Coagulation Disorders Tutorial
 
Introduction

Very Sociable Guy

Chest Pain

Girl with a Rash  

England 1944

Trouble Healing

Morning Stiffness

Bruises Easily

Shortness of Breath

Drug Interactions

Review

Thanks to

Quiz Please

How do we treat and monitor people who need to be on anticoagulant therapy?
  • If there is a DVT with pulmonary embolus, we're treating the life threatening aspect as well as the clotting system.
    • Oxygen and supportive cardiac/pulmonary management.
    • Unfarctionated heparin to get the aPTT out 2 to 2.5 times the reference.
    • Interestingly, low molecular weight heparin does not affect the aPTT, so it is dosed based on the weight of the patient.
    • Also, protamine does not totally reverse the effects of low molecular weight heparin.
  • If it's an uncomplicated DVT, we go with heparin with prolongation of aPTT as above.
  • Patients are gradually weaned from heparin while they are being placed on Coumadin.
    • By convention, we use
      • aPTT to monitor heparin and
      • PT to monitor Coumadin therapy.
    • Both tests are prolonged with either heparin or Coumadin, but since factor VII levels are quick to rebound, we use the PT to follow patients on Coumadin.
  • Coumadin is taken orally, it's cheap and we have considerable experience with it.
    • For most purposes, we're shooting for an INR between 2 and 3.
    • Rarely do we treat someone to a value of over 3, APS being the one exception.
  • One advantage of heparin is that its effect can be quickly reversed with protamine.
  • Coumadin is not without its problems.
    • It takes time to reverse with vitamin K. Up to 6-8 hours.
    • Protein C and S are also vitamin K dependent proteins. They drop too.
    • You can clot while on Coumadin.

How about a little review?                                                                                Back

Main Index | Slide Table of Contents | Case Studies Table of Contents