Short Description

This algorithm outlines the steps for the provider to efficiently assess and manage a pregnant patient with cardiac arrest.

Algorithm at a Glance

• The provider immediately recognizes cardiac arrest in the pregnant patient and begins high-quality CPR.
• The assembled team must include experts in obstetrics and neonatology in addition to the regular resuscitation team.
• The team determines if the cardiac arrest rhythm is shockable (VF or pVT) or nonshockable (PEA or asystole).
• If the rhythm is shockable, the team administers a shock as soon as a defibrillator is available.
• If the rhythm is not shockable, the team administers epinephrine as early as possible and every 3–5 minutes after that.
• High-quality CPR continues as long as the patient is in cardiac arrest.
• After 5 minutes without response, the team considers the need for an emergent cesarean section delivery.
• For VF or pVT, the provider considers antiarrhythmics if defibrillation is not successful.

Goals for the Management of Pregnant Patients with Cardiac Arrest

The provider must succeed in the following goals to successfully manage pregnant patients with cardiac arrest:

• Recognizing the rhythms of cardiac arrest: ventricular fibrillation, ventricular tachycardia, PEA, and asystole
• Recognizing the Hs and Ts as possible causes of cardiac arrest
• Appropriately intervening in the cardiac arrest, depending on the cardiac arrest rhythm
• Remembering that there are two lives involved in this scenario—both mother and unborn child

In-Hospital Cardiac Arrest in Pregnant Patient Algorithm

Related Video: Procedures for Treating a Choking Pregnant Woman – New 2020 AHA / ILCOR Guidelines

Box 1: BLS/ACLS

The team provides high-quality CPR and defibrillation to resuscitate the pregnant patient in cardiac arrest and follows other ACLS interventions as appropriate.

Box 2: Notifying Resuscitation Teams

The critical difference in this resuscitation is that the maternal and neonatal teams are present during the resuscitation to care for the mother and newborn.

Box 3: Determining Etiology of Arrest

During the arrest, the team attempts to identify and treat the cause. Possibilities include:

• Anesthesia complications
• Blood loss
• Cardiovascular issues
• Drugs
• Embolus
• Fever
• General causes (Hs and Ts)
• Hypertension

Box 4: ACLS Interventions for the Mother

The team provides 100% oxygen to the mother through a patent airway. The most experienced provider obtains and maintains the airway. A skilled provider initiates an IV above the level of the mother’s diaphragm. 

If the mother is receiving magnesium, the team discontinues that infusion and administers calcium chloride or calcium gluconate. 

Box 5: BLS/ACLS

The team continues to provide high-quality CPR and other ACLS interventions as appropriate.

Box 6: Obstetric Interventions

As team members are providing ACLS interventions, the obstetrics team detaches any fetal monitors, maintains lateral uterine displacement, and prepares for the infant’s delivery by emergent cesarean section.

Box 7: Cesarean Section Delivery

If the mother does not achieve ROSC within 5 minutes, the team leader must consider an immediate emergent cesarean section delivery.

Box 8: Transferring Care of Neonate to Neonatal Team

Following delivery, the neonatal team assumes care of the infant.

Basic Management in Pregnancy

Airway

The airway is more challenging to manage in pregnancy, due to altered anatomy, increase aspiration, and sudden-onset desaturation risk. The tilted position simply adds to these challenges. Ensure excellent use of bag-mask ventilations and suction in preparation for advanced airway. 

Breathing

Patients are at increased risk for sudden onset desaturation. Due to pregnancy-associated hyperventilation, ventilations are needed during compressions. Clinicians should have a low threshold for supplementing oxygenation and ventilation. 

Circulation: Compressions

While traditional guidance was to place the hands more superiorly on the sternum, there is no good research supporting this and no evidence indicating that the heart is superiorly displaced in pregnancy. The usual hand placement is preferred. The major goals are to provide excellent chest compressions (Class I, Evidence level C-LD) and relieve IVC and aorta compression via displacement of the gravid uterus. (Class IIa, Evidence level C-LD) 

Defibrillation

While it has not been studied, it is reasonable to provide defibrillation to the pregnant patient in cardiac arrest. There is no significant difference in transthoracic resistance in pregnancy, and the standard doses can be used in pregnancy. There is a theoretical small increased risk of fetal arrhythmia; however, defibrillation is usually considered appropriate at any gestational age (GA). 

Remove any fetal monitors before defibrillation as this will limit electric arcing and expediates cesarean delivery if imminent. (Class IIb, Evidence level C). Do not delay defibrillation for this purpose.

Advanced Management in Pregnancy

As ROSC may depend on delivery, appropriate resources should be made available whenever a pregnant woman in the latter half of pregnancy is found to be in cardiac arrest. (Class I, Evidence level C-EO). Routine training is important for achieving successful results in this complex and unusual situation. Utilize the algorithm for cardiac arrest in pregnancy for management. Class I, Evidence level C-EO).

