Evaluation of the delirium preventive effect of dual orexin receptor antagonist (DORA) in critically ill adult patients requiring ventilation with tracheal intubation at an advanced emergency center: A single-center, retrospective, observational study

Objective: ICU delirium reportedly contributes to increased mortality attributed to underlying diseases, long-term cognitive decline, and increased healthcare costs. Dual orexin receptor antagonists (DORAs), suvorexant and lemborexant, have been suggested for preventing ICU delirium. Although ventilator management is a risk factor for delirium, no study has examined the efficacy of suvorexant and lemborexant in preventing delirium in critically ill patients requiring ventilation. Thus, we retrospectively evaluated the efficacy of DORA in preventing delirium in critically ill adult patients requiring ventilatory management in the emergency room.Method: This retrospective study included patients aged >= 18 years who were admitted to the emergency room and received ventilator support between January 2015 and April 2022. The HR (95% CI) for delirium devel-opment in patients taking DORA was estimated using a Cox proportional hazards model, which was adjusted for the patient background and concomitant medications. HRs were calculated for patients taking suvorexant and those taking lemborexant using a stratified analysis.Results: Of the 297 patients included in the study, 67 were in the DORA group; 50 were on suvorexant and 17 were on lemborexant. The DORA group had a lower incidence of delirium than the control group (p < 0.0001). The risk of delirium was lower in the DORA group compared the control group (HR, 0.22; 95% CI 0.12-0.40).The risk of developing delirium was lower with suvorexant (HR 0.22; 95% CI 0.11-0.41) and lemborexant (HR 0.25; 95% CI 0.08-0.81).Conclusion: DORA is a promising drug that could have the potential to prevent delirium, and its efficacy in preventing delirium should be tested in randomized controlled trials in the future.