Effect of extracorporeal life support on survival when applied to all patients with congenital diaphragmatic hernia

Extracorporeal life support (ECLS) has been used for neonates with congenital diaphragmatic hernia (CDH) and respiratory failure at the authors' hospital since June 1981. In 1988, criteria for inclusion in ECLS were broadened to include "nonhoneymoon" infants (honeymoon: best postductal Pao₂ of > 50 mm Hg). To evaluate the impact of this approach on the treatment of CDH, the authors reviewed the records of all newborns managed at their institution, since the availability of ECLS in 1981, who were symptomatic with CDH in the first 24 hours of life (n = 111). The patients were divided chronologically into two groups: 1981 to 1987 (early ECLS, n = 36) and 1988 to 1993 (expanded ECLS, n = 75). The data demonstrate that the number of CDH patients managed at our institution each year has increased (1981 to 1987 = 6, 1988 to 1993 = 14) as has the severity of associated respiratory insufficiency (% of patients with best Pao₂ of ≤ 50 mm Hg: 1981 to 1987 = 6%, 1988 to 1993 = 28%). Overall, the survival rate was lower for patients in the expanded ECLS group (59% v 75%; P = .121). When the survival rates for patients supported with ECLS postoperatively were compared for the expanded and early groups, a significant difference (59% v 80%; P < .05) was noted. However, when ECLS patients with a best Pao₂ of ≤ 50 mm Hg were excluded from this analysis, there was no significant difference between the two groups (74% v 80%), indicating that the inclusion of nonhoneymoon patients as potential ECLS candidates has accounted for a significant portion of the observed decrease in survival among CDH patients managed with ECLS. The survival rate of salvageable CDH patients with a best Pao₂ of ≤ 50 mm Hg increased slightly for the expanded ECLS group, to 27% (4 of 15), versus 0% (0 of 2) for the early ECLS group. The authors conclude that a change in the population of CDH patients presenting to their institution along with application of ECLS to CDH patients without a honeymoon has resulted in a reduction in the survival rate, but has allowed only a modest 27% survival rate for patients who were previously considered nonsalvageable.