7. Special Coag Studies

  • Polybrene added to plasma for PT and PTT with no shortening of clotting times. Interpretation: no evidence of heparin contamination
  • Mixing study (1:1 v/v) performed using normal control plasma

Mixing Study Principles

 Coag Mixing Study Principles

Mixing Study Results


65.5 s

72.0 s

Down Arrow
Down Arrow
12.8 s
28.9 s

Interpretation : factor deficiency affecting both the PT and PTT

Breakpoint #4

  • What is your differential diagnosis at this point?
  • What additional laboratory studies do you want?
  • Do you need the results before treatment is begun? What treatment?