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Abstract: FR-PO082

Temporal Evolution of AKI After Cardiac Surgery

Session Information

Category: Acute Kidney Injury

  • 101 AKI: Epidemiology‚ Risk Factors‚ and Prevention

Authors

  • Sakhuja, Ankit, West Virginia University, Morgantown, West Virginia, United States
  • Priyanka, Priyanka, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
  • Kellum, John A., University of Pittsburgh, Pittsburgh, Pennsylvania, United States
Background

Acute kidney injury (AKI) is a common complication after cardiac surgery and is associated with high mortality. There is a well-defined timing of injury to the kidneys in these patients, which provides a unique opportunity for trial of novel therapeutic agents. There is, however, very little information about the temporal evolution of AKI after cardiac surgery. Understanding of the temporal evolution is important to inform trials for novel therapeutic strategies for prevention and management of CSA-AKI.

Methods

This was a retrospective observational study using data from High-Density Intensive Care -15 Database from University of Pittsburgh Medical Center. Data from 2008 – 2014 was included for this study. Patients undergoing cardiac surgery were identified using ICD-9-CM codes. AKI was identified using KDIGO criteria. We used Kruskal-Wallis and Chi-Square/Fisher Exact tests to compare continuous and categorical variables respectively. We used multivariable logistic regression models to identify risk factors for development of stage II/III AKI at 72 hours based on serum creatinine and urine output based criteria.

Results

Among 6,440 patients, 5228 (81.9%) developed CSA-AKI. Of those who developed CSA-AKI, 91% developed it within 24 hours and 98% within 72 hours after cardiac surgery. Stage I AKI within first 72 hours after cardiac surgery was the most common initial manifestation of CSA-AKI (98.7%). Majority of AKI within first 72 hours after cardiac surgery was due to isolated decrease in urine output. Additionally, the maximum AKI stages as scored by urine output exceeded those scored by serum creatinine by approximately 50% over first 10 days after cardiac surgery. The risk factors for stage II/III AKI by 72 hours after cardiac surgery differed based on whether the severity was seen due to rise in serum creatinine or decrease in urine output. Patients who developed AKI within first 24 hours were more often obese, with chronic kidney disease and diabetes. They also consistently had higher major adverse kidney events at 30d, 90d, 180d and 1 yr after surgery.

Conclusion

AKI is very common after cardiac surgery and is characterized by both oliguria and azotemia with former being much more frequent. Majority of CSA-AKI is notable within 24 hours after cardiac surgery with stage I being the initial manifestation. AKI manifesting as azotemia has different risk factors than that manifesting as oliguria.

Funding

  • Commercial Support