Background. Following opioid and intravenous anaesthetic, tracheal intubation may be accomplished without any muscle relaxant. In this study, we evaluated the dose requirements for sufentanil with propofol without muscle relaxant administration to obtain clinically acceptable intubation conditions and cardiovascular responses. Methods and Results. After midazolam (0.05 mg.kg-1), 90 patients were randomized into three equal groups, each receiving sufentanil 0.2 (SUF-0.2), 0.3 (SUF-0.3) or 0.4 (SUF-0.4) μg.kg-1, respectively. Following induction of anaesthesia with propofol (2 mg.kg-1), the quality of tracheal intubation was assessed as excellent or good (clinically acceptable) and poor. Excellent intubation conditions were observed in 28 %, 41 % and 54 % of patients in groups SUF-0.2, SUF-0.3 and SUF-0.4, respectively, while poor conditions were present in 31 % (SUF-0.2; p = 0.041 vs. SUF-0.3, p = 0.006 vs SUF-0.4), 7 % (SUF-0.3) and 3 % (SUF-0.4). Patients with induction-related hypotension were older than those without (60 ± 15 vs. 52 ± 17 yr, p = 0.013). Conclusions. Sufentanil (0.3–0.4 μg.kg-1) in combination with propofol (2 mg.kg-1) provided clinically acceptable intubating conditions in 93–97% patients.

        Key words: general anaesthesia, endotracheal intubation, propofol, sufentanil