A patient's platelet count drops 4 days after being placed on ...

[scienceeasy]

A patient's platelet count drops 4 days after being placed on heparin. Select the correct interpretation.
 
  a. The patient has heparin-induced thrombocytopenia.
  b. The patient has benign, limited thrombocytopenia related to heparin.
  c. A bleeding time should be performed to evaluate qualitative platelet disorders.
  d. An immunoassay for heparin-dependent anti-platelet factor 4 (PF4) should be performed to distinguish heparin-induced thrombocytopenia from benign, limited thrombocytopenia related to heparin.

Question 2

A platelet aggregation study shows diminished response to all agonists except for a small response to arachidonic acid and full response to ristocetin. Which condition is most likely?
 
  a. Glanzmann thrombasthenia
  b. Aspirin use
  c. VWD
  d. Platelet release defect

[Anton]

Answer to Question 1

ANS: D
This pattern, a drop in the platelet count 4 days after being placed on heparin, suggests heparin-induced thrombocytopenia. It could also be a benign, limited thrombocytopenia related to heparin. Assays such as the immunoassay for heparin-dependent anti-PF4 can distinguish the two.

Answer to Question 2

ANS: A
Glanzmann thrombasthenia is diagnosed by its diminished secretion and aggregation responses to all agonists except a modest response to arachidonic acid and full, although nondiagnostic, response to ristocetin.