It’s fantastic to be here in Berlin at the 2022 EuSEM conference. All conferences have their own personalities and this is no exception. There is something special about the cosmopolitan nature of EuSEM. It brings so many different healthcare experiences together under one roof, with a feeling that we are all the same, but also slightly different. I find that I learn a lot here from European colleagues who are willing to share, and also from those from further afield. It’s hard to articulate, but it just feels like a really friendly and positive learning experience.
Anyway, back to this year’s top ten trauma papers. In truth it’s been a relatively quiet year which I think reflects the delays to a lot of trials that took place during COVID. Many trauma trials were paused during that time and as a result we will need to wait a little longer for results. On a positive note I’m expecting a bumper year in 2023!
There are some good studies out there though, these are some of my favourites as suggested by friends and colleagues from the St Emlyn’s team and other #FOAMed sites.
We covered this in some depth on the website already and you can read an in depth analysis here. In essence this trial was a randomised controlled trial of blood (packed red cells) and Lyoplas in the prehospital trauma setting.
This was a UK trial of 432 patients treated by air ambulance services. Patients received either blood and lyoplas, or saline. The patients were pretty sick at randomisation with a typical SBP of around 70.
The outcome was death, lactate clearance or both. A little controversial this as one is not really a patient outcome (lactate).
What they found was no difference between the groups.
- Combined outcome: 64% vs. 65%
- Mortality: 43% vs. 45%
- Lactate Clearance: 50% vs. 55%
This surprised a lot of people prompting a great deal of chat on social media. There are certainly questions about patient selection, outcome measures and whether PRBCs are the right sort of transfusion component, but nevertheless this is a great study that asks significant questions about who, how and when. We give blood products to shocked trauma patients.
Operative vs Nonoperative Treatment of Acute Unstable Chest Wall Injuries
In Virchester there is a lot of interest in the use of surgical rib fixation for patients with flail chest and/or chest wall deformity. We ‘believe’ that it’s good for patients and that it reduces ICU bed days, but there are typically lots of discussions about which patients are most likely to benefit and when fixation should take place. The uncertainty is arguably due to the lack of high quality clinical trials on the subject.
This year we have the largest RCT to date on the topic. 207 patients were included in an RCT of operative fixation vs. conventional treatment. Those included had flail chests and/or significant deformity. Patients were a mix of ventilated and spontaneously breathing. They were randomised to either operative fixation or a standard analgesia pathway. The principle outcome measure was ventilator free days (VFD). It did take them 7 years to achieve the trial numbers which is a bit of a concern as many other aspects of chest injury care have changed over that time (in Virchester at least).
In the operative group the average ventilator free days was 22.7 vs. 20.7 days. This was not statistically significant (2.1 days CI -0.3-4.5 p=0.09). In the secondary outcomes it’s worth noting that mortality was higher in the non-operative group (6% vs. 0%).
A planned subgroup analysis suggests that if there is any benefit then it is in the ventilated patient group as there was no benefit at all seen in the spontaneously breathing patients. However, there is arguably some circularity here as if you’re in the group that is not ventilated then you are less likely to be ventilated (as the other group is 100% ventilated)
It seems like there are still unanswered questions here about patient selection and perhaps timing to try and identify a group of patients who might be more likely to benefit. I’d also like to see some longer-term data too as VFDs are clearly not the only important outcome for this very significant injury.
My early trauma teaching emphasised the need for the largest chest possible in trauma. The logic is that smaller tubes are more likely to fail due to blockage and so I spent the early part of my career following the dogma and placing drains in the 32F-40F category. There was no doubt that this was pretty awful for patients (especially when just using local) but we accepted it as the best method at the time. In more recent years there has been a significant trend away from big drains in both trauma and non-traumatic thoracic pathologies and in some cases an acceptance that drainage may not be needed at all. My current practice is to use 24-28F drains in chest trauma, and it seems I’m choosing smaller drains over time as I’ve not really seen issues with that size.
A recent RCT from the US looked at chest drain size in trauma. They randomised 119 patients in whom there was clinical uncertainty about chest drain size to either a 14F pigtail catheter or to a chest drain (in the 28F-32F range).
The principal outcome was failure rate as defined by the need for a secondary procedure and it was pretty much the same 11% for PT vs. 13% for larger drains. In the secondary outcomes they found (unsurprisingly) that smaller drains were better tolerated by patients.
Although there are some caveats (patients selection, injury burden, clinician choice), this trial adds more weight to the argument that we should be less invasive with thoracic pathologies and that 14F may be enough.
