures consists of analgesics, which may be administered orally, parenterally, or epidurally, depending on the degree of discomfort and the number of ribs involved. In the ICU setting, parenteral analgesics or regional blocks are preferable. Generally, the fractured ribs do not require any specific treatment. However, in the setting of a patient with preexisting pulmonary dysfunction, the restriction produced by fractured ribs can make the difference between normal gas exchange and severe respiratory failure. Maintenance of adequate respiratory function therefore is the mainstay of treatment in these patients.

Simple Hemopneumothorax

In contrast to a tension pneumothorax, the simple hemopneumothorax usually is diagnosed by a combination of physical examination and chest x-ray. Although it has been suggested recently that small pneumothoraces may be treated by close monitoring in the ICU without chest tube insertion, generally, if a hemothorax or pneumothorax is noted following trauma, a chest tube is inserted regardless of the size of the air or blood collection. This measure allows decompression of the pleural space, as well as monitoring of the drainage from the pleural space. It is particularly important that chest tube decompression of the pleural space be secured before mechanical ventilation is instituted or a general anesthetic administered.

General Principles

Apart from patients with pericardial tamponade or traumatic air embolism, any hemodynamically compromised patient with torso trauma in whom adequately functioning chest tubes demonstrate no free pleural blood or continued major air leakage must be considered to have an intraabdominal source of blood loss until another cause is proven. Hence, when the decision is unclear in an unstable patient with torso trauma, the combination of physical examination, chest x-ray, and chest tube insertion frequently will allow one to determine whether the lesion is located in the chest. With a negative chest film and no chest tube drainage in the absence of cardiac tamponade or air embolism, laparotomy frequently is required in the unstable patient with torso trauma.

In the OR, all such patients should have the entire abdomen and chest prepared and draped. They also should receive preoperative antibiotics that will cover aerobic gram-negative and anaerobic organisms. It is crucial that the antibiotics be administered before the incision is made in order to minimize septic complications.41 If there is no fecal contamination in the peritoneal cavity, the antibiotics may be stopped within 24 hours. However, in the presence of contamination, antibiotic administration should be continued until the temperature is normal and there is no leukocytosis. An increase in the temperature and white blood cell (WBC) count after antibiotics are stopped suggests residual sepsis, which often is in the form of an undrained intraabdominal abscess.

A generous upper midline incision extending from the xiphoid process to just below the umbilicus is the exposure of choice because most of the lesions producing instability arise from injuries to the upper abdominal contents. This incision can be extended easily up into the chest through lateral thoracotomy or a median sternotomy or extended into the lower abdomen for lower abdominal injuries. Occasionally, the history suggests an isolated lower abdominal injury, and in this circumstance, a lower midline incision beginning at the umbilicus may be undertaken.

Prior to laparotomy, the surgeon need only decide that surgical intervention is necessary; a specific diagnosis is not necessary. In deciding on laparotomy, one looks for the signs of penetration, perforation, or hemorrhage. Penetration of the peritoneum in stab wounds is diagnosed by exploration of the abdominal wound under local anesthesia with good lighting; if it is determined that the peritoneum has been violated, in most instances laparotomy is performed. This approach has been questioned, and peritoneal lavage has been conducted in conjunction with exploration of the wound to determine the need for laparotomy on a more selective basis.42,43 In these circumstances, demonstration of violation of the peritoneum and positive peritoneal lavage are used as indications for laparotomy. All bullet wounds to the abdomen are treated by laparotomy,44 although a selective approach based on careful scanning of the abdomen to identify tangential nonpenetrating wounds has been reported. The signs of perforation are abdominal pain, tenderness, guarding, and rigidity. Signs of hemorrhage also may present with signs of peritoneal irritation, shoulder tip pain, or variable degrees of hemodynamic instability.

On entry into the peritoneal cavity, the presence of dark blood usually suggests a liver injury, whereas bright red blood suggests an arterial source of bleeding. Rapid evisceration of the small intestine and liberal use of packs wherever blood is accumulating allow identification of the source of blood loss. Concentration on the first site of bleeding should be avoided. The lesions should be approached in order of severity; i.e., the areas that are bleeding most briskly should be treated first.

In general, findings on physical examination determine the need for surgical intervention. There are situations, however, in which the signs may be equivocal or impossible to elicit in the unstable patient. In these circumstances, ultrasound,45 peritoneal lavage, and CT46 are all very helpful in determining the need for laparotomy.

Massive intraabdominal hemorrhage may require thoracotomy to allow clamping of the supradiaphragmatic aorta for temporary control of intraabdominal hemorrhage and the maintenance of perfusion to the brain and myocardium.47,48 Prompt laparotomy after aortic clamping would allow identification and control of intraabdominal hemorrhage before release of the aortic clamp. In many instances, aortic clamping also may be achieved through a laparotomy with compression and/or clamping of the infradiaphragmatic abdominal aorta.

Role of Peritoneal Lavage, CT, and Ultrasound in Assessing Abdominal Trauma

Diagnostic peritoneal lavage, ultrasound, and CT are all useful diagnostic tools in assessing the traumatized abdomen. These modalities are all very sensitive for the detection of hemoperitoneum. Of the three modalities, CT is the most specific.46 However, it requires transporting the patient to the CT suite and is relatively costly and time-consuming. Its main use, therefore, is in relatively stable patients, particularly those who are already having CT for another indication, such as possible head injury. The main advantages of ultrasound are its rapidity, sensitivity, noninvasiveness, and portability. Where emergency ultrasound assessment is available (focused assessment for the sonographic examination of the trauma patient [FAST]), this is preferred and superior to diagnostic peritoneal lavage, but like all imaging techniques, is not sufficiently sensitive to be used in isolation to make judgments regarding the need for surgery.48a With proper training of personnel, FAST can be very accurate in detecting hemoperitoneum, even when conducted and interpreted by nonradiologists.45,49 Like other investigative tools, peritoneal lavage, ultrasound, and CT should be used only if the results will affect the decision on whether to perform a laparotomy. If there is an obvious need for laparotomy, then these modalities are not indicated.

Indications

1. When there are equivocal abdominal findings. Certain conditions, such as fractures of the lower ribs, pelvis, or lumbar spine, may produce abdominal signs that are difficult to separate from those injury due to intraabdominal structures.

