Initial experience with partial liquid ventilation in pediatric patients with the acute respiratory distress syndrome

Objective: Liquid ventilation with perfluorocarbon previously has not been reported in pediatric patients with respiratory failure beyond the neonatal period. We evaluated the technique of partial liquid ventilation in six pediatric patients with the acute respiratory distress syndrome of sufficient severity to require extracorporeal life support (ECLS). Design: This study was a noncontrolled, phase I/II experimental study with a single group pretest/posttest design. Setting: All studies were performed at a tertiary, pediatric referral hospital at the University of Michigan Medical School. Patients: Six pediatric patients, from 8 wks to 5 1/2 yrs of age, with severe respiratory failure requiring ECLS to support gas exchange. Interventions: After 2 to 9 days on ECLS, perfluorocarbon was administered into the trachea until the dependent zone of each lung was filled. The initial dose administered was 12.9 +/- 2.3 mL/kg (range 5 to 20). Gas ventilation of the perfluorocarbon filled lungs (partial liquid ventilation) was then performed. The perfluorocarbon dose was repeated daily for a total of 3 to 7 days, with a cumulative dose of 45.2 +/- 6.1 mL/kg (range 30 to 72.5). Measurements and Main Results: All measurements of native gas exchange were made during brief periods of discontinuation of ECLS and include PaO2 and the alveolar-arterial oxygen gradient, P(A-a)O-2. Static pulmonary compliance, corrected for weight, was also measured directly. The mean PaO2 increased from 39 +/- 6 to 92 +/- 29 torr (5.2 +/- 0.8 to 12.2 +/- 3.9 kPa) over the 96 hrs after the initial dose (p = .021 by repeated-measures analysis of variance). The average P(A-a)O-2 decreased from 635 +/- 10 to 499 +/- 77 torr (84.7 +/- 1.3 to 66.5 +/- 10.3 kPa) over the same time period (p = .059), while the mean static pulmonary compliance (normalized for patient weight) increased from 0.12 +/- 0.02 to 0.28 +/- 0.08 mL/cm H2O/kg (p = .01). All six patients survived. Complications potentially associated with partial liquid ventilation were limited to pneumothoraces in two of six patients. Conclusions: Perfluorocarbon may be safely administered into the lungs of pediatric patients with severe respiratory failure on ECLS and may be associated with improvement in gas exchange and pulmonary compliance.