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Injuries to the thorax are treated the same in pregnant and nonpregnant patients. It is important to remember that the gravid uterus elevates the diaphragm approximately 4 cm when performing procedures such as a tube thoracostomy. The insertion point for a chest tube should be 1–2 rib spaces above the usual fifth intercostal space.30
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Blunt Abdominal Trauma
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Similar to thoracic injuries, blunt abdominal injuries are treated the same in pregnant patients as in nonpregnant patients. Primary focus should be on the evaluation and rapid treatment of the mother as maternal shock is associated with an 80% fetal mortality.5 Injury to a solid organ can be safely observed if the mother remains hemodynamically stable; however, if signs of shock or infection develop, early operative intervention is indicated as a delay in treatment leads to worse fetal outcomes.
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The most devastating fetal injuries following blunt trauma include placental abruption and uterine rupture. Abruption is thought to complicate 1–6% of minor injuries and up to 50% of major injuries.3,24 Uterine rupture is rare, occurring in less than 1% of pregnant trauma patients, and is usually associated with direct impact with substantial force.24 A previously scarred uterus is more likely to rupture, and the risk increases with gestational age as the uterus grows and becomes an abdominal organ. The increased blood flow that accompanies advanced pregnancy makes rupture a severe complication which can lead to extensive hemorrhage.30 The extent of uterine damage is typically not apparent clinically and must be evaluated with operative exploration. Injuries to the skull and brain of the fetus are uncommon, but are more likely to occur if there is a maternal pelvic fracture and when the fetal head is engaged within the pelvis. Maternal orthopedic injuries are common, and one study from Parkland Memorial Hospital in Dallas, Texas, found that 6% of 1067 pregnant women had an orthopedic injury and this led to an increased risk of preterm birth, placental abruption, and fetal mortality.42
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There are no data on the use of tranexamic acid (TXA) for traumatic hemorrhage in pregnant patients, but one of the early uses of TXA was in obstetric patients for postpartum hemorrhage.43 A relative contraindication to TXA is a prothrombotic state which is common in pregnancy, but Lindoff showed there was no increase in thrombotic complications when TXA was used in pregnant women to treat bleeding disorders.44
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A pelvic fracture is the most common maternal injury that results in fetal death. Leggon et al reviewed 101 pregnant women with pelvic fractures, and the fetal mortality rate was 35%.45 Causes of death included direct fetal injury (20%), placental abruption (32%), and maternal shock (36%). Dilated retroperitoneal vessels place the mother at high risk of bleeding after sustaining a pelvic fracture and maternal mortality was reported by Leggon et al as 9%. Angiography and embolization of these bleeding vessels often delivers a higher dose of radiation than is usually considered safe, and these women should be counseled on the risk. Operative fixation of both pelvic and acetabular fractures is generally considered safe during pregnancy. Most women can safely attempt vaginal delivery after a pelvic fracture, even in the third trimester. Relative indications for a cesarean delivery include fractures of the pubic rami adjacent to the urethra or bladder, severe lateral compression fractures, and acute fractures of the pelvis with marked displacement.45
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In contrast to blunt trauma, maternal mortality is more favorable after penetrating injury as the gravid uterus protects the mother’s vital organs from injury.46 Conversely, fetal mortality is increased and has been reported as high as 73%.47 The thick uterus provides protection to the mother and fetus, particularly from low-velocity stab injuries. Gunshot wounds to the uterus are much more likely to cause fetal injury. Alternatively, visceral injuries are less likely when the entry site is anterior and below the uterine fundus.14 Potential abdominal injuries from thoracoabdominal wounds should be suspected at a higher level than normal given displacement by the uterus. Exploration should be considered for any gunshot wound or any stab wound to the upper abdomen, particularly because peritoneal irritation is blunted during pregnancy.24 Diagnostic laparoscopy is reasonable in the hemodynamically stable patient.
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A moderate or severe traumatic brain injury is associated with an adverse fetal outcome. Ikossi et al found that a Glasgow Coma Scale (GCS) score less than or equal to 8 was a significant risk factor for death of the fetus.48 The range of hyperventilation used for traumatic brain injury should be decreased in a pregnant patient as this causes a mechanical reduction in venous return and, therefore, cardiac output, which can have negative effects on the fetus. Hypothermia and mannitol should also be avoided, as well, but the use of hypertonic saline has no known deleterious effects.49
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Burn injury in the pregnant patient presents a unique management challenge as it causes increased capillary permeability and can lead to rapid fluid loss and hypovolemia. Fetal survival is dependent on fetal age and the extent of maternal injury, so, if the fetus is in the third trimester and the mother has extensive burns, early delivery is recommended.50 Wound care in the pregnant patient should limit the use of silver sulfadiazine (Silvadene) as it can potentially cause kernicterus in the newborn; however, one author has shown successful use without any adverse effects.51
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Preparing for the Operating Room
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If operative intervention is indicated, it is crucial to operate immediately, as a delay in treatment puts the fetus further at risk. Fetal viability should be documented using fetal heart tones or ultrasound pre- and postoperatively, and on-site obstetric consultation is recommended. Intubation can be difficult in the pregnant patient due to physiologic oropharyngeal edema, and inhalation anesthesia has a more rapid onset in pregnant patients, requiring an adjustment in dose.
