Developmental and neurologic effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants

Objectives: In a randomized single-center trial, we compared developmental and neurologic outcomes at 1 and 2 to 4 years of age in children who underwent reparative cardiac operations at less than 9 months of age after use of the alpha-stat versus pH-stat strategy during deep hypothermic cardiopulmonary bypass. Methods: Among 168 children eligible for follow-up, 1-year developmental evaluations were carried out on 111, neurologic evaluations on 110, and electroencephalographic evaluations on 102. Parents of 122 children completed questionnaires on behavior and development when children were 2 to 4 years of age. Results: The Psychomotor Development Index scores of the alpha-stat and pH-stat groups did not differ significantly (P = .97). For Mental Development Index scores, the treatment group effect differed according to diagnosis (P = .007). In the D-transposition of the great arteries (n = 59) and tetralogy of Fallot (n = 36) subgroups, the pH-stat group had slightly higher Mental Development Index scores than the alpha-stat group, although these differences were not statistically significant. In the ventricular septal defect subgroup (n = 16), the alpha-stat group had significantly higher scores. Psychomotor Development Index and Mental Development Index scores were significantly higher in the group with D-transposition of the great arteries than in the other 2 groups (P = .03 and P = .01, respectively). Across all diagnoses, Mental Development Index scores were significantly higher than Psychomotor Development Index scores (P < .001). Treatment group assignment was not significantly associated with abnormalities on neurologic examination (P = .70) or electroencephalographic examination (P = .77) at 1 year or with parents' ratings of children's development (P = .99) or behavior (P = .27) at age 2 to 4 years. Conclusions: Use of alpha-stat versus pH-stat acid-base management strategy during reparative infant cardiac operations with deep hypothermic cardiopulmonary bypass was not consistently related to either improved or impaired early neurodevelopmental outcomes.