Predicting post‐operative delirium in elderly patients undergoing surgery for hip fracture

Abstract

Background: Delirium in elderly patients with hip fracture has a significant negative influence on the disease course. Awareness of risk factors for postoperative delirium (POD) may lead to the development of effective preventive strategies. The aims of this study were: to find patients' features that are predictors of POD, and; to develop a model predicting the risk for POD. Patients and methods: Seventy-seven elderly patients (81.9 years of age, SD 7.5 years) were non-delirious prior to surgery and enrolled in the study. Delirium was diagnosed by Confusion Assessment Method and Algorrhithm. Patients' characteristics as potential predictors of POD were analyzed by logistic regression analysis on SAS software. Results: Postoperative delirium was diagnosed in 37 patients. Use of multiple (>3) medications, lower scores on cognitive tests (<20 on Set Test and <24 on Mini-mental Status Exam), albumin level less than 3.5 g/dL, hematocrit level less than 33% and age over 81 years were predictors of POD. A logistic regression formula including these predictors weighed by their parameter estimates can be used to calculate the probability of POD. The model had a good fit and a good predictive power. A Delirium Predicting Scale was derived based on parameter estimates of these predictors. Patients can be classified as low-, intermediate-or high-risk for POD. Conclusions: A logistic regression model, which includes patients' age, medication history, cognitive performance measured by Set Test and MiniMental Status Exam, albumin and hematocrit levels, can be used to predict risk for POD after surgical repair of fractured hip in elderly patients.

Preoperative risk factors for postoperative delirium following hip fracture repair: a systematic review

“… Body mass index (BMI) in quartiles (Lee et al ., ), BMI ≤20 kg/m 2 (Bjoro, ; Juliebo et al ., ), albumin <3.4 g/dL (Bjoro, ), albumin (median value) (Juliebo et al ., ), or albumin <3.5 g/dL (Goldenberg et al ., ).…”

“… Functional impairment was defined differently in studies: “help from others before admission”(Andersson, Gustafson, Hallberg, ), activities of daily living score ≥2 (Goldenberg et al ., ), Barthel index 19 or 20 (Juliebo et al ., ), and Functional Independence Measure score (Morrison et al ., ).…”

“… Polypharmacy was defined as “>5” (Bjoro, ), “≥5” (Juliebo et al ., ), and “>3 medications” (Goldenberg et al , ).…”

Delirium in Hospitalized Elderly Patients and Post-Discharge Mortality

“…Nevertheless, the occurrence of delirium was significantly more common among patients ≥80 years old20,21 and among those diagnosed with immobility. Additionally, delirium was associated with an increased length of hospital stay, which has already been shown in previous studies 5,16,17,19.…”

Assessment of the risk of postoperative delirium in elderly patients using E‐PASS and the NEECHAM Confusion Scale

“…In addition to delirium related to malignant tumors or infection, its onset as an adverse reaction to drugs must be considered. However, postoperative delirium is also frequent; it is observed in 51% of patients undergoing abdominal surgery and in 48-55% of those after surgery for femur neck fracture (Olin et al, 2005;Santana Santos et al, 2005;Golderberg et al, 2006). In Japan, the incidences of surgery-field disorders such as femur neck fracture and colorectal cancer in elderly persons have increased with the rapid aging of society (Committee for Osteoporosis Treatment, 2004;Isobe et al, 2007).…”