Chapter 92. Priorities in Multisystem Trauma

• To improve survival, injury management must be prioritized in the multiply injured patient.
• The order of priority among injuries is related to time and degree of life threat posed by each injury.
• Immediate priority is given to airway control and to maintenance of ventilation, oxygenation, and perfusion.
• Cervical spine protection is crucial during airway intubation.
• A trauma team leader is important to coordinate management in the multiply injured patient.
• Complete familiarity with techniques for airway control, chest decompression, and the establishment of intravenous access is essential in management of multiple trauma.
• Complete in-depth assessment of the multiply injured patient is required only after immediately life-threatening injuries have been treated.
• Repeated assessment is necessary to diagnose and treat injuries that are not obvious on initial presentation.

Mortality from multiple injuries follows a trimodal distribution.1,2 The first peak represents death occurring at the scene and results from such injuries as cardiac rupture or disruption of the major intrathoracic vessels, and severe brain injury that is incompatible with survival. Death from such injuries occurs within minutes of the traumatic event and medical intervention is usually futile. The second peak in mortality following multiple injuries occurs from minutes to a few hours after the event. Mortality during this phase is related to injuries that are immediately life-threatening, such as airway compromise, tension pneumothorax, and cardiac tamponade. This is also a period during which simple appropriate resuscitative measures can significantly affect the outcome. The third peak occurs as a result of complications of the injury, such as sepsis or multiple-system organ failure.3 However, mortality in this third phase can also be significantly affected by the type of intervention during the second phase. The intensivist dealing with the multiple trauma patient is very likely to be involved in the institution of resuscitative measures during the second phase as well as the management during the third phase of the complications of the injury or complications arising from inadequate treatment. Many of the chapters in this text deal with the complications of trauma, such as sepsis and multiple organ failure. This chapter will deal with treatment priorities during the second peak of the trimodal distribution of trauma-related mortality.

Blunt trauma from motor vehicle collision is the most frequent cause of injuries in general. This type of impact usually results in injuries to many different parts of the body simultaneously. Figure 92-1 shows the distribution of motor vehicle driver injuries over a 2-year period at Sunnybrook Health Science Centre in Toronto, Canada, where 338 drivers with 2566 injuries were treated. Head and neck injuries were the most frequent, occurring at a frequency of 1.88 per patient, and the overall frequency of injuries was 7.6 per patient.

When faced with multisystem injury, the intensivist must prioritize treatment according to the threat to the patient's survival.4 Prioritization of assessment and intervention requires a coordinated team approach. Where personnel are available from different specialties, it is of paramount importance that the entire resuscitative effort be coordinated through an identified team leader. This very simple decision should be made prior to institution of therapy and can be critical to the outcome in the patient with multisystem trauma. The team leader, who may be an intensivist, must be completely familiar with a wide variety of injuries and the relative threat they pose to life in order to prioritize intervention and direct personnel appropriately.

Certain fundamental concepts underlie the approach to resuscitation of the multiply injured patient. The most important of these is that immediately life-threatening injuries should be treated as they are identified. Therefore, assessment and resuscitation must proceed simultaneously. The initial goal in managing the trauma patient is to provide adequate oxygenation and perfusion. This goal is achieved by approaching assessment and treatment so that abnormalities in the injured patient that affect oxygenation and perfusion take top priority. It is also of prime importance to recognize findings that suggest a need for emergent surgical intervention.

The order of priorities is a key feature for successful management of the multiply injured patient and should adhere to the following sequence:

1. Establishment of the airway and of oxygenation and ventilation with cervical spine control

2. Control of hemorrhage

3. Maintenance of adequate perfusion

4. Identification and correction of neurologic abnormalities

5. Total exposure of the patient to allow complete assessment while preventing hypothermia by minimizing the duration of this exposure

6. Temporary stabilization of fractures

7. Detailed systematic assessment and provision of definitive care

In the Advanced Trauma Life Support (ATLS) course for physicians,1 steps 1 to 5 constitute the Primary Survey, during which immediately life-threatening injuries are identified by adhering to the sequence ABCDE, where A stands for airway, B for breathing, C for circulation and hemorrhage control, D for neurologic disability, and E for exposure.

