Intraoperative 5-HT receptor antagonists decrease the prevalence of postoperative delirium in older adults undergoing hip fracture surgery: a single-center retrospective study.

Purpose: Postoperative delirium (POD) occurs commonly in older adults, resulting in unfavorable outcomes. Several recent clinical studies have suggested that 5-hydroxytryptamine 3 (5-HT) receptor antagonists can treat and prevent POD. In this retrospective study, the association between 5-HT receptor antagonists and POD was investigated in older adults who underwent hip fracture surgery.

Methods: The electronic medical records of older adults aged ≥ 65 years who underwent hip fracture surgery between January 2011 and June 2018 were reviewed retrospectively. Multivariable logistic regression analysis was used to investigate the association between 5-HT receptor antagonists and the occurrence of POD. In addition to the incidence of POD, anesthesia-, surgery-, and patient-related factors related to POD were evaluated.

Results: Of the 1025 patients included, 813 (79.3%) were administered 5-HT receptor antagonists intraoperatively; 471 (45.9%) were administered ramosetron, and 342 (33.4%) were administered palonosetron. POD was identified in 242 patients (23.6%). Ramosetron and palonosetron reduced the POD incidence by 53% (odds ratio [OR] 0.47; 95% confidence interval [CI] 0.32‒0.71; P < 0.001) and 41% (OR 0.59; 95% CI 0.39‒0.89; P = 0.011), respectively. Additionally, age, American Society of Anesthesiologists physical status class 4, and male were confirmed as risk factors for POD.

Conclusion: Intraoperative 5-HT receptor antagonists may be associated with a reduced risk of POD and can be considered one of the preventive strategies for POD in older adults undergoing hip fracture surgery.