Near-infrared spectroscopy monitoring to predict postoperative renal insufficiency following repair of congenital heart disease.

Background: Infants undergoing repair or palliation of congenital heart disease are at risk of renal insufficiency. Development of renal insufficiency increases mortality. This project seeks to determine whether intra- and postoperative renal near-infrared spectroscopy (NIRS) monitoring can reliably predict renal insufficiency after cardiac surgery in infants.

Methods: In this prospective, observational cohort study 48 patients undergoing repair or palliation of congenital heart disease in the first 6 months of life were studied intraoperatively and on postoperative day 1 and 2. The NIRS mean and nadir were recorded for the 3 time periods, as were urine output, fluid balance, and serum creatinine. Renal insufficiency was defined as rise in creatinine ≥40% from baseline or oliguria for >4 hours. Near-infrared spectroscopy data were compared to creatinine increase, oliguria, and fluid balance on postoperative day 0, 1, and 2 by regression analysis.

Results: Mean renal regional saturation on postoperative day 1 has a strong correlation with increase in creatinine (P < .001 and R (2) = .6). Mean renal saturation less than 80% predicts renal insufficiency with a sensitivity of 100% and a specificity of 75% (P < .001).

Conclusion: Monitoring of intra- and postoperative renal regional saturation may provide an early, noninvasive marker of renal insufficiency after cardiac surgery in infants. This would be clinically significant if interventions to improve renal regional saturation prevent renal insufficiency.