Combined use of crystalloid preload and low dose spinal anesthesia for preventing hypotension in spinal anesthesia for cesarean delivery: a randomized controlled trial.

BACKGROUND AND OBJECTIVE Spinal anaesthesia for caesarean section is commonly associated with hypotension and crystalloid preload is widely recommended. Low-dose spinal appears to cause less hypotension. The aim of this study was to investigate whether the combined use of crystalloid preload and low dose spinal anaesthesia might further reduce the rates of hypotension. METHODS Sixty-two patients were randomly assigned to two groups: crystalloid preload anaesthesia (P): received a rapid infusion of 20 mL/kg lactated Ringer's solution (LR), and no preload anaesthesia (N). The incidence of hypotension and the amount of ephedrine used to treat it were compared. Spinal anaesthesia was performed with 0.5% isobaric bupivacaine 7.5 mg and fentanyl 10 microg and morphine 100 microg. RESULTS The incidence of hypotension was similar in the P and N groups. Same doses of ephedrine were required to treat hypotension in the two groups. CONCLUSION Crystalloid preload combined with low-dose spinal anaesthesia do not reduce the incidence of hypotension nor its severity.