The effect of remifentanil on intubation conditions in patients undergoing caesarean delivery under general anesthesia: comparison of two dosing regimens

The objective of our study was to compare the effects of two remifentanil dosing regimens, used during induction-delivery period of cesarean section, and of remifentanil-free control on maternal intubating conditions and hemodynamic response to endotracheal intubation as well as on neonatal outcome. Seventy seven ASA physical status I-II women with singleton term pregnancy, who were scheduled for elective cesarean section in general anesthesia and have given written informed consent, were enrolled in this prospective, randomized controlled study and divided in three groups: A - 31 patient received 1 µg/kg remifentanil bolus before the induction of anesthesia, followed by 0.15 µg/kg/min remifentanil infusion that was stopped after the skin incision; B - 27 patients received only 1 µg/kg remifentanil bolus; C - 19 patients did not receive remifentanil until the delivery of the baby. Intubating conditions were qualified as excellent, good or poor. Group A had significantly higher number of patients with excellent intubating conditions (p = 0.011); majority of patients with good intubating conditions were in group C (p = 0.017). Systolic, diastolic, main arterial pressure and heart rate raised significantly in group C compared to A and B (p < 0.001). Neonatal outcome did not differ between groups – all neonates were vital with first minute Apgar scores ≥ 8. In conclusion, our dosing regimen of remifentanil 1µg/kg bolus given immediately before the induction followed by 0.15 µg/kg/min interrupted after skin incision provided the best compromise between the achievement of excellent intubating conditions, attenuation of maternal hemodynamic stress response to endotracheal intubation and avoidance of neonatal respiratory depression.