Sodium oxybate with reduced-dose propofol for anesthesia induction in elective spine surgery: a randomized trial

Sodium oxybate has an established sedative action, but its contribution to contemporary propofol-based anesthesia remains incompletely characterized. We evaluated induction hemodynamics, propofol use, bispectral index (BIS), and early recovery in elective spine surgery.

In this single-center randomized trial, 127 patients received propofol alone (P; n = 62) or propofol plus sodium oxybate (PS; n = 65). Planned induction doses were propofol 2.2 versus 1.2 mg/kg, with oxybate 30 mg/kg in PS; recorded propofol doses were lower in both groups. The primary outcome was the mean arterial pressure (MAP) trajectory across 13 induction landmarks. Maximum-likelihood mixed models were supplemented by unstructured-covariance and baseline-adjusted analyses.

The primary group-by-time interaction was not significant (P = 0.607; unstructured covariance, P = 0.719). The baseline-adjusted average post-baseline MAP difference was 1.7 mmHg (PS minus P; 95% confidence interval [CI], -2.0-5.5). Systolic-pressure-defined hypotension occurred in 37/62 versus 32/65 patients (risk ratio, 0.82; 95% CI, 0.60-1.14; risk difference, -10.4 percentage points; 95% CI, -26.8-6.7). Recorded total propofol use was 31.4% lower (751.3 versus 515.4 mg; difference, -235.9 mg; 95% CI, -366.0 to -105.9). Maintenance use was also lower under unblinded BIS-guided titration. Post-intubation BIS <40 occurred in 2/62 versus 22/65 patients. The mean surgery-end-to-extubation interval was 10.5 versus 13.6 min (difference, 3.1 min; 95% CI, 0.9-5.2), although both medians were 10 min. Vasoactive-treatment documentation was incomplete.

The oxybate-containing strategy was associated with substantially lower propofol use, lower BIS values, and a longer mean extubation interval; hemodynamic superiority was not demonstrated. These findings define the observed effects and trade-offs of the combined regimen under BIS-guided care and inform further evaluation of dose selection, hypnosis monitoring, and recovery.

https://www.chictr.org.cn Chinese Clinical Trial Registry, ChiCTR2400080686.