Objective: Before the use of extracorporeal membrane oxygenation (ECMO), infants with a severe form of congenital diaphragmatic hernia (CDH) had a high mortality and morbidity. Recent studies have shown an improvement in the survival of these infants after ECMO treatment; however, the existing data do not provide sufficient informations regarding the quality of survival and developmental outcome of these infants. The objective of this study was to evaluate survival, intracranial lesions, and the neurodevelopmental outcome of infants with CDH treated with ECMO.
Methods: We retrieved data for 51 (n = 51) infants with CDH who were treated with ECMO at Huntington Memorial Hospital between 1985 and 1994. Their mean gestational age was 38.5 +/- 2.4 weeks (mean +/- SD); their mean birth weight was 3170 +/- 620 gm. Vital signs, arterial blood gases, chest radiographs, cranial and cardiac ultrasonography were routinely obtained before ECMO treatment. Cranial ultrasounds were performed daily on all infants while on ECMO; computerized tomography scans were obtained on all infants after completion of ECMO treatment. The surviving infants were followed at our neonatal follow-up clinic for neurodevelopmental assessment.
Results: A total of 39 infants were placed on venoarterial ECMO and 12 infants were placed on venovenous ECMO; a total of 35 infants had CDH repair before ECMO, whereas 16 infants had delayed surgery. A total of 31 infants (61%) survived. The infants who survived had a mean pH of 7.33 +/- 0.20, mean airway pressure of 19.6 +/- 5.8 cm H2O, and an oxygenation index (OI) of 87 +/- 55 before ECMO intervention. The infants who expired (n = 20) had a mean pH of 7.31 +/- 0.15, mean airway pressure of 23.1 +/- 5.5 cm H2O, and a mean oxygenation index of 127 +/- 56 before ECMO treatment. Before ECMO, survivors had a significantly lower oxygenation index and a higher Pao2 compared with nonsurvivors (p < 0.01). A total of 18 infants (35%) had abnormal central nervous system findings. Of the 51 infants, 10 had ventricular dilatation, 6 had intracranial hemorrhage, and 11 had focal or diffuse cerebral atrophy diagnosed by computerized tomography scan or at autopsy (1 patient had an infarct). Eight infants had more than one central nervous system abnormality. A total of 16 survivors had a neurodevelopmental evaluation at 12 months, and 11 of these survivors were evaluated at 24 months of age (Bayley Scales of Infant Development). The developmental progress of these infants falls within the low-average range of cognitive and motor abilities. Their mean Bayley Mental Developmental Index was 85 +/- 25 (50 to 145) at 24 months; their Psychomotor Developmental Index was 89 +/- 21 (50 to 113) at 24 months of age. Follow-up at 4 and 6 years of age is in progress.
Conclusion: Our preliminary findings indicate that 35% of infants with severe CDH requiring ECMO had central nervous system abnormalities (intracranial lesions, including ventricular dilatation). The survival rate in our study population is consistent with recent reports. As a group, infants with severe CDH display mild neuromotor and cognitive delay in development at 24 months of age.