Geriatric Nutritional Risk Index can predict postoperative delirium and hospital length of stay in elderly patients undergoing non-cardiac surgery

Abstract

Aim: Malnutrition is common in older patients and is associated with adverse outcomes. The Geriatric Nutritional Risk Index (GNRI) has been developed as an objective index to assess nutritional risk in these patients. However, there is limited evidence regarding the association between GNRI and postoperative delirium (POD) as well as length of stay (LOS) in surgical older patients. Therefore, our goal was to examine the impact of poor nutrition, evaluated by the GNRI, on POD and length of stay in older patients undergoing non-cardiac surgery.

Methods: In this prospective cohort study, older patients undergoing non-cardiac surgery from April to June of 2015 were included. Preoperative nutritional status was assessed by the GNRI within the first 48 h after hospital admission. The outcomes were POD and LOS. Multivariable logistic regression and linear regression analyses were used to assess the role of GNRI in predicting these outcomes.

Results: In the whole sample (N = 288), the prevalence of severe/moderate (GNRI <92) and low (GNRI 92-98) nutritional risk was 15.6% and 29.5%, respectively. The median length of hospital stay was 14 days. Delirium was present in 49 patients (17%). A linear regression analysis showed that low (β = 4.56, 95% confidence interval [CI]: 2.18-6.94) and severe/moderate (β = 3.70, 95% CI: 0.74-6.65) nutritional risk were associated with prolonged LOS. Moreover, a multivariate analysis revealed that patients with severe/moderate nutritional risk were more likely to develop POD compared with those without (odds ratio = 2.56, 95% CI: 1.11-5.89).

Conclusion: Preoperative malnutrition, as assessed using the GNRI, predicted LOS and the development of POD in elderly non-cardiac surgical patients. Geriatr Gerontol Int 2020; 20: 759-764.

Keywords: Geriatric Nutritional Risk Index; elderly; length of stay; postoperative delirium.