Defining heparin resistance: communication from the ISTH SSC Subcommittee of Perioperative and Critical Care Thrombosis and Hemostasis.

The term heparin resistance (HR) is used by clinicians without specific criteria. We performed a literature search and surveyed our SSC membership to better define the term when applied to medical and intensive care unit patients. The most common heparin dosing strategy reported in the literature (53%) and by survey respondents (80.