STONE DISEASE

Practical use of investigations in patients with hematuria
El-Galley R, Abo-Kamil R, Burns JR, Phillips J, Kolettis PN
University of Alabama, Birmingham, Alabama
J Endourol. 2008; 22: 51-56

• Objective: The majority of patients with microscopic hematuria undergo a complete evaluation resulting in negative findings. The outcome of patients with hematuria was analyzed in an effort to optimize the use of investigations.
• Patients and Methods: The records for 404 patients who presented with hematuria were reviewed. Data were collected on demographics, type of hematuria, investigations, and final diagnosis.
• Results: The hematuria was microscopic in 140 patients (35%) and gross in 264 patients (65%). In gross hematuria patients, 10% had urinary tract tumors and 12% had calculi. All patients with genitourinary tumors and 87% of patients with calculi had gross hematuria and/or 5 RBCs/HPF (red blood cells per highpower microscopic field) on urinalysis. The sensitivity and specificity were 94% and 6% for the dipstick urine test, 37% and 71% for urine cytology, 92% and 93% for computed tomography (CT), 50% and 95% for ultrasound scans, and 38% and 90% for intravenous pyelography, respectively. Logistic regression analysis showed that age and number of RBCs/HPF in the urinalyses were the only significant factors predicting genitourinary cancer. In patients 40 years old, there was one patient with malignancy and seven patients with stones. In older patients, there were 31 patients with malignancy and 32 patients with stones.
• Conclusions: Patients with 5 RBCs/HPF on three urinalyses are unlikely to have significant pathology and could possibly be followed up conservatively. Patients 40 years of age should have a noncontrast CT or ultrasound study if they present with microscopic hematuria, and a cystoscopy should be added if gross hematuria exists. In older patients, a pre- and postcontrast CT and a cystoscopy should be performed.
  
  
• Editorial Comment
  The authors’ findings suggest some significant differences in management approaches to those proposed in the American Urological Association practice guidelines. Most importantly, they suggest a cut-off of ≥ 5 RBC/hpf on microscopic evaluation as the threshold for which a hematuria work-up should be initiated. This contrasts to the ≥ 3 RBC/hpf threshold set by the AUA. As 17% of patients in their cohort had 3 or 4 RBC/hpf, a significant number of evaluations could have been avoided, resulting is savings of cost and patient discomfort. In addition, the authors draw a sharp distinction in the extent of work-up required for the younger patient with microhematuria – suggesting non-contrast imaging and no cystoscopy.
  However, it is important to emphasize that this study does not represent a screening population with a urinalysis performed at a primary care point of care. Rather, it is a select cohort of patients referred for urologic evaluation. Secondly, there was no standardization of imaging protocol or follow-up for delayed presentation of malignancy, to confirm the sensitivity of the > 5 RBC/hpf approach.

Dr. Manoj Monga
Professor, Department of Urology
University of Minnesota
Edina, Minnesota, USA