According to estimates from the Nationwide Inpatient Sample, cardiac arrest complicates approximately 1 in 12,000 delivery admissions (Mhyre, 2014) . The most common underlying causes were hemorrhage, heart failure, amnionic-Buid embolism, and sepsis. General topics regarding planning and equipment have been reviewed by the American College of Obstetricians and Gynecologists (20 17b) and the Society for Obstetric Anesthesia and Perinatology (Lipman, 2014). Special considerations for cardiopulmonary resuscitation (CPR) conducted in the second half of pregnancy are outlined in the American Heart Association 2010 guidelines (Jeejeebhoy, 2015). he committee acknowledges the following as standards for critically ill gravidas: (1) relieve possible vena caval compression by left lateral uterine displacement, (2) administer 100-percent oxygen, (3) establish intravenous access above the diaphragm, (4) assess for hypotension that warrants therapy, which is defined as systolic blood pressure < 100 mm Hg or < 80 percent of baseline, and (5) review possible causes of critical illness and treat conditions as early as possible.
he position of the heart for external compressions is not diferent from that in nonpregnant women (Holmes, 2015). In nonpregnant women, external chest compression results in a cardiac output approximately 30 percent of normal. In late pregnancy, this may be even less with compressions because of uterine aortocaval compression (Clark, 1997; Nelson, 2015). Thus, it is paramount to accompany other resuscitative eforts with uterine displacement. This can be accomplished by tilting the operating table laterally, by placing a wedge under the patient's right hip, or by pushing the uterus to the left manually (Rees, 1988; Rose, 2015). If no equipment is available, an individual may kneel on the Boor with the maternal back on his or her thighs to form a "human wedge" (Whitty, 2002).
During maternal resuscitation, because of pregnancy-induced hindrances on CPR eforts, emergent perimortem cesarean delivey for fetal salvage and improved maternal resuscitation may be considered. Some have stated that cesarean delivery is indicated within 4 to 5 minutes of beginning CPR if the fetus is viable (Drukker, 2014). In women delivered by perimortem cesarean, neurologically intact neonatal survival and the cardiac arrest-todelivery interval are inversely related (Katz, 2012). Speciically, of newborns delivered within 5 minutes of arrest, 98 percent are neurologically intact; within 6 to 15 minutes, 83 percent are intact; within 16 to 25 minutes, 33 percent are intact; and within 26 to 35 minutes, only 25 percent are intact (Clark, 1997). This, coupled with some evidence that delivery may also enhance maternal resuscitation, has led the American College of Obstetricians and Gynecologists (2017b) to recommend consideration for cesarean delivery to begin within 4 minutes of cardiac arrest in these cases.
his serious and sometimes contentious issue is far from evi dence based. To wit, Katz and associates (2005) reviewed 38 perimortem cesarean deliveries with a "large selection bias." of maternal cardiac arrest improves maternal and fetal outcomes.