2. When abdominal findings are impossible to elicit (e.g., when pain perception is abnormal, such as with severe head injury, drug intoxication, or spinal cord injuries).

3. When there may be long periods during which the patient is unavailable for repeated physical examination and observation, such as during lengthy surgical procedures.

4. When there is an obvious source of hemorrhage, such as a pelvic or extremity fracture, which could account for hypotension, but when simultaneous intraabdominal bleeding is also a possibility.

Contraindications

An absolute contraindication to diagnostic peritoneal lavage is an already identified indication for laparotomy. Relative contraindications to diagnostic peritoneal lavage include previous abdominal operations with scars in the abdomen, morbid obesity, a preexisting coagulopathy, and advanced pregnancy. An incision may be made above the umbilicus in advanced pregnancy or distant from prior surgical wounds, and the open technique may be used if necessary. Otherwise, the closed Seldinger technique for insertion of the peritoneal catheter is acceptable.50 There are virtually no contraindications to ultrasound assessment of the traumatized abdomen except an obvious need for laparotomy on the basis of clinical examination alone. The relative contraindication to CT is instability of the patient that makes transfer to the CT suite unsafe.

Techniques for CT, Ultrasound, and Diagnostic Peritoneal Lavage

CT

Whenever possible, CT of the abdomen should be conducted with oral, intravenous, and rectal contrast agents to enhance specificity. This approach allows assessment not only for solid-organ injury and hemoperitoneum but also for injury of hollow organs.

Ultrasound Examination for Fluid

The ultrasound probes are placed in four locations45:

1. Right upper quadrant—Morison's pouch

2. Epigastric area (pericardial)

3. Left upper quadrant (perisplenic)

4. Suprapubic area—pouch of Douglas

FAST detects blood in the pericardial sac as well as the perihepatic, splenoral, and pelvic regions of the abdomen.

Open Peritoneal Lavage

The urinary bladder and stomach should be decompressed by urinary catheter and nasogastric tube, respectively. The abdomen should be surgically prepared with an antiseptic solution, and local anesthetic should be infiltrated below the umbilicus in the midline if the patient perceives pain. The skin is incised in the midline, and an opening is made that permits visualization of the subcutaneous tissue and fascia. After hemostasis in the skin and subcutaneous tissue has been ensured, the fascia is incised, and the peritoneum is grasped with clamps. A purse-string suture is then inserted in the peritoneum, and an opening is made for insertion of the peritoneal dialysis catheter into the peritoneal cavity. The catheter is directed toward the pelvis, connected to a syringe, and aspirated. If no gross blood or obvious enteric contents are aspirated, 10 mL/kg of Ringer's lactate or normal saline is allowed to drain by gravity into the peritoneal cavity. The abdomen is palpated and agitated gently to distribute the fluid throughout the peritoneal cavity. After approximately 5 to 10 minutes, the fluid is siphoned off and examined.

Closed Diagnostic Peritoneal Lavage (Seldinger Technique)

In the closed technique50 of diagnostic peritoneal lavage, preparation of the patient is similar. After a puncture wound is made through the skin with a scalpel, a needle with a guidewire is inserted into the subcutaneous tissue, fascia, and peritoneum. A peritoneal lavage catheter then is introduced over the guidewire and directed toward the pelvis, after ensuring that bowel has not been penetrated by the needle by aspirating and examining for bowel liquid contents or gas.

Semiclosed Peritoneal Lavage Technique

In this technique, an incision is made down to the fascia, which is grasped and then punctured. The catheter is then introduced through the opening in the fascia.

Interpretation of Diagnostic Peritoneal Lavage

1. Aspiration of more than 5 mL of gross blood or obvious enteric contents signifies a positive peritoneal lavage.

2. A positive result is also suggested when newsprint cannot be read through the IV tubing containing the drained fluid.

3. The fluid is sent for microscopic analysis, and the following criteria are used for positivity: more than 105 red blood cells (RBCs) per microliter, more than 500 WBCs per microliter, or the presence of bacteria, vegetable fibers, etc. on Gram stain. Lower counts also are used in special circumstances, such as the selective approach to laparotomy in penetrating wounds.51

With use of these criteria, the peritoneal lavage findings are falsely negative in approximately 2% of patients, and these patients usually have isolated injuries of the pancreas, duodenum, diaphragm, small bowel, or bladder.52 Retroperitoneal injuries are missed frequently by peritoneal lavage.

Selecting the Diagnostic Modality in Blunt Abdominal Trauma

Hemoperitoneum is the major indication for laparotomy in blunt abdominal trauma. Therefore, a diagnostic technique other than physical examination that detects hemoperitoneum accurately, quickly, noninvasively, and with minimal cost, such as ultrasound, appears most attractive. However, there is still a role for other modalities, such as diagnostic peritoneal lavage and CT,53 in the assessment of the patient sustaining blunt abdominal trauma. If the ultrasound examination is negative, the patient may be followed clinically without the need for CT or diagnostic peritoneal lavage. With an equivocal ultrasound examination in a stable patient, CT should be done. An unstable patient with an equivocal ultrasound examination should either have a diagnostic peritoneal lavage or be taken directly to the OR. When the ultrasound examination in a stable patient is positive for hemoperitoneum and a more specific diagnosis is desired, CT should be conducted. CT is particularly useful in patients who have hemoperitoneum with solid-organ injury that may be treated nonoperatively. Use of this approach significantly reduces the frequency with which CT is necessary as a screening tool for hemoperitoneum. The unstable patient in whom ultrasound examination is positive for hemoperitoneum generally requires laparotomy.

Although the nonsurgeon intensivist does not need detailed knowledge of the surgical management of specific intraabdominal injuries, some familiarity with the diagnostic and management principles to be applied in the surgical treatment of specific intraabdominal organ injuries is likely to improve the confidence with which these patients are managed in the ICU.

