URINE OXYGEN TENSION MEASUREMENT AS AN EARLY DIAGNOSTIC TOOL IN CHILDREN WITH CARDIAC SURGERY ASSOCIATED ACUTE KIDNEY INJURY

Highlights Despite postoperative acute kidney injury having a significant impact on early and long-term outcomes in children after cardiac surgery, its timely identification remains challenging. Urine oxygen tension monitoring could be an additional diagnostic tool aimed at the early detection of kidney dysfunction and allowing for earlier interventions to prevent further kidney injury progression. Aim . To evaluate the prognostic value of measuring oxygen tension in urine to detect kidney dysfunction in children after cardiac surgery. Methods . A prospective observational single-center study was conducted, including 60 children who underwent elective surgery for congenital septal heart defect. Postoperative renal dysfunction in children was detected according to the criteria of KDIGO (Kidney Disease: Improving Global Outcomes), additionally, the concentration of markers of kidney damage (NGAL, KIM-1, L-FABP, IL-18) in blood serum and urine was determined at three control points: baseline (after insertion of the urethral catheter), after 4 24 hours, 16 hours after the start of artificial blood circulation, as well as the oxygen tension in the urine at three control points: baseline value (after installing the urethral catheter), 10 minutes after removing the clamp from the aorta, 16 hours after the start of artificial blood circulation. Results . The analyzed data showed that there was no correlation between the oxygen tension in the urine, determined on the blood gas composition analyzer, and the level of creatinine and biomarkers at any control points. It has been shown that a 2.2-fold decrease in this indicator after removal of the aortic clamp can serve as a predictor of AKI. Conclusion . The presented analytical review demonstrates the prospect of measuring oxygen tension in urine as an additional diagnostic option in acute kidney injury associated with cardiac surgery in children. It has been shown that oxygen tension in urine can be used in the diagnosis of postoperative renal dysfunction, however, the use of specialized devices to track this indicator is preferable.