INTRAVENOUS VOLUME EXPANSION THERAPY IN PREGNANCY-INDUCED HYPERTENSION - THE ROLE OF VASOACTIVE HORMONES

Objective: To examine the hormonal and clinical effects of intravenous volume expansion therapy in women with pregnancy-induced hypertension (PIH). Methods: Fifteen untreated women with PIH, six of whom had sig nificant proteinuria, were randomized to receive a 500 ml infusion of either Haemaccel (n = 7) or a control solution (hypotonic saline, n = 8), and the acute response of the following hormones was examined: pla sma atrial natriuretic peptide (ANP), angiotensin II (ANG II), adrenal ine (Adr), and noradrenaline (NA). These were measured by radiomimmuno assay or enzyme immunoassay as appropriate following plasma extraction . Blood pressure (BP) and pulse rate (PR) were measured before, during , and after the infusion as well as 24 and 48 h later. Results: The in fusion of Haemaccel but not hypotonic saline was associated with a sig nificant decrease in plasma albumin and hematocrit. Plasma ANP increas ed significantly in those who received Haemaccel but not in controls, while there were no significant changes in plasma ANG II, Adr, or NA i n response to either infusion. There were no acute changes in blood pr essure or pulse rate in response to intravenous volume expansion. Conc lusions: Intravenous volume expansion therapy in women with PIH is ass ociated with an increase in plasma ANP which does not acutely decrease blood pressure but may have a role in the more chronic effects of suc h treatment.