Penetrating abdominal injury differs significantly from nonpenetrating injury. Penetrating injury may result from stab wounds or wounds from other sharp objects or from bullet or shotgun wounds. Stab wounds tend to be the least serious, in that they involve organs only within the short trajectory of the weapon, and unless the stab wound impales a major vessel directly, major hemorrhage is not as likely as in other forms of penetrating or blunt abdominal injury. Patients with stab wounds require exploration of the wound to determine whether the peritoneum has been violated. If the peritoneum has been violated, a decision has to be made to proceed with formal laparotomy unless one is prepared to use peritoneal lavage as an adjunctive test in determining whether laparotomy should be conducted.42 Although a selective approach using imaging such as CT and MRI to identify tangential nonpenetrating wounds that would not require laparotomy is suggested, generally, all bullet and shotgun wounds to the abdomen require laparotomy.44 These missile injuries usually result in damage to more than one organ. Since kinetic energy transfer is affected most significantly by missile velocity (K = 1 ½ MV2), low-velocity missiles tend to produce limited surrounding injury, whereas high-velocity missiles produce greater damage. Organ involvement, therefore, is very unpredictable because of the variable trajectory and wide variable area of dissipated energy. A straight line joining the points of entry and exit usually does not represent the pathway of the missile. In shotgun injuries, much less damage is inflicted when the injury occurs from far range rather than close range.

The crushing force produced by blunt injuries results in very irregular lacerations. Multiple injuries are also common. Diagnosis and therapy are more challenging and should be more aggressive with blunt injury. Hemorrhage, devitalization of tissue, morbidity, and mortality are all increased in blunt injury compared with penetrating injuries of the abdomen.

The frequency of organ involvement in penetrating trauma is also different from that in blunt trauma to the abdomen. In penetrating trauma, the organs involved, in order of frequency, are the liver, small bowel, stomach, colon, major vessels, and retroperitoneum. In blunt injuries, the solid organs—the spleen, kidney, and liver—are damaged most often, followed by the intestines.54

Stomach Injuries

The diagnosis of stomach injury is suggested by epigastric pain and pain at the shoulder tip if there is free perforation. Usually there is very minimal hemorrhage, and the patient's hemodynamic status is not particularly affected. Upright chest x-ray reveals free air under the diaphragm. The diagnosis also may be suggested by bloody aspirate from the nasogastric tube.

The surgical treatment of stomach injuries is straightforward and involves débridement of devitalized tissue and usually primary suture or anastomosis if resection is required for wide areas of devitalization. It is essential that the entire stomach, including the posterior wall, is visualized to minimized missed injuries.

Duodenal Injuries

These injuries are seen often in association with other injuries, and the second portion of the duodenum is involved most commonly. Because the duodenum is a retroperitoneal structure, frank peritonitis is a very late sign, and the diagnosis is made only with a very high index of suspicion based on the mechanism of injury. A useful sign is the identification of retroperitoneal air on a plain film of the abdomen (Fig. 95-7). Occasionally, a free perforation of the first portion of the duodenum produces pneumoperitoneum and can be identified on an upright chest film.

In the surgical treatment of injuries to the duodenum, complete mobilization and visualization of the entire duodenum are crucial. Patients with intramural hematomas of the duodenum may present with vomiting and symptoms of gastric outlet obstruction; radiologic examination of the stomach and duodenum with contrast agents reveals the presence of an intramural hematoma. If this is the only injury, treatment can be conservative, with nasogastric suctioning and intravenous fluids until the hematoma resolves. If the lesion is found at laparotomy, the hematoma is evacuated easily through an incision in the duodenal wall.55 The principle of treatment is to débride the area of injury, removing all devitalized tissue. If, after this is accomplished, the edges of the duodenum can be approximated without undue tension, primary suture closure is appropriate. The defect also may be closed by a serosal patch from adjacent small bowel or a resection and end-to-end anastomosis. When these techniques are not possible, then roux-en-Y anastomosis between the duodenal ends and the small bowel needs to be conducted. When there is concern about the duodenal closure, it is wise to place a duodenal catheter, brought out as a tube duodenostomy. If the anastomosis is not secure, the resulting duodenal fistula will be controlled and can be treated by observation and parenteral nutrition until the fistula tract matures, after which the duodenal tube is removed.56,57 Severe duodenal injuries require pyloric exclusion procedures in which the gastric contents are diverted through a gastrojejunostomy.58

Pancreatic Injuries

Injuries to the pancreas usually result from blunt trauma and are caused by impact of the pancreas against the vertebral column. Diagnosis is often difficult because the retroperitoneal position of this organ prevents early physical signs of peritoneal irritation. Frequently, the diagnosis is made at laparotomy for other associated conditions. However, the diagnosis is suggested by an increase in the serum amylase level. If the diagnosis is suspected and findings on physical examination are minimal, upper gastrointestinal radiographic studies with gastrograffin may demonstrate a widening of the duodenal loop. CT of the abdomen allows assessment of the retroperitoneum and pancreatic area for evidence of retroperitoneal hematomas or even ductal injury. Peritoneal lavage frequently is negative in the presence of severe retroperitoneal pancreatic injuries.

Treatment of these injuries depends largely on whether or not the pancreatic duct has been violated. In simple contusions of the pancreas, drainage of the area is all that is required after mobilization of the pancreas and full inspection to rule out any associated ductal injury. Any devitalized area should be débrided, and bleeding points should be controlled by direct suture ligations combined with cautery.

Ductal injury usually is identified during laparotomy. However, in exceptional circumstances where endoscopic retrograde pancreatography (ERP) is immediately available in an otherwise stable patient, this may allow assessment of ductal integrity prior to the laparotomy.59 When the duct has been injured, there is often a mixture of pancreatic fluid and blood over the surface of the pancreas, which should be exposed for complete inspection. Although ductal injury involving the body and tail of the pancreas may be treated by transection and anastomosis of the ends of the duct to the small bowel, this injury is treated more appropriately by distal pancreatic resection without an enteroanastomosis. When the head of the pancreas is involved, a roux-en-Y anastomosis of the distal pancreatic segment is advisable.60 This type of injury usually is a combined pancreaticoduodenal injury and may require a Whipple procedure (pancreaticoduodenectomy). This procedure carries a high mortality and should be conducted only when more conservative measures are unsuccessful.61,62 An alternative approach to combined pancreaticoduodenal injury is the diverticulization procedure, in which the pylorus is closed internally, and a gastrojejunostomy is constructed with an added option of drainage of the duodenum through a tube duodenostomy after repair of the duodenal injury and wide drainage of the pancreas. The entire area is drained, with drains placed around the peripancreatic and duodenal area and exiting posteriorly.63 It should be emphasized that pancreaticoduodenal resection should be a last resort because of the high associated mortality. Less aggressive treatment should be instituted initially if possible.39 Even though this approach is more likely to result in complications such as pancreatic abscess, the overall mortality is still less with drainage than with resection.

