A novel expiratory circuit for recovery of perfluorocarbon liquid during partial liquid ventilation

Abstract

Objective: To determine whether perfluorocarbon liquid can be condensed from gases containing perfluorocarbon vapour and whether the amount recovered varies with background flow rate. Design and setting: Bench-top experimental study in a neonatal laboratory. Interventions: The expiratory limb of a standard ventilator circuit set-up was mimicked, with the addition of a chilled water jacket (Liebig) condenser. Perfluorocarbon vapour was passed through the circuit at a number of flow rates. Measurements and results: Perfluorocarbon vapour was passed through the circuit and the percentage recovery of liquid measured. More than 60% of the perfluorocarbon vapour was recovered at all flow rates (1, 2, 5 and 10 1/min), with significantly higher recovery obtained (up to 74%) at low flow rates (1 1/min). Conclusions: Using a simple condenser, more than 60% of perfluorocarbon liquid can be recovered without altering the function of an expiratory limb of a ventilator circuit.