Erythrocyte limits in haematuria.

Area of Science:

• Urology
• Nephrology
• Clinical Chemistry

Background:

• Hematuria, the presence of red blood cells (RBCs) in urine, is a significant clinical finding.
• Distinguishing between gross hematuria (visible to the naked eye) and microscopic hematuria (detectable only by microscopy) is crucial for diagnosis.
• Current quantification methods can be complex or require specialized equipment.

Purpose of the Study:

• To define a precise quantitative boundary between gross and microscopic hematuria.
• To establish a simple, visual method for estimating red blood cell concentration in urine.
• To correlate visual urine color assessment with red blood cell counts.

Main Methods:

• Red blood cell counts were performed on freshly voided, non-centrifuged urine samples.
• Urine color was visually assessed using a standardized light beam illumination technique.
• Visual color estimations were compared against direct red blood cell counts (erythrocytes/mm³).

Main Results:

• The estimated boundary between gross and microscopic hematuria was determined to be 5000 erythrocytes/mm³.
• A direct correlation was observed between the visual color of the urine and the quantified red blood cell concentration.
• Visual assessment using a light beam provides a reliable estimation of RBCs/mm³.

Conclusions:

• A threshold of 5000 erythrocytes/mm³ effectively differentiates gross from microscopic hematuria.
• Visual urine color assessment, aided by specific lighting, offers a practical and accessible method for estimating hematuria severity.
• This visual method can aid in rapid clinical assessment of patients with suspected hematuria.