Outcomes of Infants Weighing Three Kilograms or Less Requiring Extracorporeal Membrane Oxygenation After Cardiac Surgery

BACKGROUND:

Extracorporeal membrane oxygenation (ECMO) is the most common form of cardiac support for postcardiotomy cardiac failure in children. While its benefits have been thoroughly explored in infants weighing more than 3kg, similar analyses are lacking in lower weight neonates. This single-center study investigated outcomes and risks for poor survival among infants weighing 3 kg or less.

METHODS:

A retrospective review of infants 3 kg or less who required postcardiotomy ECMO support was performed (January 1, 1999 to December 31, 2010). Primary outcome was 30-day survival after decannulation. Factors analyzed for association with poor outcome included demographics, cardiac anatomy, bypass and circulatory arrest times, total ECMO support time, postoperative lactate, inotrope use, and need for renal replacement therapy.

RESULTS:

During the study period, 64 patients weighing 3 kg or less required postcardiotomy ECMO. Median gestational age and age at ECMO initiation were 38 weeks (interquartile range, 36 to 39) and 7 days (interquartile range, 4 to 9), respectively, with median ECMO support time of 164 hours (interquartile range, 95 to 231). Overall 30-day survival after decannulation was 33%. Factors associated with poor outcome were longer duration of support (231 hours or more, 12% survival, versus less than 231 hours, 40% survival; p = 0.05) and renal replacement therapy (n = 36, survival 17% versus 54%; p = 0.002). Multivariable regression analysis identified renal replacement therapy as the only independent factor associated with poor survival (odds ratio 4.3, 95% confidence interval: 1.3 to 14.9, p = 0.02).

CONCLUSIONS:

For infants weighing 3 kg or less, 30-day survival after decannulation after cardiac ECMO is poor. Factors associated with poor prognosis were need for renal replacement therapy and longer duration of ECMO support. These findings may provide a useful guide for medical decision making among this unique, high-risk patient group.