Influence of Iodixanol‐270 and Iopentol‐150 on the microcirculation in man: influence of viscosity on capillary perfusion

Purpose, Material and Methods: The aim of this study was to investigate the influence of direct intraarterial application of the contrast agents Iodixanol‐270 and Iopentol‐150 on the capillary perfusion. This was accomplished through continuous recording of the capillary perfusion in the nailfold capillaries of the right hand before and after a bolus injection of 20 ml of contrast agent into the right axillary artery.

Results: After injecting 20 ml of Iodixanol‐270, which has a high viscosity compared to the plasma viscosity, a statistically significant decrease in the erythrocyte velocity of 60.8% from 0.439\pm 0.273 mm/s to 0.172\pm 0.090 mm/s was observed already 10 s after the injection ( p=0.0001 ). The decreased velocity was maintained until the end of the observation period of 6 min. In contrast to this finding, no change in the erythrocyte velocity was observed after injection of 20 ml of the low‐viscous Iopentol‐150 ( p=0.1508 ).

Conclusions: The erythrocyte velocity in cutaneous capillaries therefore strongly depends on the viscosity of the contrast agent.