PLATELET TRANSFUSION POLICY

BASILDON AND THURROCK HOSPITAL GUIDELINES (Revised Feb 2001)

Platelet transfusion is generally indicated for patients who are unable to produce their own platelets.  This includes patients on chemotherapy, patients with marrow infiltration and patient with aplastic anaemia.  Platelet transfusions are usually not helpful and sometimes dangerous in patients whose thrombocytopenia is due to increased platelet consumption eg ITP, TTP or hypersplenism.  If in doubt, discuss with the consultant haematologist on-call.  Platelet transfusions are indicated when:

 a)  platelet count is <15 x 10⁹/l (or is expected to fall below that level) AND the patient is otherwise well.

b)  platelet count is <30 x 10⁹/l AND the patient is unwell eg patient is bleeding or septic or has a coagulopathy.

c) platelet count is <50 x 10⁹/l AND the patient is about to undergo a minor surgical procedure with a risk of internal bleeding or patient has DIC.

d)  platelet count is <80 x 10⁹/l AND the patient is about to undergo a major surgical procedure.

 Remember that platelet transfusions should usually be ABO group compatible and platelet packs have a shelf life of only 5 days at room temperature.  (Note: never store platelets in a refrigerator).  The hospital blood bank does not maintain a stock of platelets and in general, platelets have to be ordered in advance from the Blood Transfusion Centre.  It is advisable to requires platelets one working day before they are required whenever possible.  (In an emergency, platelets can be obtained within one to two hours by contacting the blood bank).

 The average adult patient should be prescribed a standard dose of platelets such as: one adult unit IV over 30 mins (total).  (Each ‘unit’ is extracted from four units of donated whole blood and contains about 55ml of plasma and 5 x 10¹¹ platelets).  Such a transfusion should result in an elevation of platelet count by 20 to 40 x 10⁹/l.  Normal platelets have a circulation lifespan of 9 days and transfused platelets have a transfusion lifespan of about 2-3 days (except where allo-immunisation supervenes when it will be much shorter).  Sometimes, the blood transfusion centre will not be able to supply pooled random donor units and will supply a pheresis pack from a single donor which will contain about the same dose of platelets.  Platelet-pheresis packs are also used for patients who have become allo-immunised to HLA antigens as they can be HLA matched to the patient and improved platelet survival will result.  These are available only by special arrangement with the blood transfusion centre.

Occasional problems may be encountered during or soon after platelet transfusions.  These commonly include pyrexial reactions, rigors and urticarial rashes.  In general, if these reactions are recurrent and symptomatic, platelet transfusion should be preceded by an IV injection of hydrocortisone 100mg and Chlorpheniramine 10mg (which can also be used for treatment of reaction).  If the patient experiences severe rigors, then IV Pethidine 25-100mg will help.  If there is any doubt about the transfusion of platelets, then contact the haematology on-call through the switchboard.

 Consultants:            Dr Paul Cervi and Dr Eric Watts