What are causes of cardiac arrest in a pregnant patient

Q: What are causes of cardiac arrest in a pregnant patient ACLS?

At a gestational age of 20 weeks and beyond, the pregnant uterus can press against the inferior vena cava and the aorta, impeding venous return and cardiac output. Uterine obstruction of venous return can produce prearrest hypotension or shock and in the critically ill patient may precipitate arrest.

Q: Can you go into cardiac arrest during pregnancy?

A number of health issues that may occur during childbirth can lead to cardiac arrest, including excessive bleeding, heart failure, heart attack, preeclampsia, blood infection and amniotic fluid embolism, where amniotic fluid enters the mothers bloodstream.

Q: What is most important about cardiac arrest in pregnancy?

A pregnant person is especially vulnerable to oxygen deprivation during cardiac arrest, as the fetus needs substantial levels of oxygen. This means a 20%+ increase in oxygen consumption2 and a 40% increase in cardiovascular metabolism to adequately supply the fetus.

Q: What is true about cardiac arrest in pregnancy?

Cardiopulmonary arrest in pregnancy is rare occurring in 1 in 30,000 pregnancies. When it does occur, it is important for a clinician to be familiar with the features peculiar to the pregnant state. Knowledge of the anatomic and physiologic changes of pregnancy is helpful in the treatment and diagnosis.

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Table of Contents Show

Clinical Features
Differential Diagnosis
Cardiac Arrest in Pregnancy
Estimated Gestational Age by Fundal Height[3]
Maternal Modifications
Disposition
External Links
What are causes of cardiac arrest in a pregnant patient ACLS?
Can you go into cardiac arrest during pregnancy?
What is most important about cardiac arrest in pregnancy?
What is true about cardiac arrest in pregnancy?

Background

Occurs in ~1 in 30,000 pregnancies[1]
Key differences from non-pregnant cardiac arrest[2]:
- Need to remove uterus from IVC (by rolling patient to side or manual lifting of uterus)
  - Do not obtain venous access below the diaphragm
- Secure airway immediately
- Non-cardiac cause of arrest is more likely
- Resuscitative hysterotomy should be performed rapidly (within 4 minutes), and may save both fetus and mother

Clinical Features

Cardiopulmonary arrest in gravid female.

Differential Diagnosis

Cardiac Arrest in Pregnancy

BEAT CHOPS

Bleeding / DIC
Embolism - coronary, pulmonary, amniotic fluid
Anesthetic complications
Tone (uTerine aTony)
Cardiac disease - MI, aortic dissection, cardiomyopathy
Hypertension, preeclampsia, eclampsia
Other - all typical H's and T's
- Hypovolemia
- Hypoxemia
- Hydrogen ion (i.e. acidemia)
- Hypo/hyperkalemia
- Hypothermia
- Tension Pneumothorax
- Cardiac tamponade
- Toxins
- Thrombosis, pulmonary
- Thrombosis, coronary
Placental abruption, placenta previa
Sepsis

Evaluation

Estimated gestational age based on physical exam.

Clinical

Estimated Gestational Age by Fundal Height[3]

Weeks	Fundal Height / Finding
12	Pubic symphysis
20	Umbilicus
20-32	Height (cm) above symphysis = gestational age (weeks)
36	Xiphoid process
>37	Regression
Post delivery	Umbilicus

Management

Standard ACLS management
- Early defibrillation - use standard energy levels (safe for fetus in maternal arrest)
  - Anterior/Posterior pad placement is preferred
  - May use AP pads to pace as well
- Give typical adult ACLS drugs/dosages
- Airway management / Ventilate with 100% FiO2
- Monitor EtCO2
- Ensure post cardiac arrest care

Maternal Modifications

Resuscitative hysterotomy (aka perimortem c-section) if estimated gestational age >24wks (fundus >~4cm above umbilicus)
- Must make decision early, <4min without ROSC
Manual left uterine displacement
- Displaces uterus to patient's left, relieving aortocaval compression
- May be of concern even if < 20 wks
- Put hands on right side of gravid abdomen, and pull upwards towards ceiling and leftwards
- OR tilt patient 15–30° to left[4]
- Downward force will worse IVC compression
IVs above diaphragm - avoids IVC which may be compressed
Administer fluids and blood products
Anticipate difficult airway with high risk of aspiration
If patient receiving IV magnesium prearrest, stop mag and give arrest dose calcium
Continue CPR, positioning, de-fib, drugs, and fluids during and after C-section
Therapeutic hypothermia contraindicated if patient still intrapartum, but may be safe for postpartum cardiac arrest[5]

Disposition

Admit (if ROSC obtained)

External Links

https://first10em.com/cardiac-arrest-in-pregnancy-the-perimortem-cesarean-section/

References

↑ McDonnell, NJ. Cardiopulmonary arrest in pregnancy: two case reports of successful outcomes in association with perimortem Caesarean delivery. Br J Anaesth. (2009)103(3):406-409.
↑ Engels PT, Caddy SC, Jiwa G, Douglas Matheson J. Cardiac arrest in pregnancy and perimortem cesarean delivery: case report and discussion. CJEM. 2011 Nov;13(6):399-403.
↑ Vasquez V, Desai S. Labor and delivery and their complications. In: Walls RM, Hockberger RS, Gausche-Hill M, et al., eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier Saunders; 2018:2296–2312.
↑ Campbell TA and Sanson TG. Cardiac arrest and pregnancy. J Emerg Trauma Shock. 2009 Jan-Apr; 2(1): 34–42.
↑ Song et al. Safely completed therapeutic hypothermia in postpartum cardiac arrest survivors. Am Jour Emer Med. June 2015. Volume 33, Issue 6, Pages 861.e5–861.e6.