APPARENT HEPARIN RESISTANCE FROM ELEVATED FACTOR-VIII IN A PATIENT WITH POSTOPERATIVE DEEP VENOUS THROMBOSIS - A CASE-REPORT

BACKGROUND: During the puerperium, heparin levels, rather than the adj usted partial thromboplastin time test, can be used to identify hepari n resistance and guide heparin therapy. CASE: A patient receiving hepa rin for deep venous thrombosis had artifactual resistance to heparin, with a short adjusted partial thromboplastin time due to elevation of factor VIII. Heparin assay revealed a heparin level above the therapeu tic range. CONCLUSION: Direct measurement of heparin concentration and factor VIII activity should be performed when heparin resistance is s uspected.