- Physiologic Changes during Pregnancy
The pregnant patient will have an increased circulatory volume. As blood volume is lost after injury, blood is shunted away from the uterus first. A much greater degree of blood loss is required to produce compensatory tachycardia.
Cardiac output and heart rate increase in later pregnancy. The heart rate will be about 20 beats per minute above the patients baseline. Blood pressure usually decreases about 10 mm Hg, but rises to normal toward the end of pregnancy.
Hematocrit falls in pregnancy as circulating volume increases a dilution anemia. The CBC shows an elevated white blood count usually around 15,000. Sedimentation rate is elevated as well.
Although clotting studies remain normal, levels of coagulation factors and fibrinogen increase. This change puts the pregnant trauma victim at increased risk of venous thrombosis or DIC. Back to Top
Stabilization of the Pregnant Patient
The well-being of the baby is entirely dependent on the welfare of the mother. Attention must therefore be directed immediately to the ABC stabilization of the pregnant victim. Good oxygenation and provision of adequate circulatory volume are critical. Maternal shock is fatal to the fetus in most cases.
Because hypotension and tachycardia do not occur in the pregnant patient until blood loss is extensive, begin a rapid IV infusion on every patient. If the secondary survey shows no evidence of blood loss, slow the infusion after 1-2 liters have been given.
Once the mother is stable, evaluate the uterus and fetus during the abdominal exam of the secondary survey. The exam includes the presence of fetal motion, the firmness of the uterus and presence of contractions, the presence of uterine tenderness, vaginal bleeding, and the fetal heart tones. When time allows, arrange formal fetal monitoring (hard-copy recording of uterine contractions and fetal heart rate). Test the vaginal fluid with nitrazine paper to screen for amniotic fluid. Consultation with the obstetrician is mandatory for every injured mother-to-be who is beyond 19 weeks gestation.
The patient may be positioned with a leftward tilt, or the uterus may be manually pulled toward the left to prevent pressure on the vena cava.
Any drug required to stabilize the mother must be used, regardless of fetal risk. Any x-ray that you would order on a non-pregnant trauma victim should be performed on the pregnant patient. Peritoneal lavage, if indicated, may be done in the pregnant patient. Use the open technique. The large uterus may mask the signs of intraabdominal injury, and the physician must maintain a high index of suspicion. Back to Top
Rupture of the uterus is almost always fatal for the fetus. Uterine rupture may occur either with rapid deceleration injury, or with direct compression injury. Severe hemorrhage may occur. Clinical Findings: Uterine rupture is suggested by a tender, asymmetric uterus, or by fetal parts palpable through the abdominal wall. Shock may be present.
Diagnosis: An abdominal x-ray may show fetal arms or legs outstretched. Ultrasound will demonstrate the fetus free in the abdominal cavity.
Treatment: Emergency surgery. Back to Top
Placenta abruption, the separation of the placenta from the uterine wall, occurs in about 5% of pregnant major-trauma victims. DIC (disseminated intravascular coagulation) is a common complication, and should be screened for.
Clinical Findings: Vaginal bleeding and pain should arouse suspicion of abruption. The uterus is often firm and very tender. Fetal heart tones should be sought (fetal mortality is around 15%). Diagnosis: Abdominal ultrasound shows the placental separation.
Treatment: Begin fetal heart rate and uterine contraction monitoring. Obtain PT, PTT, and fibrinogen studies to screen for DIC. Emergent obstetrical consultation is required. Back to Top
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All material referenced through this menu is excerpted from copyrighted works by Bruce Argyle, MD. You are welcome to use selected portions, as long as appropriate credit is given. The credit for the text referenced through this menu is:
Argyle, B., Trauma One! Computer Program Manual.
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