My Board Question about Urine

[Anonymous]

An athletic came in for a physical checkup. His urine showed red blood cell. He is very active in running. Besides rbc what can cause positive red blood cell in this athlete?

[ttranmd]

Myoglobin can also cause a dipstick urine to be positive.

It's one of the hallmarks of rhabdomyolysis, where you get an elevated creatinine kinase due to muscle breakdown despite a low (or else low percentage) of CK-MB which tends to be specific toward myocardium. But the urine shows large blood but very few RBCs due to the myoglobin.

Treatment is based on aggressive IVFs to wash out the myoglobin and to keep the kidneys well hydrated. Alkanization is preferred to prevent crystallization with a preferred urine pH of greater than 7.5, but addition of bicarbonate to the IVFs is generally not indicated unless the CK is greater than 15,000.

Tony