Reduction of pain during induction with target-controlled propofol and remifentanil
Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, 28, Yongon-Dong, Jongno-Gu, Seoul 110-744, Korea
* Corresponding author. E-mail: spss{at}dreamwiz.com
Background: Pain on injection of propofol is unpleasant. We hypothesized that propofol infusion pain might be prevented by infusing remifentanil before starting the propofol infusion in a clinical setting where target-controlled infusions (TCI) of both drugs were used. A prospective, randomized, double-blind, placebo-controlled trial was performed to determine the effect-site concentration (Ce) of remifentanil to prevent the pain without producing complications.
Methods: A total of 128 patients undergoing general surgery were randomly allocated to receive normal saline (control) or remifentanil to a target Ce of 2 ng ml–1 (R2), 4 ng ml–1 (R4), or 6 ng ml–1 (R6) administered via TCI. After the target Ce was achieved, the infusion of propofol was started. Remifentanil-related complications were assessed during the remifentanil infusion, and pain caused by propofol was evaluated using a four-point scale during the propofol infusion.
Results: The incidence of pain was significantly lower in Groups R4 and R6 than in the control and R2 groups (12/32 and 6/31 vs 26/31 and 25/32, respectively, P<0.001). Pain was less severe in Groups R4 and R6 than in the control and R2 groups (P<0.001). However, both incidence and severity of pain were not different between Groups R4 and R6. No significant complications were observed during the study.
Conclusions: During induction of anaesthesia with TCI of propofol and remifentanil, a significant reduction in propofol infusion pain was achieved without significant complications by prior administration of remifentanil at a target Ce of 4 ng ml–1.
Keywords: anaesthetics i.v., propofol; analgesics opioid, remifentanil; drug delivery, computerized; pain, injection