Postoperatively, patients with pancreatic injury are at risk for development of complications such as pancreatic abscess and pseudocyst. The former is suggested by a continued septic course with the development of a peripancreatic mass, which is identified by CT. This lesion requires drainage and antibiotic coverage.

The complication of pancreatic pseudocyst results from pancreatic secretions and debris in the lesser sac. Symptoms may be those of a mass effect and may include gastric outlet obstruction with vomiting. The presence of a symptomatic mass in these patients requires decompression of the pseudocyst. However, if the pseudocyst is not symptomatic, it may be observed for up to 6 weeks, at which time, if there are no signs of spontaneous decrease in size, it should be drained. There is much controversy as to whether drainage should be conducted internally or externally. If the external route is chosen, percutaneous drainage may be done under ultrasound or CT guidance. In any event, if this technique is attempted and the catheter is incapable of draining the very thick secretions, internal drainage should be performed via pseudocystgastrostomy or cystenterostomy.64 Apart from the mass effect of the pseudocyst, these patients require frequent monitoring of the serum amylase level, which often remains elevated during the active phase when the pseudocyst is enlarging. Percutaneous drainage also is unlikely to be effective when the pseudocyst is multiloculated.

Intestinal Injuries

Acceleration-deceleration injuries are most likely to occur at points of fixation of the bowel, e.g., the ligament of Treitz, the ileocecal junction, and the rectosigmoid area. Blowout perforations of the small bowel, however, can occur at any site. Another mechanism for bowel perforation and injury is related to the lap seat belt. The presence of contusion on the abdominal wall from a lap seat belt often makes it difficult to assess the abdomen for signs of peritoneal irritation. In these circumstances, ultrasound or CT examination of the abdomen is quite helpful in determining whether or not there is a seat belt type of related intestinal injury. The presence of peritoneal signs will necessitate laparotomy. A high index of suspicion and aggressive investigation using ultrasound and CT are required to minimize missed small bowel injuries because these injuries occur frequently in the setting of other associated injuries.65–67

Treatment of injuries to the small bowel involves débridement of devitalized tissue and control of any associated bleeding points with primary suture. Devitalized areas may require formal resection of segments of bowel; this is usually followed by primary anastomosis with excellent results. The treatment of injuries to the colon depends on the time elapsed between injury and surgery, the degree of contamination, the stability of the patient, and the presence of associated injuries. If there is minimal gross contamination, the operation is being performed within 3 to 4 hours of the injury, and the patient is not in shock, primary anastomosis may be conducted safely. Devitalization of a large portion of the right colon often necessitates resection of the ileum and ascending colon with an ileocolic anastomosis. Left colonic lesions are more likely to be associated with frank fecal spillage. However, if there is very minimal spillage and no evidence of continued hemorrhage or associated injury, even these injuries may be treated by primary closure.68 Whenever there is doubt, however, the safest technique for treating left-sided colonic injuries is the fashioning of a colostomy together with repair of the laceration and irrigation of the peritoneal cavity. In situations where the lacerated bowel can be exteriorized, the resection may be performed and the ends of the bowel brought out as a proximal defunctioning colostomy and a mucous fistula. This technique is preferable to a defunctioning colostomy and Hartmann's procedure (oversewing of the rectal stump in the pelvis), which is associated with greater difficulty in subsequent reanastomosis of the large bowel.

Injuries to the rectum should be assessed in the operating room and frequently require general anesthesia with a proctosigmoidoscopic (preferably flexible) assessment to determine whether or not the anorectum has been perforated. Because of the propensity for major septic complications, particularly in the multiply injured patient, patients with possible perforating rectal injuries should be treated by a proximal defunctioning colostomy and the fashioning of a mucous fistula through which a catheter can be inserted for performing complete rectal washout.69 The irrigation of the rectum is conducted with the anus being held dilated. The perirectal space is then drained with appropriately placed drainage tubes. Once the gross fecal contents have been irrigated, the rectal mucosa and major lacerations should be repaired and the sphincter muscles reapproximated with interrupted sutures. This approach in the acute phase prevents retraction of the transected sphincter muscles, which makes later repair and maintenance of continence very difficult. Failure to adhere to the system of drainage, irrigation, and proximal defunctioning colostomy can lead to a protracted septic course with multiorgan failure and death from rectal injuries. A patient with a rectal injury with gross fecal contamination in the perineal area may require reexploration if the he or she continues to run a septic course in the ICU.

As indicated in Chapter 89, the abdomen remains a frequent source of sepsis in surgical patients in the ICU setting. These complications arise primarily after operations on the bowel, so any traumatized patient who has had bowel lesions treated surgically and who remains septic should be considered as having an intraabdominal source for that sepsis. This requires intensive investigation using modalities such as CT scan and ultrasound; drainable lesions may be treated by percutaneous techniques under CT or ultrasound guidance. When such techniques are contraindicated or are likely to be ineffective, or when the source is not obvious despite investigations, laparotomy may be necessary to identify and treat septic complications. With the availability of sophisticated technology in the form of CT and ultrasound investigations, it is usually possible to make a diagnosis prior to laparotomy, and only under very unusual circumstances is the lesion not identified prior to laparotomy.

