Intraoperative Mild Hyperglycemia Associated With Better Outcomes Role of Intraoperative and Postoperative Blood Glucose Concentrations in Predicting Outcomes After Cardiac Surgery

Background: Surgery for congenital heart disease (CHD) in infancy is associated with brain injury and neurodevelopmental deficits in up to 50% of the infants who have had cardiac surgery. Younger infants are more vulnerable to the effects of cardiopulmonary bypass and changes in perfusion/oxygenation, and they undergo more complex procedures. Objective: To examine the published literature related to motor and cognitive development in infants who had heart surgery during the first 6 months of life. Design: Meta-analysis and literature review. Methods: The literature search resulted in 327 randomized or prospective observation studies from 1988 to 2008 including 65 reviews. Two independent investigators retrieved pertinent cognitive and motor outcome data, which were divided by age into 3 groups: early development (1 to <3 years); preschool age (3 to 5 years); and school age (>5 to 17 years). Cognitive and motor outcomes were assessed using the Bayley Scales of Infant Development. The latest neurological evaluation was used for the specific age group. Studies with the same outcome were combined, and a weighted estimate of mean outcome was reported. Heterogeneity between studies was assessed, and possible causes of heterogeneity were explored. Results: 25 articles included and described data on 8 cohorts in multiple publications. For children 1 year of age, the average cognitive score (Mental Development Index) was 90.3 (95% CI, 88.9 to 91.6), which is about 1 SD of the test mean, and the motor score (Psychomotor Development Index) was 78.1 (95% CI, 76.4 to 79.7), which is about 2 SD of the test mean. There were only few studies on preschool and school-age children; therefore, the analysis was limited. Conclusions: Children that had CHD surgery at <1 year of age are at risk of cognitive and motor development deficits. The etiology of these deficits is multifactorial. Vulnerability of white matter to injury during the first months of life, as well as the complexity of surgical techniques, may be contributing factors. The predictive value of the testing scores has been questioned, and early delays do not always predict later problems. Reviewer's Comments: CHD surgery during infancy leaves children with intellectual, cognitive, and developmental limitations. The nature of these conditions is multifactorial and is not very well understood. Underlying preoperative defect, intraoperative insults, and later environmental factors may play a role in their pathogenesis. The validity of current tests to diagnose these conditions and predict future problems is also limited by the great variability of the tests during early stages of life and the nonlinear patterns of development. (Reviewer-Ioanna Apostolidou, MD).