Maternal Cardiac Arrest

Authors: Jeffry Sakamoto MD, Colin Michels MD, Nikita Joshi MD, Rebecca Bavolek MD (Editor)
Updated: 7/25/2018

Maternal Cardiac Arrest

Maternal cardiac arrest is a low-frequency, high-risk pregnancy complication with 2 lives at stake. Incidence is approximately 1 in 12,000 to 50,000 pregnancies with a greater than 40% mortality rate. Understanding physiologic changes of pregnancy and how to perform a perimortem cesarean section (resuscitative hysterotomy) are critical aspects of caring for maternal cardiac arrest.

Maternal Physiology

  • Expanded plasma volume and hemodilution
  • Decreased systemic vascular resistance, increased heart rate (HR), increased cardiac output
  • Aortocaval collapse leading to decreased preload, worsened by supine position
  • Decreased functional reserve capacity, increased minute ventilation, decreased oxygen reserve
  • Hyperemia of upper airway

Etiology (AABCDEFGH)

Most common causes are hemorrhage, acute myocardial infarction (AMI), heart failure, pulmonary embolism, amniotic fluid embolism, sepsis, preeclampsia/eclampsia.

Anesthesia complication

  • High neuraxial block
  • Aspiration
  • Local anesthetic toxicity
  • Hypotension
  • Respiratory depression


  • Trauma
  • Suicide


  • Uterine atony
  • Placenta accreta
  • Placenta abruption/previa
  • Uterine rupture
  • Coagulopathy
  • Transfusion reaction
  • Disseminated intravascular coagulation


  • AMI (most common cause secondary to coronary artery dissection)
  • Aortic dissection
  • Arrhythmia
  • Heart failure


  • Anaphylaxis
  • Magnesium (respiratory depression)
  • Opioids
  • Oxytocin


  • Pulmonary embolism
  • Amniotic fluid embolism
  • Venous air embolism
  • Stroke


  • Sepsis

General (H’s and T’s)

  • Hypoxia
  • Hypovolemia
  • Hypothermia
  • Metabolic derangements (potassium, acidosis, glucose)
  • Tamponade
  • Tension pneumothorax
  • Toxins


  • Pre-eclampsia and eclampsia
  • HELLP syndrome (coagulopathy, bleeding, shock)

Algorithm/Management for Maternal Cardiac Arrest

1. Preparation

  1. Call for backup (anesthesia, obstetrics, neonatal intensivists)
  2. Equipment for emergency c-section to bedside (see section below on procedure)
  3. Equipment for neonate to bedside (neonatal warmer, airway supplies, umbilical access, epinephrine)

2. Begin chest compressions (100-120 rate, 2 inches depth, mid sternal position)

3. Continuous manual left uterine displacement (if uterus above umbilicus)

4. Monitors

  1. Attach to monitor and defibrillator.
  2. Remove fetal monitors.

5. Gain access (IV or IO) ideally above the diaphragm - Use large bore IV or central venous line, if concern for hemorrhage

6. Airway/Breathing

  1. Bag valve mask ventilation
  2. Intubate earlier than non-pregnant patient given low oxygen reserve
  3. Use 6.0-7.0 endotracheal tube given potential for airway edema
  4. Proceed with difficult airway algorithm as would in normal patient if cannot intubate and cannot ventilate (e.g., supraglottic airway or cricothyrotomy)
  5. Use 100% FiO2 with RR 8-10 to promote fetal oxygenation 8-10

7. Circulation: Continue advanced cardiac life support (ACLS) per protocol

  1. In general, epinephrine and all other code drugs may be given at the same dose as non-pregnant patients
  2. If shockable rhythm, defibrillate at same energy as non-pregnant patient (safe for fetus)

8. Stop magnesium if running, and give calcium (1 gm calcium chloride)

9. Consider reversible causes and their treatment

  1. Hemorrhage: Blood transfusions, control bleeding, reverse coagulopathy
  2. Pulmonary embolism: Thrombolytics (alteplase 50 mg bolus)
  3. Magnesium toxicity: Calcium chloride 1 gm IV
  4. Preeclampsia/eclampsia: Magnesium 4-6 gm IV slow push over 15 minutes then maintenance dose 1 gm/hr IV
  5. AMI: Revascularization; however caution in cases of coronary artery dissection (most common cause of AMI in pregnancy) in which must avoid anticoagulation, heparin, and TPA/thrombolytics; may require balloon pump or revascularization if there is cardiogenic shock
  6. Heart failure: Inotropes
  7. Hyperkalemia: Bicarbonate, calcium
  8. Acidosis: Bicarbonate
  9. Hypoglycemia: Glucose
  10. Tamponade/tension pneumothorax: Decompression
  11. Opioid toxicity: Naloxone
  12. Local anesthetic toxicity: Intralipid 1.5 mL/kg 20% lipid IV solution over 1 minutes, and may repeat 2-3x if refractory, followed by 0.25 mL/kg/min IV infusion

10. If no return of spontaneous circulation (ROSC) by 4 minutes of resuscitative efforts, consider performing immediate perimortem cesarean delivery

Benefit has only been shown in gestational age >24 weeks EAST 2005 guidelines, when generally the uterus is palpable at or above the umbilicus

Perimortem Cesarean Delivery

Goal is to deliver fetus expeditious manner.

1. Continue with high quality chest compressions

2. Gather equipment

  1. Scalpel (10 blade) - only critical piece of equipment
  2. 2 Kelly clamps
  3. Needle driver
  4. Russian forceps
  5. Sutures
  6. Suture scissors
  7. Lower end of Balfour retractor

3. Perform vertical abdominal wall incision

  1. Extend large incision from xiphoid to the pubis
  2. With sharp and blunt dissection cut through subcutaneous tissue
  3. Cut down to peritoneal wall

4. Vertically incise the peritoneum - Scalpel or scissors can be used

5. Deliver the uterus

6. Incise the inferior aspect of the uterus to avoid placenta, but may have to cut through if anterior

7. Deliver baby

  1. Clamp and cut cord
  2. Hand off neonate to neonatal resuscitation team
  3. Remove placenta and manually wipe out uterus

8. Place packing both in peritoneum and open uterus

9. If OB/GYN or general surgery is not yet available, close uterus with running, locking absorbable sutures

Post-Resuscitation Care

ROSC prior to perimortem C-section

  • Place in left lateral decubitus position or left uterine displacement
  • Ensure invasive hemodynamic and fetal monitoring in place
  • Low threshold for fetal delivery with any signs of non-reassuring fetal status
  • Consider therapeutic hypothermia
  • Transfer to ICU or to operating room if operation required

ROSC after perimortem C-section

  • If not already started, consider blood or massive transfusion protocol
  • As perfusion improves, bleeding will become a significant issue
  • Ensure invasive hemodynamic monitoring is in place
  • Continue multidisciplinary care for evaluation and treatment of etiology
  • Consider therapeutic hypothermia
  • Transfer to ICU or operating room


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