Evaluation of the Efficiency of Neutrophil-Lymphocyte Ratio in Predicting Delirium in Geriatric Patients Undergoing Hip Fracture Surgery

Overview

Aim: Postoperative delirium (POD) is one of the most common complications in elderly patients and is associated with increased morbidity, mortality, length of hospital stay and medical care costs. One of the mechanisms proposed for the pathophysiology of delirium is neuroinflammatory processes. The neutrophil-lymphocyte ratio (NLR) is a cost-effective and easily applicable marker of inflammation and oxidative stress. NLR has been used to predict complications, determine prognosis and evaluate mortality in various patient groups and diseases. Most of the studies investigating the relationship between NLR and postoperative delirium in the elderly patient group undergoing hip fracture surgery are retrospective, and the number of prospective studies with large case-series is insufficient. In this study, the investigators aimed to evaluate the effectiveness of NLR in predicting postoperative delirium in elderly patients undergoing hip fracture surgery.

Materials and Methods: Our study is a single-center, prospective, observational study. Our study included 100 patients aged 65 and over, with a Mini Mental Test (MMT) score of 24 and above, who would undergo hip fracture surgery, who -or their legal guardian- could give voluntary consent, with ASA scores of I-IV. Routine preoperative anesthesia evaluation of all patients was performed, and age, gender, type of hip fracture and the surgical procedure to be performed, the degree of kinship with the people they co-live and those who will accompany them in the hospital, height, weight, body mass index (BMI), level of education, existing comorbid diseases, presence of pressure ulcers, history of smoking and alcohol use, medications taken routinely, American Society of Anesthesiologists (ASA) score, and length of preoperative hospital stay were recorded. The patients' basic cognitive functions were evaluated by utilizing the Mini Mental Test (MMT) at the preoperative visit. The routine preoperative blood tests of the patients, including leukocyte, neutrophil, lymphocyte, hemoglobin, hematocrit, platelet, glucose, BUN (blood urea nitrogen), creatinine, albumin, sodium, potassium, liver function tests, C-reactive protein (CRP), and procalcitonin results were recorded. Preoperative NLR was calculated. NLR was calculated as the ratio of neutrophil count to lymphocyte count. Postoperative delirium occurrence was evaluated using the Confusion Assessment Method (CAM) twice a day in the first 3 postoperative days. The place where the delirium developed (postoperative intensive care unit or ward), the time when delirium developed, and the type of delirium were recorded in patients diagnosed with postoperative delirium by CAM. NLR was calculated and recorded from the routine hemogram results taken at the 1st, 16th and 24th hours in the postoperative period. In addition, the postoperative hospital stay of the patients was recorded.