Objectives: Neonates and infants undergoing surgery for congenital heart disease are at risk for developmental impairment. Hypoxic-ischemic brain injury might be one contributing factor. We aimed to investigate the perioperative release of the astrocyte protein S100B and its relation to cerebral oxygenation.
Methods: Serum S100B was measured before and 0, 12, 24, and 48 hours after surgery. Cerebral oxygen saturation was derived by near-infrared spectroscopy. S100B reference values based on preoperative samples; concentrations above the 75th percentile were defined as elevated. Patients with elevated S100B at 24 or 48 hours were compared to cases with S100B in the normal range. Neonates (≤28 days) and infants (>28 and ≤365 days) were analyzed separately due to age-dependent release of S100B.
Results: Seventy-four patients underwent 94 surgical procedures (neonates, n = 38; infants, n = 56). S100B concentrations were higher in neonates before and after surgery at all time points (P ≤ .015). Highest values were noticed immediately after surgery. Postoperative S100B was elevated after 15 (40.5%) surgeries in neonates. There was no difference in pre-, intra-, or postoperative cerebral oxygenation. In infants, postoperative S100B was elevated after 23 (41.8%) procedures. Preoperative cerebral oxygen saturations tended to be lower (53 ± 12% vs 59 ± 12%, P = .069) and arterial-cerebral oxygen saturation difference was higher (35 ± 11% vs 28 ± 11%, P = .018) in infants with elevated postoperative S100B. In the early postoperative course, cerebral oxygen saturation was lower (54 ± 13% vs 63 ± 12%, P = .011) and arterial-cerebral oxygen saturation difference was wider (38 ± 11% vs 30 ± 10%, P = .008). Cerebral oxygen saturation was also lower for the entire postoperative course (62 ± 18% vs 67 ± 9%, P = .047).
Conclusions: Postoperative S100B was elevated in about 40% of neonates and infants undergoing cardiac surgery. Infants with elevated postoperative S100B had impaired perioperative cerebral tissue oxygenation. No relation between S100B and cerebral oxygenation could be demonstrated in neonates.
Keywords: brain biomarkers; cardiopulmonary bypass; cerebral protection; near-infrared spectroscopy.
© 2019 Wiley Periodicals, Inc.