ANTICOAGULANT therapy at the Royal Victoria Hospital in Montreal is directed by the personnel of the hematology service. Certain technicians are highly trained in coagulation techniques and perform the prothrombin and clotting determinations. The hematologist in charge of anticoagulant therapy not only supervises the laboratory tests but is continually aware of the clinical condition of the patient; he advises as to initiation and cessation of anticoagulant therapy, selects the anticoagulants to be used, and orders their daily dosage. This has resulted in extensive experience in the clinical and laboratory aspects in managing a wide variety of patients.
As a prerequisite to starting anticoagulant therapy, each patient is assessed clinically as regards indications and contraindications, and preliminary hematologic studies are performed as indicated. Heparin is usually administered intravenously every four hours. The three-tube modified Lee-White clotting time is performed initially, two and one-half hours after the first heparin injection and twice