The basis for this order of priorities is the degree to which abnormalities in the different systems threaten the life of the patient. Adherence to this order allows assessment and resuscitation to occur simultaneously, because injuries will be identified in the order in which they are likely to threaten the patient's life. Although the patient with multiple fractures requires treatment of these fractures, apart from hemorrhage control associated with the fractures, such treatment should take lower priority compared to treatment of abnormalities affecting the airway or respiratory status.

Complete evaluation requires assessment of the entire front and back of the patient, necessitating full exposure. Once this assessment is completed, the patient should again be covered to minimize heat loss and the risk of hypothermia.

Airway, Oxygenation, Ventilation, and Cervical Spine Control

The most frequent cause of airway obstruction in the multiply injured patient is loss of tone of the muscles supporting the tongue, either because of hypoperfusion of the brain from hypovolemic shock or because of central nervous system (CNS) injury. As outlined in Chaps. 15 and 35, the simple maneuvers of chin lift and jaw thrust move the mandible forward. Because the tongue muscles are attached to the mandible, these actions move the tongue anteriorly and open the upper airway. It is essential in the trauma victim to inspect the oropharynx to ensure that there is no foreign material (including vomitus) in the pharynx that will occlude the airway. Quick observation of the patient's nares and mouth and listening for unobstructed passage of air through the upper airway, together with inspection for the presence of foreign objects in the oropharynx, are all very simple maneuvers that should be undertaken in the initial care of the multiply injured patient. The patient who is fully conscious, vocalizing and breathing adequately, and who is not in shock does not require an artificial airway.

The underlying principle of establishing an airway in the trauma victim is to institute the simplest technique that allows effective oxygenation and ventilation. Over 90% of patients do not require endotracheal intubation. Measures short of endotracheal intubation include the insertion of oropharyngeal or nasopharyngeal tubes. However, when endotracheal intubation is necessary, it should be performed promptly and expeditiously. Prolonged unsuccessful attempts at endotracheal intubation without oxygenation and ventilation should be avoided. Mask ventilation with oxygen and an oropharyngeal airway should be performed intermittently to avoid hypoxia during prolonged attempts at endotracheal intubation. All multiply injured patients should have oxygen administered by the most appropriate means as early as possible. A pulse oximeter should be attached to monitor O2 saturation, which should be maintained at 95% or greater.

In very rare circumstances, the patient's airway may not be patent and it may be impossible to establish an airway nasally or orally. In such situations, cricothyroidotomy is required. This procedure should only be done when an airway cannot be established by other, nonsurgical means. The landmarks for the cricothyroid membrane are indicated in Fig. 92-2. A cricothyroidotomy may be done using a large-bore needle or scalpel, the former method being preferable in children under 8 years of age because the cricoid cartilage is essential to the stability of the upper airway of infants and young children. A 14-gauge needle and cannula may be inserted through the cricothyroid membrane for temporary oxygenation, but this is not a very efficient means of ventilation. To maximize oxygenation and avoid hypercapnia, the needle cricothyroidotomy should be followed by tracheostomy in an operating room under ideal circumstances if a surgical airway is still required. The placement of the cricothyroidotomy needle allows approximately 30 to 45 minutes of adequate oxygenation without severe hypercapnia. The surgical cricothyroidotomy is preferable and more effective in adults. A transverse skin incision is made directly over the cricothyroid membrane, and after the subcutaneous structures are reflected, the cricothyroid membrane is identified and incised transversely. A pair of forceps is then inserted to spread the opening, and a tube of appropriate caliber, usually a 6F or 7F tracheostomy or endotracheal tube, is inserted through the opening and secured.5

