Proposed Guidelines for Platelet Transfusion

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Yulia Lin, MD, FRCPC, Lynda M. Foltz, MD, FRCPC

Proposed guidelines for platelet transfusion

Physicians can optimize patient outcome and ensure appropriate use of a limited blood supply by following transfusion guidelines.

ABSTRACT: The decision to use he guidelines that follow are let transfusions are not indicated in platelet products should be based proposed to support physi- all cases and may be contraindicat- on a careful review of the patient’s T cians in their clinical deci- ed for certain conditions, such as condition and clinical situation. As sions related to the appropriate use of heparin-induced thrombocytopenia well as considering the most up-to- platelet products. They are not intend- and thrombotic thrombocytopenic date guidelines provided by the ed to provide a rigid prescription for purpura/hemolytic uremic syndrome. British Columbia Provincial Blood care and do not replace the need to ¥ Once the cause of thrombocytope- Coordinating Office, the physician consult with an expert in transfusion nia has been established, the deci- should consult with an expert in medicine. The decision to transfuse sion to transfuse platelets should not transfusion medicine. platelets should be based on the judg- be based solely on the patient’s plate- ment of the attending physician after let count. The decision to transfuse Note: An earlier version of these careful review of the patient’s condi- should be supported by the need to guidelines has been published on tion and clinical situation. The goal is prevent or treat bleeding. the Bloodlink BC web site. to optimize patient outcomes and to ¥ Platelet transfusion should be given ensure appropriate use of the allo- only after the risks associated with geneic (donor) blood supply. These transfusion have been considered guidelines apply to platelet transfu- and only when the benefits outweigh sion in adults and are generally applic- the risks. Risks include the general able to children with the exception of risks of transfusion. The physician neonates. should also keep in mind that the These guidelines are periodically risks of bacterial contamination updated and are available electroni- (1:10 000) and alloimmunization to cally on the British Columbia Provin- platelets are increased with platelet cial Blood Coordinating Office web transfusion.1 site (www.bloodlink.bc.ca). Prescrib- ing physicians should refer to the most Drs Lin and Foltz are senior hematology current version of these guidelines. residents at the University of British Colum- bia. These guidelines were commissioned General considerations by the British Columbia Transfusion Medi- ¥ Informed consent is required for the cine Advisory Group (TMAG). TMAG is a transfusion of platelets. technical, medical, and scientific advisory ¥ The cause of thrombocytopenia body to the Ministry of Health in guiding must be established prior to platelet the development of blood program–related transfusion. This is critical as plate- policies in British Columbia.

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¥ Strategies should be undertaken to of plasma.2,3 The typical platelet pre- Threshold and target minimize the need to transfuse plate- scription is 10 mL/kg to a maximum platelet levels in the lets. For example: of five random-donor platelet units. prevention of bleeding - Investigate, diagnose, and treat Note that each platelet unit is de- As a general guide, the platelet count previously recognized thrombo- rived from a different donor. thresholds shown in theTable should cytopenia. ¥ Single-donor apheresis platelet unit: be used for considering platelet trans- - Discontinue anticoagulants and Each apheresis platelet unit contains fusion.4,5 Serious spontaneous bleed- antiplatelet agents before planned at least 300 109 platelets suspend- ing is unlikely to occur at platelet surgery. ed in 200 to 400 mL of plasma and counts >10 109/L. More specific - Use adjunctive agents in specific is derived from a single donor.2,3 recommendations are presented in the situations (e.g., desmopressin, anti- Apheresis platelet units are pre- following sections. fibrinolytics). ferred when a patient becomes re- ¥ Ensure that all other coagulation fractory to random-donor platelet For patients undergoing car- parameters are checked as well. units, though the use of single-donor diopulmonary bypass surgery ¥ When platelets are transfused, the apheresis platelet units as first-line The pathophysiology of platelet dys- reasons for the transfusion should platelet products is increasing. function in cardiopulmonary bypass be clearly and accurately recorded (CPB) surgery has not been elucidat- in the patient’s chart and in any doc- Response to ed. Platelet-related bleeding includes umentation used in ordering or ad- platelet products microvascular bleeding as indicated ministering platelets. Typically one unit of random-donor by continued oozing from surgical platelets should increase the platelet incisions and venous cannulation sites. Platelet products count of a 70 kg adult by 5 109/L.3 The platelet count following CPB Platelets have a shelf life of 5 days Response to platelet transfusions gives no indication of platelet func- and are stored at 20¡C to 24¡C with should be assessed by obtaining a tion. Thus, platelet transfusion may be continuous gentle agitation.2 Because platelet count 15 minutes to 1 hour considered in patients who are experi- platelets have a limited shelf life, posttransfusion and calculating the encing excessive postoperative bleed- platelet products are often in short corrected count increment (CCI) as ing and in whom a surgical cause has supply. Most hospitals do not rou- shown in theFigure . been excluded. Consideration for tinely stock platelets, so the transfu- ACCI of >7.5 at 1 hour after trans- transfusion should also be given to sion medicine laboratory should be fusion or >4.5 at 20 to 24 hours after those patients who have recently forewarned, whenever possible, of transfusion is considered acceptable. received antiplatelet agents. Intraop- anticipated platelet requirements. Platelet refractoriness is defined as the eratively, autologous platelet harvest Different platelet products exist, of failure to achieve an expected CCI may be used. There is no role for pro- which the most commonly used are as after two consecutive transfusion epi- phylactic platelet transfusion in CPB.4 follows: sodes.4 Patients who are refractory ¥ Random-donor platelet unit: Each should be assessed further by a trans- For patients with platelet platelet unit contains at least 55 109 fusion medicine specialist or hema- dysfunction platelets suspended in 40 to 70 mL tologist. Acquired causes of platelet dysfunction include the use of antiplatelet agents (e.g., ASA, clopidogrel) and renal disease. The platelet count is less CCI = ( posttransfusion platelet count pretransfusion platelet count ) body surface area useful in these situations and the deci- total number platelets transfused sion to transfuse should be based on clinical circumstances. The following 4 Units: recommendations should be imple- pretransfusion platelet count ( 109/L) body surface area (m2) mented in order to avoid platelet trans- posttransfusion platelet count ( 109/L) total number of platelets transfused (1011/L) fusion if possible: ¥ Discontinue drugs with antiplatelet activity. Figure. Corrected count increment (CCI) calculation. ¥ Consider the use of desmopressin in

