Venovenous versus venoarterial extracorporeal life support for pediatric respiratory failure: Are there differences in survival and acute complications?

Objectives: To examine the Extracorporeal Life Support Organization (ELSO) registry database of infants and children with acute respiratory failure to compare outcome and complications of venovenous (VV) vs. venoarterial (VA) Extracorporeal Life Support (ECLS). Design: Retrospective cohort study. Setting: ELSO registry for pediatric pulmonary support. Patients: All nonneonatal pediatric pulmonary support ECLS cases treated at U.S. centers and reported to the ELSO registry as of July 1997, Patients w ere excluded if they had one or more of the following diagnoses: hematologi c-oncologic, cardiac, abdominal surgical, burn, metabolic, airway, or immun odeficiency disorder, Interventions: Venoarterial or venovenous extracorporeal life support for s evere pulmonary failure. Measurements and Main Results: From 1986 to June of 1997, 763 pediatric pat ients met the inclusion criteria. Overall, 595 were initially managed with VA bypass, and 168 with VV bypass, The VA group was younger (mean a so, 26. 1 +/- 42.2 months for VA vs. 63.5 +/- 68.7 months for VV) and smaller (11.8 +/- 15.1 kg vs. 22.9 +/- 23.8 kg) (p < .001). There were no differences be tween groups in number of days on mechanical ventilation before ECLS, numbe r of hours on ECLS, or number of hours on mechanical ventilation post-ECLS in survivors. Mean pH and Pace, values, positive end-expiratory pressure, a nd mean airway pressure just before placing the patient on ECLS were also s imilar. VA-treated patients had higher FIO2 requirements (p = .034), lower PaO2 (p = .047), and lower PaO2/FIO2 ratio (p = .014) just before cannulati on, There was a trend of higher peak inspiratory pressure in VA-treated pat ients (p = .053), Overall, survival rate was not different for the two grou ps (55.8% for VA vs, 60.1% for VV; p = .33). Central nervous system complic ations were not different between the two groups, Examination of the same v ariables was then conducted after dividing the patients into four subgroups . There were no significant differences in survival or complications during bypass between VV and VA modes of ECLS in any subgroup. Stepwise logistic regression modeling was performed to control for variables associated with the outcome survival for VV and VA-treated groups, and variables measured b efore bypass were identified as being associated with improved survival. Th ere was a trend of improved survival in the W-treated patients (p = .12). Conclusions: Overall survival of pediatric patients with acute respiratory failure supported by VA or VV ECLS was comparable. A randomized clinical tr ial may be useful in clarifying these observations.