USMLE Forum Archives - USMLE Step 2 CK - infectious 2
infectious 2
Sarahhh - 02-03-08 20:47
A 27-yr-old homeless man presents to the ER complaining of fever, rigors and a
productive cough for the past 24-hours. He admits to have used IV heroine 24-hours
earlier. He has ronchi in both lower lung fields posteriorly. X-ray chest reveals bilateral
lobar consolidation, with an air fluid level in the lower lobe. Sputum gram staining reveals
gram-positive cocci in clusters and associated many polymorph leukocytes. Which of the
following is the most appropriate next step in management.
A. Begin therapy with oral dicloxacillin.
B. Begin therapy with ampicillin 4-times daily.
C. Initiate therapy with oral erythromycin.
D. Initiate therapy with IV erythromycin.
E. Initiate therapy with IV nafcillin.
Sarahhh - 02-03-08 20:47
A 27-yr-old homeless man presents to the ER complaining of fever, rigors and a
productive cough for the past 24-hours. He admits to have used IV heroine 24-hours
earlier. He has ronchi in both lower lung fields posteriorly. X-ray chest reveals bilateral
lobar consolidation, with an air fluid level in the lower lobe. Sputum gram staining reveals
gram-positive cocci in clusters and associated many polymorph leukocytes. Which of the
following is the most appropriate next step in management.
A. Begin therapy with oral dicloxacillin.
B. Begin therapy with ampicillin 4-times daily.
C. Initiate therapy with oral erythromycin.
D. Initiate therapy with IV erythromycin.
E. Initiate therapy with IV nafcillin.
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#1
Re: infectious 2 InSitu - 02-04-08 01:27 Homeless and compliance is an issue. This is a staph pneumonia and IV naf would do it.
#2
Re: infectious 2 radhamesramos - 02-04-08 12:02 E. Homeless with Staph pneumonia needs hospitalisation for both compliance, and of course, Staph pneumonia is super agressive. A good thing to do is a culture, and try to culture for anaerobics
#4
Re: infectious 2 funtonic - 02-04-08 21:35 nafcillin is commonly asked for treating Staph pneumonia.
#5
Re: infectious 2
Sarahhh - 02-05-08 07:58 E. This IV drug user has a classic description of a Staphylococcus
aureus pneumonia with cavitation and a diagnostic Gram's stain. Appropriate therapy
would be to admit the patient for IV nafcillin. His sputum should also be cultured to
determine sensitivity. If the patient fails to improve with IV nafcillin, or his sputum
culture demonstrates resistance to nafcillin, the appropriate next therapy would be IV
vancomycin.
Oral antibiotics, such as dicloxacillin (choice A), ampicillin (choice B), and erythromycin
(choice C) are not appropriate in this patient, who has a devastating, potentially fatal,
pneumonia (with a 30% to 40% mortality rate) that is actively destroying his lungs.
Staphylococcus aureus is one of the notoriously drug-resistant organisms, and IV
erythromycin (choice D) is not consistently active against this organism. If a
penicillinase-resistant penicillin, such as nafcillin, cannot be used because of reason of
patient allergy, suggested alternative drugs include a first or second (but not third)
generation cephalosporin or clindamycin. Methicillin-resistant Staphylococcus aureus can
be treated with IV vancomycin.
#7
Re: infectious 2 bingousmle - 06-30-10 16:17 the man has developed a lung abscess as is evident from the presence of air fluid level on the chest Xray.. treatment with iv nafcillin is warranted
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