Comparison of Propofol and Ketofol on Transcranial Motor Evoked Potentials (TcMEPs) in Patients Undergoing Thoracolumbar Surgery

Background: To compare effect of propofol and ketofol infusion (ketamine:propofol 1:4 admixture) on TcMEPs, hemodynamic parameters and muscle power at discharge.

Materials and Methods: Thirty-eight adult ASA I and II patients were randomly allocated into two groups (X and Y) in 1:1 ratio. Amplitude and latency were recorded bilaterally from abductor pollicis brevis (APB) and abductor hallucis (AH) muscles. Baseline recordings of TcMEPs in both groups were recorded under propofol infusion. Thereafter, in group X, patients received propofol and fentanyl 1 µg/kg/h, and in group Y, patients received ketofol and fentanyl 1 µg/kg/h. In both groups, bispectral index (BIS) was maintained between 40 and 60. The amplitude and latency were recorded thereafter at four time points: T1 (30 minutes), T2 (60 minutes), T3 (90 minutes), and T4 (120 minutes).

Results: In group X, propofol did not result in significant change in amplitude and latency in any muscle. In group Y, ketofol resulted in significant increase in amplitude at all the time points in bilateral APB muscles and 60, 90, and 120 minutes in left AH muscle without change in latency. When the two groups were compared, ketofol resulted in statistically higher amplitudes at 60, 90, and 120 minutes in (L) APB, at 30, 60, 90, and 120 minutes in (R) APB, and at 120 minutes in both AH muscles; latency being comparable. Blood pressures were lower whereas fluid and vasopressor requirement were higher in group X. Muscle power was comparable between the two groups.

Conclusions: Ketofol increases amplitude probably secondary to maintenance of hemodynamics.

Publication History

Article published online:
25 March 2020