[Experimental study on the treatment of smoke inhalation injury with lung lavage and exogenous pulmonary surfactant].

To investigate the prevention and treatment effects of lung lavage and exogenous pulmonary surfactant (PS) on endogenous surfactant system dysfunction and acute respiratory failure caused by severe smoke inhalation, Wistar rats were randomly divided into five groups: Group I, normal control; Group II, smoke inhalation; Group III, smoke + lavage + PS + mechanical ventilation (MV); Group IV, smoke + lavage + MV; Group V, smoke + MV. The lungs were lavaged with 30 ml/kg 0.9% NaCl containing 100 mg/kg PS or same volume of saline via tracheal catheter at 5 min after smoke inhalation, then the animals were placed on a ventilator for 4 h, and observed until 24 h postinjury. The arterial blood gas levels, lung water volume, static lung compliance (Cst), total protein and albumin contents in bronchoalveolar lavage fluid (BALF), surface tension properties of BALF, and fatality rate at 24 h were measured. Smoke inhalation caused a similar acute hypoxia and severe carbon monoxide poisoning immediately in all injuried groups. The animals in group II showed acute respiratory failure, serious high permeability pulmonary edema, and surfactant system dysfunction. The surface tension properties of BALF, Cst, and the oxygenation were significantly improved with lung lavage and exogenous PS treatment. The lung water volume, total protein and albumin contents in BALF were decreased dramatically in this group. The fatality rate at 24 h declined markedly only in group III. It was suggested that lung lavage and exogenous surfactant treatment trestores effectively endogenous surfactant function inhibited by smoke inhalation, improves lung function, prevents high permeability pulmonary edema and respiratory failure, and decreases the mortality in early stage after smoke inhalation injury.