Preoperative geriatric nutritional risk index as a predictor of postoperative delirium in revision arthroplasty: a 10-year retrospective cohort study.

OBJECTIVE

This study aims to investigate the association between the preoperative geriatric nutritional risk index (GNRI) and postoperative delirium (POD) in patients undergoing hip or knee revision arthroplasty.

METHODS

820 patients who underwent hip or knee revision arthroplasty from January 2014 to September 2024 were included. The exposure variable was preoperative GNRI, and the outcome variable was POD, diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria using the Confusion Assessment Method (CAM). The study considered covariates such as age, sex, body mass index, albumin, and comorbidities, employing multivariate logistic regression analysis to explore the association between preoperative GNRI and POD.

RESULTS

Among 820 patients, 76 (9.27%) developed POD within 7 days postoperatively. Patients with POD had a significantly lower GNRI (97.53 ± 9.54) compared to those without POD (101.05 ± 8.85,  = 0.003). For each 1-unit increase in GNRI, the risk of POD decreased by 4% (OR = 0.96, 95% CI: 0.94-0.99,  = 0.011). Quartile analysis showed that patients in the highest GNRI quartile had a significantly lower POD incidence compared to those in the lowest quartile (OR = 0.43, 95% CI: 0.20-0.92, p for trend = 0.037). A protective threshold of GNRI was identified at 101.96.

CONCLUSION

A significant association was observed between preoperative GNRI and POD in patients undergoing hip or knee revision arthroplasty. However, due to the retrospective single-center design and potential unmeasured confounding, further multicenter prospective studies are warranted to validate these findings and explore underlying mechanisms.