View source for WBR0853

 {{WBRQuestion
|QuestionAuthor= {{MM}}
|ExamType=USMLE Step 3
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|MainCategory=Emergency Room
|MainCategory=Emergency Room
|SubCategory=Infectious Disease, Infectious Disease
|Prompt=An 11 year-old boy brought to the ED by his mother complaining of progressive severe pain, and swelling in his left foot.  The mother said that she used some analgesic medications that were prescribed to him 2 weeks ago for fever after he injured himself during playing, but neither the pain nor the fever subsided.  He is a diabetic on insulin, taking no other medications.  On examination, the patient is feverish with temperature 39 C (102 F), heart rate 100/min, blood pressure 140/80 mmHg, and respiratory rate of 22/min.   His left foot is severely tender, red, and hot, with decreased range of motion on examination.  You ordered x-ray which turned back with no pathology.  You ordered a blood culture.  What is the best antibiotic treatment of choice in this patient?
|Explanation=Antibiotic therapy should be directed to culture and susceptibility findings.  When culture results are bending, broad spectrum empiric therapy should be administered.   Antibiotic treatment of Osteomyelitis consists of a 4- to 6-week course, and the best choice to start with is the intravenous nafcillin/oxacillin.
<table border="1" cellspacing="0" cellpadding="0" > 
<tr>
<td valign="top" bgcolor="#cccccc" ><p>'''Organism'''</p></td>
<td valign="top" bgcolor="#cccccc" ><p>'''Antibiotic(s) of first choice'''</p></td>
</tr>

<tr>
<td valign="top" ><p>Staphylococcus aureus or coagulasenegative (methicillin-sensitive) Staphylococci</p></td>
<td valign="top" ><p>Nafcillin (Unipen), 2 g IV every 6 hours, or clindamycin phosphate (Cleocin Phosphate), 900 mg IV every 8 hours</p></td>
</tr>

<tr>
<td valign="top" bgcolor="#cccccc" ><p>S. aureus or coagulase-negative (methicillin-resistant) staphylococci</p></td>
<td valign="top" bgcolor="#cccccc" ><p>Vancomycin, 1 g IV every 12 hours</p></td>
</tr>

<tr>
<td valign="top" ><p>Various streptococci (groups A and B β-hemolytic organisms or penicillin-sensitive Streptococcus pneumoniae)</p></td>
<td valign="top" ><p>Penicillin G, 4 million units IV every 6 hours</p></td>
</tr>

<tr>
<td valign="top" bgcolor="#cccccc" ><p>Intermediate penicillin-resistant S. pneumoniae</p></td>
<td valign="top" bgcolor="#cccccc" ><p>Cefotaxime (Claforan), 1 g IV every 6 hours, or ceftriaxone, 2 g IV once daily</p></td>
</tr>

<tr>
<td valign="top" ><p>Penicillin-resistant S. pneumoniae</p></td>
<td valign="top" ><p>Vancomycin, 1 g IV every 12 hours</p></td>
</tr>

<tr>
<td valign="top" bgcolor="#cccccc" ><p>Enterococcus species</p></td>
<td valign="top" bgcolor="#cccccc" ><p>Ampicillin, 1 g IV every 6 hours, or vancomycin, 1 g IV every 12 hours</p></td>
</tr>

<tr>
<td valign="top" ><p>Enteric gram-negative rods</p></td>
<td valign="top" ><p>Fluoroquinolone (e.g., ciprofloxacin [Cipro], 750 mg orally every 12 hours)</p></td>
</tr>

<tr>
<td valign="top" bgcolor="#cccccc" ><p>Serratia species or Pseudomonas aeruginosa</p></td>
<td valign="top" bgcolor="#cccccc" ><p>Ceftazidime (Fortaz), 2 g IV every 8 hours (with an aminoglycoside given IV once daily or in multiple doses for at least the first 2 weeks)</p></td>
</tr>

<tr>
<td valign="top" ><p>Anaerobes</p></td>
<td valign="top" ><p>Clindamycin, 600 mg IV or orally every 6 hours</p></td>
</tr>

<tr>
<td valign="top" bgcolor="#cccccc" ><p>Mixed aerobic and anaerobic Organisms</p></td>
<td valign="top" bgcolor="#cccccc" ><p>Amoxicillin-clavulanate, 875 mg and 125 mg, respectively, orally every 12 hours</p></td>
</tr>


</table>
http://www.aafp.org/afp/2001/0615/p2413.html
|AnswerA=IV nafcillin for 4-6 weeks
|AnswerAExp=Correct
nafcillin/oxacillin is the antibiotic of choice to start with as most of the causative organism is Staphylococcus aureus or coagulasenegative (methicillin-sensitive) Staphylococci
|AnswerB=IV Vancomycin for 4-6 weeks
|AnswerBExp=Incorrect
We don’t start vancomycin unless the result of the culture denotes methicillin-resistant staphylococci or Penicillin-resistant S. pneumoniae
|AnswerC=I.V Ceftazidime for 4-6 weeks
|AnswerCExp=Incorrect 
Ceftazidime  is the drug of choice if the blood culture reveals Serratia species or Pseudomonas aeruginosa
|AnswerD=I V Clindamycin for 4-6 weeks
|AnswerDExp=Incorrect
Clindamycin is used when anaerobes is the causative organism
|AnswerE=I.V Ciprofloxacin for 4-6 weeks
|AnswerEExp=Incorrect
Ciprofloxacin is used with Enteric gram-negative rods
|RightAnswer=A
|WBRKeyword=[[Osteomyelitis]]
|Approved=No
}}