Many techniques for establishing an artificial airway are associated with risks of cervical spine injury. Awareness of these risks during airway intubation is crucial in preventing spinal cord injury in the multiply injured patient. Inappropriate manipulation of the cervical spine during airway intubation could convert an unstable cervical spine injury without neurologic deficit into one with permanent neurologic deficits, including paraplegia, quadriplegia, and even death. In a patient who is unconscious or who is suspected of having a cervical spine injury, the neck should not be flexed, extended, or rotated. In-line immobilization with the neck in the neutral position should be maintained while the airway is secured. If the patient is conscious and breathing, then a blind nasotracheal intubation may be attempted with cricoid pressure anteriorly. If the patient is apneic, then orotracheal intubation with in-line cervical immobilization will have to be attempted. Failure or inability to secure the airway by nonsurgical means in a patient who requires a definitive airway necessitates cricothyroidotomy. Where fiberoptic bronchoscopy is immediately available, it may be used to facilitate endotracheal intubation. All unconscious patients or patients suspected of cervical spine injury should have a lateral cervical spine x-ray done as a minimum, and all seven cervical vertebrae and the superior aspect of the first thoracic vertebra should be clearly visualized. Failure to visualize all these vertebrae should necessitate other views of the spine, including a swimmer's view. An open-mouth anteroposterior odontoid and anteroposterior x-ray view of the cervical spine should also be done. If there is doubt as to the presence of a cervical spine injury, the neck should be immobilized with a semirigid cervical collar and computed tomography (CT) is performed to assess the integrity of the cervical spine. If the patient is awake and alert and has no cervical pain or tenderness or other abnormality on physical examination, then the cervical collar may be removed after adequate cervical spine x-rays. In the presence of clinical signs of spinal cord injury, the cervical spine is considered to be abnormal even if the cervical spine x-ray appears normal. In selected patients who have not had a period of unconsciousness or another painful distracting injury, and are alert and have no clinical evidence of cervical spine injury, x-rays of the cervical spine may be omitted and the cervical collar removed.6,7

Adequacy of ventilation is quickly assessed by observation of the chest for asymmetrical or paradoxical movement, followed by quick auscultation and percussion to determine whether there is any hyperresonance or dullness to suggest pneumothorax or hemothorax. Deviation of the trachea suggests the presence of a pneumothorax or hemothorax, but this finding is not always evident. Although one may confirm the diagnosis of a simple traumatic pneumothorax with an upright chest x-ray, suspicion of a tension pneumothorax requires immediate decompression, without prior x-ray confirmation. Further examination of the chest should be conducted to determine the presence of other life-threatening thoracic injuries, such as cardiac tamponade, open pneumothorax, flail chest, ruptured thoracic aorta, and massive hemothorax (see Chap. 95).

Adequacy of Perfusion

After airway control, oxygenation, and adequate ventilation have been secured, the next priority is maintenance of adequate perfusion. The most common source of hypoperfusion in the multiply injured patient is hemorrhage. Its clinical presentation will depend on such factors as the patient's age, as well as the duration and magnitude of the hemorrhage. The presence of a normal or even elevated blood pressure, particularly in the young patient, does not rule out blood loss. The physiologic response to hypovolemia includes sympathetic discharge with vasoconstriction and tachycardia, which will tend to maintain the blood pressure. Older patients tend to manifest hypotension much earlier in the course of hypovolemia. Therefore, other signs of hypoperfusion should be sought in assessing the trauma patient. The location and character of the pulse, the skin color, and capillary refill time are all signs that are immediately accessible to the examining physician and should be used in determining adequacy of perfusion. Failure to palpate a radial pulse may signify hypotension of the order of 70 to 80 mm Hg. Tachycardia with cool extremities suggests hypoperfusion from hemorrhage until proven otherwise. Hemorrhage may be subdivided into classes I to IV,1 each class having an associated clinical response, as indicated in Table 92-1. The patient who has a normal heart rate with a strong, bounding radial pulse, warm skin, and a capillary refill time of less than 2 seconds would be considered not to have lost any significant volume of blood, and the degree of deviation from these clinical parameters would correlate with the magnitude of blood loss.

