Extending epidural analgesia for emergency Caesarean section: a meta-analysis.

There is no high-level evidence supporting an optimal top-up solution to convert labour epidural analgesia to surgical anaesthesia for Caesarean section. The aim of this meta-analysis was to identify the best epidural solutions for emergency Caesarean section anaesthesia, with respect to rapid onset and low supplementation of intraoperative block. Eleven randomized controlled trials, involving 779 parturients, were identified for inclusion after a systematic literature search and risk of bias assessment. 'Top-up' boluses were classified into three groups: 0.5% bupivacaine or levobupivacaine (Bup/Levo); lidocaine and epinephrine, with or without fentanyl (LE ± F); and 0.75% ropivacaine (Ropi). Pooled analysis using the fixed-effects method was used to calculate the mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous outcomes. Lidocaine and epinephrine, with or without fentanyl, resulted in a significantly faster onset of sensory block [MD -4.51 min, 95% confidence interval (CI) -5.89 to -3.13 min, P < 0.00001]. Bup/Levo was associated with a significantly increased risk of intraoperative supplementation compared with the other groups (RR 2.03; 95% CI 1.22-3.39; P = 0.007), especially compared with Ropi (RR 3.24, 95% CI 1.26-8.33, P=0.01). Adding fentanyl to a local anaesthetic resulted in a significantly faster onset but did not affect the need for intraoperative supplementation. Bupivacaine or levobupivacaine 0.5% was the least effective solution. If the speed of onset is important, then a lidocaine and epinephrine solution, with or without fentanyl, appears optimal. If the quality of epidural block is paramount, then 0.75% ropivacaine is suggested.