Learning objectives

• Definition of idiopathic thrombocytopenia purpura (ITP)
• Treatment and perioperative management of ITP

Definitions and mechanisms

• Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease characterized by a low platelet count, purpura, and hemorrhagic episodes
• Resulting in easy or excessive bruising and bleeding due to unusually low levels of platelets
• The immune system produces antibodies against platelets 
  • Most often against platelet membrane glycoproteins IIB-IIIa or Ib-IX
• Normal platelet count is between 150.000 and 450.000, the platelet count is less than 10.000 with ITP
• Pregnant women with ITP have an increased incidence of fetal loss, a low fetal birth rate, and a higher incidence of premature births
• Two types:
  • Acute thrombocytopenic purpura
    • Affects young children between 2-6 years, often following a coral infection
    • Starts suddenly and symptoms usually disappear in less than 6 months, often within a few weeks
    • Most common form and resolves spontaneously
  • Chronic thrombocytopenic purpura
    • Onset can happen at any age
    • Symptoms can last a minimum of 6 months to several years or a lifetime
    • More common in adults and in females
    • Requires continual follow-up care

Signs and symptoms

• Easy or excessive bruising
• Petechiae
• Bleeding from the gums or nose
• Blood in urine or stools
• Unusually heavy menstrual flow

Complications

• Subarachnoid or intracerebral hemorrhage
• Lower gastrointestinal bleeding

Causes

• Medication (the medication absorbs the platelet cell membrane)
• Infection: the virus that causes chickenpox, hepatitis C, and AIDS
• Pregnancy
• Immune disorders: rheumatoid arthritis, lupus
• Cancer: low-grade lymphomas and leukemia
• The cause is sometimes unknown

Diagnosis

• Complete blood count
• Low platelet count, usually <40×10^9/L for over three months
• Bleeding time
• Blood and urine tests to detect a possible infection
• Antiplatelet antibody test
• Bone marrow examination shows an increased number of megakaryocytes

Management

Suggested reading

• Toyomasu Y, Shimabukuro R, Moriyama H, et al. Successful perioperative management of a patient with idiopathic thrombocytopenic purpura undergoing emergent appendectomy: Report of a case. Int J Surg Case Rep. 2013;4(10):898-900.
• Ramalingam, G., Jones, N., Besser, M., 2016. Platelets for anaesthetists—part 1: physiology and pathology. BJA Education 16, 134–139.
• Warrier R, Chauhan A. Management of immune thrombocytopenic purpura: an update. Ochsner J. 2012;12(3):221-227.
• Guidelines for the investigation and management of idiopathic thrombocytopenic purpura in adults, children and in pregnancy. 2003. British Journal of Haematology 120, 574–596.