The Pregnant Patient with Preeclampsia

Goals of fluid management of the pregnant patient with preeclampsia (see Chapter 58 ) are to restore the contracted intravascular volume,^[137] avoid excessive intravascular fluid administration because of normal postpartum fluid mobilization, replace increased sensible (sweat) and insensible (respiratory) losses due to labor, be prepared to replace rapid blood loss, avoid hypotension due to anesthetic induced vasodilation to preserve uteroplacental flow, maintain normoglycemia, avoid decreasing the COP further, and prevent pulmonary and cerebral edema.

Restoration of depleted plasma volume to normal is crucial for control of hypertension and for administration of anesthesia. Plasma volume is decreased in preeclamptic patients because of elevated lower body venous pressure from uterine compression, pressure-induced natriuresis as seen in hypertension, severe vasoconstriction, and hypoproteinemia due to proteinuria. After parturition, the fluid retained during pregnancy is usually quickly mobilized and excreted. The preeclamptic patient, however, may have compromised hepatic, renal, or cardiac function, impeding the timely excretion of this fluid. These patients are at risk for pulmonary edema because of cardiac failure due to severe hypertension and lowered COP. Cardiac filling pressures should be monitored and a PAOP of less than 12 to 15 mm Hg maintained. Plasma tonicity must be maintained by administration of isotonic fluid because these patients are at risk for cerebral edema.