Remimazolam infusion associated with easier mask ventilation than propofol during anaesthesia inductionSmall study finds remimazolam may ease mask ventilation during anesthesia induction

Anaesthesia, critical care & pain medicine Published April 2, 2026 Study authors: Lee Ji Hyeon, Kim Jin-Hee, Lee Jiyoun, Han Sung-Hee, Park Jin-Woo PubMed ↗ DOI ↗ Editorial oversight: Dr. Lars van Dijk, PhD · Surgical, Procedural & Diagnostic

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Key Takeaway

Consider remimazolam's potential for easier mask ventilation, but note slower onset and limited safety data.

A randomised controlled trial compared anaesthesia induction with continuous remimazolam infusion (12 mg/kg/h) versus target-controlled propofol infusion (4 μg/mL) in 76 adult patients scheduled for elective surgery. The primary outcome was mask ventilation difficulty assessed using the Warters scale.

Mask ventilation was significantly easier with remimazolam, with a median Warters score of 0.0 [0.0-0.8] versus 1.0 [0.0-3.0] for propofol (P=0.002). The odds of requiring more than one airway device were lower with remimazolam (OR 0.23, 95% CI 0.08-0.68, P=0.006). Mean blood pressure immediately after loss of consciousness was higher in the remimazolam group (P=0.037), though the incidence of hypotension after induction was comparable. Time to achieve loss of consciousness was significantly longer with remimazolam (P<0.001).

Adverse events, serious adverse events, discontinuations, and tolerability were not reported. The study has important limitations: it was a single trial with only 76 patients, and key safety details are absent. Funding and conflicts of interest were not reported. For practice, these findings suggest remimazolam may be associated with easier mask ventilation and better hemodynamic stability during induction compared to propofol in similar adult surgical populations, but the slower onset and limited evidence base require consideration.

Researchers conducted a small trial to compare two drugs used to put patients to sleep before surgery: remimazolam and propofol. They wanted to see if one made it easier for doctors to provide oxygen through a mask (mask ventilation) right after the patient lost consciousness. The study involved 76 adults scheduled for elective surgery under general anesthesia.

Patients who received remimazolam had easier mask ventilation, according to a specific measurement scale. They were also less likely to need more than one airway device to help them breathe. Their blood pressure was more stable immediately after losing consciousness. However, it took longer for remimazolam to make patients unconscious compared to propofol.

The study did not report details on side effects, safety, or how well patients tolerated the drugs. This was a single, small trial, so the results are preliminary. For patients, this means anesthesiologists have early data suggesting remimazolam might offer some advantages in specific situations, but much more research is needed before any changes to standard practice would be considered.

What this means for you:

Early, small study suggests a potential benefit for one anesthesia drug, but more evidence is needed.

Study Details

Study typeRct

EvidenceLevel 2

PublishedApr 2026

PMID41274378

View Original Abstract ↓

BACKGROUND: Benzodiazepines facilitate mask ventilation due to their airway relaxant properties. Remimazolam, an ultra-short-acting benzodiazepine, may offer advantages during anaesthesia induction. This study evaluated the difficulty of mask ventilation between remimazolam and propofol during the induction of general anaesthesia. METHODS: Seventy-six adult patients scheduled for elective surgery under general anaesthesia were randomised into propofol and remimazolam groups. In the propofol group, general anaesthesia was induced with target-controlled infusion of propofol at an effect-site concentration of 4 µg/mL. In the remimazolam group, continuous infusion of remimazolam was performed at 12 mg/kg/h. The primary outcome was mask ventilation difficulty assessed by the Warters scale. Secondary outcomes included time to achieve loss of consciousness (LOC) and mean blood pressure during induction. RESULTS: The remimazolam group exhibited significantly lower Warters score compared to the propofol group (0.0 [0.0-0.8] vs. 1.0 [0.0-3.0], P = 0.002). The occurrence of mask ventilation difficulties requiring more than one airway device during anaesthetic induction was also significantly lower in the remimazolam group than in the propofol group (odds ratio [95% confidence interval], 0.23 [0.08-0.68]; P = 0.006). Mean blood pressure immediately after LOC was higher in the remimazolam group (P = 0.037), although the incidence of hypotension after induction was comparable between groups. The time required to achieve LOC was longer in the remimazolam group (P < 0.001). CONCLUSION: Compared to propofol, remimazolam induction was associated with easier mask ventilation and more stable blood pressure after LOC, despite a longer time to achieve LOC. REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (registration number: UMIN000053553; registration date: 7 February 2024; registration URL: https://center6.umin.ac.jp/cgi-bin/ctr_e/ctr_view_reg.cgi?recptno=R000061086).

Remimazolam infusion associated with easier mask ventilation than propofol during anaesthesia inductionSmall study finds remimazolam may ease mask ventilation during anesthesia induction

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Remimazolam infusion associated with easier mask ventilation than propofol during anaesthesia inductionSmall study finds remimazolam may ease mask ventilation during anesthesia induction

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