[Anesthesia with epidural spinal cord stimulation--I). Its application to general anesthesia]

Epidural spinal cord stimulation (SCS) has been used for the relief of pain. We tried to apply SCS for general anesthesia. The subjects were 76 patients, undergoing thoracotomy (3 cases), thoraco-laparotomy (4), laparotomy (57) and others (12). A monopolar electrode was introduced to the epidural space via a Touhy needle. The conditions of the electrical stimulation were 12.5-50 Hz, 1.0 ms and 2-8 V. The voltage was adjusted to give comfortable sensation to the patients. After the electrode had been introduced, induction of anesthesia and tracheal intubation were performed with thiopental, diazepam and pancuronium or vecuronium. Anesthesia was maintained with nitrous oxide (70%-50%) and SCS. Nine patients inhaled low concentrations of enflurane in addition to nitrous oxide, and 39 patients received injection of vasodilators because of hypertension. All the patients were not awake during operation, and recovered their consciousness soon after the end of operations. SCS was continued for 17 hrs after operation. During 24 hrs after operation, 16 patients required no analgesics, 32 patients once and others twice or more. We conclude that SCS added to general anesthesia is useful to control pain, not only intraoperatively, but also postoperatively.