Critical care and pregnancy

Increasingly, women who are pregnant or who have recently been delivered are being admitted to intensive care units. The pregnant woman who requires intensive care medicine is unique for a number of reasons and represents a substantial challenge to the health care team because of these differences. In the critically ill pregnant woman there are at least two patients to be considered, the mother and the fetus. The pregnant woman has many physiologic adaptations as a consequence of pregnancy that will alter the definition of normal for a number of variables that are routinely monitored in intensive care units. Thus critical care obstetrics involves knowledge both of critical care medicine and of the pathophysiologic changes of pregnancy. Furthermore, pregnancy entails a host of disease processes that are unique to pregnancy itself, such as severe preeclampsia and amniotic fluid embolus. The purposes of this chapter are multiple. The physiologic changes of pregnancy are reviewed with emphasis on cardiorespiratory changes during pregnancy, circulatory changes in pregnancy, labor hemodynamics, postpartum hemodynamics, and pulmonary physiology as they apply to the parturient patient. Leading causes of maternal mortality including obstetric hemorrhage, hypertensive disease, and embolic phenomena are reviewed. Furthermore, the microangiopathic hemolytic anemias, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, and acute renal failure as they relate to the pregnant woman are reviewed in detail. Physical trauma that complicates one of every 12 pregnancies is emerging as a leading cause of nonobstetric maternal death. Both blunt abdominal trauma and penetrating trauma in the pregnant woman are discussed. Guidelines are given for the evaluation and treatment of the mother as well as for the evaluation and treatment of the fetus. Controversies related to maternal cardiac arrest and resuscitation in pregnancy are explored as well as the role of perimortem cesarean section in contemporary obstetrics. Finally, the fetal effects of various drugs commonly used in critical care medicine are reviewed.