The Impact of Incident Postoperative Delirium on Survival of Elderly Patients After Surgery for Hip Fracture Repair

Abstract

Background The impact of delirium on survival of elderly patients remains undetermined with conflicting results from clinical studies and meta-analysis. In this study we assessed the relationship between long-term mortality and incident postoperative delirium in elderly patients undergoing hip fracture repair. Methods Patients ≥ 65 years old who were not delirious before undergoing hip fracture repair were included in a database maintained prospectively from March 1999 until July 2009. All participating patients underwent delirium assessment on the 2nd postoperative day using the confusion assessment method. Survival of the participants was determined as of October 2012. Results In 459 patients the mean (SD) period of evaluation from surgery until death or study closure was 4.1 (3.5) years with patients followed for as long as 13.6 years. Preoperative cognitive impairment was present in 120 patients (26.1%) and delirium on the 2nd postoperative day was observed in 151 (32.9%) of these. Although univariate analysis demonstrated a strong association between incident postoperative delirium and survival, this relationship did not persist in a multivariate model. Survival was a function of age at the time of surgery (p < 0.001), illness severity as determined by the ASA physical status score (p < 0.001), and duration of admission to the intensive care unit after surgery (p < 0.001). Incorporation of incident postoperative delirium did not meaningfully (p = 0.22) enhance the final survival model. In such a model, the hazard ratio [CI95] for incident postoperative delirium was 1.25 [0.92, 1.48]. Conclusions Incident postoperative delirium was not significantly associated with decreased survival in elderly patients undergoing hip fracture repair.

Depth of sedation as an interventional target to reduce postoperative delirium: mortality and functional outcomes of the Strategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients randomised clinical trial

“…Large case series report a 5.1% 30-day mortality 18 and 25% 1 yr mortality, 19 with a mean survival of 3.75 yr (95% CI, 3.13e4.54). 20 The 14% 1-yr mortality in the current study is comparable with other prospective hip fracture series, 21 but lower than the smaller randomised trial conducted by members of the same research team as the STRIDE study. 8 Exclusion criteria (severe dementia and medications which prevent the safe administration of spinal anaesthesia) were similar between these studies.…”

“…Similarly, previous studies have found that, when accounting for confounders, incident delirium was not an independent risk factor for intermediate-term mortality. 20,27 However, several deliriumassociated characteristics do appear to be associated with mortality. 28 Specific to surgical patients, trend-level associations between delirium severity and 6 month mortality after hip fracture repair 29 have been reported, but STRIDE is the first study to demonstrate statistically significant relationships between POD severity and 1 yr mortality.…”

Impact of Delirium After Hip Fracture Surgery on One-Year Mortality in Patients With or Without Dementia: A Case of Effect Modification

“…As described previously, Cox regression analysis of all survival data from this current cohort yielded a mean 4.1 years of follow up per patient. Neither baseline cognitive impairment nor delirium survived as significant predictors of mortality in multivariate analysis (34). Similarly, when considering only one-year survival, neither probable dementia nor delirium alone was independently associated with increased mortality.…”

Patients prone for postoperative delirium

“…In elderly patients with hip fracture followed up for as long as 13.6 years, univariate analysis demonstrated a strong association between POD and survival, but a multivariate analysis identified only age at the time of surgery, illness severity, and duration of ICU stay after surgery as factors contributing to mortality [4]. As much as prophylaxis and treatment of POD definitely make sense from a cost and even more so from an ethical perspective, it is therefore questionable whether it will improve long-term outcome, and POD is just a marker of the fragile patient.…”