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Abstract: SA-PO119

Low Cardiac Output During Cardiac Surgery Is Associated with Renal Tubular Injury Measured by Urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL)

Session Information

Category: Acute Kidney Injury

  • 102 AKI: Clinical, Outcomes, and Trials

Authors

  • Goeddel, Lee A., Johns Hopkins University, Baltimore, Maryland, United States
  • Waldron, Natalie, Johns Hopkins University, Baltimore, Maryland, United States
  • Rodriguez, Emily, Johns Hopkins University, Baltimore, Maryland, United States
  • Buchanan, James, Johns Hopkins University, Baltimore, Maryland, United States
  • Obeid, Wassim, Johns Hopkins University, Baltimore, Maryland, United States
  • Parikh, Chirag R., Johns Hopkins University, Baltimore, Maryland, United States
Background

Low cardiac output (CO) during cardiac surgery may contribute to renal hypoperfusion and AKI. It is challenging to associate intraoperative low CO to renal injury using serum creatinine as it is non-sensitive to injury and it its increases are delayed by 24-48 hours after surgery. We assessed the relationship between low CO and urinary neutrophil gelatinase-associated lipocalin (NGAL), which is a sensitive marker of renal tubular injury.

Methods

We enrolled 30 patients with preserved left-ventricular ejection fraction undergoing coronary-artery bypass surgery to collect urine samples at baseline, after cardiopulmonary bypass, and at intensive care unit (ICU) arrival. Cardiac index (CI) was calculated from continuous arterial waveform analysis that generates CI every five seconds and value of <= 2 L/min/m2 was used as the threshold for low CI.We used the Meso Scale discovery platform to assess NGAL.

Results

Mean age was 62.7+/- 8 and 28% were female. On average, 210 ± 58 minutes of CI readings were available on each patient. Mean Low CI was 100.1± 73 minutes per patient. Figure 1a shows log2 NGAL at the three timepoints. Mean (SD) change from baseline to ICU arrival was (3.27 +/-3.89) pg/ml. On multivariable regression analysis adjusted for age, sex, and minutes MAP<65mmHg, each 10 minutes of CI <2 L/min/m2 was associated with increased NGAL (beta 0.2; p=.078, fig. 1b).There was minimal association between changes in serum creatinine and low CI

Conclusion

Low CO during cardiac surgery appears to be associated with renal tubular injury and can be detected by urinary NGAL. This finding was independent of exposure to hypotension (minutes<MAP of 65 mmHg). Additional investigation of low CO and NGAL are warranted.

Figure 1: (a) Log2 NGAL increases from baseline (0), after cardiopulmonary bypass (1) to ICU arrival (2). (b) Low CI is associated with change in NGAL from baseline to ICU arrival.