One of the common areas of sepsis in patients with a perforated bowel is wound infection. Although the incisions in these patients frequently are left packed and open, in some instances the wound is closed primarily. The possibility of suppuration in the wound always should be considered at the first sign of sepsis, and the wound should be opened for diagnosis as well as treatment.70

Liver Injuries

Although liver injuries may occur from both blunt and penetrating trauma, patients with blunt injury to the liver tend to have a higher morbidity and mortality because of the irregular type of laceration and the involvement of an entire lobe or frequently both lobes of the liver. The signs of liver injuries are very nonspecific, and the diagnosis frequently is made only at laparotomy, the patient presenting with signs of intraabdominal hemorrhage. Liver hemorrhage is sometimes the chief cause of a patient presenting in hemorrhagic shock. Although diagnostic peritoneal lavage for hemorrhage may suggest liver injuries, it is not as specific as CT or ultrasound and is indicated in the hemodynamically compromised patient when FAST is not available or the patient cannot be transferred safely to the CT suite. Otherwise, these injuries are very clearly outlined by CT or ultrasound examination of the abdomen. Other signs that suggest the possibility of liver injuries include bruising of the lower chest, particularly on the left side; contusions over the upper abdomen; fractured lower ribs: an elevated hemidiaphragm; and increased size of the liver shadow on plain films of the abdomen. The usual indication for surgery in a patient with liver injury is intraabdominal hemorrhage.71

Although reported mortality rates from major liver trauma vary from 20% to 60%, most of the deaths are due to severe associated injuries, particularly of the head and thorax. When death is attributed to the liver injury itself, it is usually secondary to uncontrollable hemorrhage and later in the course is due to sepsis and multiorgan failure. Careful surgical technique and postoperative management of these patients will decrease the morbidity and mortality. The objectives of surgical management of liver injuries are (1) control of hemorrhage, (2) removal of nonviable tissue, and (3) provision of adequate drainage.

Exposure must be adequate, which necessitates a midline upper abdominal incision with the ability to extend into the chest. The liver itself should be mobilized completely by transection of the triangular ligaments, as well as the falciform ligament, with care taken to secure the inferior phrenic artery. The operative strategy should allow exposure of all structures that are likely to be injured or have an impact on management of the injury, including the vena cava and other retroperitoneal structures, and the surgeon must be prepared to perform the Kocher maneuver, right medial visceral rotation (Cattel and Braasch maneuver)72 and left medial visceral rotation (Mattox maneuver).73

Control of Hemorrhage

In most instances, once the peritoneal blood has been aspirated, a nonbleeding hepatic laceration is identified. Such lacerations require drainage and no further surgical exploration. If hepatic bleeding is still active at the time of laparotomy, then the initial maneuver is to pack the liver area very tightly with dry gauze and continue with the remainder of the laparotomy for approximately 15 minutes. This allows time for stabilization of the patient's hemodynamic status, as well as time for replacement of fluid deficits. If, on removal of the pack, the bleeding has stopped, as is frequently the case, then the treatment is drainage of the perihepatic space. Failure to control bleeding by this technique necessitates clamping the portal triad, examining the wounds to determine the source of hemorrhage, and direct suture ligation of the bleeding points. Intermittent release of the clamp will allow examination for hemostasis. Hepatic artery ligation may be of benefit in some patients, although its effectiveness has been questioned.74 When bleeding arises from the retrohepatic vena cava, as evidenced when clamping of the portal triad fails to control the bleeding, it is necessary to rotate the liver medially and visualize the retrohepatic vena cava. Earlier reports have suggested the use of intracaval shunts to assist in preserving a dry field so that the injured hepatic veins and retrohepatic vena cava may be identified and repaired.75 However, recent data have shown a very high mortality associated with the use of the intracaval shunts, and aggressive hepatic packing has been an alternative that results in a better outcome.76,77 In extreme circumstances, complete vascular isolation of the liver by also clamping the suprahepatic and infrahepatic vena cava may be successful, although this maneuver frequently results in cardiac arrest in the already hypovolemic patient. Bleeding from through-and-through penetrating wounds of the liver also can be tamponaded by insertion of inflatable devices directly into the hepatic wound.78 In some instances, formal resection of liver tissue is required to control hemorrhage, particularly when there is major devitalization of liver tissue. This measure usually does not require formal anatomic lobectomy but instead consists of resectional débridement of the bleeding, devitalized liver tissue as demarcated by the edges of the laceration itself. The bare area of the liver is then treated with suture ligature, cautery, and the application of microfibrillar collagen or other types of topical hemostatic agents. In some instances, the patient may lose several units of blood as well as have other injuries that require attention. In addition, with the massive blood transfusions, the patient may show signs of coagulopathy. In such instances, it is advisable to pack the liver temporarily, close the abdominal wound, and correct the coagulopathy in the ICU with the hope of stabilizing the patient. The patient may then be taken back to the OR in 48 hours for removal of the pack, after which the bleeding will have either ceased or decreased considerably, allowing formal treatment of the bleeding source.79

Damage-Control Surgery

Patients presenting with major liver injury frequently sustain other intraabdominal, thoracic, extremity, and head injuries. Such patients pose a great challenge to the surgeon and anesthetist. Massive blood transfusions with hemodynamic and respiratory compromise are seen in such patients, who become hypothermic, hypocoagulapathic, acidotic, and hypoperfused. These responses are not entirely confined to the patient with major liver injuries but also accompany other injuries to the chest and abdomen. In these circumstances, operative strategy should be directed at temporarily controlling hemorrhage and contamination by the most expeditious means and allowing the patient to return to the ICU setting, where the cardiorespiratory, renal, metabolic, hypocoagulable, and hypothermic states can be monitored and corrected before returning the patient to the OR for more definitive surgical care. In the setting of abdominal injuries, this involves control of hemorrhage by packing and ligation of vessels without attempts at formal repair, as well as ligation and temporary stapling of injured bowel ends with evacuation of intestinal contents by suction, followed by temporary rapid skin closure of the abdomen. Similar damage-control techniques for thoracic injuries, including tractotomy and quick stapling of vascular and bronchial structures, allow the patient to return to the ICU environment for correction of these immediately life-threatening abnormalities before being returned to the OR for formal, definitive surgical repair of the injuries.79–82

Resection of Devitalized Tissue

Formal hepatic lobectomy is seldom necessary for trauma. Resection usually is confined to removal of frankly nonviable tissue. The area for resectional débridement usually is well demarcated by the nature of the liver laceration itself. Manual compression is maintained on the liver while the resection is conducted to control hemorrhage. Intermittent packing and compression of the liver are required to allow volume resuscitation of the patient during the procedure.

Drainage

The lacerated liver continues to drain bile, blood, and tissue fluid for a considerable period postoperatively. Accumulation of this fluid in the peritoneal cavity is prevented by appropriately functioning peritoneal drains. T-tube drainage of the common bile duct is not required unless there is a central ductal injury requiring surgical repair or unless the common bile duct is enlarged because of previous pathology.

