Maternal and foetal effects of remifentanil for general anaesthesia in parturients undergoing caesarean section: a systematic review and meta-analysis.

ABSTRACT

BACKGROUND: Remifentanil has been suggested for the induction of general anaesthesia for caesarean section. We aimed to define remifentanil effects on maternal stress response as well as neonatal effects. METHODS: Relevant articles were retrieved by a systematic literature search. Randomized, controlled trials comparing remifentanil use before delivery with placebo were selected. Maternal outcome parameters were blood pressure and heart rate; neonatal effects included the need for mask ventilation and intubation, base excess, pH values, Apgar < 7 at 1 and 5 min. The random effects model was used for meta-analysis; risk ratio or weighted mean difference (WMD) and 95% confidence interval (95% CI) were calculated. RESULTS: Five articles including 186 patients were identified. Highest and lowest systolic blood pressure were significantly lower in the remifentanil group (WMD -29.98, -50.90 to -9.07 mmHg, 95% CI; P = 0.005; and WMD -12.46, -18.21 to -6.71 mmHg, 95% CI; P < 0.0001), the lowest heart rate was significantly lower after remifentanil treatment (WMD -8.22, -11.67 to -4.78, 95% CI; P < 0.00001). Base excess was significantly higher in infants of remifentanil-treated mothers (WMD 1.15, -0.27 to 2.03, 95% CI; P = 0.01); pH was also higher in the remifentanil group, but significance was missed (P = 0.07). No differences were observed for Apgar values or the need of airway assist. CONCLUSION: Remifentanil was found to attenuate the maternal circulatory response to intubation and surgery. Higher base excess and pH suggest a beneficial effect on the neonatal acid-base status. A trial with adequate power is warranted that addresses neonatal side-effects of remifentanil.