Contrast media inhibit exogenous surfactant therapy in rats with acute respiratory distress syndrome

Abstract

To test the effects of various contrast media on the pulmonary surfactant system. In a rat model of acute respiratory distress syndrome (ARDS) induced by lung lavage, the effects of surfactant suspended in saline were compared with surfactant suspended in the contrast media Visipaque, Gastrografin, Omnipaque, Telebrix M, Telebrix and Hexabrix, to establish their influence on oxygenation and lung mechanics. After the induction of ARDS, surfactant instillation improved oxygenation, total lung capacity (TLC(35)), volume at 5 cm H(2)O end-expiration (V(5)) and Gruenwald index. The effects of Visipaque and Gastrografin were comparable with those of surfactant alone from 90 min onwards and at 120 min, respectively. Surfactant suspended in the other contrast media resulted in significantly lower values in the above-mentioned parameters. Surface tension was lowest in surfactant suspended in saline alone. Surfactant suspended in Visipaque and Gastrografin had lower surface tension compared with surfactant suspended in the other contrast media. The ionic and non-ionic contrast media used in this study, cause an impairment of the physico-chemical behaviour of exogenous surfactant. Therefore, these contrast media cannot be regarded as safe in case of accidental exposure.