Objective: To ascertain the relation between postoperative neurologic complications and variables occurring before, during, and after hypothermic cardiopulmonary bypass surgery to correct congenital heart disease in young infants.
Design: Prospective analysis of mortality and neurologic morbidity before hospital discharge; systematic comparison with patient characteristics, metabolic status, surgery variables; and preoperative neurologic findings of the patients.
Setting: Intensive care unit in tertiary care center.
Patients: Consecutive sample of 91 full-term infants who underwent 100 operations between January 1989 through December 1992. Nine infants had more than one operation during the study period.
Main outcome measures: Levels of alertness, tone, focal signs, dyskinesia, pyramidal signs, seizures, and death.
Results: Reduced level of alertness at discharge from the hospital in 19% of patients; seizures in 15% (70% focal); severe hypotonia in 11% before surgery, and in 7% at discharge from hospital; generalized pyramidal findings in six (7%); asymmetry of tone in 5%; and chorea that did not persist in 11%. Results of cranial ultrasound tests were abnormal in 20% of patients. Of these those with abnormal cranial ultrasound examinations 55% were abnormal before surgery. Overall mortality was 18%. Of the patients who died, 59% had interrupted aortic arch or hypoplastic left heart syndrome. Mortality for patients with these lesions was 40%. Alertness (P = .005), chorea (P = .03), and hypotonia (P = .02) were associated with duration of deep hypothermia longer than 60 minutes. No association was found among other outcomes and study variables, except the relation between severe left-sided heart lesions and mortality.
Conclusions: Mortality and neurologic morbidity after open heart surgery on young infants may be due to several factors, including type of lesion, preexisting brain abnormalities, duration of deep hypothermia, and strokes.