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

Clinical Case 117: Cancer Fishin’

OK – this case is for all the GPs and Internal Medicine types out there.  This is a relatively common scenario…  how do you play it?

Here’s the case.

Bruce is a 53 y.o. accountant.  He is a little overweight at 89 kg (BMI 31).  He is otherwise relatively well, he cycles to the cafe each morning in lycra and drinks a cappuccino in his helmet… why do they do that?

He has hypertension which is controlled by ramipril 5 mg daily.  No other meds or relevant medical history.  He is interested in his health and even has annual “Mens’ Health checks”.  He was in last month for one – which was unremarkable other than a borderline BP and his prostate screen (post full consent and shared decision-making) revealed a normal DRE and PSA level.

Today he has come to see you with a discharge letter from the local hospital.  He was admitted for work-up of “unilateral leg swelling” which occurred spontaneously last Friday.

The letter reads:

Dear Dr Leeuwenburg,

Thanks for following up Bruce who had an unprovoked DVT diagnosed on Doppler.  US showed a 5 cm proximal DVT at the Femoral-saphenous junction (L) leg.

He also had a series of tests: FBP, UECr, LFTs, Ca, Mg, PO4, CRP, TFTs, a prothrombotic screen was unhelpful and serum rhubarb – these were all normal.  WE did a CXR to be sure and this was also reported as normal.  

Bruce was commenced on enoxaparin until his warfarin was therapeutic.  He’s on 8 mg nocte with an INR of 2.3 today .  Please chase his subsequent INRs

Oh – and – please screen for occult malignancy as we have not found anything yet.

Yours truly….

So Bruce is sitting in front of you looking a bit worried.  He says that he feels fine, and the leg swelling is improving.  He was a bit spooked when the “young-looking” hospital doctor told him that DVTs “like this” are usually due to some underlying problem “like cancer”.  He really wants to know what to do next.  Does he have cancer?

OK – so here are my questions to you:

Q1:  What is the chances that Bruce has an occult malignancy?

Q2:  what screening tests, inquiries, imaging etc would you recommend / order for Bruce?

Specifically will you get a CT of the torso?

Q3:  Does it really matter if he has an asymptomatic cancer? Will it reveal itself in time anyway?

Let me know your thoughts…

But in case you were wondering.  Here is the link to the recently published SOME trial out of Canadia in the NEJM in June 2015

They looked at a limited vs. “limited + CT ado-pelvis” strategy and found not much difference.  Both groups had about a 1% cancer rate at work up and had a similar “diagnosis rate” of cancer in the following year.  So the CT didn’t help reduce the time lag to diagnosis much.

However, there is of course a risk of finding incidentalomas and the harms associated with those and their further IX or Rx…

So for me it si back to simple thorough Hx, Exam, do the things you would normally do for a 50 yo bloke and watch him.  Really a great case for Shared decision-making here now that we have some rough numbers that we can present to the patient as risk ?

Thoughts
Casey

Clinical Case 115: Pneumothorax puzzle

This case was interesting for a number of reasons.  It starts with a 50 year old lady whom has been assaulted.  She says she was kicked in the head and chest.  In ED she is looking sore but stable – and it was felt that she had enough mechanism to warrant a CT of her head and neck.  On the neck CT it was noted that she had some surgical emphysema on the lower slices – so she stayed in the tube for a chest scan too!  Here it is:

Pneumothorax = Tense CT!

 

Now – I know what you are all thinking…  that is a CT image that should never had been captured!  We have all heard the addage that you should always pick a tension clinically and never need to image it… but…  the honest truth is that we just are not that good at picking pneumothorax clinically.  As you know I am an ultraosund tragic – and I believe we can certainly pick em with a quick chest probe.  However, relying on clinical exam is just not, well, reliable.

In recent years one error that I have seen creeping into my practice is the tendency to “fast-track” trauma patients to imaging where appropriate without completing a fully thorough secondary survey.  There are a lot of reasons (? excuses) for this:

– trying to get the imaging done in office hours,

– trying to get patients out of collars ASAP,

– relying on second-hand info via handover which may be innaccurate….

– search satificing. Stopping at one major injury!

So my “lesson learned” here is to be systematic and make sure that you are imaging everything that needs imaging and that you have excluded the big “killers” before settling for a CT.

OK – back to the case.

A chest tube was placed and the pneumothorax decompressed.  Post ICC films showed a well expanded lung.  Our patient was admitted to the ward.  Lets jump to the next day…..

Our patient starts to deteriorate.  She is becoming more hypoxic with tachypnoea.  What is going on?

