How to Diagnose Heparin-Induced Thrombocytopenia

Heparin is an anticoagulant medicine, often called a blood thinner. Physicians prescribe heparin to treat and prevent blood clots in people with certain health conditions, to stop existing clots from becoming larger and to reduce the risk of blood clot formation during certain operations, kidney dialysis or blood transfusions. In some patients, heparin use leads to a low blood platelet count (thrombocytopenia). Thrombocytopenia usually is associated with increased bleeding, but heparin-induced thrombocytopenia has the opposite effect and causes blood clots. This can make it difficult to diagnose.

Things You'll Need

• Microscope
• Electric platelet counter
• Thermometer
• Ultrasound equipment

Show More

Instructions

• 1

  Determine whether the patient has begun heparin therapy in the past five to 14 days. This is the time frame when heparin-induced thrombocytopenia usually occurs, according to an article published in a 2006 issue of "Critical Care Nurse."

• 2

  Draw a blood sample and examine it under a microscope or with an electric platelet counter to determine low numbers of platelets. This may be indicated by a 30 to 50 percent reduction from the patient's baseline.

• 3

  Check for prothrombin time (PT) and partial thromboplastin time (PTT). These tests indicate how long it takes for blood to clot, and in heparin-induced thrombocytopenia, these tests typically have normal results.

• 4

  Rule out other possible causes of thrombocytopenia. Take the patient's temperature, as a fever can indicate an infection. Check for an enlarged spleen either through a physical examination or by ultrasound, as an enlarged spleen may be trapping platelets. Perform a blood test to check for high levels of urea nitrogen and creatinine, which indicate poor kidney function that can cause thrombocytopenia.