Guidelines on Hematuria: Determing the Cause

The American Urological Association (AUA) published guidelines for asymptomatic microhematuria. The document includes 19 guidelines with recommendation levels ranging from A to C (high to low) and some expert opinion recommendations included. The full guidelines can be accessed at http://www.auanet.org/common/pdf/education/clinical-guidance/Asymptomatic-Microhematuria.pdf.

Q: A 45-year-old man came into my office complaining that he had seen “pink” in his urine. I dipped the urine in the office, and it was positive for blood. What should I do now? Should I send him directly to nephrology or urology? Or should I do a work-up myself? And if I do the work-up, what tests should I order?

When treating the patient with hematuria, it is important to keep in mind both the most common benign causes and the more serious causes of hematuria. The most common benign causes, according to the AUA guideline 6,¹ include infection, menstruation, vigorous exercise, trauma, anticoagulant use, and a recent urologic procedure. The potentially serious causes include glomerulonephritis (which can be rapidly progressive) and malignancy.

The AUA (guidelines 1 to 4, based on expert opinion)¹ recommends confirming hematuria with a microscopic exam rather than relying on a urine dipstick.

The common benign causes of hematuria can usually be identified in the course of a thorough history and physical. Because hematuria can be a harbinger of renal disease, however, serum creatinine and blood urea nitrogen (BUN) should be ordered at the initial evaluation in the primary care setting.

If a benign cause of hematuria is identified and renal function is normal, the patient should be treated by the primary care provider and re-evaluated as indicated, based on the underlying diagnosis. If there is a rise in serum creatinine or a reduction in estimated glomerular filtration rate (eGFR) in conjunction with the hematuria, the patient should be referred to nephrology for further evaluation.

If no benign cause of hematuria is identified and renal function is unaffected, the patient should be referred to urology for urologic evaluation.¹

Alexis Chettiar, ACNP, East Bay Nephrology Medical Group, Oakland, CA

References
1. Davis R, Jones JS, Barocas DA, et al; American Urological Association. Diagnosis, Evaluation, and Follow-up of Asymptomatic Microhematuria (AMH) in Adults: AUA Guideline. Linthicum, MD: American Urological Association Education and Research, Inc; 2012. http://www.auanet.org/common/pdf/education/clinical-guidance/Asymptomatic-Microhematuria.pdf. Accessed January 24, 2013.
2. National Kidney and Urologic Diseases Information Clearinghouse. Hematuria: blood in the urine (2012). http://kidney.niddk.nih.gov/kudiseases/pubs/hematuria. Accessed January 17, 2013.
3. Geavlete B, Jecu M, Multescu R, et al. HAL blue-light cystoscopy in high-risk nonmuscle-invasive bladder cancer: re-TURBT recurrence rates in a prospective, randomized study. Urology. 2010;76(3):664-669.

Suggested Reading
Feldman AS, Hsu C-Y, Kurtz M, Cho KC. Etiology and evaluation of hematuria in adults (2012). www.uptodate.com/contents/etiology-and-evaluation-of-hematuria-in-adults. Accessed January 17, 2013.
Jayne D. Hematuria and proteinuria. In: Greenberg A, ed; National Kidney Foundation. Primer on Kidney Diseases. 5th ed. Saunders; 2009:33-42.