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

Abstract

Objectives: We evaluated whether delirium after hip fracture repair modifies the relationship between baseline dementia and one-year mortality after surgery. Methods: Patients age ≥ 65 undergoing hip fracture repair surgery at John Hopkins Bayview Medical Center between 1999 and 2009 were eligible for this prospective cohort study. Baseline probable dementia was defined as either preoperatively-diagnosed dementia per geriatrician or < 24 on Mini Mental State Examination. Delirium was assessed using the Confusion Assessment Method. Four cognitive groups were defined: 1) neither probable dementia nor delirium (NDD), 2) probable dementia only, 3) delirium only, or 4) delirium superimposed on dementia (DSD). Primary outcome of mortality was obtained through hospital records, obituaries, the National Death Index, and Social Security Death Index. Results: The current sample comprises 466 subjects (average age 80.8 ± 7.0 years; 73.6% female). Of these, 77 (17%) were categorized as DSD, 68 (15%) probable dementia only, 73 (16%) delirium only, and 248 (53%) NDD. Cox regression revealed that DSD subjects had a significantly higher hazard of one-year mortality than NDD subjects (HR 1.71, 95% CI 1.06, 2.77) after adjusting for age, sex, medical comorbidity, and surgery duration. Trends toward greater mortality for probable-dementia and delirium only subjects were not significant—HR 1.42 (0.80, 2.52) and 1.12 (0.64, 1.95). Conclusions: Delirium after hip fracture repair surgery in patients with preoperative dementia modifies the risk of mortality over the first postoperative year. Patients with DSD have a nearly two-fold greater odds of one-year mortality than those without dementia or delirium.

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

“…1 POD after hip fracture repair is associated with an increased likelihood of dependency in activities of daily living (ADLs) and instrumental activities of daily living (IADLs), 2,3 and a higher risk of not returning to pre-fracture level of mobility. 4 Furthermore, both duration of POD 5 and POD superimposed on dementia 6 are risk factors for mortality after surgery. Given the above, interventions which decrease POD have the potential to influence both functional and mortality outcomes.…”

Cognitive impairment and postoperative outcomes in patients undergoing primary total hip arthroplasty: A systematic review

“…Four of the studies are prospective studies with a combined total of 1321 patients. Lee et al showed that patients with dementia had a higher risk of one year mortality than patients without dementia, with a hazard ratio of 1.71 (95% CI 1.06-2.77, P = 0.05) after adjusting for many variables such as age, sex, medical comorbidity and surgery duration [24]. Guerini et al showed that patients who were significantly older and had lower cognitive performance died at a higher rate during the 12-month period following discharge.…”

Combination of isoflurane and propofol as general anaesthesia during orthopaedic surgery of perioperative cerebral hypoperfusion rats to avoid cognitive impairment Anaesthesia during perioperative cerebral hypoperfusion

“…Perioperative neurocognitive disorders (PND) have become the most common complications after routine surgical procedures, particularly in the elderly [1,2]. Following surgery (e.g., common orthopaedic procedures), up to 50% of patients experience cognitive disturbances that can lead to serious complications, including poorer prognosis and a higher 1-year mortality rate in subjects with pre-existing neurodegeneration [3]. Carotid artery stenosis (CAS) can be detected in 75% of men and 62% of women aged ≥65, with a stenosis extent of ≥50% occurring in 7% of men and 5% of women in this age group [4].…”