Case
Transfer from an outside hospital: 28 y/o female 4 months pregnant with multiple pelvic fractures and a left-sided first rib fracture
Hematologic changes in pregnancy
-Maternal blood volume can be increased up to 50%
-RBC mass increases by 20-30%, however this is smaller than the increase in plasma volume which leads to a physiologic anemia of pregnancy
-This leads to an attenuated initial response to hemorrhage, therefore IV fluids should be administered aggressively
-The pregnant patient is also coagulopathic with increases in clotting factors and VWF
-Pregnant patients may also have a mild leukocytosis (6-16K WBC)
-Cardiac output increases 30-50%
-Decreased lower esophageal sphincter tone and delayed gastric emptying can lead to increased aspiration risk
-The enlarged uterus causes elevation of the diaphragm by approximately 4cm, resulting in a 20% decrease in FRC
General resuscitation principles in pregnancy
-Maintain maternal pulse ox >95% secondary to increase in basal oxygen consumption of the mother and fetal sensitivity to maternal hypoxia
-Be judicious with uterine displacement. A gravid uterus of >20 weeks runs the risk of IVC compression and decreased venous return leading to maternal hypotension when lying flat
-Placement of a towel or wedge under the right hip and manual displacement of the uterus are all acceptable measures to decrease IVC compression
-Recall that any treatment needed to help the mother helps the fetus
-If a trauma CT is necessary for maternal management/resuscitation, it is a necessary test. Radiation exposure of less than or equal to 5msv is generally acceptable in the pregnant patient
-Kleihauer-Betke test: measure of the amount of fetal hemoglobin transfer from the fetus to the mother’s bloodstream
-It is safe to assume that any maternal abdominal trauma can lead to materno-fetal hemoglobin transfer and Rhogam should be considered in rh negative mothers
-Any viable pregnancy (20 weeks or greater) should be monitored for a minimum of several hours in an OB triage unit
-Intimate partner violence is the leading cause of trauma in pregnancy, all patients should be screened
Perimortem C-Section
-Primary goal is improvement of maternal resuscitation
-Decreases uterine compression of the IVC, increasing maternal venous return. In addition this reroutes all the blood flow diverted to the uterus back to the maternal circulation
-Fetus is viable at 24 weeks. If the fundus of the uterus is at the umbilicus, viability is a reasonable assumption
-At 24 weeks gestation, there is a 20-30% chance of fetal survival if neonatal facilities are available
-Decision should be made to perform within 4 minutes of beginning resuscitation. Fetus should be out by the 5th minute. At 0-5 minutes post-arrest the fetus has 70% chance of having no neurologic sequelae. At 5-10 minutes this drops to 15%
-Vertical incision should be made from the xiphoid process to the pubis
-Vertically incise the lower portion of the uterus and carefully dissect the upper half to avoid cutting the fetus
-Remove the fetus, clamp and cut the cord, consider packing of the uterine cavity
-CPR is continued throughout the entire procedure
