RAPID FLUID ADMINISTRATION AND THE INCIDENCE OF HYPOTENSION INDUCED BY SPINAL ANESTHESIA AND EPHEDRINE REQUIREMENT: THE EFFECT OF CRYSTALLOID VERSUS COLLOID COLOADING.

PURPOSE: Spinal anesthesia for caesarean delivery is often associated with hypotension. This study was conducted to evaluate the effects of rapid crystalloid (Lactated Ringer's solution; LRS) or colloid (hydroxyethyl starch; HES) cohydration with a second intravenous access line on the incidence of hypotension and ephedrine requirement during spinal anesthesia for cesarean section. METHODS: We studied 90 women with uncomplicated pregnancies undergoing elective cesarean section under spinal anesthesia. Intravenous access was established in all patients with two peripheral intravenous lines, the first being used for the baseline volume infusion. Immediately after induction of spinal anesthesia, LRS (Group L) or HES (Group C) infusions were started at the maximal possible rate via the second line in groups L and C respectively. In the third group (Group E), patients received lactated Ringer's solution at a 'keep vein open' rate to maintain the double-blind nature. The incidence of hypotension, ephedrine requirements, total amount of volume and side effects were recorded. RESULTS: The incidence of hypotension was significantly greater in group E than in groups L and C, and greater in group L than in group C (p < 0.03 and p < 0.01 respectively ). The total dose of ephedrine used to treat hypotension was significantly less in groups L and C than in group E (p < 0.001 and p < 0.001 respectively). Groups L and C received similar infusion volumes and doses of ephedrine. CONCLUSIONS: Giving either LR or HES coloading via a second IV line caused less hypotension and required less use of ephedrine compared to no coloading. There were no maternal or neonatal side effects.