Thrombocytopenia resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ogheneochuko Ajari, MB.BS, MS [2]

Introduction

Thrombocytopenia is the decreased concentration of platelets below 150,000 cells per microliter of blood.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Disseminated intravascular coagulation
• HELLP syndrome

Common Causes

• Bone marrow suppression (chemotherapy, irradiation)
• Chronic alcohol use
• Chronic liver disease
• Congenital thrombocytopenia
• Disseminated intravascular coagulation
• Hemolytic uremic syndrome
• Heparin-induced thrombocytopenia
• Immune thrombocytopenic purpura
• Infections
• Medications
• Preeclampsia
• Pregnancy
• Pseudothrombocytopenia
• Thrombotic thrombocytopenic purpura

Management

Shown below is an algorithm depicting the initial approach to thrombocytopenia.

Characterize the symptoms: ❑ Onset (acute, chronic, recurrent) ❑ Easy bruising ❑ Petechiae ❑ Rashes ❑ Melena ❑ Fevers ❑ Bleeding ❑ Headaches ❑ Abdominal pain ❑ Visual disturbances ❑ Weight loss ❑ Night sweats ❑ Bone pain Obtain a detailed history: ❑ Recent medications ❑ Pregnancy ❑ Family history ❑ Malignancy ❑ Recent infection ❑ Recent vaccinations ❑ Recent travels ❑ Recent transfusions ❑ Chronic alcohol use ❑ Recent hospitalization ❑ Recent organ transplantation ❑ Recent valve replacement surgery ❑ Dietary habits ❑ Sexual history ❑ Ingestion of quinine containing beverages

Examine the patient: ❑ Bleeding location ❑ Bleeding severity ❑ Hepatomegaly ❑ Splenomegaly ❑ Mucocutaneous bleeding ❑ Skeletal abnormalities ❑ Joint or soft tissue bleeding ❑ Rash ❑ Generalized lymphadenopathy ❑ Skin necrosis ❑ Neurologic exam

Order tests: ❑ Peripheral blood smear ❑ CBC and differential ❑ Reticulocyte count ❑ LDH ❑ LFT ❑ Renal function test ❑ Clotting screen ❑ PT ❑ aPTT ❑ Fibrinogen ❑ Haptoglobin ❑ D-dimer ❑ Request a hematology consult

❑ Order additional tests based on the results of the CBC-D and peripheral blood smear

Possible Pseudothrombocytopenia ❑ Clumped platelets

True thrombocytopenia

❑ Order platelet count on heparinized blood specimen

Isolated thrombocytopenia

Thrombocytopenia with abnormalities in other blood lineages

Consider: ITP TTP DIC

Guide your next step by specific findings

Look for: ❑ Shistocytes ❑ Spherocytes ❑ Dacrocytes ❑ Blasts Giant platelets ❑ Granulations ❑ Hypersegmented neutrophils ❑ Macrocytosis ❑ Lymphocytosis ❑ Neutropenia

Treatment of Thrombocytopenia

The treatment of thrombocytopenia is specific to the underlying cause of thrombocytopenia.

Do's

• Order a peripheral blood smear in all patients with thrombocytopenia and check out the morphology of all blood cells lineages. The peripheral blood smear is one of the most important tests to order in the evaluation of thrombocytopenia.

• Rule out leukemia, manifested by blasts, and thrombotic microangiopathy, characterised by the presence of shistocytes, in critically ill patients.

• Bone marrow biopsy should be done for patients that are older than 60 years of age to rule out myelodysplastic syndrome or lymphoproliferative disorders.
• Treatment should be considered for patients with platelet counts less than 30,000 per microliter.

Dont's

• Don't initiate cancer chemotherapy or antiviral therapy in the presence of thrombocytopenia.
• Don't start the treatment for platelet counts greater than 50,000 per microliter unless the patient is actively bleeding.
• Don't give warfarin monotherapy to an acutely bleeding patient because it may induce thrombosis.