A morphologic study of long-term retention of fluorocarbon after liquid ventilation

Study objectives: To determine how long perfluorinated hydrocarbons remain in the lung after they are used for lung ventilation in dogs, and to determ ine if residual perfluorinated hydrocarbons cause structural alteration or an inflammatory reaction of the lung. Design: Adult dogs were anesthetized and received ventilation with oxygenat ed perfluorinated hydrocarbon liquid. Morphologic studies of tissue from th e lungs of these dogs were performed at intervals of a few minutes to 10 ye ars after reconversion to breathing gas. Setting: University College of Medicine. Participants: Adult mongrel and beagle dogs. Interventions: Anesthetized adult dogs breathed oxygenated Liquid fluorocar bons for 1 h and then were reconverted to breathing air. Three fluorocarbon s, FX-80 (C8F16O; 3M company; St. Paul, MN), Caroxin-D (C10F22O2; P-1D; All ied Chemical Company; Morristown, NJ), and Caroxin-F (C9F20O; P-12F; Allied Chemical Company), were used. Morphologic studies of the lungs of these an imals were performed immediately after restoration of air breathing and at intervals for up to 10 years. Not all animals were studied at each time int erval. Measurements and results: A transient, acute inflammatory reaction was foll owed by a massive influx of macrophages, which were at first intra-alveolar and later interstitial, especially around vessels and bronchioles. Fluoroc arbons remained in the lung in diminishing amounts for at least 5 years, as evidenced by persistent vacuolated macrophages in the alveoli, interstitiu m, and hilar lymph nodes; fluorocarbon was also detected in these tissues b y chemical assays. in no case was there fibrosis or any other structural al teration associated with the residual fluorocarbon, which suggests that it was inert. At 10 years, no evidence of residual fluorocarbon was seen morph ologically.