USMLE The New "Free 138"

[Renaissance Man]

So in April of 2014, the USMLE website released a "new" set of practice questions. There are 3 blocks of 46 questions, that you can find here. Before anyone asks, yes this is the same exact set of questions that you get if you pay to go to Prometric and take a practice run. The only difference I found is 3 or 4 audio/visual questions.

Anyways, since the material is freely available, I figured that we could discuss any of the questions that people are having trouble with...I will start:

"23. A 17 year-old boy comes to the emergency department because of severe thirst and weakness and 4-kg weight loss over the past 36 hours. He began having voluminous painless watery diarrhea on the airplane while returning from a trip to Thailand 36 hours ago. He has not vomited. While supine, pulse is 110/min and blood pressure is 110/60 mmHg. While standing, pulse is 170/min and blood pressure is 70/40 mmHG. His abdomen is contender and bowel sounds are increased. Which of the following treatments is most appropriate at this time?

(A) Ciprofloxacin
(B) Doxycycline
(C) Exploratory Lapartomay
(D) Potassium Chloride
(E) Rehydration
(F) Trimethoprim-Sulfamethoxazole"

I chose (E) as I figured with his orthostatic hypotension he is extremely dehydrated but the answer is (F). Am I missing something crucial here? Thanks!

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[Psai]

Thanks bro, you too.

 

[igcgnerd]

@notbobtrustme
Actually not necessarily correct. Hemothorax means purely blood in the pleural cavity. This can create a collapsed long. Hemopneumothorax means blood AND air in the pleural cavity leading to lung collapse. You don't necessarily need to have "pneumo" in the word to denote lung collapse. The pneumo strictly refers to the presence of air in the cavity.

 

[thehundredthone]

hemothorax -> blood in the pleural area, no collapse of lung. hemopneumothorax -> blood in the pleural area, collapsed lung.

this is basically a vocab question testing whether you can string together a bunch of latin pre/suffixes to describe what's going on in this patient.

Per the latin, pneumo means air, not collapse. As a couple of people have pointed out, the terms do not denote the integrity of the lung, only the content of the thorax (or rather, pleural space). Either condition can collapse the lung, and you can have a pneumothorax without complete lung collapse.

 

[Psai]

Wouldn't the loss of negative pressure in the pleura due to air being in there cause a collapse of a section of the lung?

 

[Dr.Surgeon]

does anybody know what 75% on this thing correlate with??

 

[Psai]

does anybody know what 75% on this thing correlate with??

Probably around a 229

 

[Dr.Surgeon]

Probably around a 229

thank you sir

 

[J ROD]

really that high? i would say around 215

 

[Psai]

really that high? i would say around 215

I just went on some website called medfriends.org/step1_estimator and plugged it in
i put my nbme test score there and it was similar to what the prediction was from a chart that i used here: NBME-USMLE-SCORE-TABLE

 

[J ROD]

I just went on some website called medfriends.org/step1_estimator and plugged it in
i put my nbme test score there and it was similar to what the prediction was from a chart that i used here: NBME-USMLE-SCORE-TABLE

fair enough. thanks