50 year old man is admitted to the hospital after being diagnosed with pulmonary embolus .Treatment is started with IV heparin .24 hrs later warfarin is added .On day 2 his PTT is 52 seconds ( control 26 secs) , PT is 12 s ( control 12 sec) and INR is 1.0 .What is the best explanation for normal Pt and INR measurements in this patient ?
a) Heparin warfarin interaction
b) Hereditary resistance to warfarin
c) Hereditary resistance to heparin
d) Long half life of factor II prothrombin
e) Too low a dose of heparin
f) Too low a dose of warfarin
g) Undetected liver disease
a) Heparin warfarin interaction
b) Hereditary resistance to warfarin
c) Hereditary resistance to heparin
d) Long half life of factor II prothrombin
e) Too low a dose of heparin
f) Too low a dose of warfarin
g) Undetected liver disease