Although the most common cause of hypoperfusion in trauma patients is hemorrhage, other causes, such as tension pneumothorax, cardiac tamponade, myocardial contusion, open pneumothorax, and flail chest must be considered. Hypoperfusion in the trauma patient first requires a search for a source of hemorrhage, which should be immediately controlled. Any external source of hemorrhage should be controlled by direct pressure, without resorting to blind application of clamps or tourniquets. Improving the hemodynamic status should be the next goal. This should be accomplished by appropriate fluid replacement through at least two large-bore intravenous catheters (14 to 16 gauge minimum). It is very helpful to establish multiple IV catheters, not only to facilitate rapid volume infusion, but to ensure that an IV line will still be available if one of the catheters becomes disconnected, plugged, or otherwise nonfunctional. In the adult, the preferred peripheral percutaneous intravenous site is in the forearm or the antecubital vein. Failure to establish intravenous access through these routes should prompt establishment of intravenous access by other routes such as the internal jugular or subclavian vein in the neck or femoral vein in the groin using the Seldinger technique. Venous cutdown of the saphenous vein at the ankle or the antecubital vein or the femoral vein at the groin are other approaches, but are now seldom necessary because of the success in establishing access through the other nonsurgical routes. The route will depend on the experience and skill of the physician. Placement of central lines should always be followed by a chest x-ray as soon as feasible, not only to confirm proper location of the catheter, but also to check for the presence of pneumothorax or hemothorax. Because these lines are placed under less than ideal conditions, the risk of septic complications is high, and the lines should be replaced later under more sterile conditions. In children under age 6 years, the intraosseous route should be attempted before proceeding to the central venous routes. With specially designed devices the intraosseous route is also possible in adults but is seldom required.8 As a rule, it is best to avoid placing IV catheters in limbs that have major soft tissue or bony injuries. The intensivist must be completely familiar with the usual sites for venous access and also be prepared to proceed to venous cutdown where percutaneous techniques are not successful. Venous access should be achieved promptly, since cannulation of the veins becomes more difficult as shock continues, owing to venoconstriction and venous spasm.

In the course of establishing IV access, blood is drawn for complete blood count, cross-matching of blood, coagulation, and toxicology screens. Prior to the availability of blood products, it is essential to maintain adequate perfusion, as judged by clinical indicators, including blood pressure, pulse, status of the neck veins, and urinary output. In most circumstances, there is sufficient time to obtain the patient's blood type. However, if after approximately 2 to 3 L of crystalloid have been given, the patient's vital signs do not normalize or normalize only temporarily, and typed blood is not available, then emergency blood (group O) will be required for resuscitating the patient. Packed cells in the amount of anywhere from 4 to 10 U should be ordered for resuscitating the patient with major hemorrhage.

If there is no obvious external source of hemorrhage, bleeding from pelvic or extremity fractures should be sought. Failure to demonstrate blood loss in these areas suggests that the blood loss is in either the thorax or the abdomen. Most sources of thoracic hemorrhage can be identified by a combination of physical examination and chest x-ray. Therefore by a process of elimination it is usually possible to determine the source of the hemorrhage. If the areas identified earlier do not represent the source of hemorrhage, the most likely source is intra-abdominal. If the patient shows signs of continued hemorrhage with only a transient response or failure to respond to volume infusion, laparotomy may be required for the identification and control of intra-abdominal hemorrhage. In some cases in which there is an obvious source of blood loss such as an extremity fracture, there may still be uncertainty regarding possible concurrent intra-abdominal hemorrhage. In these situations, ultrasonography, diagnostic peritoneal lavage, or CT of the abdomen (see Chap. 95) is helpful in determining whether or not there is an intra-abdominal source of hemorrhage.9,10

As indicated earlier, other causes of hypoperfusion should be sought in the trauma patient by assessing for such signs as those of cardiac tamponade, myocardial contusion, and tension pneumothorax, with prompt institution of corrective measures.11 These intrathoracic causes of hypoperfusion are discussed in Chap. 95.

