Internal Medicine
Hematology
Hematuria

Hematuria

Introduction

Hematuria is a common clinical presentation that's crucial for Canadian medical students preparing for the MCCQE1 exam. This comprehensive guide will cover the essential aspects of hematuria, focusing on Canadian healthcare practices and MCCQE1 exam objectives.

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Hematuria is defined as the presence of blood in the urine. It can be visible (gross hematuria) or microscopic (detected only through urinalysis).

Types of Hematuria

Blood visible in the urine, often described as "cola-colored" or "tea-colored"

Epidemiology in Canada

  • Prevalence of microscopic hematuria: 2.5-13% of the general population
  • More common in older adults (>60 years)
  • Higher incidence in smokers and those with occupational exposure to chemicals

Etiology

Understanding the causes of hematuria is crucial for MCCQE1 preparation. Remember the mnemonic "VINDICATE" for a comprehensive differential diagnosis:

  1. Vascular (e.g., renal infarction)
  2. Infectious (e.g., urinary tract infection)
  3. Neoplastic (e.g., bladder cancer, renal cell carcinoma)
  4. Drugs (e.g., anticoagulants, cyclophosphamide)
  5. Inflammatory (e.g., glomerulonephritis)
  6. Congenital (e.g., polycystic kidney disease)
  7. Autoimmune (e.g., IgA nephropathy)
  8. Trauma (e.g., kidney injury)
  9. Endocrine (e.g., hypercalciuria)
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In Canada, the most common causes of hematuria in adults are urinary tract infections, benign prostatic hyperplasia (in men), and urolithiasis. However, always consider malignancy, especially in patients over 40 years old.

Clinical Presentation

History

  • Timing and duration of hematuria
  • Associated symptoms (e.g., dysuria, flank pain)
  • Risk factors (smoking, occupational exposures)
  • Medication history (anticoagulants, NSAIDs)

Physical Examination

  • Vital signs
  • Abdominal examination
  • Digital rectal examination (in men)
  • Pelvic examination (in women)

Diagnostic Approach

For MCCQE1 success, understand the Canadian approach to diagnosing hematuria:

  1. Urinalysis: Confirm presence of RBCs
  2. Urine culture: Rule out infection
  3. Serum creatinine: Assess renal function
  4. Imaging:
    • Renal ultrasound
    • CT urography (if high suspicion of malignancy)
  5. Cystoscopy: For persistent hematuria or high-risk patients

MCCQE1 Tip

Remember that in Canada, CT urography is preferred over intravenous pyelography (IVP) for upper urinary tract imaging due to its superior sensitivity and specificity.

Management

Management depends on the underlying cause. Key points for MCCQE1:

  • Treat underlying infections with appropriate antibiotics
  • Refer to urology for cystoscopy if persistent or high-risk hematuria
  • Consider nephrology referral for glomerular causes
  • Lifestyle modifications (smoking cessation, occupational safety)

Canadian Guidelines

The Canadian Urological Association (CUA) provides guidelines for the management of hematuria:

  1. All patients with gross hematuria should undergo full evaluation
  2. Patients with microscopic hematuria and risk factors should undergo full evaluation
  3. Full evaluation includes:
    • Upper tract imaging (CT urography preferred)
    • Cystoscopy
  4. Follow-up is recommended for patients with no identifiable cause

Key Points to Remember for MCCQE1

  • Differentiate between gross and microscopic hematuria
  • Know the "VINDICATE" mnemonic for hematuria causes
  • Understand the Canadian approach to hematuria workup
  • Recognize red flags: age >40, smoking history, occupational exposures
  • Be familiar with CUA guidelines for hematuria management
  • Remember the importance of CT urography in the Canadian context
  • Understand when to refer to urology or nephrology

Sample Question

A 55-year-old man presents with intermittent gross hematuria for the past month. He has a 30 pack-year smoking history and works in a chemical plant. Physical examination is unremarkable. Urinalysis confirms hematuria, and urine culture is negative. Which one of the following is the most appropriate next step in management?

  • A. Renal ultrasound
  • B. Cystoscopy
  • C. CT urography
  • D. Intravenous pyelography
  • E. Urine cytology

Explanation

The correct answer is:

  • C. CT urography

This patient presents with gross hematuria and has significant risk factors (age >40, smoking history, occupational exposure). According to Canadian guidelines, he requires a full evaluation including upper tract imaging and cystoscopy. In Canada, CT urography is the preferred imaging modality for upper tract evaluation due to its superior sensitivity in detecting urological malignancies. While cystoscopy is also necessary, CT urography is typically performed first to evaluate the upper urinary tract. Renal ultrasound alone is insufficient, and IVP has largely been replaced by CT urography in Canadian practice.

References

  1. Canadian Urological Association. (2018). Guideline: Investigation and management of hematuria. Retrieved from https://www.cua.org/guidelines (opens in a new tab)

  2. Wollin, T., & Laroche, B. (2011). Hematuria: Etiology and evaluation for the primary care physician. Canadian Family Physician, 57(1), 40-47.

  3. Linder, B. J., Bass, E. J., Mostafid, H., & Boorjian, S. A. (2018). Guideline of guidelines: asymptomatic microscopic haematuria. BJU International, 121(2), 176-183.

  4. Medical Council of Canada. (2023). MCCQE1 Examination Objectives. Retrieved from https://mcc.ca/examinations/mccqe-part-i/ (opens in a new tab)

Elevated HemoglobinBlood in Sputum (hemoptysis)