Control of Oral Anticoagulation in Patients Using Long-Term Internal Jugular Catheters for Haemodialysis Access

Patients using long-term double-lumen silastic jugular catheters for haemodialysis access frequently require oral anticoagulants to maintain patency of the catheter. It may be difficult or impossible to obtain peripheral vein blood samples for PT measurements to regulate the oral anticoagulant dose. Our studies have shown that removal of 3 mis of blood from the catheter limb containing the heparin (to be discarded) followed by 10 mis as a heparin wash-out (to be returned to the patient) allows blood to be taken from the arterial limb of the catheter for PT measurement. The PT measurement obtained from the arterial limb after a 10 ml wash-out is nearly always identical with the PT measurement on blood obtained from a peripheral vein. If the simultaneously measured aPTT is normal the PT is predictably and consistently accurate. If the aPTT is raised due to traces of residual heparin then the PT may be inaccurate and should be repeated. This method is easy and reliable and can be recommended as an aid to regulation of the oral anticoagulant dose