Spinal monitoring during vertebral column surgery under continuous alfentanil infusion.

An anaesthetic technique for surgical procedures on the vertebral column is described consisting of a continuous infusion of a short acting opioid, alfentanil, and a muscle relaxant, vecuronium, in combination with positive pressure ventilation using a nitrous oxide/oxygen mixture. It is shown that the two standard forms of spinal monitoring, wake-up testing and somatosensory cortical evoked potentials, can be employed effectively using this anaesthetic technique. Wake-up testing was performed in 23 patients. Average wake-up time was 10 min (SD 3.7 min). Evoked responses suitable for spinal monitoring could be obtained in 60 of 61 patients.