[The "wake-up correction" for preventing spinal cord injury in scoliosis surgery]

To observe the effects of "wake-up correction" technique for preventing iatrogenic spinal cord injury in scoliosis surgery.

Twenty-one patients who had scoliosis with Cobb's angle 92 degrees - 145 degrees received operation of pedicle screw insertion in all or important vertebral bodies, release of stiff segments, decompression and osteotomy. All the patients were trained how to wake up before anesthesia. Maintenance of anesthesia was achieved with infusion of propofol at target-controlled concentration 3-4 mg/L and remifentanil at 0.15 microg/(kg.min). Fresh gas 2 L/min of N(2)O:O(2) 1:1 was inhaled during mechanical ventilation. Wake-up methods:the muscle relaxant was stopped injection 30 min before wake-up, decreasing propofol's target-controlled concentration to 1-2 mg/L and remifentanil to 0.05 - 0.10 microg/(kg x min). Once the spontaneous respiration returned, woke up the patients and asked them move both toes following our orders (the first wake-up). Then patients inhaled 6% sevoflurane in fresh gas 6 L/min (N(2)O:O(2) 1:1). When the end-tidal anesthetic gas concentration was arrived 1.3 - 1.5 MAC, all of the anesthetics were stopped. The correction operation was completed and the patient was woke up again (the second wake-up). Recorded data included time used to wake up, directive action returning time, whether the patient had memory of wake-up during operation when following up.

All patients woke up with satisfaction. The time taken the first wake-up was (10.3 + or - 4.5) min, and for the second was (4.3 + or - 2.3) min. There were two patients who had slightly agitation during correction. There was no one who had neurological injury. There was no memory of wake-up and no pain in all patients during operation. Cobb' angle was corrected to 22 degrees - 38 degrees (average 29 degrees ), and the correction rate was 74%.

The "wake-up correction" is effective and satisfactory by detecting the cord function in time.