What objective data should be evaluated for obstructive symptoms in Benign Prostatic Hyperplasia (BPH)?

From the Guidelines

To evaluate obstructive symptoms in benign prostatic hyperplasia (BPH), you should assess several key objective data points, including urinary flow studies, post-void residual (PVR) volume, prostate size, urinalysis, and serum creatinine and blood urea nitrogen (BUN) levels, as recommended by the most recent guidelines 1.

Key Objective Data Points

• Urinary flow studies, particularly maximum flow rate (Qmax), with values below 10-15 mL/second suggesting obstruction
• Post-void residual (PVR) volume, measured using ultrasound or catheterization, with volumes exceeding 100 mL indicating incomplete bladder emptying
• Prostate size assessment via digital rectal examination (DRE) and transrectal ultrasound (TRUS), with enlargement typically over 30 grams suggesting BPH
• Urinalysis and urine culture to rule out infection or hematuria
• Serum creatinine and blood urea nitrogen (BUN) to assess kidney function, as chronic obstruction may lead to renal impairment

Additional Diagnostic Tests

• Prostate-specific antigen (PSA) testing to help differentiate BPH from prostate cancer, with PSA density (PSA level divided by prostate volume) providing additional diagnostic value
• Pressure-flow studies to definitively diagnose bladder outlet obstruction by measuring detrusor pressure and flow rate simultaneously
• Cystoscopy to visualize the prostatic urethra and assess the degree of obstruction

Symptom Assessment

• The AUA Symptom Index (identical to the seven symptom questions of the International Prostate Symptom Score [IPSS]) should be used as the symptom-scoring instrument in the initial assessment of each patient presenting with BPH 1
• Symptom score changes and the degree of each patient’s bother due to the symptoms should be the primary determinants of treatment response or disease progression in the follow-up period

Treatment Decisions

• These objective measures complement subjective symptom assessments like the International Prostate Symptom Score (IPSS) to guide appropriate treatment decisions for BPH, as recommended by the most recent guidelines 1.

From the FDA Drug Label

The International Prostate Symptom Score (IPSS, or AUA Symptom Score) consists of seven questions that assess the severity of both irritative (frequency, urgency, nocturia) and obstructive (incomplete emptying, stopping and starting, weak stream, and pushing or straining) symptoms, with possible scores ranging from 0 to 35. Effect on Symptom Score Symptoms were quantified using a score similar to the American Urological Association Symptom Score, which evaluated both obstructive symptoms (impairment of size and force of stream, sensation of incomplete bladder emptying, delayed or interrupted urination) and irritative symptoms (nocturia, daytime frequency, need to strain or push the flow of urine) by rating on a 0 to 5 scale for six symptoms and a 0 to 4 scale for one symptom, for a total possible score of 34.

The objective data to evaluate for obstructive symptoms in BPH include:

• International Prostate Symptom Score (IPSS): specifically the questions related to obstructive symptoms such as incomplete emptying, stopping and starting, weak stream, and pushing or straining.
• Peak urinary flow rate: measured in mL/sec, to assess the maximum flow rate of urine.
• Symptom scores: similar to the American Urological Association Symptom Score, which evaluates obstructive symptoms such as impairment of size and force of stream, sensation of incomplete bladder emptying, delayed or interrupted urination. 2 3

From the Research

Objective Data for Evaluating Obstructive Symptoms in BPH

To evaluate obstructive symptoms in Benign Prostatic Hyperplasia (BPH), several objective data points should be considered:

• Uroflowmetry: This measures the flow rate of urine and can help identify obstruction 4. Approximately 70% of men with a uroflow rate of less than 15 mL/sec are obstructed.
• Postvoid Residual Urine Volume: This measures the amount of urine left in the bladder after urination and can indicate abnormal bladder function rather than just obstruction 4.
• Prostate Volume Determination: While prostate size does not directly correlate with symptoms, it can be used to select treatment options 4.
• Pressure-Flow Studies: These studies can help assess the degree of obstruction and bladder function 4.
• Symptom Questionnaires: These can help assess the severity of symptoms, although it's noted that bother, not symptom score, drives decision-making in BPH management 4.

Diagnostic Assessment

Diagnostic assessment of BPH involves:

• Careful Medical History and Physical Examination: To identify symptoms and rule out other conditions 5.
• Uroflowmetry and Palpation of the Prostate: To assess urinary flow and prostate size 6.
• Ultrasound: To investigate palpable abnormalities and identify unexpected prostatic cancer 6.
• Symptom Scoring: Using a simple questionnaire to assess obstructive and irritative symptoms 6.

Treatment Considerations

Treatment considerations for BPH include:

• Alpha1-Adrenergic Antagonists and 5alpha-Reductase Inhibitors: Two major classes of prescription medications for managing BPH symptoms 7, 8, 5.
• Combination Therapy: May be beneficial for patients with more severe symptoms, larger prostate volume, and higher PSA levels 8.