Removal of contrast media by different extracorporeal treatments.
BACKGROUND
Although the capability of extracorporeal treatments after administration of contrast media to prevent radiocontrast-induced nephropathy is controversial, haemodialysis is performed in many institutions after radiographic procedures. There are conflicting reports on the efficacy of different dialysers and treatment modalities to remove contrast media.


METHODS
We compared the contrast medium-removing ability of different extracorporeal treatments in a randomized trial. Thirty-nine patients on chronic renal-replacement therapy or with chronic renal failure were randomized to receive low-flux haemodialysis (Low-HD, n=10), high-flux haemodialysis (High-HD, n=10), online haemodiafiltration (HDF, 10 litre substitution, n=10) and online haemofiltration (HF, 18 litre substitution, n=9) after administration of contrast medium during routine radiological procedures. Plasma concentrations of contrast medium (iopromide or iomeprol) were measured by energy-dispersive X-ray fluorescence analysis.


RESULTS
The extraction ratio for contrast media was 0.64+/-0.1 for Low HD (P<0.05 vs. High-HD and vs. HDF), 0.74+/-0.1 for High-HD (P<0.05 vs. HF), 0.81+/-0.1 for HDF (P<0.05 vs HF), and 0.62+/-0.1 for HF. Mean extracorporeal plasma clearances were 82+/-2 for Low-HD (P<0.05 vs. High-HD and vs HDF), 100+/-2 for High-HD, 115+/-4 for HDF (P<0.05 vs. HF), and 86+/-5 ml/min for HF.


CONCLUSIONS
We conclude that HDF and High-HD remove contrast media more effectively than Low-HD and HF during the time of each treatment session. However, whether this is also true for the overall elimination of contrast media by these different procedures needs to be addressed in future studies, by a precise assessment of the drug time course after the session.