Extracorporeal membrane oxygenation for severe respiratory failure in newborn infants

A complex life support procedure, called extracorporeal membrane oxygenation (ECMO), can be used in infants who are near term age to overcome severe, potentially reversible breathing problems. ECMO is similar to the technology used in cardiac bypass surgery. Blood is removed from the body of the patient, oxygen is added to the blood, and the blood is returned to the patient. Although the number of babies requiring ECMO is small, and ECMO is a very invasive and potentially expensive procedure, the benefits of this procedure are high. In this review, four randomized trials that compared the use of ECMO to the conventional approach to supporting these infants with severe breathing problems were identified. Overall, these trials showed a strong benefit for ECMO regarding survival at the time of hospital discharge. This is particularly true for infants without a specific problem of lung formation (congenital diaphragmatic hernia). The result implies that for every three babies with breathing problems and lung failure who were treated with ECMO rather than conventional ventilation, one more infant will survive. Although little information is available regarding long-term follow-up, one trial in the United Kingdom shows both benefits of ECMO and cost-effectiveness of the use of ECMO.

Authors' conclusions: 

A policy of using ECMO in mature infants with severe but potentially reversible respiratory failure results in significantly improved survival without increased risk of severe disability. The benefit of ECMO for babies with diaphragmatic hernia is unclear.

Further studies are needed to consider the optimal timing for introducing ECMO; to identify which infants are most likely to benefit; and to address the implications of neonatal ECMO during later childhood and adult life.

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Background: 

Neonatal extracorporeal membrane oxygenation (ECMO) is a complex procedure of life support used in severe but potentially reversible respiratory failure in term infants. Although the number of babies eligible for ECMO is small and the use of ECMO invasive and potentially expensive, its benefits may be high.

Objectives: 

To determine whether ECMO used for neonatal infants with severe respiratory failure is clinically and cost effective compared to conventional ventilatory support.

Search strategy: 

The Cochrane Neonatal Group Specialised Register, the Cochrane Controlled Trials Register, and MEDLINE were searched for 1974 to 2007.

Selection criteria: 

All randomised trials comparing neonatal ECMO to conventional ventilatory support.

Data collection and analysis: 

The authors independently evaluated the trials for methodological quality and appropriateness for inclusion in the Review (without consideration of their results) and independently extracted the data.

Main results: 

The four trials (three USA and one UK) recruited clinically similar groups of babies. Two trials excluded infants with congenital diaphragmatic hernias. In two trials, transfer for ECMO implied transport over long distances. Two trials had follow-up information. One study included economic evaluation.

The three USA trials had very small numbers of patients. Two trials used conventional randomisation with low potential for bias. Two used less usual designs, which led to difficulties in their interpretation.

All four trials showed strong benefit of ECMO on mortality (typical RR 0.44; 95% CI 0.31 to 0.61), especially for babies without congenital diaphragmatic hernia (typical RR 0.33, 95% CI 0.21 to 0.53).

The UK trial provided follow up information about death or severe disability, and cost-effectiveness, and showed benefit of ECMO at one year (RR 0.56, 95% CI 0.40 to 0.78), four years (RR 0.62, 95% CI 0.45 to 0.86), and seven years (RR 0.64, 95% CI 0.47 to 0.86). Overall nearly half of the children recruited had died or were severely disabled by seven years of age, reflecting the severity of their underlying conditions. A policy of ECMO is as cost-effective as other intensive care technologies in common use.