Postoperative cerebral oxygenation in hypoplastic left heart syndrome after the Norwood procedure

Cerebral near-infrared spectroscopy (NIRS) is being used with increasing frequency in the care of pediatric patients after surgery for congenital heart disease. Near-infrared spectroscopy provides a means of evaluating regional cerebral oxygen saturation (cSaO(2)) noninvasively, with correlations to cardiac output and central venous saturation. Prior studies have demonstrated that systemic venous saturation can predict outcome after the Norwood procedure. With this in mind, we sought to determine whether regional cSaO(2) by NIRS technology could predict risk of adverse outcome after the Norwood procedure.

We reviewed the first 48 hours of postoperative hemodynamic data on 50 patients with hypoplastic left heart syndrome at our institution who underwent the Norwood procedure. Cerebral oxygen saturation data within 48 hours of surgery were analyzed for association with subsequent adverse outcome, which was defined as intensive care unit length of stay greater than 30 days, need for extracorporeal membrane oxygenation, or hospital death after 48 hours.

There were 18 adverse events among the 50 subjects. The mean cSaO(2) for the entire cohort at 1 hour, 4 hours, and 48 hours after surgery was 51% +/- 7.5%, 50% +/- 9.4%, and 59% +/- 8.1%, respectively. Mean cSaO(2) for the first 48 postoperative hours of less than 56% was a risk factor for subsequent adverse outcome (odds ratio 11.9, 95% confidence interval: 2.5 to 55.8). Mean cerebral NIRs of less than 56% over the first 48 hours after surgery yielded a sensitivity of 75.0% and a specificity of 79.4% to predict those at risk for subsequent adverse events.

Low regional cerebral oxygen saturation by NIRS in the first 48 hours after the Norwood procedure has a strong association with subsequent adverse outcome. Monitoring of cerebral saturation can serve as a valuable monitoring tool and can identify patients at risk for poor outcome.