Hypotension remains an important side effect of
spinal anesthesia for cesarean delivery. There is limited evidence that reducing the spinal dose has a favorable effect on maternal hemodynamic stability. We designed the present randomized trial to test the hypothesis that reducing the spinal dose of
local anesthetics results in equally effective
anesthesia and less maternal
hypotension. Fifty term pregnant patients were randomly assigned to two study groups. In the HIGH-group combined spinal-
epidural anesthesia was performed using 9.5 mg hyperbaric
bupivacaine combined with 2.5 microg
sufentanil. In the LOW-group combined spinal-
epidural anesthesia was performed using 6.5 mg hyperbaric
bupivacaine combined with 2.5 microg
sufentanil. Demographic data, obstetrical data, visual analog scale score for
pain, number of medical interventions for
pain, maternal hemodynamics, and neonatal outcome were recorded. Patients in the HIGH-group experienced more pronounced and longer hypotensive periods as compared with the LOW-group. The mean lowest recorded systolic blood pressure was higher in the LOW-group (102 +/- 16 versus 88 +/- 16 in the HIGH-group; P < 0.05). More patients in the HIGH-group experienced
hypotension compared with the LOW-group (68% versus 16%; P < 0.05). In the HIGH-group 15 patients required pharmacological treatment for
hypotension compared with 5 in the LOW-group. Duration of effective
anesthesia (block to cold sensation above or at T3) was longer in the HIGH-group as compared with the LOW-group (95 +/- 25 versus 68 +/- 18 min, respectively, P < 0.05). We conclude that small-dose
spinal anesthesia (6.5 mg hyperbaric
bupivacaine combined with
sufentanil) better preserves maternal hemodynamic stability with equally effective
anesthesia that is of shorter duration.