Association between preoperative nutritional status and postoperative delirium in individuals with coronary artery bypass graft surgery: A prospective cohort study.

Abstract

The prevalence of delirium and undernutrition are both relatively high subsequent to coronary artery bypass graft (CABG) surgery. The aim of this study was to evaluate the association between preoperative malnutrition and the occurrence of delirium after CABG surgery. In this prospective cohort study, body mass index, mid-upper arm circumference, triceps skinfold, and adductor pollicis muscle thickness of 398 adult patients before CABG surgery were measured by a single trained dietitian. Also, Nutritional Risk Screening 2002 (NRS-2002) and subjective global assessment (SGA) were obtained from patients. Delirium was defined by the confusion assessment method for the intensive care unit. SPSS software was used for performing the statistical analyses. Logistic regression analysis was applied to examine the effect of various factors on the development of delirium. Postoperative delirium was detected in 17% of patients (n = 68). Multivariate regression analysis adjusted by other risk factors indicated that risk for delirium was 1.56-fold higher in patients with NRS-2002 >3 (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.20-3.24; P = 0.001). Severe undernutrition at admission as assessed by SGA was independently associated with the occurrence of delirium (OR, 2.58; 95% CI, 1.02-3.48; P = 0.005). Risk for delirium was 1.26-fold higher in patients with adductor pollicis muscle thickness <15 mm (OR, 1.26; 95% CI, 1.02-3.14; P = 0.02). Since the prevalence of delirium is relatively high in CABG surgery and undernutrition is related to postoperative delirium, considering nutrition status with NRS-2002, SGA, or adductor pollicis muscle thickness before surgery could decrease the risk for postoperative delirium.