During the postoperative period, these patients frequently run a febrile course, which makes it difficult to determine whether or not there is underlying sepsis. Therefore, antibiotics frequently are administered in the immediate perioperative period. With major hepatic resection, glucose infusions are required to treat hypoglycemia, and hypoalbuminemia needs to be treated temporarily with plasma and albumin infusions until the nutritional status of the patient is improved. Coagulation defects are treated with fresh frozen plasma, vitamin K supplements, and platelets when indicated. Most of these patients also develop some degree of jaundice, which usually is transient but may last from several days to several weeks. Because many of the signs indicated earlier are common in uncomplicated liver injuries, the presence of septic complications may go unnoticed. Frequent radiologic investigation and monitoring of the WBC count are necessary, and baseline estimate of these parameters would allow one to determine whether the patient is progressing satisfactorily or not. A patient whose bilirubin level and WBC count are decreasing but who suddenly shows an increase in serum bilirubin level or has a spike in temperature should be investigated carefully for a source of sepsis in the abdomen. Another complication that may arise in hepatic injury is hemobilia, which may present with upper gastrointestinal hemorrhage, as evidenced by hematemesis or blood-stained nasogastric drainage. This lesion requires immediate investigation in the form of hepatic angiography and CT or ultrasound examination. Once the source of the intrahepatic hemorrhage is identified, hepatic artery embolization or balloon tamponade is a viable option for controlling the hemobilia83 before formal hepatic resection is considered.

Spleen Injuries

Injuries to the spleen should be suspected in patients who present with left upper quadrant pain, especially in the presence of left lower rib fractures. There may be associated shoulder tip pain on the left side. A frequent mode of presentation, however, is a patient with signs of massive intraperitoneal hemorrhage requiring immediate laparotomy for hemorrhagic shock. In situations where the signs are equivocal, ultrasound examination may be diagnostic. CT of the abdomen in an otherwise stable patient also will identify splenic injury. Most patients who are able to maintain adequate hemodynamics with minimal requirements for blood transfusions, particularly children, can be treated conservatively without the need for laparotomy.84 Such patients should be monitored very closely in the ICU setting for signs of continued blood loss and requirement for continued fluid infusions. Although imaging techniques have been attempted to identify splenic injury patients that will require surgical intervention, the most important determinant of the need for surgical intervention remains the hemodynamic status of the patient and the requirement for continued fluid infusion.85 Where the patient's condition allows, angiography can identify bleeding vessels that may be embolized to control bleeding from the traumatized spleen.86 Currently, nearly all children and 50% to 80% of adults with blunt hepatic or splenic injuries are treated without laparotomy.87 Whenever there is a suggestion of associated injury or there is an acute splenic injury in an adult who is severely compromised hemodynamically, laparotomy is advised.

At laparotomy, the aim should be to control hemorrhage, with splenic salvage if possible. In order to assess the splenic injury adequately, complete mobilization and delivery of the spleen into the wound are necessary. Superficial supcapsular tears of the spleen may be treated by initial packing for approximately 15 minutes. Failure to control the hemorrhage by this means will necessitate such techniques as the application of microfibrillar collagen or fine sutures. Identifiable bleeding points are coagulated as well as suture ligated, particularly when bleeding points occur near the hilum of the spleen. Ligation of the short gastric vessels in certain instances also will arrest splenic hemorrhage. In some instances, a lacerated portion of the spleen may be excised, with suturing of the remainder of the spleen with large chromic sutures with Teflon pledgets for securing the sutures. When multiple lacerations are evident, it is possible to control the hemorrhage by placing the spleen in a net of Dexon mesh, which can be tightened to produce compression and control of hemorrhage.88 If control of hemorrhage by a combination of these techniques is impossible, then splenectomy should be conducted. Also, if the patient remains unstable from other major injuries and bleeding from the spleen is a major problem, splenectomy should be conducted most expeditiously to decrease the operating time and improve the patient's chances of survival.

Postsplenectomy patients are very prone to septic complications, particularly from infections associated with the encapsulated pneumococcous, Haemophilus influenzae, and Neisseria meningitidis. Prior to discharge from the unit, these patients should be vaccinated against these organisms. Patients also should be warned that any infective process is cause for seeking medical attention because of the increased risk of overwhelming sepsis in splenectomized patients.89 One of the areas of concern in monitoring patients after splenectomy in the ICU is the frequent occurrence of leukocytosis and thrombocytosis. This situation makes monitoring for intraabdominal sepsis difficult, and one has to follow the WBC count until it plateaus. A deviation or a sudden increase from a plateau high WBC count could be considered evidence of occult sepsis. In patients who are in the ICU for prolonged periods with platelet counts above 106/μL, consideration should be given to prophylactic anticoagulation to prevent thrombotic complications.

Injuries to the Extrahepatic Biliary Tract

These injuries are relatively infrequent. Common bile duct injuries commonly involve the other structures in the porta hepatis, with frequently associated injury to the liver, duodenum, or other structures in the abdomen. Vascular injuries isolated to the porta hepatis are relatively rare and carry a very high mortality rate. If a porta hepatis injury is suspected, the Pringle maneuver would allow better identification of the injury with dissection of the structures of this area. Vascular injuries take priority over duct injuries because of the immediate threat to survival posed by massive hemorrhage. If the portal vein is the source of the hemorrhage, then attempts should be made to repair this by lateral venorrhaphy, resection, and anastomosis or interposition grafting. Portal systemic shunting usually results in severe encephalopathy in previously healthy patients with normal hepatic flow and should be avoided if possible. Common hepatic artery injury should be repaired where possible; otherwise, ligation may be performed as a last resort.90,91

Common bile duct injuries that involve less than 50% of the circumference of the duct should be treated by débridement and primary closure with a stent (a ureteric stent or T-tube) exiting away from the anastomosis. If more than 50% of the circumference of the bile duct is involved, then there is an over 50% rate of late stricture that diminishes to about 5% if a biliary enteric anastomosis is performed.

Injuries to the gallbladder should be treated by cholecystectomy unless the patient's hemodynamic status is precarious, when a cholecystostomy may be performed as a temporizing measure.92,93

Retroperitoneal Hemorrhage

Frequently, hemorrhage in the retroperitoneal space is identified at laparotomy. This problem can be very difficult to treat, and when possible, preoperative investigation including x-ray of the pelvis, CT scan, or angiography will allow consideration of specific diagnostic possibilities and a more directed surgical approach. When the patient is taken to the OR prior to any of these investigations because of instability, however, a decision needs to be made regarding proper treatment of the retroperitoneal hemorrhage.

