Unusual choices for "best initial test" or "best next test"?

[shan564]

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Most of the time, when a question says "what's the most appropriate diagnostic test?", the answer is something straightforward and nonspecific, like "X-ray of the injured bone" or "serum level of the affected hormone" or the like. There may even be some disease-specific choices that are still fairly straightforward because we know them so well, like "dexamethasone suppression test" or "osmotic fragility test."

But has anybody ever made a list of all of the really specific tests and their indications? For instance, here's a brief list of tests that I've seen in Step 2 books, but I really don't know when exactly to use. I'm familiar with the principles well enough to answer a Step 1 question, but I'm not sure when these are the "most appropriate next step."

Gastrograffin contrast esophagram (vs. barium swallow)
Nuclear erythrocyte labeled study (vs. barium enema or colonoscopy for lower GI bleed)
Sestamibi scan (vs. regular stress test)
Methacholine challenge test (vs. clinical history/exam)
Bone scan (vs. X-ray or MRI)
Coombs' test (vs. blood smear or going straight to treatment)
Flow cytometry (vs. blood smear, bone marrow biopsy, etc.)
IV pyelogram (vs. traditional imaging techniques)

That's just off the top of my head, but I'm sure there are scores of other examples. Does anybody know of a list that I can use to summarize all of these and make sure I know them?

 

[NewYorkDoctors]

Sometimes, the question refers to "next best AVAILABLE step."

For instance, no one would really do a methacholine challenge test for asthma as a first step to take during spirometry. Rather, they look for FEV1 improvement with bronchodilators. Reason being giving methacholine may cause a respiratory emergency and is used cautiously.

Moreover, Gastrograffin is an important one. That is the brand name for a water soluble contrast agent. For rupture esophagus or possible ruptured peptic ulcer, if barium and XRay is to be done, then giving the water soluble one is better because the Barium one tends to lead to mediastinitis and peritonitis.

 

[docray]

Unfortunately, there's no such list, well, in my opinion though. The next best step or most appropriate next step is never constant. It depends on the clinical presentation or situation + the status of the patient. In an emergency, you prioritise resuscitation, minimally invasive tests and urgent treatment over elaborate investigations except if absolutely inevitable. While in an office setting, you go through screening /initial tests to more diagnostic tests etc.

Again, taking some of your examples, with suspected esophageal pathologies, the most appropriate test is usually barium swallow, however if you suspect a perforation, you better go for gastrograffin study to avoid causing mediastinal irritation and inflammation if barium leaks through the perforation. Gastrograffin is water soluble and less irritant.

Also, with Asthma diagnosis, it's usually clinical but if the diagnosis is still not clear despite everything then you do the metacholine challenge test. (of course, not during an acute attack).

The only types of questions with constant answers are the most accurate tests, most diagnostic tests, definitive treatment etc.

 

[sylvanthus]

Most of the time, when a question says "what's the most appropriate diagnostic test?", the answer is something straightforward and nonspecific, like "X-ray of the injured bone" or "serum level of the affected hormone" or the like. There may even be some disease-specific choices that are still fairly straightforward because we know them so well, like "dexamethasone suppression test" or "osmotic fragility test."

But has anybody ever made a list of all of the really specific tests and their indications? For instance, here's a brief list of tests that I've seen in Step 2 books, but I really don't know when exactly to use. I'm familiar with the principles well enough to answer a Step 1 question, but I'm not sure when these are the "most appropriate next step."

Gastrograffin contrast esophagram (vs. barium swallow)
Nuclear erythrocyte labeled study (vs. barium enema or colonoscopy for lower GI bleed)
Sestamibi scan (vs. regular stress test)
Methacholine challenge test (vs. clinical history/exam)
Bone scan (vs. X-ray or MRI)
Coombs' test (vs. blood smear or going straight to treatment)
Flow cytometry (vs. blood smear, bone marrow biopsy, etc.)
IV pyelogram (vs. traditional imaging techniques)

That's just off the top of my head, but I'm sure there are scores of other examples. Does anybody know of a list that I can use to summarize all of these and make sure I know them?

