Iodixanol inhibits exogenous surfactant therapy in rats with acute respiratory distress syndrome

Abstract

Optimal alveolar distribution of exogenous surfactant is an important determinant of its beneficial effect. This distribution can be determined by suspending surfactant in a radiological contrast medium before intratracheal instillation, followed by radiological imaging. Iodixanol is reported to be a safe contrast medium that causes no lung injury when instilled intratracheally.In this study, the effects of surfactant suspended in saline were compared with surfactant suspended either in 4:1 saline-iodixanol (64 mg iodine?mL -1 ) or in 1:1 salineiodixanol (160 mg iodine?mL -1 ), on oxygenation and lung mechanics in a rat model of adult respiratory distress syndrome (ARDS) induced by lung lavage.After the induction of ARDS, surfactant instillation improved oxygenation, total lung volume at inflation with a distending pressure of 35 cmH 2 O, lung volume at transpulmonary pressure of 5 cmH 2 O and Gruenwald index. The effects of surfactant suspended in 4:1 saline-iodixanol were similar to those of surfactant alone. However, instillation of surfactant suspended in 1:1 saline-iodixanol resulted in significantly lower values in all measured parameters. Surface tension was the lowest in surfactant suspended in saline alone and addition of iodixanol led to an increase in surface tension in a dose-dependent manner.In conclusion, iodixanol at the higher dose caused an inhibition of the exogenous surfactant effect, characterized as a lack of improvement in oxygen tension in arterial blood, low total lung compliance, volume at 5 cmH 2 O end-expiration and Gruenwald index. This effect of iodixanol was probably due to its high surface tension, especially if a high concentration was used. Surfactant suspended in a lower concentration of iodixanol seems a better alternative, allowing for radiological imaging of the distribution of surfactant when intratracheally instilled.

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

“…It is also time‐dependent and variable, depending on the type of contrast medium used. Based on previous findings the concentrations of the different contrast media used in the present study were 60–70 mg iodine ml −1 (Kesecioglu et al. , 2002).…”

“…However, there are no data on the effect of contrast media when instilled or accidentally ingested into lungs with acute respiratory distress syndrome (ARDS). In an ARDS model in rats which is always associated with capillary leakage in the lungs, it has been recently demonstrated that exogenous surfactant dissolved in 160 mg iodine ml −1 Visipaque ® (iodixanol) resulted in an increase of surface tension, which in turn inhibited the exogenous surfactant activity (Kesecioglu et al. , 2002).…”

Improved Electrophoretic Deposition of Vertical Single Wall Carbon Nanotubes with Nanoscopic Electrostatic Lenses

“…Thus, the true external diameter was about 1.2 nm. The nanotubes were in a suspension of 0.15 mg/mL with 1% mass/volume sodium deoxycholate surfactant (SDC) (24 mM) and 6-7% mass/volume iodixanol salt (IS) [27]. The lengths were measured in the SEM as previously described to be 83 ± 26 nm.…”