The influence of fentanyl vs. s-ketamine on intubating conditions during induction of anaesthesia with etomidate and rocuronium

Background and objective In the present study, we investigated the combination of etomidate and s-ketamine with regard to its suitability for modified rapid-sequence induction using rocuronium for muscle relaxation. Methods In a prospective, randomized and double-blinded study, 90 patients were assigned to one of three groups for induction of anaesthesia in combination with etomidate (0.3 mg kg−1) and muscle relaxation with rocuronium (0.6 mg kg−1). The groups were as follows: (a) control, i.e. placebo; (b) fentanyl, fentanyl (1.5 μg kg−1); (c) ketamine, s-ketamine (0.5 mg kg−1). Tracheal-intubating conditions after 1 min were classified as excellent, good or poor. During the induction of anaesthesia, arterial pressure and heart rate were measured every 60 s. Results Intubating conditions were best using etomidate and s-ketamine (23 excellent, 7 good, 0 poor) compared with the control (8, 16, 6 respectively) and fentanyl groups (7, 21, 2 respectively) (P < 0.01). While heart rate and arterial pressure remained stable in the control and fentanyl groups during induction, both significantly increased in the ketamine group (P < 0.01). Conclusions The combination of etomidate and s-ketamine for anaesthesia induction produces mostly excellent intubating conditions after 60 s using only 0.6 mg kg−1 of rocuronium. This combination of drugs may be a useful alternative, if succinylcholine needs to be avoided, for modified rapid-sequence induction.