General versus spinal anaesthesia and postoperative delirium in an orthogeriatric population

Aim Postoperative delirium is common among elderly hip surgery patients. We aimed to pragmatically evaluate whether type of anaesthesia influenced postoperative delirium in an orthogeriatric population following hip fracture. Method This observational study comprises prospectively collected data on hip fracture patients admitted between October 2010 and November 2011. Delirium was diagnosed clinically by geriatricians. Results Of the 344 patients admitted, seven managed conservatively and 19 with incomplete data were excluded; 318 patients were analysed. Average age was 81.6 (SD 9.8) years; 28% were men and 167 (53%) were administered general anaesthesia. Mean length of stay was 18 (SD 9.4) days. Overall, 172 patients (54%) experienced delirium. There was no apparent difference in postoperative delirium by anaesthetic type (88 vs 84, P = 0.15). Conclusion Delirium was common in both general and spinal anaesthetic patients. Further randomised controlled trials would be required to determine whether anaesthesia type influenced delirium rates.