Remifentanil patient-controlled analgesia for labour: optimizing drug delivery regimens: [L'analgesie au remifentanil controlee par le patient pour le travail obstetrical : l'optimisation des regimes d'administration des medicaments].

Author(s): Balki M, Kasodekar S, Dhumne S, Bernstein P, Carvalho JC

Affiliation(s): Department of Anesthesia and Pain Management, Mount Sinai Hospital, 600 University Avenue, Room 781, Toronto, Ontario M5G 1X5, Canada. mrinalini.balki@uhn.on.ca.

Publication date & source: 2007-08, Can J Anaesth., 54(8):626-33.

Publication type:

PURPOSE: A pilot study was undertaken to compare the efficacy of two regimens of intravenous patient-controlled analgesia (PCA) with remifentanil for labour analgesia. METHODS: Twenty term parturients requesting labour analgesia were randomized to receive one of two regimens of intravenous remifentanil. The initial settings in both groups consisted of an infusion of 0.025 mug.kg(-1).min(-1), a PCA bolus of 0.25 mug.kg(-1) and a lockout interval of two minutes. In Group A, the infusion was increased in a stepwise manner from 0.025 to 0.05, 0.075 and 0.1 mug.kg(-1).min(-1) as required; the bolus was kept constant at 0.25 mug.kg(-1). In Group B, the bolus was increased from 0.25 to 0.5, 0.75 and 1 mug.kg(-1) as necessary; the infusion was kept constant at 0.025 mug.kg(-1).min(-1). Maternal pain, satisfaction and sedation scores, remifentanil requirement, and side effects were recorded. RESULTS: Mean pain and patient satisfaction scores, and cumulative doses of remifentanil were similar in the two groups. The overall incidence of side effects was greater in Group B (P = 0.0007), with drowsiness observed in 100% of patients, as compared to 30% in Group A (P = 0.003). The minimum oxygen saturation levels were 94.3% +/- 2.6% and 92.2% +/- 3.8% in Groups A and B respectively (P = 0.19). CONCLUSIONS: Although pain and satisfaction scores were similar in both groups, the regimen used in Group A was associated with fewer side effects compared to the Group B dosing regimen. This pilot study suggests that remifentanil intravenous PCA is efficacious for labour analgesia as a bolus of 0.25 mug.kg(-1), with a lockout interval of two minutes and continuous infusion of 0.025-0.1 mug.kg(-1).min(-1). The potential for respiratory depression mandates close respiratory monitoring. Large-scale trials to evaluate safety issues are warranted.