Quantitative hemodynamic effects of acute volume expansion in severe preeclampsia

In a study of eight patients with severe preeclampsia, cumulative rapid infusions of 500 mL (set of eight patients) and 1000 mL (subset of five patients) of 5% albumin in normal saline were followed with invasive hemodynamic measurements at 5 and 30 minutes. Pulmonary capillary wedge pressure and central venous pressure rose. Cardiac index rose 23 and 34% at 5 minutes after the 500-mL and 1000-mL infusions, respectively; at 30 minutes, it remained at 17 and 34%, respectively, above control. The systemic vascular resistance index fell 24 and 29% below control values at 5 minutes after the respective infusions; at 30 minutes, it remained at 15 and 25%, respectively, below control. Mean systemic arterial pressure was unchanged, except for a small reduction shortly after the initial 500-mL infusion. In contrast, mean pulmonary arterial pressure rose significantly. Hence, the dominant effects of acute volume expansion in severe preeclampsia include an unchanged (or slightly reduced) mean systemic arterial pressure, resulting from marked elevations in cardiac index and concomitant, proportionate declines in systemic vascular resistance index.