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9 9 Table. Platelet count thresholds for >50 10 /L prior to lumbar puncture >10 10 /L in patients without other platelet transfusion. as platelet counts <20 109/L have risk factors such as fever or coagu- been associated with increased risk of lopathy is considered safe. Maintain- Setting Platelet count hematoma or traumatic tap.6,8,9 No ing a lower threshold of 5 109/L or Neurosurgery clear minimum platelet count has been withholding prophylactic transfusion <100 109/L CNS trauma identified for the insertion of epidural may be appropriate in selected stable Epidural catheter catheters, with published recommen- patients. Hemorrhage should be treat- <50 80 109/L 4 insertion or removal dations ranging from >50 80 ed with platelet transfusion. 109/L.4,10,11 Significant microvascular bleeding Vaginal delivery can be performed For patients with leukemia or <50 109/L Surgery safely with maternal platelet counts undergoing hematopoietic stem Lumbar puncture >50 109/L,12 as hemostasis after pla- cell transplantation cental separation is largely mechanical. Patients with acute leukemia (exclud- Vaginal delivery <50 109/L Bone marrow biopsy can be per- ing acute promyelocytic leukemia) Thrombocytopenia with <20 109/L formed safely without platelet support commonly require platelet transfusion fever or coagulopathy if adequate surface pressure is applied.4 support throughout their treatment Thrombocytopenia due <10 109/L Posttransfusion platelet counts course. Several studies have provided to marrow failure should be obtained before any inva- evidence that the threshold for pro- sive procedure. Platelets should be phylactic platelet transfusion can be available for transfusion if bleeding lowered to 10 109/L.4,13-15 This thresh- patients taking ASA, as well as pa- complications arise. old is similar for hematopoietic stem tients with uremia and other con- cell transplantation. If the patient has genital and acquired causes of For critically ill patients with fever, sepsis, disseminated intravas- platelet dysfunction. thrombocytopenia cular coagulopathy, or minor bleed- ¥ Correct the hematocrit to >0.30 in No specific data exist regarding trans- ing, the platelet count should be main- patients with renal failure; consider fusion thresholds in the critically ill. tained above 20 109/L.4,14,16 the use of desmopressin and dialy- The following recommendations are Though there are no specific stud- sis, which also have hemostatic ben- extrapolated from data in patients with ies for patients with acute promyelo- efits in this situation. acute leukemia. For patients who are cytic leukemia, patients with this form ¥ Use platelet transfusions where the critically ill with fever, sepsis, or co- of leukemia who have a concomitant above methods are inappropriate or agulopathy, the platelet count should coagulopathy should receive prophy- ineffective. be maintained above 20 109/L. If lactic platelet transfusion to maintain Patients with congenital platelet there is significant bleeding, the plate- a platelet count >20 109/L.4 dysfunction must be managed in con- let count should be maintained above sultation with a hematologist. 50 109/L. For patients with acute blood loss resulting from trauma For patients undergoing surgery For patients with A decrease in the platelet count to 50 and invasive procedures thrombocytopenia due to 109/Lis expected when red cell con- Expert consensus and retrospective chronic marrow failure centrates equivalent to two blood vol- case series suggest that a platelet count The role of prophylactic platelet trans- umes have been transfused. In patients of >50 109/L is sufficient for most fusion in patients with chronic stable with acute bleeding, the platelet count invasive procedures, including gas- thrombocytopenia due to myelodys- should be maintained above 50 troscopy and biopsy, insertion of in- plastic syndrome or aplastic anemia is 109/L.4,17 If injuries include multiple dwelling lines, transbronchial biopsy, unclear, as many patients do not expe- trauma or CNS injury, published rec- liver biopsy, laparotomy, or similar rience serious hemorrhagic complica- ommendations suggest a target plate- procedures.4,6,7 Platelet counts >100 tions with platelet counts <5 10 let count of 100 109/L.4,18 In practice, 109/L are recommended for neuro- 109/L. Long-term prophylactic platelet however, local experience suggests surgery or ocular surgery.4 transfusion is associated with transfu- that a count of 75 109/L as a target is For adults and children, most ex- sion risks, including alloimmuniza- more realistically achievable in the perts recommend platelet counts of tion. Maintaining a platelet count of context of finite platelet resources.