There is a lot of evidence for differential prescribing in lots of conditions and between different groups. This also extends to diagnoses in emergency medicine. It seems that the further a patient is from the male, caucasian, empowered and privileged model then the less likely they are to receive important diagnoses and medications (see the papers on differential pain prescribing by ethnicity , or ACS diagnosis in women as examples). What about trauma though? Do we see differentials here? Well, the answer is probably yes and there are a number of studies around that support this view. One example, published this year is a secondary analysis of the CRASH 2 and 3 trials. You will remember that these were large RCTs of TXA in trauma.
This paper is really 2 studies. The first was to look at the results of the CRASH trials and divide the patients by sex. They then looked to see if there was a differential effect between these groups. There was not (in statistical terms) and so we should conclude that TXA works well for men and women. Therefore we should expect it to be equally prescribed, but is it?
The second part of this paper is an interrogation of the TARN database to see if men and women get TXA prescribed equally. The answer is that they do not. They looked at ISS>9 patients and found that TXA was prescribed in 7.6% of women and 16.8% of men. Now, there are reasons why this may be as the women were generally oder and with lesser mechanisms of injury, but even in the younger and high energy trauma there is a difference. The bottom line is that this is probably a real difference and we can (and must) do better.
Extrication and spinal protection.
I like papers that have the ability to change practice and this is certainly one of them. For years we have prioritised spinal protection in the treatment of trauma patients. This is borne of the idea that we should prevent secondary injury to the spine and spinal cord. That’s laudable, but it has its problems. There is no doubt that prioritising spinal care can compromise other aspects of patient care. It may prevent us getting access to patients, it might mean that we are forced to do complex procedures in difficult environments, it might mean that our patients are subject to positions and devices that are harmful, but perhaps most importantly it has the potential to rob our patients of the precious time that exists between point of injury and definitive care. It is the last of these, the issue of time that I most commonly see when meeting a patient several hours after injury in the ED, delayed because of spinal protection concerns.
Increasingly the data suggests that we have got the balance wrong. The number of patients who are at risk of a worsening of their spinal injury through movement is small. We need to reset the balance.
This paper is a Delphi study that seeks to bring together expert opinion in a structured way to provide sensible and deliverable guidance on how to manage patients with a spinal injury, You should really read the whole paper, but the big highlights for me are shown below.
- Self extrication or minimally assisted extrication is the standard first line approach except in those with
- An inability to understand or follow instructions
- Injuries or baseline function that prevents standing on at least one leg (specific injuries include: unstable pelvic fracture, impalement, bilateral leg fracture)
- All patients with evidence of injury should be considered time-dependent and their entrapment time should be minimised
- Clinical care during entrapment should be limited to necessary interventions
- Manage and mitigate the patient experience
This paper provides a consensus of reflected authority that can help prehospital (and hospital) teams achieve high quality and timely care to seriously injured patients. It has the potential to be a real game changer.
What’s the outcome from thoracotomy?
Thoracotomy remains a controversial procedure in the UK. Here at St Emlyn’s we have long argued that patient selection is the key to the success of this procedure. You obviously don’t want to go too early, and definitely not too late, and you also need the right sort of injury that you can actually do something about. The problem in clinical practice is that all three of these elements may lack certainty at a time when you have to make a time-critical/information-light decision.
This year EHAAT, one of the larger UK air ambulance services, published a 6-year experience of resuscitative thoracotomy (RT), and it’s interesting reading. The headline figure is that they performed 44 RTs but none survived. That’s disappointing and may be due to geographical factors as compared to other services, but there is some interesting data within the cases that might help us understand future indications and practice.
Interestingly 26 of the RTs were in patients with blunt trauma. Cardiac tamponade was found in 15% of blunt trauma patients and 39% of penetrating patients. That’s what I would expect for penetrating, but the number in the blunt group was higher than anticipated. I’ve often heard about rib fractures resulting in penetrating cardiac wounds as a potential indication for thoracotomy, but in this series the injuries were due to vessel injury and therefore less amenable to prehospital repair.
Although none survived to hospital discharge, 11 patients (25%) had ROSC. Nine of these were in blunt trauma patients and two in penetrating trauma. Again, this is an interesting finding that suggests that blunt thoracotomy may not be entirely futile as some have argued.
Do occult pneumothoraces require a chest drain?
