Polycythemia resident survival guide

Fatigue Resident Survival Guide
Overview
Causes
Diagnosis
Treatment
Do's
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alieh Behjat, M.D.[2]

Synonyms and keywords: Approach to polycythemia, Approach to high hemoglobin level, Approach to high red blood cell count

Overview

Polycythemia is defined as high hemoglobin (>16.5 g/dl in men and >16 g/dl in women) or hematocrit level (>49%in men and >48% in women). This elevated level might be due to declining the plasma volume (relative or spurious polycythemia) or rising the number of red blood cells (true polycythemia).

Causes

Life Threatening Causes

• Critical dehydration owing to fluid loss such as severe diarrhea or vomiting, which can result in Spurious Polycythemia
• Severe cyanotic heart diseases with right-to-left shunts
• End-stage cancer related to EPO-secreting tumors such as hepatocellular carcinoma, parathyroid carcinoma, pheochromocytoma, or renal cell carcinoma

Common Causes

Primary polycythemia

• Polycythemia vera and its complications

Secondary polycythemia

• Chronic lung disease
• High altitude
• EPO-producing tumors
• High carboxyhemoglobin: mostly observed in smokers
• Kidney diseases, such as Renal cysts and renal artery stenosis
• Iatrogenic Causes:

• Steroids
• Erythropoietin treatment
• Anabolic testosterone replacement therapy

Diagnosis

Shown below is an algorithm summarizing the diagnosis of polycythemia according to hematology guidelines.

Abbreviations: Hgb: Hemoglobin, Hct: Hematocrit RBC: Red blood cell, EPO: Erythropoietin, COPD: Chronic obstructive pulmonary disease

Elevated Hgb or Hct

Assess RBC mass

if normal

Relative erythrocytosis

If high level

Measure EPO level

If low

Polycythemia vera

Check JAK2 mutation to confirm

If high level

Assess arterial O2 saturation

If low

Assess cardiac or pulmunary diseases, such as right to left shunts, COPD, high altitute

If normal

Is the paitient smoker?

If no

Measure Hgb O2 affinity

If normal

Diagnostic evaluation for finding tumor producing EPO: Kidney sonography, Brain CT, Abdominopelvic Ct scan

If incresed

High oxigen affinity hemoglobinopathy

If yes

Evaluate carboxihemoglobin levels

If normal

If high

Smoker's polycythemia

Treatment

Curing the underlying causes of secondary polycythemia is the primary way of treatment in this disease. Shown below is an algorithm summarizing the treatment of polycythemia vera.

The main treatment in Polycythemia Vera

Phlebotomy in order to keep hematocrit lower than 45% and prescribe Aspirin(40-100 mg) once every day

Low-risk patient (without any history of thrombosis and ≤60 years)

High-risk patient (with a history of thrombosis or older than 60 years )

If a patient has microvascular symptoms, which have not been controlled sufficiently or leukocytosis or cardiovascular symptoms specifically hypertension

Add hydroxyurea with the initial dose of 500 mg twice daily

If the patient could not tolerate hydroxyurea or was resistant to it

Prescribe Aspirin BID

If the patient has a history of arterial thrombosis

If the patient has a history of venous trombosis

prescribe Pegylated IFN-α or Busulfan

Prescribe Aspirin BID

Add systemic anticoagulant therapy

Do's

• First, you should differentiate between absolute polycythemia and relative polycythemia
• Ask the patient about using diuretics and products athletes use to improve their function
• Low-dose of Aspirin must be prescribed for all cases of polycythemia vera who do not have any contraindication

Don'ts

• Do not analyze JAK2 mutation in every case as a first step when there is no clinical finding related to polycythemia vera
• In women with polycythemia vera do not consider pregnancy as a contraindication
• Aspirin should not be prescribed in cases of acquired von Willebrand disease

References

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