Well there is a few possibilities.  The chief concern was that the tube was occluded / dislodged resulting in reaccumulation of the Ptx.  So another CXR was performed…

Take a few minutes to look at this CXR.  It was reported by the Radiologist as “recurrence of pneumothorax on the right, with overlying subcutaneous emphysema mimicking lung markings.”

There is no recurrence of the pneumothorax. Clinically: the ICC is “swinging” but not “bubbling” – so the tube is patent and CXR shows it is still intrapleural. There is of course considerable mediastinal shift – which is due to the loss of volume on the left side which is collapsed.

Of course – Ultrasound will be useful. The left side is going to be tricky as there is a heap of SubQ emphysema – so the pleura will be hard to visualise. However, if you can find a gap you can see sliding, great. Really the utility of US is to define the collapse on the left side – consolidation, is there an effusion?

So here is where it gets easy – back to basics. The problem here on ultrasound was consolidation with likely atelectasis. The nurses noted the patient was too sore from rib fractures and had been positioning herself right-side up with some haemoptysis. It was very likely that she had plugged some largish bronchi with blood and debris. So we engaged a trusty expert chest Physio to bang out some mucus and blood. Provided good analgesia and got her up and walking. The next day – here lung was re-expanded and her hypoxia was resolved

OK –  let’s hear your comments.  I you were at #SMACCUS last week then you will have a distinct advantage over the other readers as this case was put up in a session there and discussed.

There are so many potential errors that we can make in even the simplest of cases.  Trauma is a complex scenario with information overload, serious sequelae and time critical decisions to be made. So over the next few months I am hoping got run with a theme of “common errors and their mitigation”.  Hoping to have a few special guests on to help show how we can avoid the pitfalls and do better on the floor.

Casey

Clinical Case 114: Skull and Crackedbones

This case is inspired by a recent Twitter discussion with fellow Pads ED enthusiasts – Tessa Davis [ @TessaRDavis ] , Andrew Tagg [ @andrewjtagg ] , Rachael Rowlands [ @rachrwlnds ] and whoever else was reading.

As a background – you probably should read my previous ramblings about Paediatric head injury assessments here: Kids Coconuts and CTs

I think that the PECARN decision tool [MdCalc clickable version HERE ] is probably the most useful and robust data out there for making the call on children with minor head injuries in the ED.  In the past we have often taught or been taught to observe kids for hours and hours, or CT them.  The PECARN data set certainly has changed my practice in the last 5 years.

I now use it to identify children whom are at extremely low risk and feel confident to discharge them with follow-up instructions of course , one needs to be assured that the parents / carers are comfortable with this and able to access appropriate follow-up if required.  The PECARN study also gives us a basis for discussing the risks of observation, imaging and non-investigation in kids who are not in the low-risk group.

Now take a look at this part of the PECARN Algorithm – this is the section for kids aged under 2 years of age.

Screen Shot 2015-03-21 at 10.16.20 pm

The majority of kids that I see in this group are little ones who have walked / run / fallen head first into something solid.  They usually have a frontal “egg” or laceration over the forehead.

So lets walk through the algorithm.  If this kid has a large frontal haematoma then it is going to be tough to say that they do not have a skull fracture, or at least you may think you can feel something.  Let’s face it – pushing on a fresh, boggy swelling over a kids head is just plain cruel!

If you think that you can palpate a fracture – then they immediatley jump into the ‘high risk’ group i.e. the group that is recommended to CT early.  This was about 1 in 8 of the kids in this age group.

However, if there is no fracture palpable then you are very likely heading down the pathway to simple observation, or possibly into the super low-risk group.

Hence the question of the presence or absence of a skull fracture seems to be a big hinge-point when it comes to making this decision.  And here is what I suspect:  we are terrible at picking these!  OK, I understand that the PECARN trial is a pragmatic set-up.  It was a simple clinical call – was the clinician able to palpate a fracture.  However, in reality this does seem very subjective and prone to bias.

Enter our friend – the Ultrasound.  Is there nothing we cannot do with the probe?

Ultrasound is useful in picking fractures elsewhere in the body – particularly in superficial bones.  So can we detect skull fractures with any accuracy?

