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…
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.
(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.
With those vital numbers, oxygenation impairment and an obvious diagnosis of pneumo = tube
No other reason for low Sp02?
Other possible option, monitor closely in the short term and if any deterioration ‘crack on’ with the tube
Then maybe transfer for CT if concerned about damage to other structures.
I say place the tube now. With the hemopneumothorax, you really want to know how much blood there is – and how fast it’s accumulating. And, I agree with the above comment that a symptomatic PTX needs to be relieved. As far as the transfer goes, that’s kinda outside of my realm. I’ve never worked 1) outside a trauma center or 2) without a CT scanner.
Great case Casey!
Few points to raise:
1) Sensitivity of US vs CxR for detection of PTX/HTX in trauma:
The best summary of this is the new NICE Major Trauma draft guidelines, available here:
In a nutshell – US is more sensitive than CxR, specificity is similar
There is the issue of operator dependence for US, time to complete the study (everyone says “it’s faster than a CxR”, but that ’s hugely patient and operator dependent – see below) and availability – it’s almost ubiquitous but not available everywhere yet, and don’t forget that things like obesity and subcutaneous emphysema can seriously bugger up your US beams!
CxR can pick things that US can miss – for example in this case – a broken off blade in the chest – that can change management.
On speed of obtaining US vs CxR:
Where I work I can get a CxR taken & up on the computer screen in resus before anyone can complete a full chest US, especially if there’s technical issues with US (e.g. inexperienced operator, obese body habitus, sub cut emphysema – which can all drastically slow an US down), and if the CxR is diagnostic & the patient is compromised, I’d stop the US & decompress the chest. If not, we can carry on with the US.
So my take home message is – both have pros and cons, neither carry significant risks, and you should just do both, being aware of the sensitivity & specificity issues mentioned in the NICE guidelines.
Here’s a case I saw that covered some of these issues:
2) Causes for abnormal vital signs
It’d be unusual to get a completely normal erect CxR with that degree of clinical compromise (dyspnoea, tachypnoea and marked hypoxia). Supine CxR – yes, erect – I’d be very surprised.
Causes of tachycardia?
Any or all of:
Hypovoloaemia (from open wounds)
? Drugs (e.g. Amphetamines)
Cause for the hypoxia?
Can only really be PTX/HTX, and at 90%, one would assume that there is tension occurring, regardless of the normal BP.
Here’s an interesting study that describes the pathophysiology of tension PTX – in summary hypoxia occurs early, and CVS collapse occurs later.
3) What to do in this case?
It’s a no brainer:
You have a high risk mechanism, diagnostic US and clinical compromise, and we know that the “normal” CxR lacks sensitivity
1) Relieve actual or potential obstructive shock – place a 28-32Fr ICC
2) Give volume if ongoing shock despite relief of obstruction
2.1) Replace blood with blood
2.2) Minimise saline use
2.3) Serial US to look for tamponade
The question is actually more about what to do after the drain goes in, regarding need for transfer/CT and/or cardiothoracics input!
a) Just keep ‘em in Broome and do serial US/CxR for 24-48hrs and decide what to do based on clinical course/imaging.
b) Wait and see what comes out of the drain – i.e. lots of blood = transfer for CT? (Given the completely normal CxR I’d expect minimal blood in the drain in this case).
b) Transfer regardless as all stabbings with significant PTX need a CT and specialist input as they’re high risk for haemothorax, empyema and/or persistent air leak.