Mechanism of acute lung injury caused by inhalation of fabric protector and the effect of surfactant replacement

Abstract

Objective: To evaluate the role of surfactant in the mechanism and treatment of acute lung injury caused by inhalation of fabric protector. Design: Prospective, randomized study. Setting: University laboratory. Interventions: In vitro experiment: a porcine surfactant suspension (10 mg · ml-1) was exposed to a fabric protector aerosolized with an ultrasonic nebulizer for 1 min. Minimum surface tension (γ min) was sequentially measured using pulsating bubble equipment. Animal experiment: 14 adult rats were anesthetized with pentobarbital and mechanically ventilated with pure oxygen. Then, all rats inhaled fabric protector aerosolized with the nebulizer for five breaths. Three hours after inhalation, the rats were randomly assigned to two groups: a surfactant group (n = 7), in which surfactant (100 mg · kg-1 was replaced, and a control group (n = 7), in which no substance was given. Measurements and results: In vitro experiment: exposure to fabric protector aerosol increased the mean γ min of the surfactant from 1.7 to 19.2 mN · m-1 (n = 5, p < 0.05). Animal experiment: the mean partial pressure of oxygen in arterial blood (PaO2) in all rats decreased from 62.8 to 17.1 kPa at 3 h after inhalation. The PaO2 in the surfactant group increased to 49.8 ± 11.1 (SD) kPa at 30 min after surfactant replacement (p < 0.05), while the PaO2 in the control group remained below 20 kPa. Conclusions: Impairment of surfactant is a factor involved in the development of acute lung injury caused by inhalation of fabric protector. Surfactant replacement may be therapeutic for such injuries.