Incidence and associated factors of delirium after orthopedic surgery in elderly patients: a systematic review and meta-analysis.

Abstract

A total of 4.5-41.2% of orthopedic surgery patients experience delirium. Until now, no formal systematic review or meta-analysis was performed to summarize the risk factors of delirium after orthopedic surgery. The present study aimed to comprehensively and quantitatively conclude the risk factors of delirium after orthopedic surgery in elderly patients. A search was applied to Medline, Chinese National Knowledge Infrastructure (CNKI), Embase, and Cochrane central database (all up to February 2020). All studies on the risk factors of delirium after orthopedic surgery in elderly patients without language restriction were reviewed, and qualities of included studies were assessed using the Newcastle-Ottawa Scale. Data were pooled and a meta-analysis was completed. A total of 15 studies altogether included 10,053 patients with orthopedic surgery, 825 cases of delirium occurred after surgery, suggesting the accumulated incidence of 8.2%. Results of meta-analyses showed that age > 70years (odds ratio (OR) 3.78, 95% confidence interval (CI) 2.97-4.80), advanced age (standardized mean difference 0.82, 95% CI 0.54-1.09), male sex (OR 1.78, 95% CI 1.13-2.79), medical comorbidities (OR 2.18, 95% CI 1.23-3.88), malnutrition (OR 3.10, 95% CI 2.19-4.38), preoperative and postoperative haemoglobin (SMD - 0.37, 95% CI - 0.54 to - 0.19; SMD - 0.33, 95% CI - 0.55 to - 0.11), postoperative sodium (SMD - 0.52, 95% CI - 0.74 to - 0.29) and longer hospitalization after surgery (SMD 0.27, 95% CI 0.11-0.43), hearing impairment (OR 2.78, 95% CI 1.98-3.90), multiple medications (OR 1.36, 95% CI 1.21-1.52), psychotic drugs(OR 4.27, 95% CI 1.37-13.24), morphine (OR 1.97, 95% CI 1.11-3.51), cognitive impairment (OR 2.72, 95% CI 1.96-3.78), length of stay (SMD 0.26, 95% CI 0.14-0.39) and hip surgery (OR 1.63, 95% CI 1.08-2.48) were more likely to sustain delirium after hip surgery in elderly patients. ASA I and II was less likely to develop delirium after orthopedic surgery (OR 0.52, 95% CI 0.34-0.79). Related prophylaxis strategies should be implemented in the elderly involved with above-mentioned risk factors to prevent delirium after orthopedic surgery.