Effect of General Versus Spinal Anesthesia on Postoperative Delirium and Early Cognitive Dysfunction in Elderly Patients

Abstract

Background: Postoperative cognitive dysfunction (POCD) and delirium are common in the elderly patients, given the controversial results of previous studies about the impact of anesthesia type on the occurrence of these complications. Objectives: This study was planned to compare the effects of general and spinal anesthesia on the prevalence of POCD and delirium. Methods: A single-blind non-randomized clinical trial. Setting was in two academic hospitals. Ninety-four patients over 50 years old scheduled for hip fracture fixation. Patients were divided into two groups to receive either general (GA) or spinal (SA) anesthesia. Both Mini-Mental State examination (MMSE) and Wechsler tests were used before the operation and 3 times postoperatively to assess the cognitive function and detect early POCD. The DSM-IV criteria were also used for the diagnosis of delirium. The incidence of delirium and POCD and their precipitating factors were compared between the two groups. Results: Ninety-four patients with a mean age of 67.12 years were studied. The overall prevalence of POCD and delirium was 17.02%; however, it was significantly higher in the GA group rather than the SA group, 29.7%, and 4.25%, respectively (P < 0.001). There was a significant relationship between age (P = 0.048), ASA class (P = 0.034), and educational level with the incidence of POCD, meaning that the probability of developing cognitive impairment decreases with patients’ higher level of education and lower ASA-physical status. Also, the rate of POCD in men was significantly higher than in women (P = 0.026). Conclusions: The finding of this study showed that, if there is no specific contraindication, neuraxial anesthesia may be preferred over general anesthesia in elderly patients.