12-27-2008, 01:39 AM
A previously healthy 15-year-old boy is brought to the
physician
because of a 5-day history of fever, intractable
nausea and vomiting, sore
throat, and muscle pain. His mother has been giving
him ibuprofen and
amoxicillin that was remaining from a previous
streptococcal throat
infection. He appears ill, and his lips are parched.
His temperature is
38.9 C (102 F), blood pressure is 120/74 mm Hg while
supine and 100/70 mm
Hg while standing, and pulse is 92/min while supine
and 120/min while
standing. Examination shows dry mucous membranes.
The oropharynx is
erythematous without exudate. There is shotty
cervical adenopathy. The
abdomen is soft without organomegaly. Laboratory
studies show:
Serum
Na+ 138 mEq/L
Cl“ 98 mEq/L
K+ 3.4 mEq/L
HCO3“ 21 mEq/L
Urea nitrogen (BUN) 55 mg/dL
Glucose 105 mg/dL
Creatinine 1.3 mg/dL
Amylase 40 U/L
Urine
Ketones moderate
WBC negative
RBC negative
Na+ 8 mEq/L
Protein negative
Which of the following is the most likely explanation
for this
patient's renal insufficiency?
A
) Acute tubular necrosis
B
) Amoxicillin-induced acute interstitial nephritis
C
) Ibuprofen-induced renal failure
D
) Post-streptococcal glomerulonephritis
E
) Severe volume depletion