Cerebral oxygenation during pediatric congenital cardiac surgery and its association with outcome: a retrospective observational study

PURPOSE: Non-invasive cerebral oxygen saturation (ScO(2)) monitoring is an established tool in the intraoperative phase of pediatric congenital cardiac surgery (CCS). This study investigated the association between ScO(2) and postoperative outcome by investigating both baseline ScO(2) values and intraoperative desaturations from baseline. METHODS: All CCS procedures performed in the period 2010-2017 in our institution in which ScO(2) was monitored were included in this historical cohort study. Baseline ScO(2) was determined after tracheal intubation, before surgical incision. Subgroups were based on cardiac pathology and degree of intracardiac shunting. Poor outcome was defined based on length of stay (LOS) in the intensive care unit (ICU)/hospital, duration of mechanical ventilation (MV), and 30-day mortality. Intraoperatively, ScO(2) total time below baseline (TBBL) and ScO(2) time-weighted average (TWA) were calculated. RESULTS: Data from 565 patients were analyzed. Baseline ScO(2) was significantly associated with LOS in ICU (odds ratio [OR] per percentage decrease in baseline ScO(2), 0.95; 95% confidence interval [CI], 0.93 to 0.97; P < 0.001), with LOS in hospital (OR, 0.93; 95% CI, 0.91 to 0.96; P < 0.001), with MV duration (OR, 0.92; 95% CI, 0.90 to 0.95; P < 0.001) and with 30-day mortality (OR, 0.94; 95% CI, 0.91 to 0.98; P = 0.007). Cerebral oxygen saturation TWA had no associations, while ScO(2) TBBL had only a small association with LOS in ICU (OR, 1.02; 95% CI, 1.01 to 1.03; P < 0.001), MV duration (OR,1.02; 95% CI, 1.01 to 1.03; P = 0.002), and LOS in hospital (OR, 1.02; 95% CI, 1.01 to 1.04; P < 0.001). CONCLUSION: In pediatric patients undergoing cardiac surgery, low baseline ScO(2) values measured after tracheal intubation were associated with several adverse postoperative outcomes. In contrast, the severity of actual intraoperative cerebral desaturation was not associated with postoperative outcomes. Baseline ScO(2) measured after tracheal intubation may help identify patients at increased perioperative risk.