Efficacy of Orexin Receptor Antagonist for Delirium after Coronary Artery Bypass Grafting Compared with Melatonin Receptor Agonist

Abstract

Objective: Delirium is a morbid and costly problem. Though melatonin receptor agonist (Ramelteon) is also reported to decrease delirium, the effect of orexin receptor antagonist (Suvorexant) is unclear. We examine the effectiveness of Suvorexant in decreasing postoperative delirium in comparison with Ramelteon retrospectively. Materials and methods: We reviewed 138 patients (29 women, mean age 69.7 ± 3.4 years) who underwent coronary artery bypass grafting (CABG) alone. Patients have divided into three groups; patients received orexin receptor antagonist (S-group, n=45), patients received melatonin receptor agonist (R-group, n=26), and patients not received neither orexin receptor antagonist nor melatonin receptor agonist (N-group, n=67), and the following data were analyzed in three groups. Results: Intensive Care Unit Delirium Screening Checklist Score was significantly lower in S-group compared with N and R-group (N: S: R=2.4 ± 2.0: 0.9 ± 1.1: 2.2 ± 1.4, p<0.001). Although POD was present in two patients (4.4%) in S-group, seven patients (26.9%) in R-group and twenty patients in N-group (29.9%) developed (p=0.002). In S-group, hospital stay (N: S: R=23.6 ± 8.9: 18.8 ± 2.9: 20.7 ± 4.4 days, p=0.005) was significantly shorter than in R and N-group. Conclusion: Orexin receptor antagonists has shown positive outcomes in the prevention of delirium after CABG. Large trials are necessary to further comparing the efficacy of Suvorexant to other sleep modulating options.