Effects of different etomidate doses on intraoperative somatosensory-evoked potential monitoring

Somatosensory-evoked potentials (SSEPs) are widely used for intraoperative spinal cord monitoring. Although many general anesthetics inhibit SSEPs, etomidate has been reported to boost SSEPs. This clinical study aimed to test whether etomidate doses less than 0.3 mg/kg amplify SSEP monitoring.

Patients were divided into four groups: A, B, C, and D. Etomidate doses of 0.1, 0.2, and 0.3 mg/kg were infused into patients in groups A, B, and C, respectively, after baseline SSEPs were obtained. Group D patients were infused with saline. In the subsequent 15 min, the amplitudes and latencies of SSEPs were recorded and compared.

Etomidate exhibited amplification effects on SSEPs, and this effect increased with dose escalation. The amplitude changes in groups A, B, and C were significantly different (P = 0.002, P = 0.000, and P = 0.000, respectively) from that of group D. The amplitude change was largest in group C and significantly greater than those in groups A and B (P = 0.006, P = 0.000). Latency was not significantly affected (P < 0.05) by etomidate.

Small doses of etomidate that were less than 0.3 mg/kg had dose-related amplification effects on SSEP monitoring.