NRCME Urinalysis and Renal Disorders 4 — Questions and Answers
Question 1: A CMV driver's urinalysis shows a specific gravity of 1.001. Which condition does this most likely indicate?
- Diabetes insipidus or overhydration (Correct answer)
- Dehydration
- Urinary tract infection
- Chronic kidney disease
Correct answer: Diabetes insipidus or overhydration
A specific gravity of 1.001 indicates very dilute urine, consistent with diabetes insipidus or excessive fluid intake.
Question 2: Under FMCSA regulations, a driver with an eGFR of 45 mL/min/1.73m² (Stage 3b CKD) should be:
- Certified for 1 year with monitoring
- Disqualified permanently
- Certified for 2 years with no restrictions
- Referred for specialist evaluation before certification decision (Correct answer)
Correct answer: Referred for specialist evaluation before certification decision
Stage 3b CKD requires specialist evaluation to assess stability, risk of progression, and cardiovascular risk before the ME makes a certification decision.
Question 3: Which urinalysis finding is MOST associated with rhabdomyolysis in a commercial driver?
- Bilirubinuria
- Myoglobinuria causing brown/tea-colored urine (Correct answer)
- Glycosuria without proteinuria
- Leukocyte esterase positive with nitrite negative
Correct answer: Myoglobinuria causing brown/tea-colored urine
Rhabdomyolysis releases myoglobin into the bloodstream, which is filtered by the kidneys producing brown or tea-colored urine on dipstick.
Question 4: A driver reports taking ibuprofen daily for back pain. What renal concern should the NRCME examiner prioritize?
- Risk of renal tubular acidosis
- NSAID-induced nephropathy causing declining eGFR (Correct answer)
- Increased urine output and dehydration
- Acute glomerulonephritis
Correct answer: NSAID-induced nephropathy causing declining eGFR
Chronic NSAID use can cause analgesic nephropathy and progressive decline in renal function that may disqualify the driver.
Question 5: On urinalysis, waxy casts are MOST indicative of:
- Early acute kidney injury
- Normal renal tubular function
- Advanced chronic renal failure with slow urine flow (Correct answer)
- Urinary tract infection
Correct answer: Advanced chronic renal failure with slow urine flow
Waxy casts form from degenerated granular casts in tubules with very slow flow, indicating advanced chronic renal disease.
Question 6: A driver with polycystic kidney disease (PKD) applies for DOT certification. The examiner's MAIN concern is:
- Risk of hematuria causing distraction while driving
- Progressive renal failure, hypertension, and associated intracranial aneurysm risk (Correct answer)
- Frequent urination requiring stops
- Medication side effects from pain management
Correct answer: Progressive renal failure, hypertension, and associated intracranial aneurysm risk
PKD is associated with progressive CKD, hypertension, and a significant risk of intracranial berry aneurysms that can cause sudden incapacitation.
Question 7: Which finding on urine microscopy is pathognomonic for acute glomerulonephritis?
- Hyaline casts
- Red blood cell casts (Correct answer)
- Fatty casts
- Granular casts
Correct answer: Red blood cell casts
Red blood cell casts are pathognomonic for glomerulonephritis, indicating bleeding within the glomerulus itself.
NRCME Urinalysis and Renal Disorders 4
A CMV driver's urinalysis shows a specific gravity of 1.001.
Which condition does this most likely indicate?