Analysis of an improved survival rate for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a condition associated with significant mortality. This study examines the survival rate of neonates with CDH treated by a multidisciplinary team in a single pediatric hospital. Actual survival rate is compared with predicted outcome based on severity of illness.

A consecutive series of neonates with CDH was evaluated beginning January 1, 2000. There were no excluded patients. A treatment protocol emphasizing minimal barotrauma and control of pulmonary hypertension was used. Predicted survival rate was estimated using birth weight and Apgar score at 5 minutes per the logistic regression equation published by the CDH Study Group. Actual survival rates were calculated and compared with predicted values using a one sample binomial test with significance deemed to be present at P less than.05.

Thirty-six of 39 (93%) neonates with CDH survived, whereas the predicted survival rate for this cohort was 68% (P <.001). Twelve of 14 (86%) neonates requiring extracorporeal membrane oxygenation (ECMO) survived, despite a predicted survival rate of 52% for this subset (P <.01). Twenty-five percent of survivors required supplemental oxygen at home.

Using a simple analysis, centers may now objectively compare their CDH survival rates with predicted outcomes adjusted for disease severity. This technique confirmed that a consecutive series of neonates with CDH, treated in one hospital, had a significantly higher than predicted survival rate. Thus, it may be possible to identify other centers with higher than expected survival rates and to define common therapeutic strategies associated with decreased mortality.