Coagulation Panel

Question 1

Activated Partial Thromboplastin Time (aPTT)

Answer 1

• Tests intrinsic coagulation cascade
  30 - 40 sec
  - Critical: > 70 sec
• On Heparin, ‘therapeutic’ aPTT: 1.5 - 2.5x normal

Question 2

Prothrombin Time (PT)

Answer 2

• Tests the extrinsic coagulation cascade - warfarin
  11 - 12.5 sec
  
  • Critical: > 20 sec

‘Therapeutic’ range: 1.5 - 2.5x normal

Question 3

INR

Answer 3

Calculated from a PT + used to monitor how well warfarin is working

0. 8 - 1.1
   - Critical: > 5

On Warfarin: 2 - 3

Question 4

Partial Thromboplastin Time (PTT)

Answer 4

60 - 70 sec greater than 100 sec

‘Therapeutic’ range: 1.5 - 2x normal