The effect of pre-ECLS ventilation time on survival and respiratory morbidity in the neonatal population

Although mechanical ventilation for more than 7 to 10 days has been considered a contraindication to the application of extracorporeal life support (ECLS) in neonates, the outcome and respiratory morbidity for newborns placed on ECLS after more than 7 days of ventilation have not been well characterized. The purpose of this study was to determine the impact of pre-ECLS ventilation time on the rate of survival, the likelihood of the development of bronchopulmonary dysplasia (BPD), and the need for supplemental oxygen at the time of discharge. Examination of the Extracorporeal Life Support Organization (ELSO) Registry showed that 6,110 neonates were treated for respiratory failure with a pre-ECLS ventilation time of less than 14 days between January 1990 and May 1995. Gestational age (GA), birth weight (BW), indication for ECLS, and diagnosis were compared with the rate of survival, the discharge diagnosis of BPD, and the need for home oxygen. The GA and BW of neonates placed on ECLS during the first week of life (n = 5,888) did not differ significantly from those of neonates whose ECLS was begun in the second week of life (n = 222). The neonates were divided into two groups (early, ventilation time of 3 to 6 days; late, ventilation time of 7 to 10 days) to determine the odds ratios for survival, BPD, and home oxygen. Logistic regression analysis was used to develop a model to predict the rate of survival, the risk for the development of BPD, and the need for home oxygen given the length of pre-ECLS ventilation time. The late group was less likely to survive (odds ratio, 1.8; 95% confidence interval [CI], 1.21 to 2.68). The late group also had approximately twice the risk for the development of BPD (odds ratio, 1.9; 95% CI, 1.2 to 3.04) and a trend toward an increased incidence of home oxygen use (odds ratio, 1.55; 95% CI, 0.92 to 2.60). The authors conclude that (1) there is a greater risk of mortality and BPD and a trend toward an increased need for home oxygen with increased time on the ventilator before ECLS; (2) at 14 days the predicted probability of survival is still 53% (95% CI, 31% to 74%); (3) at 14 days the predicted probability of BPD is 54% (95% CI, 28% to 78%); and (4) based on these data, it is reasonable to consider application of ECLS to patients who have had mechanical ventilation for up to 14 days.