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

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. 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 micro g and morphine 100 micro g. 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. Crystalloid preload combined with low-dose spinal anaesthesia do not reduce the incidence of hypotension nor its severity

Reduction of bupivacaine dose in spinal anaesthesia for caesarean section may improve maternal satisfaction by reducing incidence of low blood pressure episodes

Spinal anaesthesia for caesarean section exposes to high incidence of arterial hypotension which can result in maternal and neonatal morbidity. We hypothesized that the reduction of this dose from 10 mg to 7.5 mg would minimize hypotension without altering pain relief. In this double-blind prospective study, 80 ASA1 women scheduled for elective caesarean section were randomized into two groups A and B receiving respectively 10 and 7.5 mg of isobaric bupivacaine both with 25 micro g of fentanyl and 100 micro g of morphine in spinal anaesthesia. Intravenous ephedrine was administered for each episode of hypotension. We recorded sensory and motor block, intraoperative pain, nausea and vomiting. In postanaesthesia care unit, sensory and motor recoveries were measured and maternal satisfaction rate was assessed. In group A, a larger dose of ephedrine was needed [32 +/- 23 vs 19 +/- 16 mg; p=0.004]. Incidence of sensory block above T4 [52 vs 10%; p<0.001], nausea [52 vs 22%; p=0.005] and vomiting [25 vs 8%; p=0.03] were all higher than in group B. Arterial hypotension was less frequent in group B [68 vs 88%; p=0.03]. The time required for recovery to T10 sensory level and motor regression were shorter than in group A [p<0.001] and the satisfaction rate was higher than in group A [excellent and good in 90% vs 67%; p=0.03]. There was no difference in pain relief. A dose of 7.5 mg of isobaric bupivacaine reduced incidence of hypotension, nausea and vomiting and improved patient satisfaction