Well there are a few smallish trials looking gat this question in the literature:

One form New York, Jim Tsung and co. in Paediatrics, June 2013 – “Accuracy of Point-of-Care Ultrasound for Diagnosis of Skull Fractures in Children”

Another from Riera et al in Paediatric Emergency Care, May 2012 – “Ultrasound Evaluation of Skull Fractures in Children: A Feasibility Study”  This one had more small kids in it – i.e.. mean age 2 years

These are small trials – 115 patients combined.  19 had a fracture on CT – so the incidence was ~ 16%.  Like many POCUS papers they show the usual characteristics of bedside ultrasound techniques – very specific and reasonably sensitive – so if you see a fracture – there almost certainly is a fracture, but you will miss 15 – 20 % potentially based on the numbers here.  In the Tsung paper – only one fracture was missed – that was a fracture that was adjacent to the hematoma – rather than directly beneath it.  So you could improve this with a more thorough scan field.  In terms of likelihood ratios: bedside US give a +LR of 27 (excellent!) and a -LR of 0.13 (pretty good!).  As always – we need more data to validate this and make it more generally applicable.

So how would a bedside skull US fit into the PECARN pie?

Hard to say what our “Sensitivity and specificity” is for clinical palpation of skull fractures – I would guess we are 50% sensitive and 75% specific.

So using that as a comparison – we should be able rule in a few more kids who should probably get an early CT.

So will this mean we do more CTs?  I think not – as there are a lot of kids who have a nasty looking egg on the head – and we are often biased by the external picture into believing that we can feel a ‘step’ as we are worried and want to rule out badness.  So if we scan the kids with the ugly looking hematoma and find no fracture on US – then this would probably be a group where it is safe to push them into the “observe, wait ‘n see” strategy.  Although US is not super sensitive – it surely must be better than a subjective prod over a boggy lump.

[Note: if you use a stand-off pad or lots of gel – you can do this US without inflicting much pain at all.  No pressure needs to be applied.  So I think this is a more humane approach to the kids with a large, boggy swelling of the noggin.]

So overall I think that US would allow us to separate the goats from the sheep – allow us to create a bit of diagnostic daylight between these 2 groups:

(1) Those who definitely have a fracture and may need early imaging of the brain

(2) Those at lower risk of fracture who can be safely observed.

Bedside US probably doesn’t add too much to the kids whom can be classified as very low risk by the PECARN algorithm.

My practice is to promptly discharge kids who meet the “extremely low risk” criteria.  I give the parents reassurance and information for what to look out for.  But… this is my new pet peeve…  forcing a kid / family to sit in the ED for 4 – 6 hours to have “Neuro obs” completed seems like a really antisocial and low-yielding exercise in this group.  So if I am satisfied that the parents understand the risk and what to do if… happens, and there is no NAI question – I will send them home from triage.

Love to hear how you manage this common problem in your ED.

 

Casey

Clinical Case 111: Toddler’s Tibia Tale

Another quick ultrasound case.

I usually work nights and weekends – and that means that we have no onsite Xray services.  Hence there is always a reason to use ultrasound to enhance our diagnostics!  In fact if you are coming to SMACC Chicago in June this year – you can hear me prattle on about ultrasound in ED. Chris Nickson has given me the title: “No Xray, No Problem!” to talk on… and I cannot wait.  The real reason I enjoy working after hours – I can practice the way I like – using US in place of Xray.  To me that is a heap of fun and very satisfying!

So onto today’s case.

3 year old girl is brought into the ED one Sunday morning.  She was playing with her older cousins at aunty’s house last night when there was a scream and then silence from the bedroom.  Her aunt went into the room and found her crying and holding her leg.  She was carried out and put to bed.

Fast forward to the next morning – and she is still not wanting to walk.  Refuses to put her foot onto the ground, insisting on being carried.

She is well, afebrile, no other symptoms.  She isn’t really yet developmentally able to localise her exact site of pain – but is clearly upset when I touch her lower leg.  There is no lesion, wound or puncture to the sole of the foot and her hip, knee and ankle all move well without much discomfort.

So – being me and it being a Sunday… ultrasound is indicated.

Now be warned – this is outside the realm of “current practice” although there are a handful of case studies looking at long bone fractures in kids with ultrasound.  Most show it is useful.  However toddler’s fractures are subtle – very subtle.  Even with a solid history and a good Xray it can be hard to see those spiral cracks.

So what did our patient’s tibia look like?

tibia fract

Well it is subtle.  This image is the result of a few minutes searching.  It is very easy to miss subtle fracture on ultrasound.  One really needs to be slow and methodical

 

Here is the plain film for comparison:

tib fract toddler The US image here is profiling the anterior surface of the tibia, the fracture was not detectable on lateral views.

  1. So my learning points from this case:
  2. (1)  that one needs to be careful and methodical
  3. (2) Use the contralateral limb for comparison – there are a heap of growth plates etc
  4. (3) Call any subtle anomaly if you see it – confirm on Xray if uncertain

Casey