Clinical Case 119: Trauma & the Sensitive New Age Ultrasound

OK tonight I have a trauma case for you.

Billifred is a 24 year old man whom lives with his partner.  There relationship took a turn for the worse this evening when she found her sister’s underpants in his car.

Billifred is a “lover, no a fighter…” but tonight he was forced to defend himself against a series of stabbings.  He is brought in by taxi with multiple bleeding wounds.

Editorial note:   Presentation by taxi carries a significantly increased risk of serious badness in my world.  Ambulance services are essentially free, so they often get used as a public transport service.  However, if you are sick / worried enough to fork out $20 for a cab fare – there is a good chance that you are actually pretty sick.  Auto triage is a real thing IMHO.

On arrival he is bleeding from cuts to both hands and his ulnar forearms.  He has blood on his leg from wounds on his lateral calf.  There is a small spot of blood on his left shirt pocket.  He is not really very cooperative.  When asked what happened he says he “fell whilst sharpening his hunting knife…”

Obs:  HR 120/min,   RR 28/min,  SpO2 on RA = 90% but up to 98% on 6L/min HM,  BP140/100.  He looks sweaty and anxious.

After stripping off his shirt you see a 1 cm stab wound just below the clavicle on the (L) anterior chest, midclavicular line…

So – control the bleeders – he gets a tourniquet to his arm to stem the loss from the cuts there and then needs a chest US….  bugger, the O&G doc has taken the machine to labour ward.

After securing IV access x2 and giving him some analgesia the radiographer pops in and does a quick portable CXR.  It is a rough shot with him breathing fast, not really vertical and taking shallow breaths.

Whilst you are waiting for the films to be processed ( yes, we still use actual plastic films!!) the Bedside US machine reappears.  So you do a quick chest scan looking for pneumothorax or haemothorax on the left.

You scan from the clavicle down the anterior chest and…  no sliding.  A static pleural line with no sliding.  His right chest is normal with good sliding easily seen.  The heart looks good and there is no pericardial effusion.

Being a super-sleuth sonowarrior, you scan now across the chest laterally towards the bed looking for a lung point [contact point] – and at about the posterior axillary line you see this:   CLICK TO SEE US CLIP

Now – that is golden – a good sized pneumothorax with the whole anterior chest showing no sliding and a lung point around laterally.  The evidence suggests 100% specificity for US when a clear lung point is seen.

A quick look at the left lung base shows a small effusion ~ 1cm deep, looks like partially clotted blood with mixed echo texture .

Meanwhile the friendly radiographer has returned with the plain film and the verbal report is ” ALL Clear, no pneumothorax…”  Here is the CXR…

CXR norm

Alright then – we will pause the case at this point.

This is the “le moment decisif” the point in time where you need to decide what are you going to do next.

Do you:

(A)  Crack on a put in a chest tube

(B)  Sit on the patient, admit and observe.

(C)  Fly them to the closest CT scanner (1000 km away) for a CT chest.

We covered the pneumothorax / Airplane transfer debate a while back in Clinical Case 108.

(D) Something else / smarter??

 

You have about 20 minutes of suturing time to think about it as you close his lesser injuries.

You even decide to repeat the chest US after sewing up his limbs – and it looks the same – pneumothorax to the posterior axillary line with a small effusion – stable in size.

OK let me know how you will play this one.

Casey

Lung Ultrasound with Dr. Kylie Baker

For about a year now I have been spending time “working” for the Ultrasound Leadership Academy – run by the team from the Ultrasound podcast.  It is really cool to be able to chat with enthusiastic US learners all over the globe about the clinical coal-face of US in medicine.  One question I get asked a lot: – what is the most useful US modality for me?

Well I reckon that lung US is now a clear winner.  Why?  Because it is so useful in really common, everyday scenarios.  It does guide diagnosis and also therapy and can be a life-saver from time to time.  A lot of the other uses of ED Bedside US are applied in less common situations and may not really effect outcomes in a lot of patients [I will get in trouble for saying that!].

So I feel that lung US is the thing I would teach to a keen MEd Student if they asked me to give them one US skill to make their early postgrad years go better.  But the problem is that this is a relatively new concept – unless you are from Europe – where it has been going on for 20 + years.  But for the English-speaking world it is pretty new and just making its way into clinical algorithms.

There are a few problems to overcome when learning lung US;

  1. The set-up on your machine is unlike any other that you have used before [mostly there are no pre-programmed modes.]
  2. It is all about artefacts – we are looking for things that are not really there – patterns in the smoke that represent various entities, rather tun actually visualising the “real anatomy”
  3. There is a steep learning curve… clinical correlation is required
  4. This is like many US uses – very user-dependent.  It takes practice to get consistently good images.