In patients sustaining major blood loss, end points of resuscitation and the volume of infused fluids should be based on the rapidity with which such patients can be taken to the operating room for definitive control of hemorrhage. In patients without major head injury, particularly those with penetrating torso trauma, borderline hypotension in the range of 90 mm Hg systolic should be the goal in preparation for the operating room, since massive volume infusion towards normalization of the hemodynamic status could aggravate blood loss.12,13

In evaluating the patient's response to volume infusion, it is important to recognize that massive blood loss may trigger a vagally mediated bradycardia, and that in these circumstances the absence of tachycardia does not represent adequate volume resuscitation.14 When one is judging the amount of fluid required and the requirement for blood, a useful guideline is that if blood pressure has not approached normalcy after infusion of 50 mL/kg of crystalloid, then blood administration should be considered.15 As indicated earlier, if type-specific blood is not available, then emergency type O packed red blood cells may be used. Because one of the most common causes of hypothermia and its complications is the rapid infusion of cold solutions in the resuscitation of trauma patients, techniques for warming both the patient and the infused fluid must be employed.16,17 In addition to electrocardiographic monitoring and continued assessment of vital signs, core temperature monitoring is therefore important, using a device that is capable of reading temperatures at hypothermic levels.

Although volume deficit is the major cause of hypoperfusion in the trauma patient, failure to respond to adequate volume infusion may represent cardiovascular decompensation. If such causes as cardiac tamponade or tension pneumothorax have been ruled out as the cause of this cardiovascular decompensation, consideration should be given to the use of inotropes and vasoactive agents to support the circulation in these circumstances. Such intervention is accomplished with close hemodynamic monitoring, as outlined in earlier chapters.

In situations in which the hypoperfused patient fails to respond to massive fluid infusion and there is no obvious nonhemorrhagic source of the hypoperfusion, emergency thoracotomy18,19 may be required. This allows (1) identification and treatment of pericardial tamponade, (2) internal cardiac massage, (3) identification and control of intrathoracic hemorrhage, and (4) cross-clamping of the thoracic aorta to maintain cerebral perfusion and coronary blood flow while decreasing bleeding from a subdiaphragmatic source. Emergency thoracotomy also allows the diagnosis and treatment of air embolism, which is discussed in Chap. 95.

Neurologic Status

Following control of the respiratory and circulatory status, attention is directed at assessment and management of the neurologic status. The hallmark of CNS injury is a change in the level of consciousness. Therefore it is essential that the level of consciousness be defined, so that repeated assessment will detect any changes over time. The Glasgow Coma Scale score (GCS; see Chaps. 67 and 93) is the generally accepted means of establishing this level of consciousness in the trauma patient.

The brain is very sensitive to hypoxia and hypoperfusion, and one of the most common causes of a depressed level of consciousness in the multiply injured patient is uncorrected hypovolemia resulting in hypoperfusion and cerebral hypoxia. Therefore, overall resuscitative measures aimed at maintaining vascular volume and arterial oxygenation are of prime importance in the treatment of a patient with a possible head injury. Volume restriction as a primary goal, with the aim of decreasing intracranial pressure and cerebral edema, is inappropriate in the hypovolemic head-injured patient. In fact this approach is more likely to aggravate the head injury and increase cerebral edema and intracranial pressure. The key features of initial assessment and resuscitation of the brain-injured patient are to prevent secondary brain injury due to hypoperfusion and hypoxemia, control of cerebral edema, and identification and evacuation of significant mass lesions based on careful clinical and CT scan assessment under the guidance of a qualified neurosurgeon. The detailed assessment and management of such patients is discussed in Chap. 93.

