Lung compliance as a measure of lung function in newborns with respiratory failure requiring extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) can now be used as an alternative mode of therapy for infants 2.0 kg or more with life-threatening respiratory failure. Current criteria for removal from ECMO are limited. We attempted to determine whether lung compliance (CL) could be used as a sensitive indicator of the neonates' lung improvement while they are on ECMO, as well as a predictor of their ability to tolerate removal from bypass. We obtained serial CL measurements in 13 infants, all of whom weaned successfully from ECMO. All had an initial CL on ECMO of 0.5 ml/cm H2O X kg or less (mean = 0.3), with a final CL of 0.8 ml/cm H2O X kg or more (mean = 1.7). The average change in CL from the initial to the final measurement was 0.6 ml/cm H2O X kg or more (mean = 1.5). CL findings correlated well with estimated bypass, expressed as a percent of cardiac output, and a radiographic score of pulmonary abnormality (r = -.66, p less than .0001, and r = -.52, p less than .0001, respectively). We conclude that CL measurements can be used to monitor clinical improvement in infants on ECMO, to predict their successful removal from bypass, and ultimately to shorten their total time spent on bypass.