Author Question: All of the following serine proteases are bound and inhibited by antithrombin except: a. Xa b. ... (Read 72 times)

rayancarla1 · **on:** Jun 25, 2018

All of the following serine proteases are bound and inhibited by antithrombin except:

a. Xa
b. IXa
c. VIIa
d. XIa

Question 2

Why is the platelet count monitored daily for a patient receiving heparin therapeutically?

a. Platelets increase when a patient is overheparinized.
b. Platelets decrease when a patient is overheparinized.
c. A significant decrease in the platelet count is evidence for heparin-induced thrombocytopenia.
d. A significant increase in the platelet count is early evidence for heparin-induced thrombocytosis.

dyrone · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: C
Antithrombin covalently binds and inhibits XIIa, XIa, Xa, IXa, and thrombin. It does not bind VIIa.

Answer to Question 2

ANS: C
A decrease of 40 or greater in the platelet count, even if the platelet count remains in the reference range, is evidence for heparin-induced thrombocytopenia. This is a serious consequence, and unfractionated heparin therapy must be immediately stopped and replaced with a direct thrombin inhibitor.