Extracorporeal membrane oxygenation in infants with congenital diaphragmatic hernia: a systematic review of the evidence

Abstract

The aim of this study was to evaluate the evidence supporting the use of extracorporeal membrane oxygenation (ECMO) in infants with congenital diaphragmatic hernia and severe respiratory failure. Several databases were searched using a defined strategy. Case reports and opinion articles were excluded. The authors performed a systematic review of nonrandomized studies comparing mortality when ECMO was not available with a period when ECMO was available. Mortality was classified as “early” (before hospital discharge) and “late” (after discharge). Patients were classified as ECMO and non-ECMO candidates according to criteria reported by the authors. The authors also performed a meta-analysis of controlled randomized trials (RCTs) comparing ECMO and conventional mechanical ventilation. Differences in mortality were reported as relative risk (RR) and 95% confidence intervals (CIs). Results: (a) Systematic review: 658 and 21 studies, respectively, including 2043 patients fulfilled the entry criteria. Both early (RR, 0.60; 95% CI, 0.51-0.70; P < .001) and late mortality (RR, 0.63; 95% CI, 0.53-0.73; P < .001) were significantly lower when ECMO was available than when ECMO was not available. This difference in mortality was observed only in ECMO candidates (RR, 0.46; 95% CI, 0.32-0.68; P < .001), but not in non-ECMO candidates (RR, 0.80; 95% CI, 0.58-1.10; P = .17). (b) Meta-analysis: 3 trials comparing ECMO with conventional ventilation including 39 infants were identified. The early mortality was significantly lower with ECMO as compared with conventional mechanical ventilation (RR, 0.73; 95% CI, 0.55-0.99; P < .04). However, late mortality was similar in both groups. It is concluded that nonrandomized studies suggest a reduction in mortality with ECMO. However, differences in indications for ECMO and improvements in other treatment modalities may contribute to this reduction. The meta-analysis of RCTs indicates a reduction in early mortality with ECMO but no long-term benefit. A larger number of RCTs in infants with congenital diaphragmatic hernia and severe respiratory failure are warranted.