Comparison of effect of remimazolam and propofol on respiration of patients under deep sedation for colonoscopy: a prospective multicenter randomized controlled trial.

Summary

In a multicenter RCT of 450 colonoscopy patients under deep sedation (target OAA/S ≤2), remimazolam prolonged time to first airway intervention versus propofol (11±8 vs 5±6 minutes), reduced airway interventions and apnea incidence/duration, and maintained higher minute ventilation at early time points and procedure end. These benefits occurred without sacrificing sedation adequacy.

Key Findings

• Time to first airway intervention was longer with remimazolam (11±8 min) than propofol (5±6 min), P<0.001.
• Remimazolam required fewer airway interventions and had lower incidence and shorter duration of apnea (all P<0.001).
• Minute ventilation at 1, 2, 4 minutes post-induction and at procedure end was higher with remimazolam (all P<0.001) at equivalent target sedation (OAA/S ≤2).

Clinical Implications

For procedural sedation (e.g., GI endoscopy), remimazolam may reduce hypoventilation, apnea, and airway maneuvers compared with propofol, at equivalent sedation depth. Protocols may prioritize remimazolam in patients at higher respiratory risk or where airway interventions are undesirable.

Limitations

• Blinding of providers to sedative may not have been feasible, potentially influencing intervention thresholds.
• Findings pertain to colonoscopy deep sedation; generalizability to other procedures, ASA classes, or concurrent opioid use requires confirmation.

Future Directions

Evaluate outcomes across broader procedural contexts and risk strata, assess cost-effectiveness and recovery profiles, and test protocolized airway management thresholds with remimazolam.