[Comparative study on two total intravenous anesthesia techniques in complex spine surgery].

Objective: To compare anesthesia profiles of target-controlled infusion (TCI) and manual-controlled infusion (MCI) of propofol and remifentanil in kyphosis correction or scoliosis correction surgery, in which intraoperative spinal cord monitoring was employed.

Methods: In the study, 160 patients scheduled for kyphosis correction surgery or scoliosis correction were enrolled and randomly allocated into 2 groups, group TCI and group MCI. In group TCI, induction and maintenance of general anesthesia were carried out by target-controlled infusion of propofol and remifentanil. Marsh and Minto, three-compartment pharmacokinetic models for propofol and remifentanil were used respectively. In group MCI, the patients received propofol and remifentanil by conventional dose-weight infusion method. Muscle relaxants were only applied for ease of induction. In both the groups, anesthesia depth was monitored by bispectral index (BIS), and the change of hemodynamic parameters was kept in the range of 20% of the baseline. The control convenience of anesthesia depth and change amplitude of BIS in the main steps of the procedure were compared. The total amounts of propofol and remifentanil, influence on the hemodynamics, influence on the successful rates of somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) and electromyography (EMG) were compared too.

Results: The time of pump regulation in group TCI was significantly less than in group MCI (P<0.05). The BIS fluctuation in the main steps of the procedure was significantly smaller in Group TCI than in group MCI (P<0.05). There was no significant difference in the amounts of propofol and remifentanil(P=0.158 and P=0.168). The time to awake (P=0.972) and time to extubation (P=0.944) had no significant difference. The successful rates of SSEPs and MEPs had no significant difference between groups TCI amd MCI (P>0.05).

Conclusion: Both TCI and MCI can offer practical anesthesia for spinal deformity correction surgery. TCI has the advantage in keeping smooth and steady depth of anesthesia.