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 underw ent reparative cardiac operations at less than 9 months of age after use of the alpha-stat versus pH-stat strategy during deep hypothermic cardiopulmo nary bypass. Methods: Among 168 children eligible for follow-up, 1-year developmental ev aluations were carried out on 111, neurologic evaluations on 110, and elect roencephalographic evaluations on 102. Parents of 122 children completed qu estionnaires 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 tetralo gy of Fallot (n = 36) subgroups, the pH-stat group had slightly higher Ment al Development Index scores than the alpha-stat group, although these diffe rences were not statistically significant. In the ventricular septal defect subgroup (n = 16), the alpha-stat group had significantly higher scores. P sychomotor Development Index and Mental Development Index scores were signi ficantly higher in the group with D-transposition of the great arteries tha n in the other 2 groups (P = .03 and P = .01, respectively). Across all dia gnoses, Mental Development Index scores were significantly higher than Psyc homotor 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 wit h 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 cardiopu lmonary bypass was not consistently related to either improved or impaired early neurodevelopmental outcomes.