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 microg 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.