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Caroline Bell: Test Results

EKG

Patient: Caroline Bell
Referring Physician: Dr. Grey

CBC

wbc 8000 (5-10,000)
hct 37% (female 36-44% male 40-50%)
polys 70% (60-80%)
lymphs 30% (20-40%)

Chemistries

bun 28 (18-25mg%)
creatinine 1.8 (5-1.7 mg%)
random glucose 106 (up to 109)
sodium 143 (135-145 mmol/liter)
potassium 5.2 (3.3-4.9 mmol/liter)
bicaronate 24 (22-32 mmol/liter)
chloride 100 (97-110 mmol/liter)

The correct answer is c.

Atrial fibrillation is defined by absence of organized p wave activity, variable R-R intervals, and constant QRS configuration as seen in the lead 2 rhythm strip at the bottom of the tracing. Note that there appear to be flutter-like p waves in lead 1. These are an artifact seen in that lead only.

What is the most likely explanation for Caroline's abnormal chemistry results?

a. Medication side effect
b. Prerenal azotemia resulting from low cardiac output secondary to persistent tachycardia
c. Renal artery stenosis

The correct answer is a.

Mild elevations in serum BUN, creatinine and potassium are common with ACE (angiotensin converting enzyme inhibitor) drugs such as lisinopril and are not necessarily an indication to discontinue the medication. A low potassium diet would help to lower the potassium. High renin and aldosterone levels associated with renal artery stenosis tend to cause hypokalemia, rather than hyperkalemia. There is no evidence for low cardiac output, such as hypotension, pallor, diaphoresis, cool skin or poor mentation on physical examination.

Next: Questions about this case

Caroline Bell: Test Results

EKG

CBC

Chemistries

Self-assessment questions:

The correct answer is c.

The correct answer is a.