Use gastrograffin if you are worried about esophageal rupture as it does not irritate the tissues in the thoracic cavity like barium would.

 

[shan564]

Thanks for the responses.

Has anybody tried this?
http://www.amazon.com/Kaplan-Medica..._B0024JEL82_1_7?ie=UTF8&qid=1339369232&sr=1-7

It looks like the answer to my question, but the Amazon page doesn't tell me how challenging the flashcards are... it wouldn't be worth the $30 if it's just a bunch of "25 year-old lady comes in with pelvic pain and amenorrhea; what's the most appropriate initial test?"

 

[NewYorkDoctors]

Thanks for the responses.

Has anybody tried this?
http://www.amazon.com/Kaplan-Medica..._B0024JEL82_1_7?ie=UTF8&qid=1339369232&sr=1-7

It looks like the answer to my question, but the Amazon page doesn't tell me how challenging the flashcards are... it wouldn't be worth the $30 if it's just a bunch of "25 year-old lady comes in with pelvic pain and amenorrhea; what's the most appropriate initial test?"

There's an iPhone app for this. I used it.

It did not tell me anything that the Kaplan videos/notes did not already tell me.

There's something called USMLE Wizard Step 2 flashcards on iPhone. Admittedly not the best source, but it paraphrases everything taught in the Kaplan notes and is something you can do on the go.

 

[AndyRSC]

I've actually been looking for a resource that clearly delineates this for quite sometime. Having found nothing of the sort, I've started work on my own study guide. If you'd like, shan, we can collaborate on it.

 

[OveractiveBrain]

Most of the time, when a question says "what's the most appropriate diagnostic test?", the answer is something straightforward and nonspecific, like "X-ray of the injured bone" or "serum level of the affected hormone" or the like. There may even be some disease-specific choices that are still fairly straightforward because we know them so well, like "dexamethasone suppression test" or "osmotic fragility test."

But has anybody ever made a list of all of the really specific tests and their indications? For instance, here's a brief list of tests that I've seen in Step 2 books, but I really don't know when exactly to use. I'm familiar with the principles well enough to answer a Step 1 question, but I'm not sure when these are the "most appropriate next step."

Gastrograffin contrast esophagram (vs. barium swallow) -- Boorheave's
Nuclear erythrocyte labeled study (vs. barium enema or colonoscopy for lower GI bleed) After Colonoscopy or Arteriogram Fail
Sestamibi scan (vs. regular stress test) Never on the Step
Methacholine challenge test (vs. clinical history/exam) Diagnosis of Asthma
Bone scan (vs. X-ray or MRI) If Xray negative and no overlying cellulitis
Coombs' test (vs. blood smear or going straight to treatment) History sounds like AIHA, blood smear not specific
Flow cytometry (vs. blood smear, bone marrow biopsy, etc.) you do flow on smears and barrow
IV pyelogram (vs. traditional imaging techniques) almost never; if contrast, why not just do CT?

I think its better to study the topics and know when to use one test or another, rather than making a list of tests "you dont use" because you DO use them. They all have their indications. If you learn it as an illness script you will know the only time you use a gastrographin esophagram is in esophageal perforation. If you just try to memorize the list above, it will screw you.

If it fits in "Vomit Vomit Vomit, sick as **** patient with fever and leukocytosis, mediastinal crunch, air in mediastinum on chest xray, gastrographin, barium, egd, repair" then its actually not that hard to pick out the use for gastrographin. Getting there for every disease IS HARD, but once youre there. Magic.

See this site to get you started.

www.onlinemeded.org Its free.

 

[drizzt3117]

While it's true that gastrografin > barium in esophageal perf, ideally you'd use a low-osmolality contrast agent like omnipaque > gastrografin.