TOPLINE

Remimazolam was associated with higher rates of postoperative delirium than propofol in older patients undergoing lung resection. Emergence delirium was observed more frequently in the remimazolam group, with a longer stay in the postanesthesia care unit (PACU).

METHODOLOGY

• Researchers conducted a randomized noninferiority trial at two academic hospitals in China, enrolling 460 patients aged 65 years or older who were scheduled for elective lung resection under general anesthesia. Of these, 455 patients were included in a modified intention-to-treat analysis.
• Patients were randomly assigned to receive either remimazolam (0.3-0.4 mg/kg for induction and 1.0-1.5 mg/kg/h for maintenance; n = 227) or propofol (target-controlled infusion using the Marsh model: 3.0-4.0 μg/mL for induction and 2.0-3.0 μg/mL for maintenance; n = 228), both combined with remifentanil (1.0-2.0 ng/mL).
• Delirium was evaluated by trained assessors who were unaware of group assignments using the Confusion Assessment Method along with the Riker Sedation-Agitation Scale. Assessments were performed every 10 minutes during emergence and twice daily for 3 days after surgery.
• The primary outcome was delirium detected at any time during the first 3 postoperative days, including emergence delirium in the PACU. The absolute risk difference was calculated, with noninferiority established if the upper limit of the 95% CI did not exceed the prespecified margin of 10%.
• Secondary outcomes were the rates of delirium-positive assessments, the length of stay in the PACU, the duration of stay in the hospital after surgery, and Mini-Mental State Examination scores at 30 days.

TAKEAWAY

• Postoperative delirium within 3 days was observed in 48% vs 31% of patients in the remimazolam group vs propofol group (risk ratio [RR], 1.53; 95% CI, 1.21-1.94). The absolute risk difference for postoperative delirium was 16.5% (95% CI, 7.7%-25.3%), which exceeded the prespecified noninferiority margin.
• Emergence delirium occurred more often in the remimazolam group than in the propofol group (RR, 1.65; 95% CI, 1.28-2.12), whereas delirium on postoperative days 1-3 was uncommon in both groups.
• The proportion of delirium-positive assessments was 9% and 7% in the remimazolam and propofol groups, respectively.
• Patients in the remimazolam group had a longer duration of stay in the PACU than those in the propofol group (median, 66 vs 61 minutes; P < .001). However, the length of stay in the hospital after surgery and Mini-Mental State Examination scores at 30 days were similar between the two groups.

IN PRACTICE

The findings “support heightened vigilance during early recovery when remimazolam is used,” the researchers of the study reported.

SOURCE

The study was led by Wei Wang of the Department of Anaesthesiology at the Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine in Shanghai, China. It was published online on July 17, 2026, in Anaesthesia.

LIMITATIONS

The trial identified delirium that occurred at any time in the first 3 days after surgery rather than ward delirium, and because emergence delirium represented a substantial proportion of events, the statistical power to detect differences after PACU discharge was limited. Confusion assessments were conducted only when patients were sufficiently arousable, which might have led to missing cases of hypoactive delirium. The findings specifically apply to older patients undergoing lung resection surgery and may not be generalizable to other groups of patients.

DISCLOSURES

The National Natural Science Foundation of China provided support for this study. The authors reported having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.