A randomized study of the effects of perioperative i.v. lidocaine on hemodynamic and hormonal responses for cesarean section

Abstract

Purpose: Intravenous infusion of lidocaine attenuates the stress response to surgery. We aimed to evaluate the effects of perioperative lidocaine on the hemodynamic and hormonal responses for cesarean delivery.

Methods: After the gaining of ethical approval, 90 patients scheduled for elective cesarean delivery were randomly allocated to receive either lidocaine 1.5 mg x kg(-1) i.v. bolus 30 min before induction, followed by an infusion of 1.5 mg x kg(-1) x h(-1) until 1 h after surgery (n = 45), or saline placebo (n = 45). Anesthesia was maintained with 50% nitrous oxide in oxygen with 0.7% isoflurane. Hemodynamic variables, plasma cortisol, maternal and neonatal lidocaine concentrations, Apgar scores at 1 and 5 min, neonatal acid-base status, and the neurologic and adaptive capacity score (NACS) were recorded.

Results: After induction, patients receiving lidocaine had a smaller increase in heart rate and mean arterial blood pressure (P < 0.02) and lower plasma cortisol concentrations (31.1 +/- 9.91 vs 45.6 +/- 8.43 microg x dL(-1); P < 0.001). There were no differences between the two groups in Apgar scores, NACS, or neonatal acid-base status. After delivery, maternal and umbilical venous concentrations and umbilical vein-to-maternal vein ratios of lidocaine were 2.05 +/- 0.42 microg x mL(-) and 1.06 +/- 0.31 microg x mL(-1), and 0.52 +/- 0.07, respectively.

Conclusion: Perioperative lidocaine is safe and effective in attenuating the maternal stress response to surgery for cesarean delivery.