Plasma volume expansion in the treatment of pre-eclampsia. Haemodynamic changes in gestational proteinuric hypertension: the effects of rapid volume expansion and vasodilator therapy.
The effects of plasma volume expansion with hyperosmolar solutions with the use of dextran 40 and plasmanate were studied in a controlled manner in 32 primiparous pre-eclamptic patients. The patients who were being studied received either dextran 40 (Rheomacrodex) or plasmanate in addition to the routine treatment with sedatives, bed rest, and magnesium sulfate when indicated. The patients were randomly assigned by blind draw to control (13), dextran (10), and plasmanate (nine) groups. The renal status of all patients was evaluated prior to volume expansion therapy. Patients were monitored for blood pressure, proteinuria, output of urine, hematocrit, and creatinine clearance. There was significant improvement in hemoconcentration and output of urine, and a trend toward a lowering of the mean arterial blood pressure in patients who were receiving plasmanate or dextran for volume expansion. Ten patients with gestational proteinuric hypertension were studied with a Swan-Ganz thermodilution haemodynamic catheter before, during and after plasma volume expansion. Five patients were treated with dihydralazine before volume expansion and five after volume expansion. Before treatment all patients had a low pulmonary capillary wedge pressure (PCWP), low cardiac index (CI) and high systemic vascular resistance (SVR). Following volume expansion the PCWP and CI increased, the SVR decreased but the blood pressure (BP) was unchanged. Administration of dihydralazine following volume expansion led to a decrease in PCWP, an increase in CI and a decrease in SVR and BP. Dihydralazine alone caused an increase in heart rate, PCWP, and CI, and a decrease in SVR and BP. Volume expansion, by increasing CI and decreasing SVR, may be of therapeutic benefit in the severely hypertensive pregnant patient with a low cardiac index.
There is insufficient evidence for any reliable estimates of the effects of plasma volume expansion for women with pre-eclampsia.
[Note: The 14 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]