Use of platelets

Use platelets for therapeutic treatment of patients with bleeding due to severely decreased platelet production or due to functionally abnormal platelets. It may be given appropriately when the platelet count is <50 x 109 /L in the presence of diffuse microvascular bleeding.

Platelets may be given as prophylaxis to patients with rapidly falling or low platelet counts:

  • <10 x 109 /L secondary to cancer or chemotherapy or bone marrow failure without risk factors

  • <20 x 109 /L in bone marrow failure in the presence of additional risk factors (eg, fever, antibiotic or evidence of systemic haemostatic failure)

  • Maintain >50 x 109 /L for most surgical procedures; and >100 x 109 /L for surgeries with high risk of bleeding (eg, ocular or neurosurgery).

Platelet transfusions are not usually effective or indicated in patients with rapid platelet destruction. They may be used in treating some bleeding patients with platelet consumption or dilutional thrombocytopenia.

Contraindications

Do not use platelets if bleeding is unrelated to decreased numbers of platelets or abnormally functioning platelets.

Do not use in patients with destruction of endogenous and exogenous platelets, such as in immune thrombocytopenic purpura, thrombotic thrombocytopenic purpura, haemolytic uraemic syndrome or heparin-induced thrombocytopenia, unless the patient has life-threatening haemorrhage.

Dosage

The number of platelet units to be administered depends on the clinical situation of each patient.

One unit (one standard adult dose) of Platelets Apheresis or Pooled Leucocyte Depleted would be expected to increase the platelet count of a 70 kg adult by 20–40 x 109 /L. The usual dose in an adult patient is 1 unit (apheresis) or 1 pool (pooled).

One unit of Platelets Paediatric Apheresis Leucocyte Depleted would be expected to increase the platelet count of an 18 kg child by 20 x 109 /L.

For prophylaxis, one unit adult dose may need to be repeated in 1–3 days because of the short life span of transfused platelets. Immune and non-immune mechanisms may contribute to reduced platelet recovery and survival.

 

Reference

  1. National Health and Medical Research Council & Australasian Society of Blood Transfusion. Clinical Practice Guidelines on the Use of Blood Components. Commonwealth of Australia, October 2002.