Pathogenesis of and management strategies for postoperative delirium after hip fracture: A review

Postoperative delirium is a frequent and serious complication in elderly patients following operation for hip fracture, leading to an increased risk of complications. The pathophysiological mechanisms are unresolved, but probably multifactorial. The purpose of this review is to summarize current knowledge about the pathogenesis of postoperative delirium with a view to finding strategies for prevention and management. We conducted an Internet search through the Medline database (1966-March 2003) and supplemented it with a manual search. We included 12 studies which specifically discussed pathogenic factors or interventions against postoperative delirium following operation for hip fracture. 1,823 patients were included with an average incidence of delirium of 35%. We concentrated on pre-, intra-, and postoperative risk factors. Only advanced age and dementia met our fixed criterion of "strong evidence" for a significant association. Hence, from the studies that we reviewed we were unable to find intraoperative or postoperative factors with "strong evidence" for a significant association with delirium. Postoperative delirium is a serious complication. The pathophysiology leading to delirium after hip fracture surgery still remains to be clarified and no single drug or surgical regimen has proven to be preventive. This calls for more detailed investigations of the differential role of different pathogenic mechanisms, as well as an aggressive multimodal approach to enhance recovery and reduce morbidity, as has proven to be successful in a variety of elective surgical procedures. Such multimodal interventional studies represent a major task for orthopedic departments in collaboration with anesthesiologists, geriatricians, physiotherapists and nursing staff.