Outcomes with spinal versus general anesthesia for patients with and without preoperative cognitive impairment: Secondary analysis of a randomized clinical trial.

Introduction: The effect of spinal versus general anesthesia on the risk of postoperative delirium or other outcomes for patients with or without cognitive impairment (including dementia) is unknown.

Methods: Post hoc secondary analysis of a multicenter pragmatic trial comparing spinal versus general anesthesia for adults aged 50 years or older undergoing hip fracture surgery.

Results: Among patients randomized to spinal versus general anesthesia, new or worsened delirium occurred in 100/295 (33.9%) versus 107/283 (37.8%; odds ratio [OR] 0.85; 95% confidence interval [CI] 0.60 to 1.19) among persons with cognitive impairment and 70/432 (16.2%) versus 71/445 (16.0%) among persons without cognitive impairment (OR 1.02; 95% CI 0.71 to 1.47, p = 0.46 for interaction). Delirium severity, in-hospital complications, and 60-day functional recovery did not differ by anesthesia type in patients with or without cognitive impairment.

Discussion: Anesthesia type is not associated with differences in delirium and functional outcomes among persons with or without cognitive impairment.