What is the optimal remifentanil dosage for providing excellent intubating conditions when coadministered with thiopental? A prospective randomized dose-response study.

Background And Objective: The aim of the present study was to determine the dosage of remifentanil that must be added to thiopental 5 mg kg(-1) to provide excellent intubating conditions in 95% of patients.

Methods: Sixty-eight premedicated female American Society of Anesthesiologists class 1 and 2 patients were randomly allocated to four remifentanil dose groups (3, 4, 5 or 6 microg kg(-1)). Induction of anaesthesia was performed with a blinded dose of remifentanil infused over 60 s, simultaneously coadministered with thiopental 5 mg kg(-1) infused over 20 s; and tracheal intubation was attempted 150 s after the beginning of induction.