What is the approach to diagnosing and managing hematuria (presence of blood in the urine)?

From the Guidelines

The diagnosis and management of hematuria should begin with determining whether the blood is visible (gross hematuria) or microscopic, followed by a thorough evaluation to identify the underlying cause, as recommended by the most recent guidelines 1.

Initial Assessment

Initial assessment should include a complete history, physical examination, urinalysis, and urine culture.

• A thorough history should be taken to identify any risk factors for underlying conditions such as malignancy, including age over 35, smoking history, or persistent hematuria.
• Physical examination should include a pelvic examination in women and a rectal examination in men.
• Urinalysis should be performed to confirm the presence of hematuria and to rule out other abnormalities such as pyuria, bacteriuria, and contaminants.
• Urine culture should be performed to identify any underlying urinary tract infection.

Further Evaluation

For patients with risk factors or persistent hematuria, further evaluation with imaging studies like CT urography or renal ultrasound is recommended 1.

• Cystoscopy is often necessary, particularly for patients with risk factors for bladder cancer.
• Laboratory tests should include complete blood count, renal function tests, and coagulation studies.

Management

Management depends on the identified cause -

• Urinary tract infections require appropriate antibiotics (such as trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3-7 days or nitrofurantoin 100 mg four times daily for 5-7 days) 1.
• Kidney stones may need pain management and possibly urological intervention.
• Glomerular causes might require nephrology referral.
• Anticoagulant-related hematuria should prompt medication review and possible adjustment.

Urgent Evaluation

Patients with gross hematuria, significant pain, fever, or signs of urinary obstruction require urgent evaluation, as they may have a higher risk of underlying malignancy or other serious conditions 1.

• The urgency of this workup is justified by the need to rule out serious conditions like malignancy, which can present with hematuria as the only symptom, and to prevent complications from treatable conditions like infections or stones.

From the Research

Approach to Diagnosing Hematuria

The approach to diagnosing hematuria involves a combination of medical history, physical examination, and diagnostic tests.

• The initial evaluation should include a thorough medical history and physical examination to identify potential causes of hematuria 2.
• Microscopic urinalysis is a key element in reaching a diagnosis, and further testing is based on these results 2.

Diagnostic Tests for Hematuria

Several diagnostic tests can be used to evaluate hematuria, including:

• CT urography, which is a rapidly evolving technique that can provide high diagnostic accuracy for urothelial cell carcinoma (UCC) and other conditions 3.
• Ultrasonography, intravenous urography, and retrograde ureteropyelography, which can be used to evaluate the upper and lower urinary tract 3, 4.
• Cystoscopy, which can be used to visualize the bladder and urethra 4, 5.
• Urine cytology, which can be used to detect abnormal cells in the urine 5.

Evaluation of Microscopic Hematuria

The evaluation of microscopic hematuria depends on the patient's age and risk factors.

• Patients over 40 years of age, those with a history of cigarette use, and those with occupational exposure or history of chronic phenacetin use should undergo complete upper tract imaging, cystourethroscopy, and cytologic examination of the urine 4.
• Patients under 40 years of age with microscopic hematuria may be evaluated with a noncontrast CT or ultrasound study, and a cystoscopy should be added if gross hematuria exists 5.

Referral to a Urologist

Referral to a urologist is important for patients with hematuria, especially those with gross hematuria or high-risk factors.

• A study found that only 36% of men and 8% of women with hematuria were referred to a urologist, highlighting the need for improved referral patterns 6.
• Male gender, ethnicity, and gross (vs. microscopic) hematuria were associated with a higher rate of urological referral 6.

Limitations of Current Practice

Current practice patterns for evaluating hematuria may be limited, with many cases not being fully evaluated according to guidelines.

• A study found that use of cystoscopy, cytology, and upper tract imaging is limited, and further studies are needed to determine the extent of the problem and impact on morbidity and survival 6.