INTRATRACHEAL PERFLUOROCARBON ADMINISTRATION COMBINED WITH MECHANICALVENTILATION IN EXPERIMENTAL RESPIRATORY-DISTRESS SYNDROME - DOSE-DEPENDENT IMPROVEMENT OF GAS-EXCHANGE

Objectives: To test the efficacy of intratracheal instillation of a pe rfluorocarbon, combined with conventional mechanical ventilation, as w ell as to establish the dose response of this application on pulmonary parameters in adult animals with acute respiratory failure. Design: P rospective, randomized, placebo-controlled study. Setting: Anesthesiol ogy laboratory of a university. Subjects: Twelve, adult male New Zeala nd rabbits. Interventions: After inducing respiratory failure by repea ted lung lavage with saline, one group of animals was treated with per fluorocarbon, while another group was treated with saline to serve as controls (n = 6 per group). Treatment consisted of intratracheal insti llation of incremental doses of 3 mL/kg of each liquid up to a total v olume of 15 mL/kg. Animals were mechanically ventilated for 15 mins af ter each treatment dose with volume-controlled ventilation, a tidal vo lume of 12 mL/kg, frequency of 30 breaths/min, FIO2 of 1.0, and a posi tive end-expiratory pressure of 6 cm H2O. Measurements and Main Result s: Arterial blood gases and lung mechanics were determined. In the per fluorocarbon group, PaO2 increased with increases in dosage from 75 +/ - 15 to 420 +/- 27 torr (10.0 +/- 2.0 to 55.9 +/- 3.6 kPa); PaCO2 decr eased from 49 +/- 6 to 43 +/- 5 torr (6.5 +/- 0.8 to 5.7 +/- 0.6 kPa) after the first dose, and remained stable thereafter. Airway pressures were significantly lower after treatment compared with pretreatment v alues. Conclusion: The remarkable improvements in pulmonary parameters suggest that this type of ventilatory support offers an effective and simple method of perfluorocarbon application in acute respiratory fai lure.