TSR Med Students' Society Part III

hmm... i can see them being used in a GP setting. but surely, in terms of practicality, you wouldnt go and read up papers before treating someone with a ?DVT, right? unless you knew the values on top of your head of course.

There's certainly an expectation that you know which investigations are accurate and which aren't even if you don't know the numbers.

For example;
Rugby player hit in chest, c/o L rib pain, chest clear, RR & SpO2 good. Do you XRay for ?#ribs? No. Won't treat #ribs unless there's multiple ones, and if RR and sp02 are fine then likely no damage.
Unwell elderly patient has an blood gas which shows a K+ of 5.8. Do you treat? What if it's 6.2? Do you wait for the U&Es result? Would want to know symptoms. How likely is it that the sample haemolysed on the way to the ABG machine? If it were >6, would treat if symptoms appeared to match suspicions. Else would wait for U&E.
Unrestrained driver, multiple trauma, c/o abdo pain. FAST scan is negative. What does that mean? FAST neg = apparently no blood or fluid 'loose' in the abdomen, so likely no serious trauma like splenic rupture. However doesn't rule out organ laceration and bleeding cos ultrasound isn't that sensitive.

There's certainly an expectation that you know which investigations are accurate and which aren't even if you don't know the numbers.

For example;
Rugby player hit in chest, c/o L rib pain, chest clear, RR & SpO2 good. Do you XRay for ?#ribs?
Unwell elderly patient has an blood gas which shows a K+ of 5.8. Do you treat? What if it's 6.2? Do you wait for the U&Es result?
Unrestrained driver, multiple trauma, c/o abdo pain. FAST scan is negative. What does that mean?

Guessing
1 - if no flail chest, and just tenderness on palpation, sats and resps holding up, pain control and send home. Even if there is a break, theres not much that can be done.
2- consider drugs, is pt on drugs where k+ matters - digoxin. is pt cardio compromised? ?AF? Maybe stablise heart with Calcium gluconate to buy time. K+ effects kick in at around 6.5/7ish, so not panic, but monitored bed and prepare dextrose+fast insulin.
3 - FAST is ultrasound for signs of trauma. Nil FAST dosn't necesssarily mean ok, because fluid capacitance of the abdomen means 1.5/2 ls needed before reliable detection, also ultrasound won't necessarily pick up tissue damage. errect CXR if possible to hunt for bowl perforations, also serum amylase. Otherwise CT chest abdo pelvis. ?Consider pericardiocentisis, surg reg r/w incase of theatre.

Guys, the point I'm trying to make is not about management per se but limitations of various investigations.

1. Chest XRs do not reveal broken ribs unless there's real significant displacement, regardless of whether we'll treat or not.
2. Blood gas measurement of electrolytes is notoriously inaccurate and can be up to +/-0.5 from the 'real' value.
3. Simply, FAST is strictly rule in only. Therefore a negative FAST means nothing.

Guys, the point I'm trying to make is not about management per se but limitations of various investigations.

1. Chest XRs do not reveal broken ribs unless there's real significant displacement, regardless of whether we'll treat or not.
2. Blood gas measurement of electrolytes is notoriously inaccurate and can be up to +/-0.5 from the 'real' value.
3. Simply, FAST is strictly rule in only. Therefore a negative FAST means nothing.

Fair enough, I was using it as a mini quiz for revision purposes

Surely CXR is the same as any other x-ray for looking at fractures - if there's a break in the cortex you can see it, unless we're talking right round the back, in which case get a side-on view? I thought with PACS and the ability to adjust contrast etc on screen rib fractures would be visible...

There are some fractures that are notoriously hard to find even with all the tricks, hairline fractures - scaphoid for example is a classic clinical diagnosis. Yes, you can look for padding, and smoothness and stuff, but meh.

Point taken, out of curiosity, what about the management though . Ultimatly tests inform management...

Surely CXR is the same as any other x-ray for looking at fractures - if there's a break in the cortex you can see it, unless we're talking right round the back, in which case get a side-on view? I thought with PACS and the ability to adjust contrast etc on screen rib fractures would be visible...

Scaphoid is a fairly obvious clinical diagnosis though. Pain on ASB compression/thumb telescoping = have a splint, come back in 2/52. I'm confused about why we x-ray twice tho (I get the whole delayed # presentation on x-ray bit) - 1st x-ray: displaced # -> deal with it. Undisplaced # -> splint. ?# -> splint. If you get a second x-ray in two weeks, for the ?#, what are you really going to change about your management? They've been in a splint for 2/52 already, why not just assume all clinical # is a real # and keep them all in splint for 6/52? What can you actually do if the end necroses anyway? I'm just confused because I've had a true # on one side and a ? on the other which turned out to be fine, and had exactly the same for both of them - x-ray, x-ray, MRI at 2 week intervals. That pretty much takes you to 6 weeks by which it's largely healing anyway...

im convinced they are important to have a general idea of as a clinician. sometimes it seems as though there is no answer and the implication on management depends on the clinician's judgement. for example the x-ray dude, if we think its inconclusive, someone could send home and someone else could ask for a CT (or whatever the next approriate test is). anyway, i just have a case analysis project which asks you to quote specific numbers, inc. reference ranges, that relate to the patient's case and im having trouble finding them so i wanted to rant

im convinced they are important to have a general idea of as a clinician. sometimes it seems as though there is no answer and the implication on management depends on the clinician's judgement. for example the x-ray dude, if we think its inconclusive, someone could send home and someone else could ask for a CT (or whatever the next approriate test is). anyway, i just have a case analysis project which asks you to quote specific numbers, inc. reference ranges, that relate to the patient's case and im having trouble finding them so i wanted to rant

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Scaphoid is a fairly obvious clinical diagnosis though. Pain on ASB compression/thumb telescoping = have a splint, come back in 2/52. I'm confused about why we x-ray twice tho (I get the whole delayed # presentation on x-ray bit) - 1st x-ray: displaced # -> deal with it. Undisplaced # -> splint. ?# -> splint. If you get a second x-ray in two weeks, for the ?#, what are you really going to change about your management? They've been in a splint for 2/52 already, why not just assume all clinical # is a real # and keep them all in splint for 6/52? What can you actually do if the end necroses anyway? I'm just confused because I've had a true # on one side and a ? on the other which turned out to be fine, and had exactly the same for both of them - x-ray, x-ray, MRI at 2 week intervals. That pretty much takes you to 6 weeks by which it's largely healing anyway...

You might recognise a couple of faces here

http://www.bbc.co.uk/programmes/b00yb30f

As far as I was aware, the clinical picture only raised the possibility of a scaphoid fracture, not the diagnosis, hence the need for x-rays. The splinting after the first x-ray is just erring on the safe side. A negative second x-ray after 1-2 weeks makes a fracture v unlikely (you can never rule out anything in medicine!).

Or you can just do what they do in Glasgow A&E. They have a wrist sized MRI scanner there which can pick up scaphoid fracture at presentation.

Btw, you want to orthopaedics and research? :mindblown:

Apparently academic orthopod is not an oxymoron