Frequency of haemoglobin desaturation with the use of succinylcholine during rapid sequence induction of anaesthesia

Background: The percieved safety of the use of succinylcholine is based on the fact that recovery from its effects will occur before oxygen desaturation occurs in case of failure to intubate or ventilate. The purpose of this study was to examine the incidence of oxygen desaturation after the use of succinylcholine prior to resumption of spontaneous ventilation following four different preoxygenation techniques. Methods: Twenty-five patients each were randomly alocated to preoxygenation with 4 deep breaths of 100% oxygen or by breathing oxygen for 1, 3 or 5 min following which they recieved a rapid sequence induction of anaesthesia with fentanyl 1 mug kg(-1), a sleep dose of thiopentone and succinylcholine 1 mg kg(-1). Oxygen saturation was monitored continuously using a finger probe. Ventilation was not assisted unless the saturation decreased to 90%. Results: Eleven out of the 100 patients had a decrease in their oxygensaturation to less than or equal to 90% before the resumption of effective spontaneous ventilation irrespective of the technique of preoxygenation. Conclusion: We conclude that use of succinylcholine may not always prevent desaturation if there is a failure to iintubate and ventilate during a rapid sequence induction of anaesthesia. (C) Acta Anaesthesiologica Scandinavica 45 (2001).