Fracture Stabilization

Although the most dramatic injury in the multiply injured patient is frequently the mangled limb resulting from major fractures, fractures as such do not pose an immediate threat to life, and therefore are generally lower in our list of management of priorities. However, the secondary effects of fractures may have high priority. For instance, massive hemorrhage associated with a fracture will require direct control of the hemorrhage where possible, aggressive early fluid resuscitation, reduction of the fracture, and in the case of massive hemorrhage from pelvic fractures, the use of such techniques as external fixation. Time is also of the essence in the management of fractures when there is interference with the blood supply to the limb, as from spasm of the blood vessels or direct injury to the blood vessels adjacent to the fracture. Early assessment of neurovascular integrity and the correction of any abnormality are essential in the management of fractures to ensure limb salvage and to prevent rhabdomyolysis and compartment syndrome. Limb ischemia associated with the fracture should be initially treated by reduction of the fracture and immobilization. If this maneuver fails to restore perfusion, early angiographic assessment should be undertaken. To improve the chances of saving the limb, the period of limb ischemia should be less than 4 to 6 hours. Therefore all efforts should be made to obtain early angiography and definitive repair of the vascular injury associated with a fracture. The possibility of compartment syndrome should be kept in mind, particularly after perfusion has been re-established to a previously ischemic limb. Definitive management of the fracture itself is discussed in Chap. 96.

Detailed Systematic Assessment and Definitive Care

Once the initial rapid assessment and resuscitation of the patient has been completed, a more in-depth assessment is conducted systematically, beginning with the head and ending with the lower extremities. The multiply injured patient must be completely undressed so that a complete physical examination can be done. This includes assessment of the back and requires careful log-rolling of the patient to visualize the back while protecting the spinal column. X-rays of the thoracolumbar spine should be considered in unconscious patients or those with major torso trauma with or without neurologic deficit, and in those in whom the mechanism of injury suggests the possibility of spinal column injury. Until adequate radiologic assessment is complete, these patients should be moved with caution by log-rolling, and any rotation, flexion, or extension of the thoracolumbar spine should be avoided.

All multiply injured patients should have (1) large-bore intravenous access, (2) a nasogastric tube to decompress the stomach and monitor for evidence of upper gastrointestinal hemorrhage (unless contraindicated, as discussed below), and (3) a transurethral Foley catheter for monitoring urine output, unless contraindicated by the presence of a urethral injury. Patients in whom urethral injury may be present include those with a major pelvic fracture, perineal and scrotal ecchymosis, or bleeding through the urethral meatus, and those in whom a high-riding, boggy prostate is found on rectal examination. If these signs are present, a urethrogram should be performed; only if the results are normal should the Foley catheter be inserted per urethra. The presence of a cribriform plate fracture is a relative contraindication to insertion of a nasogastric tube.20,21 Gastric decompression in this situation should be achieved by orogastric intubation.

If a rectal examination has not already been conducted to rule out a urethral injury prior to the insertion of a urethral catheter, it should be done as part of the complete assessment. The rectal examination not only assesses the integrity of the rectum, but provides information on the presence of blood in the gastrointestinal tract, the possibility of extrarectal pelvic injury (bony as well as soft tissue, e.g., injury of the prostatic urethra), and the presence of rectal sphincter tone, which may be abnormal in patients with spinal cord injury. During this phase of the assessment, potentially life-threatening injuries or injuries that are likely to produce morbidity and require correction on a nonurgent basis are detected. If the techniques of inspection, percussion, palpation, and auscultation are used appropriately, injuries such as simple pneumothoraces, uncomplicated fractures, and soft tissue wounds are detected and managed.

Reduction and stabilization of uncomplicated fractures are conducted once the life-threatening injuries have been treated. The tetanus immunization status of the patient should be determined, and appropriate prophylactic measures instituted. The trauma flow sheet should be completed, and the use of agents such as tetanus toxoid should be clearly documented and must be available for continued reference during the patient's stay in the ICU. It is at this point that subspecialty services such as plastic surgery and otolaryngology may be consulted.

