Predictors And Associated Outcomes Of Postoperative Delirium After Open Abdominal Aortic Aneurysm Repair
Richard D. Gutierrez, B.S., Zachary A. Matthay, MD, Eric J. Smith, B.A., Warren J. Gasper, MD, Jade S. Hiramoto, MD, Michael S. Conte, MD, Emily Finlayson, MD, Louise C. Walter, MD, James C. Iannuzzi, MD, MPH.
University of California, San Francisco, San Francisco, CA, USA.
OBJECTIVES: Open abdominal aortic aneurysm (AAA) repair is a major vascular procedure that incurs a large physiologic demand, increasing the risk for complications such as postoperative delirium. We sought to characterize delirium incidence, identify delirium predictors, and evaluate the effect of delirium on postoperative outcomes. We hypothesized that delirium following open AAA repair would be predictable and associated with increased postoperative complications and resource utilization.
METHODS: This was a retrospective study of all AAA cases from 2012-2020 at a single tertiary care center. Delirium was identified via a validated chart review method based on key words and Confusion Assessment Method assessments. The primary outcome was postoperative delirium and secondary outcomes included length of stay, non-home discharge, 90-day mortality and 1-year survival. Bivariate analysis as appropriate to the data was used to assess the association of delirium with post-operative outcomes. Multivariable binary logistic regression was used to identify predictors of postoperative delirium and cox regression predictors of 1-year survival. RESULTS: Overall, 199 cases of AAA were included, and postoperative delirium developed in 34% (n=68). Delirium was associated with older age (74 years vs 69 years, p<0.01), preoperative dementia (100% vs 33%, p<0.01), end-stage renal disease (89% vs 32%, p<0.01) and coronary artery disease (45% vs 28%, p=0.02). Of those who presented with a ruptured AAA, 8 (33%) developed postoperative delirium. Additionally, of those with delirium, 27 (40%) received a delirium prevention bundle. Postoperative delirium was associated with 90-day mortality (13% vs 5%, p=0.03), non-home discharge (53% vs 26%, p<0.01), longer length of stay (20 days vs 11 days, p<0.01) and postoperative pneumonia (19% vs 8%, p=0.02). On multivariable analysis, independent predictors for delirium included older age, history of coronary artery disease, and non-elective procedure (Table 1). A Cox proportional hazards model revealed that postoperative delirium was independently associated with worse survival at 1 year (Hazard Ratio = 2.84; CI: 1.08-7.47; p=0.034). CONCLUSIONS: Postoperative delirium is associated with worse postoperative outcomes and increased resource utilization. Future studies should examine the role of improved screening, implementation of delirium prevention bundles and multidisciplinary care for the most vulnerable patients undergoing open AAA repair.
| Variable (Ref Age<60) | Odds Ratio | p-Value | 95% CI |
| 60-69 years old | 3.35 | 0.093 | 0.82-13.73 |
| 70-79 years old | 4.68 | 0.026 | 1.21-18.10 |
| 80-89 years old | 4.90 | 0.039 | 1.08-22.19 |
| Non-elective procedure | 3.02 | 0.002 | 1.50-6.08 |
| History of ESRD | 9.31 | 0.056 | 0.94-91.78 |
| History of CAD | 2.37 | 0.015 | 1.18-4.77 |
| C-Statistic = 0.70 | |||
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