Laboratory Findings in Various Platelet and Coagulation Disorders

A peripheral-blood smear is a vital investigation tool in most cases to confirm a low platelet count and the presence or absence of other diagnostic features, such as red-cell fragmentation, platelet morphologic abnormalities, or evidence of dysplasia or hematinic deficiency.

Laboratory Findings in Various Platelet and Coagulation Disorders

Condition	Prothrombin Time	Activated Partial-Thromboplastin Time	Fibrinogen Level	d-Dimer Level	Bleeding Time	Platelet Count	Findings on Blood Smear
Vitamin K deficiency or use of vitamin K antagonist	Prolonged	Normal or mildly prolonged	Normal	Unaffected	Unaffected	Unaffected
Aspirin or thienopyridines	Unaffected	Unaffected	Unaffected	Unaffected	Unaffected	Unaffected
Liver failure Early stage End stage	Prolonged Prolonged	Unaffected Prolonged	Unaffected Low	Unaffected Increased	Unaffected Prolonged	Unaffected Decreased
Uremia	Unaffected	Unaffected	Unaffected	Unaffected	Prolonged	Unaffected
Disseminated intravascular coagulation	Prolonged	Prolonged	Low	Increased	Prolonged	Decreased	Fragmented red cells
Thrombotic thrombocytopenic purpura	Unaffected	Unaffected	Unaffected	Unaffected	Prolonged	Very low	Fragmented red cells
Hyperfibrinolysis	Prolonged	Prolonged	Low	Very high	Possibly prolonged	Unaffected

 

References:

1. Hunt BJ. Bleeding and coagulopathies in critical care. N Engl J Med. 2014 Feb 27;370(9):847-59. [Medline]
2. Parker RI. Etiology and treatment of acquired coagulopathies in the critically ill adult and child. Crit Care Clin. 1997 Jul;13(3):591-609. [Medline]

 

Created Jul 21, 2014.