Transcranial Motor Evoked Potential Monitoring Using Propofol-Fentanyl Versus Desflurane-Dexmedetomidine Anesthesia During Spinal Cord Tumor Resection: A Randomized Controlled Trial

BACKGROUND: Patients undergoing resection of spinal cord tumours require intraoperative neuromonitoring. Transcranial electrical stimulation is used to record myogenic responses during surgery. This study aimed to compare the effect of 2 anaesthetic regimens, propofol/fentanyl versus desflurane/dexmedetomidine, on the ability to record MEPs with an amplitude of 50 µV or greater. Our secondary outcome compared intraoperative haemodynamics, recovery profile, and postoperative analgesia between the groups. METHODS: We conducted a prospective, double-blinded, open-label, single-centre, randomized controlled trial of 50 adult patients undergoing spinal cord tumour resection with TcmMEP monitoring. Patients were randomized to 2 groups: Group P (n=25) received intravenous anaesthesia with propofol and fentanyl; group D (n=25) received desflurane and dexmedetomidine. RESULTS: We recorded TcmMEP's in 80% of group P and 76% group D (95% CI: -23% to 31%, P =1.00). The time in minutes for spontaneous breathing (21.04±11.31 vs. 8.00±3.42 [8.29-,17.79, P =0.01]), extubation (31.56±17.56 vs. 10.84±3.99 [13.48-27.96; P =0.01]), emergence (33.68±18.11 vs. 10.92±4.01 [15.30-30.22, P =0.001]), discharge readiness (45.00±25.24 vs. 15.56±6.08 [19.00-39.88; P =0.001]) and requirement of first analgesia (136.6±108.04 vs. 230.8±81.33) (-148.58 to -39.82; P =0.01) was lower in group D compared with group P. Postoperative analgesia assessed using the Visual Analogue Score was lower in group D compared with group P at 12 and 24 hours. (1.68±1.18 vs. 0.64±1.31 [0.33-1.74 P =0.001]) :1.4±0.95 vs. 0.36± 0.70 (0.56-1.51; P =0.001). CONCLUSIONS: We found similar rates of successful TcMEP monitoring using desflurane-dexmedetomidine and propofol-fentanyl. Patients who received desflurane-dexmedetomidine had reduced emergence time, discharge readiness, and lower pain scores in the postoperative period.