Is 2+ urine blood worse than 6-9 urine Red Blood Cells (RBC) on a urinalysis?

Understanding Urinalysis Results: 2+ Blood vs. 6-9 RBCs/HPF

2+ blood on urine dipstick is generally equivalent to or possibly less severe than 6-9 RBCs per high-power field (HPF) on microscopic examination, as dipstick testing alone is insufficient for clinical decision-making and requires microscopic confirmation. 1

Interpretation of Urinalysis Results

Dipstick Blood Testing

• Dipstick testing (2+ blood) measures peroxidase activity, which can be confounded by factors including povidone iodine, myoglobinuria, and dehydration 1
• A positive urine dipstick test (trace blood or greater) should prompt formal microscopic evaluation of the urine 1
• Clinicians should not define hematuria by positive dipstick testing alone 1

Microscopic Examination

• Microscopic hematuria is defined as >3 red blood cells per high-power field (RBC/HPF) on microscopic evaluation of a single, properly collected urine specimen 1
• 6-9 RBCs/HPF represents a quantitative measurement that provides more precise information about the degree of hematuria 1, 2
• Microscopic examination is essential for confirming the presence and degree of hematuria suggested by dipstick testing 1

Clinical Significance Comparison

Dipstick 2+ Blood

• Semi-quantitative measurement that roughly correlates with the presence of RBCs but lacks precision 2
• May produce false positives due to hemoglobinuria, myoglobinuria, or certain medications 1
• Cannot distinguish between intact RBCs and free hemoglobin 2

6-9 RBCs/HPF

• Represents a specific, quantitative measurement of intact RBCs 1
• Provides more reliable information for clinical decision-making 1, 2
• Allows for assessment of RBC morphology (dysmorphic vs. isomorphic), which can help determine the source of bleeding (glomerular vs. non-glomerular) 3

Clinical Implications

Diagnostic Value

• Microscopic confirmation with RBC count (6-9 RBCs/HPF) is more valuable than dipstick alone (2+) for clinical decision-making 1
• The American College of Physicians recommends confirming heme-positive results of dipstick testing with microscopic urinalysis that demonstrates 3 or more erythrocytes per high-powered field before initiating further evaluation 1

Risk Assessment

• Neither measurement alone determines the risk of underlying pathology; risk assessment should consider patient factors including age, sex, smoking history, and other risk factors 1, 3
• Both findings exceed the threshold for microscopic hematuria (>3 RBCs/HPF) and warrant appropriate evaluation 1

Common Pitfalls to Avoid

• Relying solely on dipstick results without microscopic confirmation 1
• Attributing hematuria solely to antiplatelet or anticoagulant therapy without further investigation 1, 3
• Failing to repeat urinalysis after treatment of presumed benign causes 2
• Neglecting to evaluate women with hematuria as thoroughly as men 2

Conclusion

When comparing 2+ blood on dipstick with 6-9 RBCs/HPF on microscopic examination, the microscopic finding provides more precise and reliable information. The dipstick result is a screening tool that requires microscopic confirmation, while the microscopic count offers quantitative data that better guides clinical decision-making. Therefore, 6-9 RBCs/HPF represents a more definitive finding than 2+ blood on dipstick, though both warrant appropriate clinical evaluation.