NRCME Urinalysis and Renal Disorders 5 — Questions and Answers
Question 1: A CMV driver is found to have orthostatic proteinuria. The appropriate NRCME action is:
- Permanent disqualification
- Certify normally; orthostatic proteinuria is a benign condition (Correct answer)
- Certify for 6 months only
- Refer to nephrology immediately
Correct answer: Certify normally; orthostatic proteinuria is a benign condition
Orthostatic proteinuria is a benign condition in young individuals where protein appears in urine only in the upright position and carries no cardiovascular or renal risk.
Question 2: A driver's urine dipstick is positive for nitrites. This finding MOST specifically suggests:
- Kidney stones
- Gram-negative bacterial urinary tract infection (Correct answer)
- Bladder cancer
- Acute tubular necrosis
Correct answer: Gram-negative bacterial urinary tract infection
Nitrites are produced by gram-negative bacteria that convert urinary nitrates to nitrites, making this finding highly specific for gram-negative UTI.
Question 3: Which medication commonly used by CMV drivers can cause FALSE-POSITIVE urine glucose on dipstick testing?
- Metformin
- High-dose vitamin C (ascorbic acid) (Correct answer)
- Lisinopril
- Atorvastatin
Correct answer: High-dose vitamin C (ascorbic acid)
High-dose vitamin C can interfere with the glucose oxidase reaction on dipstick, causing false-negative results for glucose (and false results for other analytes).
Question 4: A dialysis-dependent driver applies for a DOT medical certificate. Under FMCSA standards, this driver is:
- Eligible for a 1-year certificate with nephrologist clearance
- Eligible for a 6-month certificate only
- Disqualified from interstate commerce (Correct answer)
- Eligible if hemoglobin is maintained above 10 g/dL
Correct answer: Disqualified from interstate commerce
FMCSA regulations disqualify drivers who are on dialysis from operating CMVs in interstate commerce due to the unpredictability of uremic complications and treatment schedules.
Question 5: A urine dipstick shows bilirubin positive and urobilinogen elevated. This pattern is MOST consistent with:
- Obstructive jaundice (bile duct obstruction)
- Hemolytic anemia
- Normal variation
- Hepatocellular disease (hepatitis/cirrhosis) (Correct answer)
Correct answer: Hepatocellular disease (hepatitis/cirrhosis)
Both conjugated bilirubin (filtered by kidneys) and urobilinogen are elevated in hepatocellular disease because the liver cannot clear urobilinogen reabsorbed from the gut.
Question 6: A driver with a solitary kidney (unilateral nephrectomy) should be evaluated PRIMARILY for:
- Automatic disqualification regardless of function
- Compensatory hypertrophy adequacy, blood pressure control, and residual renal function (Correct answer)
- Frequency of urination affecting driving schedule
- Increased risk of urinary tract infections
Correct answer: Compensatory hypertrophy adequacy, blood pressure control, and residual renal function
The NRCME must assess whether the remaining kidney provides adequate function (eGFR), whether hypertension is well-controlled, and overall cardiovascular risk.
Question 7: When should a commercial driver with asymptomatic microscopic hematuria be referred for further urological evaluation before certification?
- Never; microscopic hematuria is always benign in drivers
- When 3 or more RBCs per HPF are found on two separate properly collected specimens (Correct answer)
- Only if gross hematuria is present
- Only in drivers over age 60
Correct answer: When 3 or more RBCs per HPF are found on two separate properly collected specimens
Persistent microscopic hematuria (≥3 RBCs/HPF on two specimens) warrants urological workup to exclude bladder cancer, kidney stones, or glomerular disease before certification.
NRCME Urinalysis and Renal Disorders 5
A CMV driver is found to have orthostatic proteinuria.
The appropriate NRCME action is: