1999 OPEN FORUM Abstracts

PARTIAL LIQUID VENTILATION: PHYSIOLOGIC DIFFERENCES BETWEEN FRC AND LOW DOSE AMOUNTS WITH EXOGENOUS SURFACTANT.

Patricia A. Meyers RRT, JM Manaligod MD, EM Bendel-Stenzel MD, DR Bing RRT, SC Simonton MD, MC Mammel MD. Infant Pulmonary Research Center, Children's Hospital-St. Paul, Minnesota and Dept. Of Pediatrics, University of Minnesota, Minneapolis, MN.

Introduction: Does low dose partial liquid ventilation (PLV) with perflubron (LiquiVentÒ) and surfactant (SurvantaÒ; S) provide the same level of improvement in lung injured animals as FRC dose with S. We evaluated physiologic responses in 32 surfactant depleted newborn piglets. Method: 32 newborn piglets were sedated, paralyzed, and ventilated using a volume target of 12cc/kg. We induced lung injury, defined as PaO2<60 torr at FiO2 1.0 and lung compliance reduction by > 30%, with repeated saline lavage. After stabilization on CV (Dräger BabylogÒ), we randomized animals to 4 groups of 8 each: conventional ventilation (CV)+S+PLV to FRC(28.5±5.7 mL/kg), high frequency ventilation (HFV; SensorMedics 3100)+S, HFV+S+low PLV (10 mL/kg) and HFV+S+PLV to FRC(27.5±6.8mL/kg) and ventilated for 20 hrs. PLV animals had perfluorocarbon instilled intratracheally. Evaporative loss were replaced hourly by assessing meniscus in ET tube, HFV+S+low PLV received 3ml/kg/hr replacement. We measured arterial blood gases, arterial and central venous pressures, heart rates, and calculated A/a ratio and OI every hour. Ventilators were adjusted as in clinical use. All techniques provided similar physiologic stability. HFV required higher Paw than CV.

Conclusions: Gas exchange and cardiovascular stability was not enhanced by the combination of HFV+PLV. HFV+S+low PLV was not different from other PLV groups.

OF-99-029