**3.6 Resuscitation 'S&T and ABC'**

Preventing a cardiac arrest should be a key priority. Unstable women should be immediately positioned left lateral or left lateral tilted to prevent vena cava compression syndrome. Compromised venous return and reduced cardiac output can precipitate cardiac arrest in critically ill pregnant women. High flow oxygen should be administrated, and venous access established. Maternal hypotension (<100 mmHg systolic or < 80% baseline blood pressure reading) should be treated with a fluid bolus of crystalloid or colloid infusion. Reversible causes of maternal collapse should be considered and treated as necessary. Resuscitation efforts in pregnant women should follow the standardized A, B, C approach with no alternations in the basic algorithm or drugs. The following modification should occur to take into account physiological changes in pregnancy that may hinder successful resuscitation.

S&T: Shout for help and ensure a safe environment. Tilt the patient left lateral if visibly pregnant or beyond 20 weeks gestation. Use a wedge or ask another person to manually displace the uterus during resuscitation.

A for airway: Assess and open airway. Turn the patient onto her back (keep left lateral tilt or manually displace uterus). Check for airway obstruction. Use head tilt and chin lift. Secure airway with endotracheal tube as soon as possible or consider second generation supraglottic airway devices that can prevent aspiration. There is a higher incidence of failed intubation in pregnancy with significant maternal morbidity and mortality. Airway maneuvers should therefore be performed only by an experienced operator and ideally capnography used to confirm correct tube placement.

B for breathing: Assess breathing for 10 seconds. If the patient is not breathing normally start cardiopulmonary resuscitation (CPR).

C for circulation: check the carotid pulse and ensure volume replacement via two large-bore cannulas.

CPR Chest compressions should be performed slightly higher on the sternum than usual, as the maternal diaphragm is elevated in lateral stages of pregnancy. It is important to deliver efficient compressions, which can be less effective with a 15–30 tilt.

Venous access should be established above the diaphragm as soon as possible. Blood product including clotting factors should be made available at early stage of resuscitation.

Automated external defibrillator (AED): There is a small risk for inducing fetal arrhythmias with defibrillation; however, external defibrillation is considered safe in all stages of pregnancy [4].
