Perioperative risk factors of postoperative delirium in elderly patients with hip fractures

Abstract

Abstract Background Postoperative delirium (POD) is a common complication in elderly patients with hip fractures, it is characterized by disorders of consciousness, attention, perception, thinking, memory, mental activity and emotions. Objective Our aim was to identify the perioperative risk factors of postoperative delirium in elderly patients with hip fracture. Methods We carried out a prospective cohort study on 80 elderly patients 60 years and older with recent fragile hip fractures, who attended the orthopedic department of Ain shams university hospitals, Cairo, Egypt. Patients who were delirious on admission and those with major traumatic fractures were excluded from the study. Each patient gave an oral consent and then subjected to history taking with assessment of perioperative risk factors of delirium. Delirium was assessed in preoperative period, day 1 and 2 postoperative by CAM (confusion assessment method). Cognitive impairment was assessed by MiniMental-state-examination (MMSE), severity of pain by pain scale, depression by patient health Questionnaire 2 (PHQ2), functional assessment by activity of daily living (ADL) and instrumental activity of daily living (IADL), assessment of risk of delirium by DEAR score. Radiological assessment of the fracture femur by X-ray. Preoperative lab investigations including: CBC, serum electrolyte panel, kidney & liver function test & fasting blood glucose were done Results 38% of our study population developed delirium preoperatively after admission, 68% developed delirium at day 1 postoperative versus only 37% at day 2 postoperatively. There was a significant difference between delirious & non delirious patients preoperatively in presence of hypertension, IHD & COPD, presence of cognitive impairment by MMSE, severity of pain and presence of risk of delirium by DEAR score and there was a significant difference between delirious & non delirious patients in day one postoperative in presence of co-morbidities as diabetes, ischemic heart diseases (IHD), chronic obstructive pulmonary disease (COPD), visual & hearing impairment, while there was a statistically significant difference between delirious & non delirious patients in day two postoperative in presence of visual & hearing impairment and in presence of cognitive impairment by MMSE, depression by PHQ2, severity of pain & risk of delirium by DEAR score Logistic regression model revealed that cognitive impairment and severity of pain were independent predictors of POD preoperatively, while functional dependency by IADL, visual & hearing impairment & diabetes were independent predictors of POD in day 1 postoperative while depression by PHQ2 was independent factor of POD in day 2 postoperative. Conclusion Postoperative delirium is common in patients with hip fractures as 68% of patients developed delirium at day one postoperative and 37% at day two postoperatively. Logistic regression revealed that cognitive impairment and severity of pain were independent predictors of POD preoperatively.