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Abstract: SA-PO023

Intraoperative Urine Oxygen During Cardiac Surgery and 12-Month Kidney Injury

Session Information

  • Bioengineering
    November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Bioengineering

  • 300 Bioengineering

Authors

  • Parry, Samuel R., Brigham Young University College of Physical and Mathematical Sciences, Provo, Utah, United States
  • Hall, Isaac E., The University of Utah Department of Internal Medicine, Salt Lake City, Utah, United States
  • Silverton, Natalie, The University of Utah Department of Anesthesiology, Salt Lake City, Utah, United States
  • Stoddard, Gregory J., The University of Utah Department of Internal Medicine, Salt Lake City, Utah, United States
  • Lofgren, Lars, The University of Utah Department of Anesthesiology, Salt Lake City, Utah, United States
  • Kuck, Kai, The University of Utah Department of Anesthesiology, Salt Lake City, Utah, United States
Background

Acute renal effects from changes in intraoperative urine oxygen during cardiac surgery are well documented; however, longer-term effects of these fluctuations are unknown. We created a non-invasive oximeter to continuously measure urine oxygen levels during cardiac surgery. We hypothesized that low intraoperative urine oxygen associates with poor 12-month kidney outcomes.

Methods

This is a secondary analysis of a prospective cohort of patients undergoing cardiac surgery. 63 patients with at least one serum creatinine measurement within the 12-month follow-up were eligible and included. We measured intraoperative urine oxygen during the post-cardiopulmonary bypass period to determine associations with 12-month kidney outcomes. The post-discharge primary outcome was patient death, chronic dialysis, or estimated glomerular filtration rate (eGFR) decline by more than 30% without recovery by 12 months post-surgery.

Results

A total of 9 (14%) patients developed the primary outcome (2 died, 1 started chronic dialysis, 6 had eGFR decline >30%). For every 5 minutes spent below urine oxygen tension cutoffs during the post-cardiopulmonary bypass period of <25, <20, <15, and <10 mmHg, risk for the primary outcome increased via an exposure-response relationship with hazard ratios (95% CI) of 1.15 (1.01-1.31), 1.37 (1.10-1.72), 1.93 (1.34-2.77) and 5.85 (1.42-24.1), respectively.

Conclusion

Lower intraoperative urine oxygen values were associated with worse 12-month kidney outcomes in this small cardiac surgery cohort. While these findings support our hypothesis, additional larger prospective studies are warranted for external validation. We believe additional studies are also needed to further explore the potential clinical importance of specific intraoperative urine oxygen tension cutoffs.

Funding

  • Other NIH Support