Cerebral autoregulation monitoring using the cerebral oximetry index after neonatal cardiac surgery: A single-center retrospective cohort study.

Objective: To investigate whether cerebral autoregulation is impaired after neonatal cardiac surgery and whether changes in autoregulation metrics are associated with different congenital heart defects or the incidence of postoperative neurologic events.
Methods: This is a retrospective observational study of neonates undergoing monitoring during the first 72 hours after cardiac surgery. Archived data were processed to calculate the cerebral oximetry index (COx) and derived metrics. Acute neurologic events were identified by an electronic medical record review. The Skillings-Mack test and the Wilcoxon signed-rank test were used to analyze the evolution of autoregulation metrics over time; the Mann-Whitney U test was used for comparison between groups.
Results: We included 28 neonates, 7 (25%) with hypoplastic left heart syndrome and 21 (75%) with transposition of the great arteries. Overall, the median percentage of time spent with impaired autoregulation, defined as percentage of time with a COx >0.3, was 31.6% (interquartile range, 21.1%-38.3%). No differences in autoregulation metrics between different cardiac defects subgroups were observed. Seven patients (25%) experienced a postoperative acute neurologic event. Compared to the neonates without an acute neurologic event, those with an acute neurologic event had a higher COx (0.16 vs 0.07; P = .035), a higher percentage of time with a COx >0.3 (39.4% vs 29.2%; P = .017), and a higher percentage of time with a mean arterial pressure below the lower limit of autoregulation (13.3% vs 6.9%; P = .048).
Conclusions: COx monitoring after cardiac surgery allowed for the detection of impaired cerebral autoregulation, which was more frequent in neonates with postoperative acute neurologic events.
Competing Interests: Conflict of Interest Statement P.S. reported receiving licensing fees for ICM+ software, licensed by Cambridge Enterprise Ltd, University of Cambridge. A.M. reported serving on an advisory board for Air Liquide for the administration of iNO in cardiac surgery. C.R. reported consulting fees from Masimo. E.B. reported support from the Medical Research Council (Grant MR N013433-1) and the Gates Cambridge Scholarship. G.R.B. has been supported in part by the MacCutcheon Family Foundation (grant No. 44607). The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.
(Copyright © 2023 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)