Objective: To investigate the effect of an intratracheal surfactant fog on oxygenation, blood pressure, distribution, and recovery rate as a pilot study to intratracheal surfactant aerosol.
Design: Prospective, randomized study.
Setting: University laboratory.
Subjects: A total of 15 New Zealand White rabbits.
Interventions: The anesthetized ventilated rabbits were surfactant-deprived by repeated lung lavages and then received 200 mg/kg of a 99mTc-labeled porcine surfactant (Curosurf) either as bolus or as intratracheal surfactant fog.
Measurements and main results: Blood gases and pressure were measured and distribution as well as recovery rate of the surfactant determined by means of the radio label (gamma camera images and lung processing with subsequent gamma counter measurements). Respiratory function normalized immediately, no difference could be found between the two groups with regard to PaO2, PaCO2, and blood pressure. Even distribution of the radiolabel was found with both methods, the bolus group showing a higher percentage of lung pieces with label concentrations of double average or more. Recovery rates were 82.5%+/-13.1% (mean +/- SD) in the bolus group and 86.5%+/-7.7% in the fog group.
Conclusion: Endotracheal surfactant fog application is as effective as bolus instillation and may have a role in the treatment of adult respiratory distress syndrome. It has to be considered as a first step in producing an effective aerosol.