Increased PT Only: A Prolonged PT with a Normal PTT

Differential Diagnosis

Initiation of Coumadin therapy or a very low dose of Coumadin

Inadequate intake of foods rich in vitamin K, such as cauliflower, broccoli, chick peas, other leafy vegetables

A stimulus for disseminated intravascular coagulation (DIC)

Evidence of liver disease from clinical or laboratory parameters

Family history of bleeding that could be associated with factor VII deficiency

Suggested Additional Lab Testing

Get liver function tests to assess whether the patient has liver disease and decreased synthesis of coagulation factors from the liver

Get a D-dimer or FDP as an assessment of DIC

• If the test is positive, follow up with platelet count and measurement of fibrinogen.

• In patients with DIC, these can be decreased or show decreasing values in two consecutive specimens at least several hours apart.

• If DIC, Coumadin therapy, and vitamin K deficiency have been ruled out, measure the factor VII level and assess the possibility of an isolated factor VII deficiency.