Luckily [for me and you] I had the good fortune of bumping into Dr Kylie Baker a few weeks ago at the ASUM [Australasian Society of US in Medicine] Conference in Melbourne.  Kylie is an ED doc from Ipswich in Queensland and has been contributing pearls to the Intensive Care Network on lung US in critical care.  So I put her on the spot and asked her some really dumb questions about lung sonography!  The result is this podcast.

I highly recommend having a listen if you are at all interested in improving your ability to treat patients with acute chest disease.

Here is a basic “How To” list that I have compiled from my discussions with Kylie.  You need to know how to make your machine do chest scans  – this is the quick guide for dummies.

(1)  Patient: enter patient ID and data for future ref and learning.  Review is crucial to learning!

(2)  Probe: select curvilinear probe initially for routine 8 zone scan

(3)  Position: patient supine / semi-supine. If they can sit for posterior scans – great. Depends on clinical context and your diagnostic goals.

(4)  Settings: TURN OFF any automated features that may decrease artefacts – e.g.. Tissue harmonics, multi beam, sonoCT, minimise greyscale range

(5)  Preset: Abdomen is OK. [NB: Lung preset on newer machines is really only optimised for pneumothorax scans – not other lung scanning.]

(6)  Depth: 10 – 12 cm in a normal sized person. You may need to adjust this if your machine has a fixed focal depth

(7)  Focus – aim to focus on the pleural line. (If this is fixed – then decrease depth to bring pleura close to mid screen.)

(8)  Frequency: push the probe to the lowest (Penetration) frequency possible.

(9)  Hand position: visualise the pleural surface and aim to keep the beam perpendicular to he pleura. [for pneumothorax – a slight angle may help] ***The absence of “A lines” suggests an incorrect setup or too large an angle on the pleura

(10)  The scan: Sample each of the zones (2 anterior, 2 lateral +/- posterobasal on each side)   If abnormalities are found – esp. focal changes – then this area can be further interrogated with a more thorough scan or a linear probe

Other great resources on Lung Scanning :

This from the Queen of Lung US – Dr Vicki Noble via Ultrasound Podcast – there are 2 parts to the lecture

One cannot talk lung US and not include an Italian – this great 6 minute talk by Mattia Quarta (@squartadoc ) is very good

Back to Basics on the Lung artefacts with Dr Mike Stone (the other Mike) of US Podcast – also a 2 part deal.

Some great pointers from Dr Rob Arntfield from Western Uni IN Canada at Western Sono tutorials. This video shows the positions of the probe well.

And guess what – most of these great lung US teachers are also “professors” with me at the Ultrasound Leadership Academy.  Check it out if you want to take your US skills to the next level.

If you have questions, comments or your own Lung US pearls – then please share on the comments below

Big thanks to Dr Baker for her time and expertise

Casey

Clinical Case 106: The mysterious Pink Lady

Time for another quick clinical case

Your next patient is Joan – a semi-regular attender to your family practice.

Joan is a 67 yo woman who is usually reasonably well.  She works as a book keeper in a small business.

She has been troubled by some gastro-oesophaeal reflux symptoms over the last few years and has been taking some omeprazole “most days” for symptom relief.

Today she presents with a sheaf of discharge letters from the local ED.  7 in total!  She has been seen in the ED 7 times in the last 6 weeks with “chest pain – non-specific”.

She tells you that she has been experiencing dull, spasms of pain in her substernal area that sometimes radiate to her back.   They are not really like her usual ‘heartburn’ symptoms.  She doesn’t feel sick or sweaty.  Just worried.

These are quite unpleasant and stop her from working at her computer.  The last couple of episodes have occurred at night and woken her from sleep – her husband has called the ambulance service twice in the last fortnight!  On each attendance to the ED she has been “fast tracked” into the chest pain protocolised management.  And spent a few uncomfortable nights on a stretcher in the corridor of the ED…..  awaiting a second  troponin.

Amidst the paperwork there are formatted letters from ED interns, Registrars and even one from a consultant ED Physician.

There are a batch of plumb normal ECGs and photocopies of many negative troponin results.  She even stayed in for an exercise stress test one day – which was non-suggestive of ischemia.

She has been diagnosed consistently with:  “Chest pain – non-specific.”  or “Chest pain, not cardiac.” on each occasion.  On the latest visit the senior Doc has ventured a positive diagnosis – “Probable Oesophageal spasm.”

