PREVENTION OF HYPOTENSION DURING SPINAL-ANESTHESIA - A COMPARISON OF INTRAVASCULAR ADMINISTRATION OF HETASTARCH VERSUS LACTATED RINGERS SOLUTION

This study was designed to compare the efficacy of 6% hetastarch to th at of crystalloid administration in reducing the incidence and severit y of hypotension during spinal anesthesia. Forty ASA grade I patients sched uled for postpartum tubal Ligations under spinal anesthesia were randomly allocated to receive either 500 mt of hetastarch solution or 1000 mt of lactated Ringer's solution prior to spinal anesthesia. Spi nal anesthesia was managed identically in both groups by anesthesiolog ists who were unaware of the type of fluid administered. The incidence of hypotension was 11 of 21 (52%) in the lactated Ringer's solution g roup and 3 of 19 (16%) in the hetastarch group. The difference in the incidence of hypotension was significant (P < 0.05). The requirement o f 5-mg bolus doses of ephedrine to main rain systolic arterial blood p ressure > 75% of baseline was significantly greater in the lactated Ri nger's group than in the hetastarch group (15 vs 4, P < 0.05). We conc lude that an intravenous infusion of 500 mt of 6% hetastarch solution is more effective than 1000 mt lactated Ringer's solution in attenuati ng spinal anesthesia induced hypotension in women undergoing postpartu m tubal ligation.