Alternatives to prophylactic platelet transfusions
Prophylactic platelet transfusions are given to prevent bleeding when the platelet count is low(<10 x 109/L), orwhen the person has severe platelet dysfunction or thrombocytopenia and requires a procedure.1,2 However, despite prophylactic platelet transfusions, a significant proportion of people with prolonged severe thrombocytopenia due to haematological malignancies have clinically significant bleeding.3 Thrombopoietin mimetics act by stimulating megakaryopoiesis resulting in increased thrombopoiesis. In immune thrombocytopenia they increased platelet counts but did not decrease the incidence of serious bleeding events.4 In people with liver disease on antiviral therapies, an increased risk of thrombosis occurred following thrombopoietin mimetic administration.5 Use of thrombopoietin mimetics in the treatment of myelodysplastic syndrome has been shown to reduce the exposure-adjusted bleeding rate.6 The administration of thrombopoietin mimetics for people with aplastic anaemia is of particular interest, as in addition to increasing the platelet count they may also have a disease-modifying effect.7 Antifibrinolytics have been used to prevent bleeding in people undergoing surgery.8 There is currently little evidence for their benefit in people with low platelet counts,9 but there are three ongoing studies assessing the use of antifibrinolytics to prevent bleeding in people with haematological malignancies.10–12 Procedures with a low risk of bleeding, or bleeding that can be controlled easily by pressure at the procedure site, may not require platelet transfusions. Vascular closure devices can also be used to reduce the risk of bleeding.13 Desmopressin promotes coagulation by stimulating factor VIII release from endothelial stores and increasing vWF activity.14 One randomised trial has compared DDAVP to platelet transfusion for treatment of cirrhotic patients with platelet counts between 30–50 x 109/L undergoing dental extractions. This trial was too small to demonstrate efficacy, as only a single bleeding event occurred.15 Thelimited efficacy, side effect profile and expense of recombinant factor VIIa limits its use as an alternative to platelet transfusion.16 REFERENCES 1. Kaufman RM, Djulbegovic B, Gernsheimer T, et al. Platelet transfusion: a clinical practice guideline from the AABB. Ann Intern Med 2015;162:205–13. 2. Padhi S, Kemmis-Betty S, Rajesh S, Hill J, Murphy MF. Blood transfusion: summary of NICE guidance. BMJ 2015;351:h5832. 3. Stanworth SJ, Estcourt LJ, Powter G, etal. A no-prophylaxis platelet-transfusion strategy for hematologic cancers. N Engl J Med 2013;368:1771–80. 4. Zeng Y, Duan X, Xu J, Ni X. TPO receptor agonist for chronic idiopathic thrombocytopenic purpura. Cochrane Database Syst Rev 2011:CD008235. 5. Afdhal NH, Dusheiko GM, Giannini EG, et al. Eltrombopag increases platelet numbers in thrombocytopenic patients with HCV infection and cirrhosis, allowing for effective antiviral therapy. Gastroenterology 2014;146:442–52 e1. 6. Prica A, Sholzberg M, Buckstein R. Safety and efficacy of thrombopoietin-receptor agonists in myelodysplastic syndromes: a systematic review and meta-analysis of randomized controlled trials. Br J Haematol 2014;167:626–38. 7. Desmond R, Townsley DM, Dumitriu B, et al. Eltrombopag restores trilineage hematopoiesis in refractory severe aplastic anemia that can be sustained on discontinuation of drug. Blood 2014;123:1818–25. 8. Ker K, Edwards P, Perel P, Shakur H, Roberts I. Effect of tranexamic acid on surgical bleeding: systematic review and cumulative meta-analysis. BMJ 2012;344:e3054. 9. Wardrop D, Estcourt LJ, Brunskill SJ, et al. Antifibrinolytics (lysine analogues) for the prevention of bleeding in patients with haematological disorders. Cochrane Database Syst Rev 2013;7:CD009733. 10. ISRCTN73545489. TREATT: Trial to EvaluAte Tranexamic acid therapy in Thrombocytopenia 2014. Available at: http://public. ukcrn.org.uk/search/StudyDetail.aspx?StudyID=18157. 11. American Trial Using Tranexamic Acid in Thrombocytopenia (A-TREAT). Available at: https://clinicaltrials.gov/ct2/show/ NCT02578901. 12. PRevention Of BLeeding in hEmatological Malignancies With Antifibrinolytic (Epsilon Aminocaproic Acid) (PROBLEMA). Available at: https://clinicaltrials.gov/ct2/show/NCT02074436. 13. Hon LQ, Ganeshan A, Thomas SM,Warakaulle D, Jagdish J, Uberoi R.An overview of vascular closure devices:what every radiologist should know. Eur J Radiol 2010;73:181–90. 14. Svensson PJ, Bergqvist PB, Juul KV, Berntorp E. Desmopressin in treatment of haematological disorders and in prevention of surgical bleeding. Blood Rev 2014;28:95–102. 15. Stanca CM, Montazem AH, Lawal A, Zhang JX, Schiano TD. Intranasal desmopressin versus blood transfusion in cirrhotic patients with coagulopathy undergoing dental extraction: a randomized controlled trial. J Oral Maxillofac Surg 2010;68:138–43. 16.Simpson E, Lin Y,Stanworth S, Birchall J,Doree C,Hyde C. Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia. Cochrane Database Syst Rev 2012;3:CD005011.