When I was in training, and especially when in my critical care/anaesthetic training I was told that any traumatic pneumothorax required drainage if the patient was going to be ventilated. In truth I learnt a lot of my chest drain skills in exactly this group. It’s also noteworthy that at that time we did not do a lot of chest CTs and so that decision was made on the basis of CXR evidence of a pneumothorax (so probably a big one). Now that we CT patient I realise that loads of trauma patients have occult pneumothoraces (not seen on CXR) and so it’s a absolute certainty that we did, in the past, ventilate loads of patients with pneumothoraces that we simply did not know about.
In recent years a number of papers have come out suggesting that we can be more conservative in the management of traumatic and non-traumatic pneumothoraces, so where does the evidence now lie.
A recent meta-analysis of papers looking specifically a the need to drain occult pneumothoraces in ventilated patients has recently been published in the Journal of Trauma and Acute Care Surgery.
In summary. If you take a conservative approach to treatment (watch and wait) then 74% of patients will need no further intervention. A very small proportion (2.8%) may develop signs of a tension pneumothorax, and inevitably those patients who did get a drain have a much higher rate of complications. The summary is that a conservative approach is a reasonable strategy so long as a patient is clearly identified as having an occult pneumothorax and that means are available to treat any deterioration in a timely manner.
Is my patient likely to die and/or need a massive transfusion.
I’ll happily admit that I find the decisions around who will and who will not require massive transfusion difficult, and I don’t think I’m alone. The RePHILL trial showed that patients who can appear to be extremely unwell may not require that much volume replacement. The bottom line is that it can be tough.
These difficulties have led to the development of scoring tools to try and help clinicians identify at risk patients. You may be familiar with the ABC, TASH and Shock Index scores that have been around for many years. The problem is that the validation studies for these scores have often shown them to be of relatively little help in predicting death and/or massive transfusion.
A more recent score is the BATT score, which appears to have better validation than some of the established scores. The BATT score is shown below and as you can see is a little tricky to calculate, but is achievable with minimal information.
In this latest study Swiss researchers attempted to validate the BATT, ABC, TASH and Shock index scores against a national database of trauma cases. The headline data is that BATT performs much better at the identification of patients who will die. However, it is less discriminatory for the identification of the need for massive transfusion.
I think the conclusion is still that scores such as these are not really that good. Not good enough to be the sole arbiter of decision making in the ED or prehospitally. It also reminded of an alternative approach which is to look for more qualitative assessments of patients who are seriously unwell. The ‘Hateful Eight’ as described originally by the London HEMS teams (I think) would be a fantastic comparison to these scores, and I’d love to see a paper looking at this.
Summary
There are some useful learning points in the papers above and I hope you find them helpful. It’s been a bit of a lean year for trauma papers in the literature. I think COVID is a significant reason for this. I expect that next year will see a number of studies that were delayed during COVID published next year.
References
- RePHILL trial https://www.thelancet.com/journals/lanhae/article/PIIS2352-3026(22)00040-0/fulltext
- The small (14 Fr) percutaneous catheter (P-CAT) versus large (28-32 Fr) open chest tube for traumatic hemothorax: A multicenter randomized clinical trial. https://pubmed.ncbi.nlm.nih.gov/33843831/
- Operative vs Nonoperative Treatment of Acute Unstable Chest Wall Injuries: A Randomized Clinical Trial https://jamanetwork.com/journals/jamasurgery/article-abstract/2796556
- A Delphi study of rescue and clinical subject matter experts on the extrication of patients following a motor vehicle collision. https://sjtrem.biomedcentral.com/articles/10.1186/s13049-022-01029-x
- A 6-year case series of resuscitative thoracotomies performed by a helicopter emergency medical service in a mixed urban and rural area with a comparison of blunt versus penetrating trauma. https://sjtrem.biomedcentral.com/counter/pdf/10.1186/s13049-022-00997-4.pdf
- Validation of the BATT score for prehospital risk stratification of traumatic haemorrhagic death: usefulness for tranexamic acid treatment criteria https://sjtrem.biomedcentral.com/articles/10.1186/s13049-020-00827-5
- Conservative management of occult pneumothorax in mechanically ventilated patients: A systematic review and meta-analysis https://pubmed.ncbi.nlm.nih.gov/34225346/
- Use of tranexamic acid in major trauma: a sex-disaggregated analysis of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2 and CRASH-3) trials and UK trauma registry (Trauma and Audit Research Network) data. https://www.bjanaesthesia.org/article/S0007-0912(22)00184-2/fulltext
