Effect of suxamethonium vs rocuronium on onset of oxygen desaturation during apnoea following rapid sequence induction

This study investigates the effect of suxamethonium vs rocuronium on the onset of haemoglobin desaturation during apnoea, following rapid sequence induction of anaesthesia. Sixty patients were randomly allocated to one of three groups. Anaesthesia was induced with lidocaine 1.5 mg. kg(-1), fentanyl 2 mu g.kg(-1) and propofol 2 mg.kg(-1), followed by either rocuronium 1 mg.kg(-1) (Group R) or suxamethonium 1.5 mg.kg(-1) (Group S). The third group received propofol 2 mg.kg(-1) and suxamethonium 1.5 mg.kg(-1) only (Group SO). The median (IQR [range]) time to reach SpO2 of 95% was significantly shorter in Group S (358 (311-373 [215-430]) s) than in Group R (378 (370-393 [366-420]) s; p=0.003), and shorter in Group SO (242 (225-258 [189-370]) s) than in both Group R (p<0.001) and Group S (p<0.001). When suxamethonium is administered for rapid sequence induction of anaesthesia, a faster onset of oxygen desaturation is observed during the subsequent apnoea compared with rocuronium. However, time to desaturation is prolonged whenever lidocaine and fentanyl precede suxamethonium.