Author: Dina Al-Joburi, DO (EM Resident Physician, Drexel University College of Medicine) // Editor: Alex Koyfman, MD & Justin Bright, MD

You are working a night shift in a community ED and in rolls EMS with a 34 y/o pregnant patient. Per EMS, they were called because the patient was at the mall with her family, became diaphoretic and complained of chest pain. Upon arrival, patient states that although her father had a heart attack when he was 40, she is sure she is fine and is ready to go home.

Patient’s vitals: BP: 120/80 HR: 85 RR: 22 O2Sat: 98% Temp: 98.3 F

Physical Exam is completely unremarkable, other than her gravid uterus, which you approximate is more than 24 weeks pregnant.

You place the patient on a monitor and place an IV. This brings us to our first point in resuscitating a pregnant patient. Make sure IV access is above the level of the diaphragm. The gravid uterus compresses the IVC; if you place your IV access below the diaphragm you risk fluids and medications not reaching the heart.

As soon as you are done placing the line, the patient looks diaphoretic, pale, listless and her new set of vitals show BP: 90/60 HR: 130 RR: 30 O2Sat: 95% Temp: 98.3F. When you first saw the patient you did not take into consideration the physiologic changes of pregnancy and as a result had a false sense of security. Women develop a relative hypervolemic state during pregnancy to prepare for the blood loss of delivery. As a result 40% of blood volume may be lost prior to manifesting signs and symptoms of maternal shock. Be prepared for a seemingly stable patient to decompensate quickly. You begin fluid resuscitation and then mobilize your resources and consultants early – contacting Obstetrics/NICU and getting ready to prepare for the worse case scenario (such as a peri-mortem C-section).

Next step is to provide supplemental oxygen; pregnant women become hypoxemic sooner than their non-pregnant counterparts secondary to a decreased functional residual capacity and an increased oxygen demand. Maintain a very low threshold to intubate as a low PaCO2 places the fetus at risk for anoxia. You should act under the assumption that all pregnant patients are difficult airways. Progesterone causes gastro-esophageal sphincter insufficiency that can result in an increased risk for aspiration. Intubating may be a challenge; excess weight on the neck can make inserting a laryngoscope difficult. Furthermore, increased breast size caused by pregnancy may obstruct traditional laryngoscope handles, and a shorter handle is recommended. Finally, estrogen causes pregnant patients to have an edematous airway; therefore have a tube .5-1mm size smaller in diameter ready. Have back-up, such as LMA and cricothyrotomy kit, ready and pre-oxygenate well prior to attempting intubation. Traditional RSI with etomidate and succinylcholine is safe in pregnancy. Etomidate will cross the placental barrier, but causes less fetal respiratory suppression than other medications, and succinylcholine does not cross the placental membrane.

Your patient now has IV access and her airway is secured. You look up and the patient is unresponsive and in V fib. Follow ACLS guidelines (and think outside of the box), do not withhold care to the mother because of fear of harming the fetus. Therefore, administer medications and defibrillate using the standard ACLS doses (only medication exception is use of amiodarone). The only modification that should be made is to remember to remove fetal or uterine monitoring devices prior to defibrillating.

Displace the uterus to the left (controversial in that it doesn’t improve hemodynamics for all) while initiating chest compressions. You can do this by placing a towel/wedge underneath the right hip or by having someone manually move the uterus. The gravid uterus can compress the inferior vena cava and aorta, resulting in decrease venous return and cardiac output. While performing chest compressions, hand placement should be slightly higher than the center of the sternum to account for the upward shift in the diaphragm.

While running through the code, you are thinking about what could have precipitated this event. Broaden your differential by thinking beyond Hs & Ts.

BEAU-CHOPS is a mnemonic developed by the AHA specific to causes of cardiac arrest in pregnant women.

B=Bleeding/DIC

E=Emboli: coronary, pulmonary, amniotic fluid

A=Anesthetic Complications (aspiration, local anesthetic toxicity)

U=Uterine Atony

C=Cardiac Disease i.e. cardiomyopathy, aortic dissection

H=Hypertensive disease i.e. preeclampsia-eclampsia

O=Other-think about the Hs and Ts

P=Placental abruption, previa

S=Sepsis

Your designated timer has now informed you are 4 minutes into the code…

Now you must decide whether or not you will perform a Peri-Mortem C-Section (see here for further details: http://emcrit.org/wee/peri-mortem-c-section/ ). Delivery of the fetus allows for all of the blood to be diverted to the mother, decompresses the IVC, and improves the efficacy of chest compressions. Furthermore, following the delivery of the fetus, the vertical incision can be used to access the heart and apply direct cardiac massage.

It is best to initiate C-section 4 minutes into resuscitation if the mother has not had return of spontaneous circulation. Resuscitative efforts should continue in conjunction with the delivery of the fetus.

During your initial exam of the patient you were able to determine the approximate gestational age at >24 weeks. This is important because it will help guide the steps taken throughout resuscitation. When a patient is <20 weeks no C-section is indicated because at this gestational age the chance of a viable infant is minimal, as is the uterine compression of the aorta. At 20-24 weeks, the uterus is compressing the aorta, so a C-section can aid in resuscitating the mother. At 24-42 weeks C-section can be done to increase the chances for survival in both the fetus and mother.

A quick and easy way to figure out gestational age when in a time crunch is at 20-24 weeks the uterus is at about the level of umbilicus and at 24-42 weeks it is about 4cm above the umbilicus.

The Obstetrician has arrived, as has the NICU team. You designate a team to deliver the fetus and a team to continue resuscitative efforts on the mother.

In Summary:

When approaching the pregnant patient you must take into account the physiologic and anatomic changes pregnant women go through and what obstacles this may bring during the resuscitation. Follow ACLS guidelines (with additional curiosity) as treating the mother is the best way to care for the fetus and get your consultants in the game early!

Further Reading

1) Part 10.8: Cardiac Arrest Associated With Pregnancy. American Heart Association. Circulation. 2005;112:150–153.

2) Campbell, Tabitha A, and Tracy G Sanson. “Cardiac Arrest and Pregnancy.” Journal of Emergencies, Trauma and Shock 2.1 (2009): 34–42. PMC. Web. 27 Nov. 2014

3) Zelop, Carolyn M., MD. “Cardiopulmonary Arrest in Pregnancy.” UpToDate. N.p., 1 Apr. 2014. Web. 21 Nov. 2014.

4) http://www.ncbi.nlm.nih.gov/pubmed/22257783

5) http://www.ncbi.nlm.nih.gov/pubmed/23178869

6) http://www.ncbi.nlm.nih.gov/pubmed/21549495