Coagulation Studies

 

• Platelet count (PLT): 150,000 to 400,000 cells/mm³
• Activated partial thromboplastin time (APTT): 20 to 60 seconds, depending on the type of activator used.
• Prothrombin time (PT): 11 – 13 seconds
• Partial Thromboplastin Time (PTT): 25 – 35 seconds
• International Normalized Ratio (INR): The INR standardizes the PT ratio and is calculated in the laboratory setting by raising the observed PT ratio to the power of the international sensitivity index specific to the thromboplastin reagent used.
• Fibrinogen: 203 – 377 mg/dL
• Bleeding time: 1 to 3 minutes (Duke method), 3 to 6 minutes (Ivy method)
• D-Dimer: < 500 ng/mL