What is the proper procedure for ordering a microscopic report for a urinalysis in a patient with a potential urinary tract infection or kidney stones?

How to Order a Microscopic Urinalysis

When ordering a urinalysis, you should specifically request "urinalysis with microscopy" or "complete urinalysis" to ensure microscopic examination is performed, as dipstick-only testing is insufficient for clinical decision-making. 1, 2

Understanding the Components of Urinalysis

A complete urinalysis consists of three distinct components that must all be performed for proper evaluation 2:

• Physical examination: Assesses color, clarity, and specific gravity 2
• Chemical examination: Dipstick testing for blood, protein, leukocyte esterase, nitrites, and other parameters 2
• Microscopic examination: Direct visualization of urinary sediment for red blood cells, white blood cells, casts, crystals, and bacteria 2, 3

The Critical Importance of Microscopic Examination

Dipstick testing alone misses 30% of clinically significant urinary findings that are only detected on microscopic examination. 3 This is why you cannot rely on dipstick results alone—the microscopic component is essential 3, 4.

Key Limitations of Dipstick Testing

• Dipstick has only 65-99% specificity for detecting blood, producing frequent false positives 1, 5
• Dipstick positivity for blood must be confirmed with microscopic examination showing ≥3 red blood cells per high-power field before initiating any hematuria workup 1, 5
• Approximately 15% of all urines reveal significant findings only on microscopic examination that were completely missed by dipstick 3

How to Order the Test Correctly

Specific Order Entry Language

Use these exact phrases when ordering to ensure microscopic examination is included 1:

• "Urinalysis with microscopy" (preferred)
• "Complete urinalysis"
• "Urinalysis with microscopic examination of sediment"

What NOT to Order

Avoid ordering 2, 4:

• "Urinalysis" alone (may default to dipstick only at some facilities)
• "Urine dipstick" (chemical testing only, no microscopy)
• "Routine urinalysis" (ambiguous, may not include microscopy)

Clinical Scenarios Requiring Microscopic Examination

Mandatory Microscopic Examination

The following clinical situations absolutely require microscopic urinalysis 1:

• Suspected urinary tract infection: To confirm pyuria (≥10 WBCs/HPF) before ordering urine culture 1
• Evaluation of hematuria: To confirm ≥3 RBCs/HPF and assess for dysmorphic RBCs or casts 1
• Assessment for proteinuria: To examine for cellular casts suggesting glomerular disease 1, 6
• Screening in patients with lower urinary tract symptoms: To exclude infection, hematuria, and bladder pathology 1

Specific Guideline Recommendations

For benign prostatic hyperplasia evaluation: Urinalysis by dipstick testing OR microscopic examination should be performed to screen for hematuria and UTI 1

For overactive bladder evaluation: Dipstick or microscopic urinalysis should be performed in all patients, with urine culture if urinalysis suggests infection or hematuria 1

For long-term care facility residents with suspected infection: Minimum evaluation should include urinalysis for leukocyte esterase and nitrite by dipstick AND microscopic examination for WBCs 1

Specimen Collection and Timing

Collection Method

For accurate microscopic examination 1, 2:

• Midstream clean-catch specimen is acceptable in most situations 2
• In-and-out catheterization may be necessary for women unable to provide clean-catch specimens 1
• Freshly applied clean condom catheter with frequent monitoring for cooperative men 1

Critical Timing Requirement

The specimen must be examined within 2 hours of collection to prevent cellular degradation and bacterial overgrowth. 2 This is a common pitfall—delayed processing renders microscopic findings unreliable 2.

Common Pitfalls to Avoid

Pitfall #1: Accepting Dipstick Results Alone

Never initiate hematuria workup based solely on dipstick positivity 1, 5. The 65-99% specificity means up to 35% of positive dipsticks are false positives 1. Always confirm with microscopic examination showing ≥3 RBCs/HPF 1, 5.

Pitfall #2: Not Specifying "With Microscopy"

At many laboratories, ordering "urinalysis" defaults to dipstick only unless microscopy is specifically requested 3, 4. This results in 30% of significant findings being missed 3.

Pitfall #3: Delayed Specimen Processing

Specimens examined >2 hours after collection have unreliable microscopic findings due to cellular lysis and bacterial proliferation 2. If immediate processing isn't possible, refrigeration can extend viability slightly, but fresh specimens are always preferred 2.

Pitfall #4: Ordering Urine Culture Without Confirming Pyuria First

In long-term care residents with suspected UTI, urine culture should only be ordered if pyuria is confirmed on microscopic examination (≥10 WBCs/HPF or positive leukocyte esterase). 1 This prevents unnecessary cultures in patients with asymptomatic bacteriuria 1.

When Microscopy Changes Management

Microscopic examination provides critical diagnostic information that dipstick cannot 3, 6:

• Dysmorphic RBCs (>80%) indicate glomerular bleeding requiring nephrology referral 1, 5, 7
• Red blood cell casts are pathognomonic for glomerulonephritis 5, 6
• White blood cell casts suggest pyelonephritis or interstitial nephritis 6
• Crystals may indicate metabolic stone disease 1
• Bacteria with pyuria confirms UTI and justifies culture 1, 2