Intratracheal perfluorocarbon administration combined with mechanical ventilation in experimental respiratory distress syndrome: dose-dependent improvement of gas exchange.

OBJECTIVES

To test the efficacy of intratracheal instillation of a perfluorocarbon, combined with conventional mechanical ventilation, as well as to establish the dose response of this application on pulmonary parameters in adult animals with acute respiratory failure.

DESIGN

Prospective, randomized, placebo-controlled study.

SETTING

Anesthesiology laboratory of a university.

SUBJECTS

Twelve, adult male New Zealand rabbits.

INTERVENTIONS

After inducing respiratory failure by repeated lung lavage with saline, one group of animals was treated with perfluorocarbon, while another group was treated with saline to serve as controls (n = 6 per group). Treatment consisted of intratracheal instillation of incremental doses of 3 mL/kg of each liquid up to a total volume of 15 mL/kg. Animals were mechanically ventilated for 15 mins after each treatment dose with volume-controlled ventilation, a tidal volume of 12 mL/kg, frequency of 30 breaths/min, FIO2 of 1.0, and a positive end-expiratory pressure of 6 cm H2O.

MEASUREMENTS AND MAIN RESULTS

Arterial blood gases and lung mechanics were determined. In the perfluorocarbon 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 decreased 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 values.

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 failure.