title: Effect of contrast media on in vitro bleeding time: assessment by a hollow fiber instrument.
abstract: OBJECTIVE
  We used a global screening device that operates under physiologic flow conditions to monitor the effects of ionic and nonionic contrast media (CM) on hemostasis.
  
  
  METHODS
  This flow dynamic technique perfuses unanticoagulated whole blood through a hollow fiber. A leak in the fiber is created by a precision needle, and the resulting pressure fluctuations within the fiber are monitored to examine the ability of the hemostatic system to close the leak by forming a stable platelet plug.
  
  
  RESULTS
  Both ionic and nonionic CM (25% CM/blood, v/v) were shown to lengthen the mean in vitro bleeding times (IVBTs) compared with normal blood. Ionic CM (ioxaglate and diatrizoate) consistently produced IVBTs longer than 30 min. The nonionic CM iopamidol, iohexol, and ioversol gave mean IVBTs of 16.43, 17.63, and 19.84 min, respectively.
  
  
  CONCLUSIONS
  Of the three nonionic CM tested, iopamidol had the greatest probability (31%) of producing an IVBT in the normal range, with probabilities of 5% and 7% for iohexol and ioversol, respectively. Thus, iopamidol offered the least anticoagulant effect among the ionic and nonionic CM we studied.
authors.affiliation: Department of Medicine, University of North Carolina School of Medicine, Chapel Hill 27599, USA.
authors.forename: L G
authors.initials: LG
authors.lastname: Melton
authors.forename: K M
authors.initials: KM
authors.lastname: Muga
authors.forename: D A
authors.initials: DA
authors.lastname: Gabriel
mesh_terms: D001760:Bleeding Time; D001783:Blood Flow Velocity / Q000187:drug effects*; D003287:Contrast Media / Q000009:adverse effects / Q000494:pharmacology*; D006487:Hemostasis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D008955:Models, Cardiovascular; D015539:Platelet Activation; D013927:Thrombosis / Q000139:chemically induced
chemical_list: D003287:Contrast Media