A 41-year-old executive presents to your office with a chief complaint
of blurred vision. He went to the optometrist in the shopping mall,
who found nothing wrong with his eyesight. The optometrist suggested
a checkup from a primary care physician. The patient has not seen a
doctor in over 10 years.
The nurse in your practice tells you that the fasting fingerstick glucose
level for Mr. David Dunn was 220 mg/dL. Upon entering the examination room, you see an overweight man in no acute distress. His weight
is approximately 190 pounds, and he is 5 feet 8 inches tall.
Vital Signs:
Temperature 98.6°F
Blood pressure 130/80 mmHg
Heart rate 86 beats per minute
Respiratory rate 12 breaths per minute.Mr. David Dunn is a 41-year-old executive who presents with a 2-month
history of blurred vision. He has had a 10-lb weight loss despite an
excellent appetite; he reports polydypsia, polyuria, and polyphagia.
He has no urgency, burning on urination, or hesitancy but has nocturia. He denies dizziness on standing, incontinence, and early satiety but has had occasional erectile dysfunction. He has been experiencing numbness and tingling of his feet but denies claudication. His
family history is remarkable for his mother having type 2 diabetes. He
denies alcohol use but has smoked 1 pack of cigarettes per day for
15 years. Mr. Dunn has not seen a physician for a checkup in 10 years
and takes no medications.
PHYSICAL EXAMINATION—Indicate only the pertinent positive and negative findings related to the patient’s chief complaint.
Obese male in NAD. Weight = 190 lb. HT = 68 in. BMI = 28.89 kg/m2.
FS = 220 mg/dl.
BP = 130/80 mmHg and HR = 86 beats/min lying.
BP = 135/83 mmHg and HR = 88 beats/min standing.
HEENT: PERLA. EOMI. No JVD. No carotid bruits. Thyroid gland
normal. Fundi: No exudates, hemorrhages, or papilledema.
Heart: PMI 5th ICS MCL. Normal S1 and S2.
Extremities: Dorsalis pedis and posterior tibialis pulses 2+.
Neuro: Decreased sensation to touch bilaterally in stocking-like distribution. Decreased plantar pressure sensation bilaterally.
188 MASTERING THE USMLE STEP 2 CS
DIFFERENTIAL DIAGNOSIS
In order of likelihood, write no
more than five differential diagnoses for this patient’s current
problems.
1. diabetes mellitus
2. erectile dysfunction
3. peripheral neuropathy
4. obesity
5.
DIAGNOSTIC WORKUP
Immediate plans for no more
than five diagnostic studies.
1. fasting blood sugar
2. electrolytes
3. urinalysis
4. lipid profile
5. electrocardiogram
LEARNING OBJECTIVE FOR MR. DUNN
PROVIDE APPROPRIATE COUNSELING TO A NEW DIABETIC PATIENT
Mr. Dunn has been complaining of blurred vision, polyuria, polydipsia, polyphagia, and weight loss. He has recently developed impotence.
He has a family history of diabetes and a fasting fingerstick test in your
office reveals a glucose level of 220 mg/dL (a fasting blood glucose of
>126 on two occasions would meet the diagnostic criteria for diabetes).
Heart and lung examinations are normal; there are no signs of cardiac decompensation. Neurologic evaluation reveals a peripheral
neuropathy. He has no carotid bruits or evidence of peripheral vascular disease.
The patient has several complications of diabetes mellitus. He has
neuropathy (both peripheral and autonomic) and needs further evaluation for cardiac dysfunction and microalbuminuria (30 to 300 mg
albumin in 24 hours).
The patient requires intensive teaching regarding his diabetes. He
must learn how to monitor his own glucose level. He must be instructed
about proper diet and smoking cessation. The patient must understand
that regular foot care and eye examinations are needed to prevent
infections and blindness.
Mr. Dunn should be aware that diabetes is a chronic disease requiring ongoing evaluation and treatment to prevent the life-altering complications of the disease, such as renal failure, infections requiring
amputation, stroke, blindness, and cardiomyopathy. The patient must
be involved in his own management and enter into a partnership with
the physician in an effort to enhance his quality of life. The goals of
treatment include a hemoglobin A1c of less than 7 percent and a
blood glucose level of 80 to 120 mg/dL.
Physical Examination Pearls: Know the screening test for loss of sensation on the plantar surface of the foot. A 10-g nylon filament is used
for this test. If the patient cannot feel this filament, there is loss of pressure sensation and the patient is at risk for foot ulcers (the examinee
should remove the shoes and socks of every diabetic patient and examine the feet carefully).
Patient Note Pearl: The differential diagnosis for blurred vision, other
than diabetes mellitus, includes hypertension, cataracts, macular
degeneration, and open-angle glaucoma.