Prolonged studies of perfluorocarbon associated gas exchange and of the resumption of conventional mechanical ventilation.
OBJECTIVE
To determine whether oxygenation and lung mechanics are preserved during perfluorocarbon associated gas exchange of 24 hrs duration and after evaporation of perfluorocarbon.


METHODS
Prospective, experimental animal trials.


METHODS
Animal laboratory in a university setting.


METHODS
Ten normal, neonatal piglets weighing 2.5 to 4.5 kg.


METHODS
Ten piglets were anesthetized with fentanyl (25 micrograms/kg/hr), paralyzed with metocurine iodide (0.3 mg/kg) and placed on volume regulated continuous positive pressure breathing instituted at an FIO2 setting of 1.0, tidal volume of 15 mL/kg, respiratory rate of 25 breaths/min and positive end-expiratory pressure of 4 cm H2O. Perfluorocarbon associated gas exchange was initiated by intratracheal instillation of perflouorooctylbromide (30 mL/kg) followed by gas ventilation at the same settings. Evaporative losses were replaced by intratracheal instillation of 2.5 mL/kg/hr of perfluorocarbon. In one group of five piglets, evaporative losses were replaced for 24 hrs until the end of the study. In the other group of five piglets, replacement of perfluorocarbon was discontinued after 2 hrs, although gas ventilation was continued for 24 hrs. Blood gases and lung mechanics were measured in both groups. Histologic evaluation of lungs from both groups of animals was performed.


RESULTS
Airway pressures and blood gases were stable throughout the 24-hr study period in both groups. Airway pressures in the evaporative group increased as evaporation of perfluorocarbon neared completion. There was no hemodynamic deterioration during the 24-hr study period. Histology showed good preservation of lung architecture in both groups.


CONCLUSIONS
Perfluorocarbon associated gas exchange was safe and effective in normal piglets for a period of 24 hrs. Evaporation of perfluorocarbon and resumption of continuous positive pressure breathing was well tolerated.
Salman
N H
NH
School of Medicine and Biomedical Sciences, State University of New York at Buffalo, USA.
Fuhrman
B P
BP
Steinhorn
D M
DM
Papo
M C
MC
Hernan
L J
LJ
Leach
C L
CL
Fischer
J E
JE
D000818:Animals; D001784:Blood Gas Analysis; D005069:Evaluation Studies as Topic; D005240:Feasibility Studies; D005466:Fluorocarbons / Q000009:adverse effects / Q000627:therapeutic use*; D008168:Lung / Q000187:drug effects / Q000473:pathology; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D015656:Respiratory Mechanics / Q000187:drug effects; D013552:Swine; D013997:Time Factors
D005466:Fluorocarbons