Background: Perioperative monitoring with multisite near-infrared spectroscopy (NIRS) for congenital cardiac surgery with cardiopulmonary bypass may aid in predicting adverse clinical outcomes. Methods: Forty-one consecutive neonates and infants undergoing bypass were monitored with right + left cerebral and renal NIRS. Near-infrared spectroscopy and lactate were measured at 20 time points, from baseline 1 day preoperatively, during bypass and modified ultrafiltration (MUF; 10 minutes), until 24 hours postoperatively. Adverse events were extracorporeal membrane oxygenation (ECMO)/death, prolonged intensive care unit (ICU) or length of hospital stay. Results: Perioperative mean renal NIRS remained higher than baseline (n = 41) as did cerebral NIRS in all undergoing biventricular repair. During bypass (n = 41), mean right and left cerebral NIRS were equal. During MUF, cerebral and renal NIRS values increased (P <.001). Cerebral NIRS and lactate inversely correlated during the first six postoperative hours. Extracorporeal membrane oxygenation /death occurred in four patients, correlating with cerebral and renal NIRS below 45% (P = .030) and 40% (P = .019) at anytime, respectively, and with mean lactate levels >9.3 mmol/L in the first postoperative 24 hours (P <.001). Among survivors, renal NIRS below 30% at any time predicted a longer ICU stay. Conclusions: At bypass conclusion, 10 minutes of MUF does not adversely affect cerebral or renal NIRS. Left and right cerebral NIRS are equal, so that biparietal cerebral NIRS monitoring is probably not warranted. Perioperative cerebral and renal NIRS readings, respectively, below 45% and 40% correlate with ECMO/death and renal NIRS below 30% with prolonged ICU stay. Cerebral NIRS and lactate levels showed a strong inverse correlation during the first six postoperative hours.
