Kidney Week

Abstract: TH-PO040

Early Detection of AKI Using Intraoperative Urine pO2, pCO2, and Lactate during Cardiopulmonary Bypass

Session Information

• AKI: Epidemiology, Risk Factors, and Prevention - 1
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Svensson, Anders S., Linkopings universitet, Linkoping, Östergötland, Sweden

Anders S. Svensson, MSc

• Kvitting, John-Peder Escobar, Universitetet i Oslo, Oslo, Norway

John-Peder Escobar Kvitting, MD, PhD

• Holm, Jonas, Linkopings universitet, Linkoping, Östergötland, Sweden

Jonas Holm, MD, PhD

• Szabo, Zoltan, Linkopings universitet, Linkoping, Östergötland, Sweden

Zoltan Szabo, PhD

• Kovesdy, Csaba P., The University of Tennessee Health Science Center, Memphis, Tennessee, United States

Csaba P. Kovesdy, MD, FASN

Background

Intraoperative acute kidney injury (AKI) is a common complication after cardiopulmonary bypass (CPB), and it is associated with poor outcomes. Methods to detect AKI in CPB are limited by delayed diagnosis or limited availability. Urinary biomarkers can be measured continuously in the operating room, but their role in detecting AKI is unclear.

Methods

A pilot study in 18 patients undergoing CPB at a single institution. Urine was collected immediatley prior to CPB and every 15 minutes intraoperatively until the end of CPB. Urine biomarkers (pO₂, pCO₂ and lactate) were measured in the operating room using a standard blood gas analyser. Intraoperative AKI was defined as a 0.3 mg/dl increase in serum creatinine within 48 hours post-CPB. We analysed urine biomarkers overall and in patients stratified by AKI status. We used repeated measures ANOVA and Tukey`s HSD, and characterized intraindividual changes using mixed effect models adjusted for baseline demographics, EuroScore-II, precence of CKD, CRP level and intraoperative hemodilution.

Results

Five of 18 patients (28%) developed AKI. Overall, intraindividual levels of urine pO₂ (p=0,03), pCO₂ (p=<0,001) and lactate (p=<0,001) levels were significantly different in ANOVA analyses (figure). In patients with vs. without AKI, pO₂ showed more substanial decline (slope in mixed effect models:-0,06 vs. -0,005 mmHg/min); pCO₂ showed less decline (-0,006 vs. -0,11 mmHg/min); and lactate showed more increase (0,007 vs. 0,004 mmol/L/min) during CPB in adjusted mixed effect models.

Conclusion

Urine pO₂, pCO₂ and lactate show significant changes during CPB. These changes are different in patients with vs. without AKI. Intraoperative monitoring of urine biomarkers may offer a rapid and readily available means of diagnosing AKI in clinical practice. Larger studies are needed to confirm these findings.