54. A 46-year-old patient presents to the clinic with a complaint of gross hematuria. Approximately one month ago, the patient reported having had a fever and severe sore throat but received no medical treatment. Physical examination reveals mild costovertebral tenderness (CVA). The remainder of the exam was unremarkable. Which laboratory findings would be expected with this condition?
Answer: C
Elevated blood urea nitrogen (BUN)
In the context of this patient with gross hematuria, a history of fever, and mild costovertebral tenderness, elevated blood urea nitrogen (BUN) is expected. This finding suggests possible renal impairment or dehydration, which can accompany conditions causing hematuria.
A) Normal creatinine clearance test
A normal creatinine clearance test would indicate that kidney function is intact, which is unlikely given the patient's symptoms of hematuria and costovertebral tenderness. These signs suggest a potential renal pathology, which would typically result in abnormal creatinine clearance.
B) Urine specific gravity 1.010
A urine specific gravity of 1.010 suggests dilute urine, which may occur in certain conditions but does not specifically correlate with the expected findings in cases of hematuria associated with renal impairment. More concentrated urine would be expected if there is dehydration or renal dysfunction.
C) Elevated blood urea nitrogen (BUN)
Elevated blood urea nitrogen (BUN) is consistent with this patient's presentation. Conditions causing hematuria, particularly those that are inflammatory or infectious in nature, can lead to increased BUN levels due to kidney stress or dehydration, making this the most appropriate laboratory finding.
D) Clear, yellow urine color
Clear, yellow urine is indicative of normal hydration and kidney function, which does not align with the patient's symptoms of gross hematuria and possible renal involvement. The presence of blood in the urine typically results in a different appearance, often indicating pathology.
Conclusion
Elevated blood urea nitrogen (BUN) is the correct laboratory finding in this scenario, reflecting potential renal impairment or dehydration associated with the patient's gross hematuria and previous infection. Other options do not accurately represent the expected laboratory results given the patient's clinical presentation, reinforcing that elevated BUN is the most relevant indicator of the underlying condition.