Blood Product Usage Case Studies


CASE 7


Clinical History:

A 30-year-old woman is diagnosed with thrombotic thrombocytopenic purpura (TTP) in the hospital and treatment with plasmapheresis is given. After seven plasmapheresis procedures, her platelet count is now back in the normal range, but she continues to have stools which are positive for occult blood. A nurse finds the patient unconscious, without a palpable pulse and with a melanotic stool in the bed. She calls a code. The code team suspects the patient is having a large GI bleed and they begin fluid replacement through the large central line that has been used for plasmapheresis. The patient is moved to the intensive care unit (ICU) and emergency O negative red cells are requested from the blood bank. While the red cells are infusing, laboratory results are called to the unit and the prothrombin time (PT) and the partial thromboplastin time (PTT) are both greater than 150 seconds. The patient appears to still be bleeding. The ICU attending physician calls the blood bank physician to ask for help.

Questions:

  1. What did the blood bank physician recommend?

    2. The blood bank physician recommended that protamine sulfate be given.

  2. What laboratory test or tests could be ordered to confirm this?

    3. A correction or mixing study can be done. In this case the PT and PTT were still >150 seconds. A heparin assay would confirm the presence of heparin.

  3. Why did the blood bank physician suspect the cause for this problem, even without laboratory testing to confirm it?

    4. Heparin is placed in all catheters used for dialysis or apheresis. These are dual lumen catheters which require 5,000 units of heparin per lumen for a total of 10,000 units to prevent clot formation when the line is not in use. The blood bank physician suspected that when the line was used emergently, the heparin was flushed into the patient along with the fluids used for resuscitation.