Canterbury DHB

Platelet Transfusions

Ideally, platelet transfusions should be of the same ABO and Rh(D) groups as the patient. The supply of platelets may make this impossible to achieve. If Rh(D) positive platelets have to be given to an Rh(D) negative woman of childbearing age or a female child, Anti D will need to be given.

See:

• Use of Anti-D in Rh(D) Negative Individuals who have Received Rh(D) Positive Blood Components.
• SJ Slichter, Evidence-Based Platelet Transfusion Guidelines, ASH 2007 pp 172-178.

Indications

Administer one adult therapeutic dose (>2.4 x 10¹¹) of platelets (all platelet concentrates are irradiated) on the same day for the following indications:

Morning Platelet Count <10 x 10⁹/L

• In every case (unless Consultant advises otherwise, e.g. refractoriness).

Morning Platelet Count <20 x 10⁹/L

• Patient shows signs of haemorrhage. Epistaxis, haemoptysis, GI bleed, abnormal fundoscopy examination. Excessive purpura (>10% body surface area) or bruising.
• Fever.
• Evidence of systemic infection.
• Rapidly falling platelet count.
• Haemoglobin < 80 g/L.
• Acute leukaemia with a high blast count.
• A patient has abnormal coagulation profile (PT, APTT) and/or evidence of DIC. (Check coagulation parameters weekly.)
• Before intralumenal urokinase/alteplase therapy for blocked catheters.
• < 72 hours after insertion of Hickman Catheter.
• Any other open wound, or <72 hours after surgery.
• Before bone marrow trephine.

Note: If daily platelets are not being given when the platelet count is <20 x 10⁹/L, daily fundoscopy must be performed.

Morning Platelet Count <30 x 10⁹/L

• Aplastic anaemia patients receiving ALG/ATG.

Morning Platelet Count <50 x 10⁹/L

• Before surgery or major therapeutic procedures. Two adult doses of platelets should be available for the patient during these procedures.
• Before LP procedure.
• All patients receiving ATRA therapy for APML.
• Suspected intracranial pathology.

Morning Platelet Count <100 x 10⁹/L

• Before operations on critical sites, e.g. brain, eyes.

Note: Thorough examination of the patient for haemorrhagic symptoms must be evaluated and documented daily.

If poor platelet increments are suspected, check a post-platelet count 1 hour after the infusion; this should ideally be assessed on more than one occasion and with use of ABO-compatible platelets. Patients may become refractory to platelets due to HLA, or less commonly, HPA antibodies, which can be checked by sending a 10 mL clotted sample plus 4 CPDA tubes (yellow top) to the Blood Bank. However, consider other causes such as sepsis, DIC, hypersplenism, etc. In this setting, platelets given throughout day 1 ATD 8-hourly, frequently prevents evidence of clinical bleeding.

Refer to the Platelet Refractory Guidelines. Discuss with transfusion medicine registrar or consultant before requesting investigation for platelet refractoriness.

All NZBS platelets are irradiated.

Note: See the NZ Blood Tissue Typing form.

Verbal Orders

Verbal orders within the haematology department are governed by three policies/procedures. Each has a specific process that must be followed to ensure the order remains valid and legal:

• CDHB verbal orders policy
• Verbal Orders for Platelets and Red Blood Cell Transfusions for Haematology Patients (239810) – This procedure is valid in any area of the haematology department. It allows for timely prescribing and administration of platelets and red blood cells to patients with a haematological disorder.

  Note: With the introduction of electronic prescribing, the use of verbal orders should only be used in exceptional circumstances. Where possible, consider prescribing the required medication electronically.

Topic Code: 5107