Interestingly there have been a number of therapeutic trials of “Pink Lady” i.e.. the Mylanta & Xylocain viscous cocktail so loved by triage nurses the world over!  Joan says that the pain is usually short-lived – coming in spasms. It seems to go away after a few minutes then return.  She says a lot of the doctors ordered the Pink stuff and when her pain got better…  told her it was from her oesophagus. [ see this post from Dr Seth Trueger on this topic. ]  Maybe best left until after the troponin has settled the question!!

She has received advice to take her omeprazole twice a day and to follow up with her GP.  OK, here she is….

So, it seems clear that she is in the low-risk group for cardiac disease as a cause of her chest pain.  Let us assume that the ED Docs have excluded ACS as a cause.

SO, if you are the GP how do you go about making an actual diagnosis in this scenario?

Is a therapeutic trial of PPIs a reasonable strategy?

Depends…. are you trying to give relief to the patient or make a diagnosis? After searching through the databases I found this decent sized trial from Flook et al, in Amer Journal of Gastroenterology (January 2013)

It looked at 600 patients with reflux symptoms giving chest pain.  A placebo, RCT (esomeprazole 40 mg BD for 4 weeks) They found a significant improvement in symptoms at the end – but this was really only for patients with less frequent reflux sx at the outset.  Not so effective for the pts with more than 2 days a week of symptoms.

There is also a meta-analysis [Wang et al, JAMA, June 2005 ] looking at 6 papers ( only 220 pt in total) which tried to answer the question about the diagnostic characteristics of a “trial of PPI” for reflux-related chest pain in patients with “non-cardiac chest pain” .  The conclusion of the authors was that is was an acceptable “test” with a sensitivity of 80% and specificity of 74% roughly.  So – it might help – but to my mind those are not stellar numbers.  I would want a reasonable high or low pretest probability of “GORD” before hanging my patient’s hat upon those figures.

Should she have endoscopy to look for serious upper GI problems?

Well that is a tricky one.  Not a lot of data.  Just opinion.  The surgeons that I work with would suggest everyone with severe enough , persistent symptoms should probably have a scope to exclude malignancy or other correctable lesions in the oesophagus.  In the good old days we would send them for a Barium swallow.  But nowadays it seems easy to get a scope, and then you have the option of a CLO, biopsy or whatever else they need on the day.

So I think it is reasonable to get a scope if you have persisting symptoms or severe symptoms so that you know what you are dealing with.  It would be disastrous and unfortunate to treat a malignant process for months and months with symptomatic care.

What is the role of manometry or pH monitoring to try and correlate her symptoms with  events in her oesophagus?

This is not something that I really see much of – but I work a long way from any Gastroenterolgists!  Certainly I have seen this done in patients with bad GORD – i.e.. those whom are contemplating a fundoplication procedure.

Found this paper in the BMJ – Barham et al from Gut, 1997. [Diffuse oesophageal spasm: diagnosis ] It is old – but suggests that for intermittent symptoms like our patient is suffering – you really need to get continuous outpatient / 24 hour ambulatory monitoring of pH and pressure in order to make this diagnosis.  Diffuse oesophageal spasm is also known as “nutcracker oesophagus” or “corkscrew oesophagus” as it has characteristic appearances on imaging.  However – you would be lucky to see this phenomenon as it is fleeting!  IN order to correlate symptoms with measured anomalous peristalsis or pH spikes – you would need ambulatory monitoring.  I guess it is like the Holter of the gut?

http://download.figure1.com/broome

Image courtesy of Figure 1

SUMMARY:

The task of the ED team is to exclude life threatening diseases and give relief from symptoms.

When it comes to chest pain – once the serious diagnoses have been “excluded” to a reasonable degree of certainty [aortic dissection, ACS, pneumothorax, large PE….] then we are left with a cluster of other possibilities.

These are rarely “diagnosed” in the ED.  The evidence would suggest that the oesophagus is a major source of chest pain in this group – with GORD and motility disorders being the most likely disease processes.

So – if you want to have a go at symptom relief after excluding the bad diagnoses then it seems reasonable to tackle the oesophagus as your first  step.

Given to complex and costly nature of the investigations involved – this is not really within the scope of the ED provider to actually ‘make’ these diagnoses.  They can wait until review by the primary care doc or Gastro team if warranted.

