NBME 1 question

[LuckiestOne]

---

Members don't see this ad.

A 45 year old man has nausea, vomiting, and abdominal pain. He has tachycardia, absent bowel sounds, and involuntary guarding and rebound tenderness of the abdomen. The most likely cause?

cholecystitis
Gastritis
gastroenteritis
peritonitis
small bowel obstruction.

How should I go about answering this question? If you could provide your answer and explanation, it would be great!

 

[Boardz]

A 45 year old man has nausea, vomiting, and abdominal pain. He has tachycardia, absent bowel sounds, and involuntary guarding and rebound tenderness of the abdomen. The most likely cause?

cholecystitis
Gastritis
gastroenteritis
peritonitis
small bowel obstruction.

How should I go about answering this question? If you could provide your answer and explanation, it would be great!

peritonitis

 

[LuckiestOne]

peritonitis

Thanks, but how does peritonitis cause absent bowel sound and other described physical signs?

 

[Myxedema]

A 45 year old man has nausea, vomiting, and abdominal pain. He has tachycardia, absent bowel sounds, and involuntary guarding and rebound tenderness of the abdomen. The most likely cause?

cholecystitis
Gastritis
gastroenteritis
peritonitis
small bowel obstruction.

How should I go about answering this question? If you could provide your answer and explanation, it would be great!

Guarding and rebound tenderness indicate that the peritoneum has been involved. --> Peritonitis. The other answer choices will not involve the peritoneum, unless with the presence of complications and concurrent peritonitis.

 

[Belleza156]

A 45 year old man has nausea, vomiting, and abdominal pain. He has tachycardia, absent bowel sounds, and involuntary guarding and rebound tenderness of the abdomen. The most likely cause?

cholecystitis
Gastritis
gastroenteritis
peritonitis
small bowel obstruction.

How should I go about answering this question? If you could provide your answer and explanation, it would be great!

The fact that there are absent bowel sounds should lead u towards small bowel obstruction or peritonitis.

Pt has fever and tachycardia so definitely an active infection.

Pt has peritoneal signs, so now you should rule out small bowel obstruction, becuz these symptoms are more telling of a perforated viscus which would cause peritonitis.

Of the answer choices peritonitis is the answer. Now if they also had appendicitis as an option, then it would still be peritonitis because of the involuntary guarding. Remember voluntary guarding = appendicitis, involuntary guarding = peritonitis.

Sent from my PC36100 using SDN Mobile
Sent from my PC36100 using SDN Mobile

 

[firstaid2012]

i might be a little confused but i though that in small bowel obstruction there are bowel sounds? 🙁

 

[Myxedema]

i might be a little confused but i though that in small bowel obstruction there are bowel sounds? 🙁

Depends on the time elapsed. Early: hyperactive; late: hypoactive/absent.

 

[Belleza156]

i might be a little confused but i though that in small bowel obstruction there are bowel sounds? 🙁

Exactly like myxedema said.

First the SI tries to compensate for the obstruction by increasing peristalsis. But eventually this leads to inflammation and the inflammatory factors present will cause ileus.

 

[LuckiestOne]

Exactly like myxedema said.

First the SI tries to compensate for the obstruction by increasing peristalsis. But eventually this leads to inflammation and the inflammatory factors present will cause ileus.

Right, so the answer is still peritonitis, JUST BECAUSE there is an involuntary guarding? Could small bowel obstruction be a potential answer as well?

 

[Myxedema]

Right, so the answer is still peritonitis, JUST BECAUSE there is an involuntary guarding? Could small bowel obstruction be a potential answer as well?

Not by itself, but it can develop as a result of a complication. For example, bowel perforation can occur as a result of obstruction, which will cause intestinal contents to spill into the peritoneal cavity --> peritonitis

 

[Belleza156]

Right, so the answer is still peritonitis, JUST BECAUSE there is an involuntary guarding? Could small bowel obstruction be a potential answer as well?

I think the only differential for a board like abdomen is peritonitis. It's really important that you know physical exam descriptions. It's more important to know physical exam signs than pathological conditions. Because if you ever don't know what the pathology is, then you can deduce it with the physical exam signs. And by the end of MSII you are responsible for knowing what guarding is, it's very high yield. How can you tell when appendicitis has progressed to peritonitis if you don't know how guarding progresses. You should also know all the differentials for when there is hematemesis and hematochezia. You should be able to tell when its from a perforated duodenal ulcer, or portal hypertension, invading mass, etc.

Any time you get an NBME question and you aren't 100% positive what the physical exam sign is, look it up. If it's on an NBME that means it's fair game for Step 1. Even if not in the vignette, listed as an answer choice, still fair game.