Detrimental effects of standard medical therapy in congenital diaphragmatic hernia

Objective: To evaluate the impact of a nonstandard ventilation strategy on survival in congenital diaphragmatic hernia (CDH). Background: Despite recent advances, including nitric oxide, CDH remains an unsolved problem with a mortality rate of 35% to 50%. Hyperventilation and alkalization remain common therapies. Methods: In 1992, the authors prospectively abandoned hyperventilation and alkalization. Patients are lightly sedated and ventilated with the lowest pressure providing adequate chest movement, and the rate is set to patient comfort. Nitric oxide and extracorporeal membrane oxygenation (ECMO) are reserved for life-threatening instability. Surgical repair is delayed 1 to 5 days. Sixty consecutive patients are compared with 29 previous patients treated with hyperventilation and alkalization, 13 before and 16 after the availability of ECMO. Results: Overall, 47 of 60 patients (78%) in study era 3 survived compared with 2 of 13 (15%) in the hyperventilation era and 7 of 16 (44%) in the hyperventilation/ECMO era (p < 0.0001). The disease severity and the incidence of associated anomalies did not differ between groups. To compare management strategies, patients who had treatment withheld because of lethal associated conditions were then removed from analysis. Peak inspiratory pressure and arterial pH were lower (p < 0.0001) and PaCO₂ was higher (p < 0.05) in era 3 than in the previous eras. The rate of pneumothorax (1.9%) decreased (p < 0.0001). In era 3, survival was 47 of 53 (89%) treated patients, and 23 of 25 inborn patients with isolated CDH survived (92%). Conclusions: Nonstandard ventilatory support of patients with CDH has led to significantly improved survival rates. This study sets a survival benchmark and strongly suggests the negative effects of hyperventilation and alkalization.