Clinical Case 137: It’s the quiet ones…

Another case from the Broomedocs archives.  This is a pretty simple case that contains a few good lessons.

Our patient is a 30 year old woman called Bessy who has been in a long term abusive relationship.  She has a long history of injuries including ulna fractures, facial fractures and burns to her skin.  Sadly this story is all too common in our world.

Bessy was seen in the ED yesterday with epigastric pain.  She was described as “a difficult historian”.  She had normal Obs and examination revealed RUQ tenderness with Murphy’s sign being positive.  She underwent a limited bedside US including a FAST and a gallbladder scan – both of which are documented as being negative.  No free fluid, no gallstones or cholecystitis changes seen.  In the absence of a firm diagnosis she has discharged with analgesia and asked to “return if worse…”

Now, 24 hours later at 10 PM Bessy represents to ED complaining of epigastric pain and has vomited x 1 just prior to arrival.  She is very quiet and laying still on the bed.

Her observations are all normal:  HR 80. BP 100/65, RR 15/min, SpO2 98% RA.

Abdo exam reveals tenderness and guarding across the epigastrium.  She has mild distension but there is no bruising or other evidence of trauma.

Time to review the history….

“When did this pain start?  What was going on at the time?”

“Oh, it started just after my partner kicked me…”   DOH!

Difficult History…. indeed!

This is now a trauma case.  The rules have changed.

Lesson #1 from this case:  victims of domestic violence are often reluctant to disclose specific details, even when it seems pretty obvious to us.  You need to approach this carefully and ask the right questions in the right manner, otherwise you will remain in the dark.

Back to the case…

Bessy agrees to be re-scanned as it is late and the CT tech is long departed.  Once again her RUQ is interrogated… and it is normal.  Despite having good going tenderness in the epigastrium her gallbladder is normal.  Given that we are now thinking trauma, this is unsurprising.  However, it means that we have definitely not found the source of her pain.  We are playing the probabilities – so a normal GB scan decreases the odds of biliary disease, BUT it also increases the chances of all the other possibilities e.g. an ulcer or visceral injury etc.

The error made the day prior can be partly subverted through a simple cognitive framing exercise when doing US in the ED.

Lesson #2  :  Before scanning a patient, think about the most probable diagnosis – then imagine what you expect to see when you apply the probe.  [ eg. In this case if you are expecting to diagnose cholecystitis, then you would expect to see gallstones with a thickened GB wall and sonographic Murphy’s sign…]  However, if you see something different… then that means something.  A normal scan means your hypothesis is wrong.  Normal is not normal… you need to either rethink the diagnosis or look harder for the pathology.  In Bessy’s case, the absence of gallbladder pathology would prompt one to re-examine the story or look further afield.

Lesson #3:

Now let us talk about “FAST scans”.  Bessy had a FAST scan, well sort of…

The FAST scan was developed as a binary tool to decide on the best disposition for an unstable, shocked trauma patient.  Alas, the majority of “FAST scans” that I see being performed are:-

1. done on stable, well perfused trauma patients in ED
2. Not too fast, i.e.. they tend to take 5 – 10 minutes to search all the areas we traditionally look at!
3. Should not be called “FAST scans”

I think this is one of the reasons that FAST scans have gotten a bad wrap – what some folk call a ‘FAST scan‘ is in reality a very limited abdominal ultrasound that tries to localise the injuries.  This is not a FAST scan.

Having a ‘sono-gander’ around the belly can be a very useful thing to do in a stable patient who may have on occult injury that one cannot find clinically and where other diagnostic tests are either unavailable or inappropriate.  However, can we please, please stop calling it a “FAST scan”?  Lets call it a “limited abdominal US” or a “Trauma Trawl…”

I am not saying that we should not look around if time and the clinical context permits… but we should appreciate that this “test” carries a very different set of diagnostic and practical characteristics to the traditional FAST exam. I have had many a good save as the result of some curious probing of the belly… however, I appreciate that this is a specific and very insensitive “test” and almost always mandates subsequent imaging if an abnormality is revealed.

OK, where were we… oh yes, Bessy has a normal gallbladder.  Lets do a bit of a trauma trawl.  He FAST [true FAST] shows no free fluid in the pelvis, LUQ or Morison’s pouch… but  when trying to look at the LUQ there is something odd going on.

Here is a sagittal view through the epigastrium just left of midline.

If that is a bit confusing – here is an annotated version:

The red X is a large heterogenous mass of mixed echo texture which should not really be there… Huh?  What is that?  It could be the stomach – but on further scanning it was adjacent to the stomach… 

This is where you need to exercise a bit of insight.  Especially if you are starting out in POCUS it is easy to ‘not see’ the unanticipated anomaly – more so  when you are seeing it for the first time.  Your brain’s instinct is to gloss over tough, or noisy images… and this how we often miss important findings when learning..

So what is going on in Bessie’s epigastrium?

Just as you are thinking it through she spikes a fever… her pulse rate jumps up to 130 and she looks crook… time for action.

We need a diagnosis-  there is a clear story of trauma, a confusing mass in the abdomen and now a picture that looks like sepsis.

Off to CT. I want to know what that mass is ASAP.

So what did the CT show?

Lesson #4:   Although bedside US rocks, and can really shine a light in the dark, it I see often not enough..

A positive in this case combined with the clinical situation empowered me to push on an image aggressively.  Broome is a long way from everywhere-  so getting solid information and making a plan early is usually preferable to “wait n see” when dealing with sick patients. It took me a few years to work this out  – deciding to transfer to ICU once the patient crashes is bad medicine..

Stay tuned for more POCUS pearls on the podcast this week.

Casey