Hypovolemic shock

Ruptured ectopic pregnancy is the leading cause of life-threatening obstetric hemorrhage in the first trimester. Most serious obstetric hemorrhage, however, occurs in the postpartum period. Hemorrhagic morbidity and mortality are mediated by hypovolemic shock. Hypovolemic shock evolves through several pathophysiologic stages as body mechanisms combat acute blood volume loss. The most important fundamental prerequisite in approaching hypovolemic shock is a complete understanding of maternal blood volume and how that volume is affected by pregnancy. Initial type and screening of labor and delivery patients can provide valuable information if the need for blood replacement arises in hemorrhagic morbidity. Massive blood replacement is defined as transfusion of total blood volume within 24 hours. In certain situations, such as uterine rupture with intraperitoneal bleeding, definitive surgical therapy may need to be instituted before stabilization can be achieved.