Division of the retroperitneum into three zones may be used to guide therapeutic decisions (zone 1, central; zone 2, lateral; zone 3, pelvic). In general, hemorrhage that is associated with a major pelvic fracture and confined to the pelvis or originating in the pelvis should be treated without exploration unless either there is a penetrating injury that is likely to involve the iliac vessels or the hematoma is pulsatile.94,95 Exploration of such retroperitoneal hematomas usually results in massive uncontrollable hemorrhage when the source is the pelvic fracture. This type of hemorrhage often is best treated by external fixation of the fractured pelvis and blood transfusions. Angiography is required when hemorrhage is continuing with a view to embolizing any identifiable bleeding artery. The mainstay of controlling hemorrhage from pelvic fractures, however, is immediate stabilization of the pelvis to prevent undue motion of the fracture fragments, and this is accomplished most expeditiously by external fixator application.96

Apart from hematomas arising from the pelvis, hematomas that are not pulsatile or expanding and that are located in the lateral retroperitoneal spaces (zone 2) also should be left unexplored, and further investigation should be done postoperatively in the form of contrast-enhanced CT scan and angiography as indicated. If the lesion is expanding or pulsatile, the retroperitoneal space has to be explored to identify the bleeding source and control it. Temporary control of an infradiaphragmatic source of hemorrhage can be achieved by thoracotomy and clamping of the supradiaphragmatic aorta.47 However, when the hematoma or bleeding does not extend to the aortic hiatus, temporary control may be achieved within the abdomen by compressing the aorta at the diaphragmatic crura. This compression can be done by an assistant's hand, an aortic compressor, or a sponge stick. By incising the peritoneum and mobilizing and displacing the esophagus, a clamp also may be applied directly to the aorta to achieve temporary control of intraabdominal hemorrhage.97

A retroperitoneal hematoma that is centrally located (zone 1) in the midabdomen represents possible injury to the pancreas and major retroperitoneal vessels. These hematomas require exploration with a view to determining the extent of the injury and, in the case of the pancreas, to determine whether the pancreatic duct has been violated. The lesion is then treated as outlined earlier for pancreatic trauma. Surgical exposure strategies are as outlined previously to allow adequate visualization of retroperitoneal structures as well as vascular control.

Occasionally, retroperitoneal hemorrhage, particularly in the pelvis, cannot be controlled by surgical means, and one has to resort to packing of the retroperitoneal space and closure of the abdomen with a view to exploring the patient within 48 hours, hopefully after cessation of the bleeding. These patients require very close observation in the ICU with correction of any coagulopathy, acidosis, hemodynamic derangement, and hypothermia.66

Genitourinary Injuries

Although hematuria is absent in 5% to 10% of patients with genitourinary trauma,98 it still is a most important sign of genitourinary injury. The patient frequently has sustained blunt or penetrating injury to the flank or diffuse transfer of force to the abdomen. Occasionally, there is a direct penetrating injury into the bladder or kidney. Penetrating injury resulting in ureteric lacerations is very rare, and where possible, these injuries are repaired by débridement, primary repair, and stenting. Although in the past traumatic hematuria of any degree has been investigated with IV pyelography, a more selective approach is more appropriate. This change in approach has resulted from the low yield of IV pyelography in all patients with trauma; also, in the presence of hematuria, the yield in terms of positive lesions identified varies from 15% to 60%.99 Most of the injuries discovered (65% to 70%) are considered minor, involving a parenchymal laceration or contusion that does not require surgical intervention. Major parenchymal laceration through the corticomedullary junction and often into the collecting system usually causes gross hematuria and represents 10% to 15% of renal injuries.100 The remainder of renal injuries are associated with a shattered kidney or renal pedicle injury. These considerations, together with the cost of the procedure, as well as the incidence of allergic reaction (5.7%), including anaphylaxis, renal failure, and death (0.0074%), have led to a change in the approach to hematuria in the assessment of genitourinary trauma. In most instances, the major cause of death from genitourinary trauma is the associated injuries, and the investigation using IV pyelography has had very little effect on management or outcome in general.

Microhematuria without shock has not been shown to be associated with lesions requiring surgical intervention, whereas gross hematuria or microhematuria with shock or a major abdominal injury has been associated with lesions requiring surgery in up to 10% of cases.99,100 Penetrating renal injuries are associated with lesions requiring surgery both with and without hematuria.100 On the basis of these observations, IV pyelography should not be routine in abdominal trauma.101 Also, if the patient is having a CT scan of the abdomen for another reason, or if there is only microhematuria without shock or any evidence of severe injury, IV pyelography is not recommended. The IV pyelogram, however, is helpful in the following circumstances: (1) if a CT scan is not being done and there is gross hematuria or microhematuria with shock, (2) if there is hematuria in the presence of a major abdominal injury, or (3) if there is a penetrating injury and the trajectory suggests the possibility of renal injury, even without hematuria. One other relative indication for IV pyelography is if the patient is unstable but hematuria is present; if time allows, a one-shot IV pyelography may be conducted to assess the functioning of both kidneys in the event that nephrectomy may be required during laparotomy.

The main indication for surgical intervention in renal trauma is an injury with major hemorrhage such that the patient's hemodynamic stability cannot be maintained with rapid transfusion of crystalloid and blood. Otherwise, most patients with renal trauma are treated nonoperatively (Fig. 95-8) at first. They should be observed very closely in an ICU setting for any deterioration in hemodynamic status suggesting continued major hemorrhage that requires surgical intervention. If there is failure to visualize both kidneys on IV pyelography, then contrast-enhanced CT or angiography should be conducted to determine the extent of the injury producing nonfunctioning of the kidneys.

The main principle in surgical treatment of kidney injury is to control hemorrhage while preserving kidney function; this is best achieved by exploring the kidney only in selected patients in whom there is an expanding of pulsatile hematoma or signs of urine extravasation. In order to ensure adequate hemorrhage control, the renal vascular pedicle should be isolated first and secured to allow occlusion if this becomes necessary. If after attempts at repair or partial nephrectomy there is still massive bleeding after release of renal pedicle occlusion, then nephrectomy becomes necessary, especially in the unstable patient who is known to have a contralateral normal kidney.