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For patients with immune transfusions. Br J of Haematol 2003;122: The threshold for prophylactic platelet thrombocytopenic purpura 10-23. transfusions in adults with acute myeloid Platelet transfusions are often ineffec- 5. Callum JL, Pinkerton PH. Bloody easy: leukemia. N Engl J Med 1997;337:1870- tive in immune thrombocytopenic Blood transfusions, blood alternatives 1875. purpura (ITP) and should be reserved and transfusion reactions. Toronto: Sun- 15. Wandt H, Frank M, Ehninger G, et al. for patients with life- or limb-threat- nybrook and Women’s College Health Safety and cost effectiveness of a 10 ening bleeding, in which case platelets Sciences Centre; 2003. 109/L trigger for prophylactic platelet should be maintained above 50 6. Schiffer CA, Anderson KC, Bennett CL, transfusions compared with the tradi- 109/L. Patients with ITPwith a platelet et al. for the American Society of Clinical tional 20 109/L trigger: A prospective count <10 109/L should be trans- Oncology. Platelet transfusion for pa- comparative trial in 105 patients with fused only in the setting of serious tients with cancer: Clinical practice guide- acute myeloid leukemia. Blood 1998; bleeding. In the rare circumstances lines of the American Society of Clinical 91:3601-3606. when platelet transfusion is required Oncology. J Clin Oncol 2001;19:1519- 16. Gmur J, Burger J, Schanz U, et al. A. Safe- in the management of ITP, other ther- 1538. ty of stringent prophylactic platelet trans- apies such as corticosteroids and/or 7. Bishop JF, Schiffer CA, Aisner J, et al. fusion policy for patients with acute intravenous immunoglobulin should Surgery in acute leukemia: A review of leukemia. Lancet 1991;338:1223-1226. be given at the same time to enhance 167 operations in thrombocytopenic pa- 17. Hippala S. Replacement of massive blood platelet survival.4 tients. Am J Hematol 1987;26:147-155. loss. Vox Sang 1998;74(suppl 2):399-407. 8. Edelson RN, Chernik NL, Posner JB. 18. Horsey PJ. Multiple trauma and massive Contraindications Spinal subdural hematomas complicat- transfusion. Anaesthesia 1997;42:1027- Platelet transfusions are contraindi- ing lumbar puncture. Arch Neurol 1974; 1029. cated in thrombotic thrombocytopenic 31:134-137. purpura/hemolytic uremic syndrome 9. Vavricka SR, Walter RB, Irani S, et al. Safe- (TTP/HUS) and heparin-induced ty of lumbar puncture for adults with thrombocytopenia (HIT) unless there acute leukemia and restrictive prophylac- is life- or limb-threatening hemor- tic platelet transfusion. Ann Hematol rhage. Platelet transfusions have been 2003;82:570-573. associated with exacerbation of TTP/ 10. Abramovitz S, Beilin Y. Thrombocytope- HUS and arterial thrombosis in HIT.4 nia, low molecular weight heparin, and obstetric anesthesia. Anesthesiology Competing interests Clin North America 2003;21:99-109. None declared. 11. Beilin Y, Bodian CA, Haddad EM, et al. Practice patterns of anesthesiologists References regarding situations in obstetric anesthe- 1. British Columbia Provincial Blood Coordi- sia where clinical management is contro- nating Office. Physician’s Guide 2001: versial. Anesth Analg 1996;83:735-741. Informed consent for blood and blood 12. American Society of Anesthesiologists products. Vancouver: British Columbia Task Force on Blood Component Thera- Provincial Blood Coordinating Office; py. Practice guidelines for blood compo- 2001. nent therapy: A report by the American 2. Canadian Blood Services. Circular of Society of Anesthesiologists Task Force Information. Ottawa: Canadian Blood on Blood Component Therapy. Anesthe- Services; 2002. siology 1996;84:732-747. 3. American Association of Blood Banks. 13. Heckman KD, Weiner GJ, Davis CS, et al. Blood Transfusion Therapy: A Physician’s Randomized study of prophylactic plate- Handbook. 7th ed. Bethesda, MD: Amer- let transfusion threshold during induction ican Association of Blood Banks; 2002. therapy for adult acute leukemia: 10,000/ 4. British Committee for Standards in microL versus 20,000/microL. J Clin Haematology, Blood Transfusion Task Oncol 1997;15:1143-1149. Force. Guidelines for the use of platelet 14. Rebulla P, Finazzi G, Marangoni F, et al.

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