Airway

Provide early attention to securing the airway due to physiological changes. Changes include edema, anterior displacement, increased aspiration risk, and increased bleeding with airway devices, including oro- and naso-pharyngeal airways. Some recommendations include

• Treat the pregnant woman as having a difficult airway. Only experienced providers should attempt intubation.
• The associated edema can narrow the airway. A smaller ETT may be required (internal diameter about 0.5- 1mm smaller) during pregnancy. Note that smaller ET tubes are at increased risk for obstruction and increase resistance and breathing work.
• Ensure effective preoxygenation due to the increased risk for rapid desaturation and the more difficult intubation that is anticipated. 
• Use rapid sequence intubating techniques. Consider cricoid pressure. IN pregnant patients, thiopental and etomidate are preferred for anesthetics

Breathing

Ensure proper placement of the ETT using clinical signs and waveform capnography. Remember that while FRC is lowered, minute ventilation and tidal volume are increased. Ventilatory settings will need adjustment to support the physiology.

Circulation

The ACLS recommendations for medications should be followed. While vasopressive medications like dopamine and epinephrine will reduce uterine blood flow, there are no good alternatives to these medications or doses. Remember that maternal recovery ultimately benefits the fetus. 

Differential

Be aware of obstetric syndrome and conditions that may affect patient management. Abdominal ultrasound can be used to detect pregnancy (if unclear); do not delay acute management for this.

Sodium Bicarbonate Use

Sodium bicarbonate is not recommended routinely. In pregnancy, it can buffer the mother’s pH, but will not do so for the fetus and may obscure fetal acidosis.

Magnesium sulfate

Overdose is possible in women receiving magnesium therapy for eclampsia, especially if the woman has low urine output. Hypermagnesemia can lead to cardiac effects, including AV nodal block, bradycardia hypotension, and cardiac arrest. Neurologic effects include loss of reflexes, muscle weakness, and respiratory arrest. Stop any ongoing magnesium therapy and provide IV calcium therapy (15-30 mL 10% calcium gluconate or 5-10 mL calcium chloride).

Sepsis

This is the number one cause of maternal death and is rising.

Congenital cardiac disease

Many pregnant patients may have congenital cardiac disease. This comorbidity is associated with increased risk for pregnancy complications, including arrest.

Acute coronary syndrome (ACS)

As women delay pregnancy to older ages, they are at increased risk of coronary artery disease. Pregnancy is a relative contraindication to fibrinolytic therapy, so PCI is the preferred treatment in STEMI.

Hemorrhage

This is a major cause of maternal death. This can be unrecognized until the woman has a cardiovascular compromise, especially in the postpartum period. Oxytocin is the treatment of choice for postpartum hemorrhage as it causes uterine contraction. However, the medication has side effects, including tachycardia, cardiac ischemia, hypotension, and arrhythmia. Also, it can precipitate fluid retention, resulting in hyponatremia, seizure, and coma. The use of oxytocin in the unstable cardiac arrest patient should be done cautiously.

Cardiomyopathy

Idiopathic cardiomyopathy of pregnancy is a significant cause of maternal mortality. It usually occurs in the post-partum period and up to 6 months after delivery.

Eclampsia/Preeclampsia

These conditions lead to hypertensive related complications after 20 weeks’ gestation. Hypertension negatively affects maternal organs and can lead to placental insufficiency. In the case of eclampsia, this leads to seizures that can acutely threaten the lives of both mother and fetus.

Aortic Dissection

Pregnancy physiology increases the risk of spontaneous aortic dissection. Comorbid conditions such as connective tissue disorders (i.e., Ehlers-Danlos, Marfan’s) increase the risk. 

Venous thrombosis

Pregnant women can have both pulmonary emboli and strokes as both conditions are increased with hormonal changes of pregnancy. Fibrinolytics have been reported in this case with successful maternal outcomes. Follow guidelines for the management of PE and stroke in these cases.

Anesthetic complications

There are increased risks of anesthetics during pregnancy. Consequently, obstetric related anesthesia specialization has emerged. Regional anesthetics can precipitate spinal shock and result in cardiac arrest. At the same time, general anesthesia and routine intubation are more complicated in the pregnant patient. 

Amniotic fluid emboli

Cardiopulmonary bypass has been reported to manage peripartum acute amniotic fluid emboli successfully. Cesarean delivery may be required at this time. 

Trauma/Overdose

Pregnancy is not immune to these conditions. In fact, domestic violence is increased in pregnant women, and there is a real risk of homicide or suicide in this population. Additionally, post-partum depression may increase the risk of suicide attempts.