Effect of intravenous infusion of remimazolam versus propofol on intraoperative neurophysiological monitoring stability and postoperative neurological function in patients undergoing spinal surgery.

OBJECTIVES

Intraoperative neurophysiological monitoring (IONM) plays a critical role in spinal surgery by reducing the risk of nerve injury; however, its quality can be significantly influenced by anesthetic agents. This study aimed to compare the effects of remimazolam and propofol on IONM performance and postoperative recovery.

METHODS

This retrospective analysis included patients who underwent prone-position spinal surgery with IONM between January 2021 and June 2025. Patients were divided into either a remimazolam group or a propofol group according to the primary sedative administered. The outcomes assessed included IONM parameters [somatosensory evoked potentials (SEP)/motor evoked potentials (MEP) amplitude/latency] after intubation (T1) and at 30 min (T3) and 50 min (T4) following recovery from neuromuscular blockade. Additional outcomes included hemodynamics, remifentanil consumption, recovery time, and cognitive function scores.

RESULTS

A total of 204 patients included in the analysis (Remimazolam group: 101 cases, Propofol group: 103 cases). Compared to the propofol group, the remimazolam group demonstrated significantly improved IONM signals, higher SEP amplitude at T4 (2.16 vs. 1.97 μV, P<0.001), and higher MEP amplitude at T4 (1680.73 vs. 1500.64 μV, P<0.001). The incidence of hypotension (6.93% vs. 19.42%, P=0.009) and bradycardia (5.94% vs. 14.56%, P=0.043) were significantly lower, while remifentanil consumption was significantly higher (2005.64 vs. 1425.44 ug, P<0.001) in the remimazolam group. In addition, patients in the remimazolam group exhibited shorter recovery times (awakening time: 18.91 vs. 24.25 min, P<0.001) and better cognitive function (MoCA score on postoperative Day 3: 24.41 vs. 23.54, P<0.001).

CONCLUSIONS

Remimazolam provides superior IONM conditions, a lower incidence of intraoperative hypotension and bradycardia, and faster postoperative recovery compared to propofol in patients undergoing spinal surgery.