Trauma in Pregnant Women
Daniel J. Grabo
C. William Schwab
I. Introduction
Trauma complicates 6% to 7% of all pregnancies and accounts for 46% of maternal deaths. It is the leading non-obstetrical cause of maternal morbidity and mortality. Maternal injury severity is directly related to trauma-related fetal demise. The optimal early management of the pregnant trauma patient affords the best outcome for the fetus, that is, save the mother; save the fetus. While initial treatment priorities remain the same, anatomic and physiologic changes that accompany pregnancy alter the mother’s response to injury and modify trauma care.
II. Anatomic and Physiologic Changes of Pregnancy
Anatomic and physiologic changes involve essentially every organ system occur throughout all trimesters of pregnancy (Table 21B-1).
Table 21B-1 Anato mic and Physiologic Changes of Pregnancy and Potential Clinical Consequences
System or anatomic location
Anatomic/physiologic change
Potential clinical consequence
Neurologic
Eclampsia
Increase in ICP; seizures; can mimic head injury
Cardiovascular system
Increase cardiac output, heart rate, blood pressure (second trimester)
Decrease CVP, peripheral vasodilation
Altered vital signs
Hyperdynamic state
Peripheral edema
Pulmonary/thoracic
Increase tidal volume, minute ventilation (30–50%)
Decreased function residual capacity
Airway edema
Diaphragm elevated (4 cm) with increased excursion
Decreased PaCO2 (32 mm Hg)
Decreased tolerance for hypoxemia
Airway obstruction
Difficult intubation
Altered anatomic landmark (e.g., misplaced chest tube)
Renal
Increase renal blood flow, glomerular filtration rate
Dilation of collecting system
Altered sodium reabsorption and water retention
Decreased serum creatinine
Radiographic abnormalities
Hematologic
Intravascular volume expansion
Larger increase in plasma volume than RBC volume
Increase procoagulant factors
Anemia of pregnancy
Blood loss volume of up to 1,500 mL before manifesting signs of hypovolemia
Hypercoagulable state
Incidence of DVT/PE higher.
Endocrine
Pituitary enlarges with increased blood flow
Sheehan’s syndrome: Shock-related pituitary insufficiency
Abdomen and pelvis
Enlarging uterus displaces viscera cephalad and alters injury patterns.
Engorgement of pelvic veins increases the risk of bleeding with pelvic fracture.
Pelvic ligaments relax and can alter radiographic appearance of pelvis.
Location of gastro-esophageal junction is altered and gastric emptying is delayed, increasing risk of reflux and aspiration.
Uteroplacental unit
The uterus increases in size, assuming a full pelvic and intra-abdominal location, and the muscular wall becomes progressively thinner increasing the susceptibility to direct uterofetal injury. The mother’s inferior vena cava (IVC) is compressed in the supine position.
There is increased uterine blood flow as pregnancy advances, increasing the potential for hemorrhage.
The placenta lacks elasticity and is prone to separation (abruption).
The uteroplacental unit lacks autoregulation and is sensitive to catecholamines and vasopressors. This means maternal hypovolemia or use of vasoconstrictor can compromise placental blood flow and fetal perfusion and should be avoided.
III. Mechanisms of Injury
Blunt trauma
Blunt abdominal trauma is associated with up to 38% incidence of fetal mortality and can be associated with obstetrical complications such as preterm labor, placental abruption, and fetomaternal hemorrhage.
Falls are more common later in pregnancy as the center of gravity shifts and increases spinal lordosis.
Domestic violence is prevalent and associated with 5% risk of fetal death.
Motor vehicle collisions (MVCs) account for 50% to 80% of all traumas in pregnant women.
Penetrating trauma
GSW are more common than stab wounds (SWs), again often from domestic violence.
As pregnancy progresses, the risk of uterine and fetal injury increases due to enlargement and intra-abdominal location. Upper abdominal penetrating wounds can be associated with gastrointestinal injury (visceral displacement and abdominal crowding).
GSW to the abdomen that cause uterine injury result in fetal injury in up to 70% of cases as well as preterm labor; 40% to 70% result in fetal death.
IV. Principles of Management
General considerations
Consider pregnancy in all female trauma patients between 10 and 50 years and perform beta-human chorionic gonadotropin (HCG) testing unless known inability to conceive.
Initial treatment priorities remain the same as American College of Surgeons Committee on Trauma Advanced Trauma Life Support (ATLS®) protocols and focus on assuring maternal oxygenation and cardiopulmonary stability.
In cases of maternal blood loss, the mother will shunt blood from the fetus, so volume resuscitation and early fetal monitoring are key.
Early obstetrical consultation and fetal assessment are necessary.
Transport to a trauma center if any concerns of moderate to severe trauma.
Primary survey modifications
Place women in the second and third trimesters on the left side with a torso bump (15% leftward roll with pillow or bump under the right buttock and back) to displace the gravid uterus off the IVC and maximize venous return to the heart.
Give supplemental oxygen, and intubate if this fails or severe compromise exists to minimize fetal hypoxia. Laryngoscopy and intubation may be difficult due to airway edema and body habitus.Related posts:
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