Haemostatic effects of low osmolar non-ionic and ionic contrast media: a double-blind comparative study

In this prospective, double-blind, randomized study the effects of a non-io nic contrast medium (Iopromide) on the haemostatic system were compared wit h those of a low osmolar ionic medium (Ioxaglate). The aim was to investiga te in vivo whether a non-ionic contrast agent is less anticoagulant or more pro-thrombotic than an ionic medium. A large number of haemostatic paramet ers, including activation markers, were measured. Either Iopromide (n=16; m edian volume 102 ml, 95% confidence interval 90-108 ml) or Ioxaglate (n=15; median 105 ml; 95% confidence interval 95-114 ml) was given to 31 patients scheduled for abdominal and femoral arteriography. Blood for laboratory in vestigations was collected before, and 5 and 30 min after, administering th e contrast medium. Indications for activation of coagulation and platelets were already found in nearly 50% of the patients before any contrast medium was given. Both Iopromide and Ioxaglate caused further increases in thromb in-antithrombin complex, prothrombin fragments 1+2 and beta-thromboglobulin . The degree of activation was similar for both agents. Anticoagulant effec ts were not observed. The haemorheological effects were compatible with hae modilution by 5-8%, again without differences between the contrast agents. Contrary to the findings from in vitro studies, we found no significant dif ferences between the effects of the non-ionic Iopromide and the ionic Ioxag late on coagulation and platelets. Both agents activated these systems to a limited, but identical, degree. Our results support the notion that the ca theterization procedure pet sc may represent a source of haemostatic activa tion and that the ionic contrast agent studied has insufficient anticoagula nt effect to prevent clotting activation being induced by the contrast medi um.