Repeated examination of the trauma patient is important so injuries that are not obvious at presentation may be diagnosed and treated appropriately. The mechanism of the injury should be carefully noted in the history, and a high index of suspicion is required so that occult injuries are not missed. Patients who are relatively stable but who have been involved in a collision in which there is an associated fatality must be monitored very carefully in an ICU setting, since it must be assumed that they were exposed to the same force and energy transfer as the dead victim. Such patients may have temporarily contained hematomas in the spleen, liver, or retroperitoneum or around major vascular structures. These patients can decompensate abruptly with sudden spontaneous hemorrhage. Slowly progressive tachycardia, hypotension, a fall in hemoglobin concentration, or any worsening of abdominal findings, such as increasing pain or signs of peritoneal irritation, should warrant aggressive investigation and consideration of intervention, including surgical exploration. For these high-risk patients, approximately 4 to 6 U of blood should be available at all times in the early phase of treatment. An unexplainable fall in hemoglobin concentration must be considered a sign of continued hemorrhage, and any sudden increase in heart rate or decrease in blood pressure must be considered signs of major hemorrhage. The source of this hemorrhage should be identified promptly and treated appropriately. A more subtle sign of impending hemodynamic instability is a progressive decrease in urine output despite volume replacement that appears to be adequate in relation to the recognized injuries. Deterioration in the respiratory status should prompt assessment for the presence of a pneumothorax, lung contusion, or another type of subtle injury, such as a ruptured esophagus with pleural effusion that may present later in the patient's course. Delayed cardiac decompensation without obvious blood loss should warrant investigation for myocardial contusion, cardiac tamponade, or tension pneumothorax. The latter condition may develop on institution of positive pressure ventilation in a patient who sustained a simple pneumothorax which was not treated by tube thoracostomy. As discussed in Chaps. 42 and 95, the clinical presentation and operative findings may suggest the possible development of traumatic abdominal compartment syndrome in the ICU, prompting decompression of the abdominal cavity to improve the patient's cardiorespiratory and hemodynamic status.22 Respiratory deterioration may also occur in spontaneously breathing patients who sustained a rupture of the diaphragm and in whom the abdominal viscera at first remained in the abdominal cavity but later migrated above the diaphragm, causing respiratory compromise. For these reasons, continuous close monitoring in an ICU setting is crucial to improving survival of the multiply injured patient.

X-rays are obtained as indicated. In most multiply injured patients, these will include cervical spine x-rays if there is any suggestion of cervical spinal injury, a chest x-ray, and an x-ray of the pelvis. Other radiologic investigations will be undertaken as indicated by the assessment, such as the presence of deformity in an extremity warranting x-ray to confirm a fracture.

One of the most important decisions to be made in the emergency management of the trauma patient is whether or not surgical intervention is necessary. If the decision based on the initial assessment is that surgery is not warranted, then continued observation in an intensive care setting is necessary for most multiply injured patients. This approach, combined with a high index of suspicion, will minimize the risk of overlooking occult injuries, such as a subcapsular hepatic hematoma in a patient who is stable initially, which carries the potential for major sudden hemorrhage and hypovolemic shock.

In considering the need for surgical intervention, the common emergency indications are for thoracic, abdominal, and intracranial injuries. For thoracic injuries, this includes an uncontrollable pneumothorax representing a major airway laceration, a massive hemothorax usually representing laceration of a systemic artery (e.g., intercostal or internal mammary) or central pulmonary vessel, a widened mediastinum or other sign of aortic disruption, or signs of a ruptured esophagus, cardiac tamponade, or air embolism. The hypovolemic patient who suddenly becomes asystolic or suffers electromechanical dissociation is also a candidate for emergency thoracotomy. The details of assessment and management of these indications for thoracic surgery are considered in Chap. 95. The indications for laparotomy in the multiply injured patient are signs of peritoneal penetration, perforation, or hemorrhage in general; these are discussed in more detail in Chap. 95.

The indication for surgical intervention in head injuries is usually a change in level of consciousness in the presence of a mass lesion requiring evacuation or placement of an intracranial pressure monitoring device (see Chap. 93).

The author acknowledges the assistance of Sunnybrook Studios of the Sunnybrook and Women's College Health Science Centre, Toronto, for preparation of the illustrations.