Prediction of mortality in neonates with congenital diaphragmatic hernia treated with extracorporeal membrane oxygenation.

OBJECTIVE

To determine if data collected by the Extracorporeal Life Support Organization Registry could be used to identify neonates with congenital diaphragmatic hernia who had a > 90% mortality rate, despite the use of extracorporeal membrane oxygenation (ECMO) support.

DESIGN

We retrospectively reviewed data reported to the Extracorporeal Life Support Organization Registry on neonates with congenital diaphragmatic hernia.

PATIENTS

Data regarding 1,089 neonates with congenital diaphragmatic hernia reported to the Extracorporeal Life Support Organization Registry between 1980 and 1992 formed the basis of this study. All of the neonates studied had been treated with ECMO. This patient population includes neonates with right- and left-sided diaphragmatic hernia. This registry does not include neonates with congenital diaphragmatic hernia who were not treated with ECMO.

MEASUREMENTS AND MAIN RESULTS

Of 1,089 neonates with congenital diaphragmatic hernia, 679 (62%) survived. There were no differences between the two groups in gender or in the year they were treated. Survival rate did not significantly increase over the years between 1980 and 1992. When compared with survivors, nonsurvivors were more immature (38 +/- 2 vs. 39 +/- 2 wks; p = .01), had lower birth weights (3.0 +/- 0.5 vs. 3.21 +/- 0.53 kg; p = .001), were more often prenatally diagnosed (42% vs. 32%; p = .03), were cannulated at a younger age (31 +/- 54 vs. 40 +/- 50 hrs; p = .01), and had more severe respiratory compromise (higher peak pressures and PaCO2, lower PaO2 values). Multivariate analysis showed that arterial pH and PaO2 just before ECMO, and birth weight, had the highest discriminant coefficients. By using these variables in a discriminant function (D[fx] = 0.68 x pH + 0.62 x birth weight + 0.29 x PaO2; using standardized coefficients and variables), we could identify neonates who died with a sensitivity of 62%, a specificity of 63%, a positive-predictive value of 50%, and a negative-predictive value of 74%. No single variable or combination of variables yielded better results.

CONCLUSIONS

Although a number of factors identify neonates with diaphragmatic hernia as being at higher risk of dying despite ECMO support, data currently collected by the neonatal Extracorporeal Life Support Organization Registry do not allow clinicians to effectively discriminate nonsurvivors from survivors.