Intra-operative awakening during scoliosis surgery

A method of intra-operative awakening which allows assessment of spinal cord function during Harrington rod spinal fusion for scoliosis is described. The anaesthetic technique is based on a standard muscle relaxant, N2O anaesthetic sequence supplemented with intravenous morphine 0.1 mg/kg at the commencement of surgery and 0.2 mg/kg intramuscular premedication. This relatively large total dose of morphine may reduce intra-operative awareness, and may also provide substantial pain relief during the initial 24 h postoperative period. It has been used successfully in 20 patients aged between 6 and 16 yr. Five patients remembered being woken, but did not regard it as unpleasant. In one patient, this technique allowed intra-operative detection and correction of impaired motor function of the legs.