But…  it would seem that a trial of a decent dose of PPI is not a bad option.  There seems to be little on the downside and a good number of patients will get symptomatic relief.  In my opinion – if you are going to do this then give a good dose for a reasonable period [as in above study] e.g.. a month of b.i.d. PPI-de jour seems like a good start. ** This is my opinion – not evidence*

This may even prevent them needing to come back to the ED with subsequent chest pain and go through the whole rigmorole again!  Not that this should be a primary objective of therapy – but it does seem to be a win-win for patient and the ED.

PE Prognostication: Weingart Weighs In

OK friends – it has been an interesting week for me on the blog – lots of discussion about the part 2 of the PE Prognostication podcast. If you haven’t listened to the last 2 podcasts then this episode will sound like an American man who has totally lost his mind, but if you go back and listen to part 1 and 2 of the PE Prognostication podcast then it will sound like pure genius  [the two are easily confused I find!]

Don’t worry – I am not going to do a whole PE month – nobody deserves that!  I will be releasing a few non-PE posts and cases this week for those of you with a more diverse taste.

Fair to say there was a bit of a twitter shit-storm going on there for a few days and the dust is still settling.  I think Minh might have RSI of the thumbs from all his tweeting!

So a little bit of editorial orientation before we get onto today’s podcast.  I would like to take a few lines to explain what is going on so that you all have some context for this discussion and the podcast below:

  1. Dr Anand Senthi is a smart guy who has looked deeply into the PE literature
  2. There is not much evidence at all to support the “status quo” for low-risk PE work-ups in ED patients.  Largely the standard of care is based on expert consensus and the relatively poor volume of quality data available.
  3. We all know that there is a real risk of over investigation when it comes to PE work-up – especially in the patients that would be described as “low risk” by whatever system you prefer… Wells, PERC, Geneva, Gestalt.
  4. It is likley that a really conservative approach that attempts to identify every PE that presents to ED will in fact harm more patients than it helps
  5. Anand is worried about this and would like to change the way we approach these patients.
  6. Anand has generated an algorithm – a new approach to this group which is based in the evidence that is currently available
  7. Anand’s approach is at this stage a hypothesis.  It is an idea that needs to be tested in a rigorous, randomised trial in order to determine if his approach results in better patient outcomes than the current “standard of care”.
  8. We are not suggesting that you take this approach and apply it to your patients tomorrow.   It is a great idea –  but do not lose your job over it!
    1. Actually that goes for anything you read on this blog!  You are a doctor – read widely and make up your own mind.
  9. This is an idea that is evolving – this is what I love about the FOAM community – through debate and constructive feedback we can refine rough and raw ideas into actual practical and testable hypotheses.

So now that you know what is happening.

In case you don’t know Dr Weingart is an ED Critical Care guy from New York who runs the Emcrit blog / podcast.  He is also a man who has written a book about evidence-based medicine, one of the more readable guides to biostatistics that I have encountered!  So he is a clinician who understands numbers and decision-making.  This makes him a great “devil’s Advocate”, and I really appreciate the time he has taken to point out the logical and clinical problems with the Prognostication algorithm.

Scott [ @emcrit – as if I need to tell you. ] sent me this response to the PE Prognostication podcast.   He covers a lot of ideas in rapid fire.  So have a listen.

THe blog post review that Scott refers to of contrast-induced nephropathy is here at EDTCC.

I will be having Dr Anand Senthi back on the podcast soon to offer some counterpoint and we will see if the algorithm has evolved in the last few weeks!  Let me know what you think on the comments below.

DIRECT DOWNLOAD HERE

Ventilation Basics

Hi Broomers

Todays vodcast is an introductory talk on the basic physics and physiology of positive pressure ventilation – IPPV or NIV.

For some of you this might be teaching you to suck eggs.  But for me this is full of stuff I wish that I had been taught in my early days of Anaesthesia.

Lets be honest – if you practice elective anaesthesia as a rural doc you spend a lot of time ventilating patients with really good heart and lungs.  This is good – life is not so stressful and our patients do well – great.  However, it does mean we may develop a false sense of security.  Can we manage the trickier cases, the sick lungs, the emergency-can’t back-out cases?

So this talk is about giving you a solid theoretical basis from which you can twiddle the knobs, fine tune, troubleshoot and talk sense to the smart docs in the receiving centre.

Enjoy and let me know if you see any obvious falsehoods or have unanswered questions.  Direct download here

Might do a few shorter talks on specific disease vent strategies.

Also check out the following:

Borrow the OXYLOG  from LITFL

SPINNING DIALS from Emcrit

The Crashing Asthmatic from Andy Neill