Pathophysiology: Critical care in obstetrics has many similarities in pathophysiology to the care of nonpregnant women. However, changes in the physiology of pregnant woman necessary to maintain homeostasis for both mother and fetus, especially during critical illness, result in complex pathophysiology. Understanding the normal physiologic changes during pregnancy, intrapartum, and postpartum is the key to managing critically ill obstetric patients with underlying medical diseases and pregnancy-related complications.
Hemodynamic monitoring: When the pathophysiology of critically ill obstetric patients cannot be explained by noninvasive hemodynamic monitoring and the patient fails to respond to conservative medical management, invasive hemodynamic monitoring may be helpful in guiding management. Most important, the proper interpretation of hemodynamic data is predicated on knowledge of normal values during pregnancy and immediately postpartum. Invasive hemodynamic monitoring with pulmonary artery catherization has been used in the obstetric population, particularly in patients with severe preeclampsia associated with pulmonary edema and renal failure.