J. Idrees1, N. Schiltz1, E. E. Roselli1, A. Badjatiya1, D. Johnston1, E. G. Soltesz1 1Cleveland Clinic Foundation,Thoracic And Cardiovascular Surgery,Cleveland, OH, USA
Objective:
Delirium commonly occurs following major surgery in the elderly. It is a known predictor of adverse outcome and increased hospitalization. In this study, we sought to determine the incidence of delirium, the prevalence of risk factors, and impact on healthcare resource use after cardiac surgery using a large administrative dataset.
Methods:
We identified 6,389,977 patients who underwent coronary bypass, valve, or thoracic aortic surgery between 1998 and 2011 from the Nationwide Inpatient Sample database. Multivariable regression was used to identify risk factors for post-operative delirium and risk-adjustment was performed in order to estimate the effect of a delirium on outcomes.
Results:
The incidence of postoperative delirium was 15.0 per 1000 cardiac surgery procedures. Patients with delirium were significantly older (mean age 72 vs. 66 years; p<0.001), male (69.7% vs. 67.6%; p<0.001), and had more Elixhauser comorbidities (6.2 vs. 4.0; p<0.001). Older age, Medicare or Medicaid coverage, and treatment at a teaching hospital were significantly associated with postoperative delirium, while hospital volume was not. Alcohol and drug abuse, depression, psychotic and neurologic disorder, anemia, fluid electrolyte imbalance and weight loss were independent clinical predictors of delirium. Patients who suffered delirium had a longer length of stay (13.8 days vs. 12.8; p<0.001), higher total costs ($52,843 vs. $50,586; p<.001), but lower risk of mortality (0.9% vs. 1.5%, p<0.001) than patients without delirium. Delirious patients were also more likely to be transferred to a skilled nursing facility or require home health care post discharge.
Conclusion:
Our results have shown that postoperative delirium in cardiac surgery patients is associated with increased resource use but lower mortality. Detailed pre-operative assessment and mitigation of certain risk factors can potentially improve outcomes and minimize resource utilization.