Hematuria also may result from injury to the bladder, and the suspicion of bladder injury should be investigated by cystography, at least three views being taken with the bladder both filled and emptied to determine whether or not there is any extravasation of bladder contents. Retrograde cystography has been reported to be more accurate in diagnosing bladder injuries than the spiral CT.102 Extraperitoneal bladder rupture may be treated by catheter drainage alone, whereras intraperitoneal bladder rupture usually warrants open laparotomy with débridement and formal repair of the laceration.103,104

Although in most multiply injured patients urinary catheterization per urethra is routine for monitoring the urine volume and consistency as a reflection of the hemodynamic status, there are certain contraindications to catheterization per urethra. Blood at the urethral meatus or the presence of scrotal or perineal hematomas with a large, high-riding, boggy prostate may signal injury to the urethra; these findings necessitate a urethrogram to exclude urethral laceration prior to transurethral placement of a Foley catheter. Urethral rupture necessitates urologic consultation and treatment.

Postoperative care of these patients requires maintenance of renal perfusion; thus careful attention to maintenance of hemodynamic stability is important. In addition, maintenance of good urinary output and close monitoring of the degree of hematuria, as well as the volume of urine, are required in the ICU setting. An occult injury to the genitourinary tract with extravasation of urine that is left undiagnosed is another means by which a multiple-trauma patient may develop septic complications in the ICU. This type of complication is diagnosed by ultrasonography or CT and is treated by drainage of the urinoma with or without repair of the source of the urinoma.

Traumatic Abdominal Compartment Syndrome

Although the deleterious effects of increased intraabdominal pressure have been identified prior to the twentieth century,105 improvements in prehospital care and the rapidity with which multiply injured patients are taken to the OR room have led to an increased recognition of the syndrome caused by acute increases in intraabdominal pressure (see Chap. 42) because this syndrome is more likely to occur in the presence of multiple major intraabdominal injuries resulting in severe blood loss, massive fluid requirements, and prolonged surgery. Previously, most of these patients would not survive to reach the operating room. The traumatic abdominal compartment syndrome may be defined as the adverse clinical consequences of an acute increase in intraabdominal pressure following trauma. The generally accepted parameters for defining this syndrome include an increase in intraabdominal pressure above 20 cm H2O, peak airway pressure of greater than 40 cm H2O, oxygen saturation of less than 90% on 100% oxygen, and oxygen delivery index of less than 600 mL/m2 per minute, as well as oliguria of less than 0 .5 mL/kg per minute.106 The condition is diagnosed usually at the end of a surgical procedure when attempts are made to close the abdomen or early in the postoperative period of the massively injured patient, although it may occur in patients with major intraabdominal hemorrhage or retroperitoneal hemorrhage prior to surgical intervention. The source of the increased intraabdominal pressure is usually edema, blood accumulation, or distention of the hollow viscera. Prevention of this syndrome therefore is achieved by minimizing intraabdominal edema through decreasing the period of hypotension, minimizing manipulation of the bowel, limiting the duration of surgical procedures, adequate control of hemorrhage, and appropriate decompression of the gastrointestinal tract.107

In the setting of hemodynamically compromised patients requiring massive blood transfusions leading to hypocoagulability states, acidosis, and hypothermia, major definitive surgical procedures should be postponed in order to eliminate factors that predispose to increases in intraabdominal pressure. The concept of damage-control laparotomy is therefore an important consideration in this setting.79–81

The increase in intraabdominal pressure affects virtually all systems in the body,108,109 including a decrease in cardiac output from the decrease in venous return arising from compression of the vena cava, decreased renal perfusion, decreased myocardial perfusion, and increased airway pressure resulting in inability to mechanically ventilate and maintain oxygenation of the patient—all of which are associated with a poor outcome unless the increase in intraabdominal pressure is treated promptly by abdominal decompression. In the OR, apart from the practice of damage-control laparotomy, if on attempting formal closure of the abdomen there is major increase in intraabdominal pressure, as reflected by an extraordinary increase in airway pressures with difficulty in ventilating the patient, the formal closure should be aborted. In these circumstances, the abdominal contents are contained by using temporary devices such as plastic bags sutured to the edges of the skin. In some instances, skin closure without fascia closure may be possible without a major increase in intraabdominal pressure. The patient is returned to the ICU for stabilization, monitoring, and correction of associated abnormalities. With improvement in these parameters and signs of reduction in the intraabdominal pressure, the patient is returned to the OR for further surgical intervention, which may allow either primary closure of the fascia with skin closure or the use of mesh for closing the fascia followed by skin closure or skin grafts later on. Other more elaborate techniques of abdominal wall closure are required in the long term for these patients.110,111

Apart from recognition of this entity in the OR, it may develop slowly or abruptly without previous surgery (e.g., the patient with major retroperitoneal hemorrhage from a pelvic fracture) or in the postoperative period during the patient's ICU stay. In a patient in whom this syndrome is likely to develop, close monitoring of airway pressures, hemodynamics, renal perfusion, gas exchange, and intraabdominal pressure is required. A simple means of monitoring intraabdominal pressure is by attaching a three-way stopcock to the side tubing of a Foley catheter after instilling 50 to 100 mL of sterile saline into the bladder through the catheter. On clamping the Foley catheter tubing distal to the three-way stopcock, the stopcock is opened to a manometer that is zeroed at the level of the symphysis pubis.112

The mainstay of treatment of patients with this traumatic abdominal compartment syndrome is immediate abdominal decompression, which can be performed in the ICU. Without decompression, mortality is prohibitive and arises from the development of cardiopulmonary failure, renal failure, hepatic failure, and bowel ischemia.

Patients at particularly high risk of developing this entity include those with massive retroperitoneal hematomas from conditions such as pelvic fractures and those with major intraabdominal hemorrhage requiring prolonged operative procedures, the use of massive amounts crystalloids and blood transfusions leading to hypothermia and hypocoagulable states. Treatment should be directed at correction and prevention of these precipitating factors. A high index of suspicion should be maintained in order to predict the onset of this condition so that preventive measures and early diagnosis will result in prompt abdominal decompression.

We acknowledge the assistance of Sunnybrook Studios of the Sunnybrook and Women's College Health Science Centre, Toronto, for preparation of the illustrations.