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During a laparotomy for trauma, the goals should be the same as in a nonpregnant patient—hemorrhage and contamination control. The uterus should be retracted inferiorly while exploring the other abdominal organs. Once completed, the uterus is thoroughly inspected for any injuries, particularly in the setting of penetrating trauma. Small lacerations to the uterus can be repaired with chromic sutures. If the laceration extends into the uterus and the fetus is at a survivable age, then a cesarean delivery should be performed. A cesarean delivery can also be performed if the gravid uterus prevents adequate exploration of the mother. After significant blunt trauma, a uterine rupture may occur. Attempts should be made to repair the uterus primarily if possible, but, if there is extensive uterine damage or hemorrhage cannot be controlled, hysterectomy should be performed; however, fetal survival after extensive uterine damage is rare.30 An injury to the gastrointestinal tract increases the risk of loss of the pregnancy, and the abdomen should be irrigated extensively in addition to the administration of perioperative antibiotics.30
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Cesarean Section Following Injury
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Indications for cesarean delivery after trauma are vague and must be made on an individual basis. The three possible goals when a cesarean section is indicated include save the mother, save both the mother and baby, and save only the child. Cesarean section prior to 23 weeks usually results in fetal death and should only be done to allow successful resuscitation of the mother.15 After 23 weeks, cesarean section should be performed if fetal distress outweighs the risk of prematurity or if the uterus prevents repair of maternal injuries during laparotomy.52 A cesarean delivery is not indicated with exploratory laparotomy for trauma, but it is important to have the obstetrical team available for any unforeseen problems.
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Cardiopulmonary Resuscitation in Pregnancy
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The America Heart Association (AHA) recommends four key interventions to prevent a possible cardiopulmonary arrest in the critically injured pregnant patient as follows: (1) place the patient in full left lateral position to relieve aortocaval compression; (2) give 100% oxygen; (3) establish intravenous catheter access above the diaphragm; and (4) assess for hypotension defined as systolic blood pressure less than 100 mm Hg which reduces placental perfusion.53 If cardiopulmonary resuscitation (CPR) is required, the mother should be taken out of a left lateral tilt as this reduces the efficacy of chest compressions.30 To relieve aortocaval compression, manual left lateral and upward displacement of the uterus can be done by a member of the treating team. Chest compressions should be performed slightly higher than normal due to the upward displacement of the thoracic structures by the uterus.54 The rate of compressions and the use of defibrillation and cardiac medications remain unchanged from the recommendations in a nonpregnant patient.
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The AHA and ACOG both recommend cesarean delivery be considered within 4 minutes of maternal cardiopulmonary collapse if there is no return of spontaneous circulation.53,55,56 Delivery within 5 minutes in women beyond 20 weeks is encouraged in order to facilitate maternal resuscitation. This recommendation is based on the assumption that the compression of the vena cava and aorta by the gravid uterus may interfere with maternal hemodynamics. Katz et al reviewed the literature and found case reports in which 12 out of 18 patients had sudden and often profound improvement in hemodynamic status with return of blood pressure and pulse immediately after a cesarean delivery,57 changing the concept of delivery from a postmortem cesarean to perimortem cesarean. The four minute time frame advocated for postmortem cesarean delivery is often unmet, yet neonatal survival is still likely if delivery occurs within 10 or even 15 minutes of arrest.56 Earlier cesarean delivery theoretically benefits both mother and neonate by minimizing ischemic neurological damage.
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Emergency cesarean delivery should be performed at the location of arrest. Time should not be taken to check for fetal viability or to move to an operating room. CPR should continue during the procedure in case maternal circulation is restored. Gestational age can quickly be estimated as the uterine fundus should be two finger breadths above the umbilicus at 24 weeks.58 To perform delivery, a large midline skin incision from xiphoid to pubis is made and the uterus is opened with a vertical incision through the upper portion. The surgeon should then place their hand between the fetal head and pubic symphysis to deliver the baby and placenta.24 The uterus should be closed with a single layer, running chromic suture followed by quick closure of the fascia. CPR should continue well after the procedure and, if successful, the mother should be transported to the intensive care unit for recovery. A summary of the guidelines for perimortem cesarean section is provided in Table 37-5.
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