UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 1111
Question:
Heparin is a commonly used anti-coagulant agent. Normally a dose of 10-15 units/kg/hr is used. But patients with acute pulmonary emboli require larger doses of heparin during the first few days.
The reason for an increased dose initially is that in the acute phase of pulmonary embolism

a) pulmonary emboli are more difficult to dissolve
b) there is increased heparin clearance
c) recurrence is more likely in the first few days
d) pulmonary emboli are multiple in number
e) the above statement is incorrect, the dose of heparin should be smaller initially