SASEM 2023. Top 10 papers. St Emlyn’s

I’ve attended the Saudi Arabian Society of Emergency Medicine (SASEM) conference several times and it’s fantastic. It certainly looks as though EM is a healthy speciality in the country and the presentations I’ve seen there have been excellent, with some great content and some really accomplished presenters. Sadly I’ve only been able to attend in person on one occasion back in 2019 when the conference was in Jeddah. Back then I learned a huge amount about the country, the city, the people and the EM journey within the country. The blog post accompanying that visit is available here. If you’re in the region or fancy a trip to somewhere a little different to the usual conference circuit it’s a recommend from me.

This year the conference is in Jeddah and you can see the program here. This year I am attending virtually and delivering a catch up on the latest top notch evidence in EM/PHEM.

Paper 1. The PATCH trial. Does TXA work in trauma?

TXA has been controversial (for some) as despite positive results in many trials there has been scepticism about it’s effectiveness in high performing trauma systems. The PATCH trial was designed as an RCT comparing the outcomes for major trauma patients treated in a high performing trauma system (Australia, NZ, Germany). 1310 patients were recruited and followed through to 6 months with a principle outcome of functional outcome at six months. In terms of the primary outcome there was no difference, with 307 of 572 patients (53.7%) in the tranexamic acid group and 299 of 559 patients (53.5%) in the placebo group having a favourable outcome (GOS-E of 5 or above) at 6 months. So you might say that TXA has no impact, but I’m not so sure as the data also shows that there are more survivors at 6 months, so we have more lives saved, but that those survivors are more likely to have disabilities, which should be no surprise really.

For me the trial once again shows that TXA saves lives, and that we should give it to achieve the short term impacts it is designed to deliver. There is clearly more work to be done on further management and rehabilitation to try and move those additional survivors into favourable neurological outcomes.

Prehospital Tranexamic Acid for Severe Trauma. The PATCH-Trauma Investigators and the ANZICS Clinical Trials Group NEJM 2023: June 14, 2023 DOI: 10.1056/NEJMoa2215457 https://www.nejm.org/doi/10.1056/NEJMoa2215457

Paper 2. Should we use video laryngoscopy routinely?

I trained using direct laryngoscopy and up until recently that was all I knew and so all that I used, but after starting with HEMS it’s now routinely used and available, but is it really any better? Some would say obviously yes, but there are also those who point out that the sort of airways that we deal with in EM are often soiled and therefore VL may be limited (although in practice I don’t find this to be an issue). In this RCT from the US 1417 patients were randomised to either VL or DL. The study looked at a number of outcomes, with the main one being the rate of first pass success. Successful first-attempt intubation in the VL group was 85.1% (600 of the 705 patients) vs 70.8% (504 of the 712 patients) in the DL group. Giving a p value of < 0.001 and a 95% confidence interval of 9.9-18.7.

So that’s really significant and a good argument for using VL, but there are some caveats. Most notably was the difference in rates between experienced operators and learners. Once you get to over 100 intubations the difference is minimal, and so it is amongst learners that we really see a difference. This is something I agree with, not just that it’s a great learning tool for the operator but also that the use of VL is a fantastic way to coach learners to improve (a point made really well by Scott Weingart on the EMCRIT podcast). I think this is one of the best arguments for adopting VL into my practice, working in an academic system. However, I try to discipline myself to use our VL (a McGrath model) as a DL initially, and then to only use the screen for teaching or when needed. I encourage my colleagues to do the same as there will always be circumstances where DL is needed and it’s essential to learn and practice those skills.

Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults. Prekker et al NEJM 2023 https://www.nejm.org/doi/full/10.1056/NEJMoa2301601

Paper 3. Alternate defibrillation strategies. The DOSE VF trial.

Refractory VF is defined as a patient who is still in VF after three shocks, and so for most hospital based clinicians, or PHEM teams that is the majority of the patients we see. What then do we do to get them out of VF? Usually this means drugs such as amiodarone, but we do know that these are not as effective as we would wish. For many years the possibility of using an alternative pad position has been on the guidelines as an option, but I’ve rarely seen it used in practice in the UK. On reflection this was odd, we were dealing with a group of patients who had failed the first part of the ALS algorithm, but carrying on doing pretty much the same thing. That seems unwise!

The DOSE-VF trial was an RCT that compared three different defib strategies for patients in refractory VF. Carrying on as standard (Antero-lateral), moving to AP (antero-posterior) or using dual sequence defibrillation using two shocks, from two devices in AP/AL, one second apart.

405 patients were enrolled which was less than the intended 900 +. In terms of allocations, 136 (33.6%) were assigned to the standard group, 144 (35.6%) to the VC group, and 125 (30.9%) to the DSED group.

In terms of the main outcome (survival to hospital discharge) DSD performed best, and AP performed better than AL.

• Survival with DSD 30.4% (38/125 patients)
• Survival with AP 21.7% (31 of 143 patients)
• Survival with AL 13.3% (18 of 135 patients)

So, there was clear evidence of benefit to DSD and that is now my practice in those patients who I just cannot get out of VF.

Defibrillation Strategies for Refractory Ventricular Fibrillation. Cheskes et al NEJM 2023. https://www.nejm.org/doi/full/10.1056/NEJMoa2207304

Paper 4. New triage methods in Major Incidents

Effective triage is a fundamental task in the management of major incidents, but what’s the best approach. It’s a surprisingly difficult question to answer as the best tools will not only identify those patients who are the most unwell, but also the subset of those who will benefit from intervention, whilst also being quick and easy to use. It’s therefore a task that requires a great deal of thought and design. This year we have seen the launch of the 10-second triage tool which uses a system that tries to address all these components, and whilst no triage tool with ever be perfect this one has the ability to be completed with minimal training and in a very short space of time. This tool probably performs better than the more traditional Triage Sieve/Sort methodology and also incorporates a tool for the triage of small children (which in other systems is really quite complex). The system is being adopted across the UK this year, and as it is probably now the best evidenced tool out there I suspect it will be adopted internationally.

Although this tool is based on consensus design, it is based on the MITT score, and prior to that the MPTT-24 tool that was developed and tested against military databses of trauma victims. It is therefore arguably the most evidence based approach to triage that we have seen so far.

Vassallo, J., Cowburn, P., Park, C., Bull, D., Harris, S., Moran, C.G. and Smith, J.E. (2023), Ten second triage: a novel and pragmatic approach to major incident triage, Trauma, available at https://journals.sagepub.com/doi/10.1177/14604086231156219

Vassallo J, Moran C, Cowburn P, et al. New NHS prehospital major incident triage tool: from MIMMS to MITT. Emerg Med J 2022; 39: 800–802. Vassallo J, Smith JE, Wallis LA Major incident triage and the implementation of a new triage tool, the MPTT-24. https://militaryhealth.bmj.com/content/164/2/103

BMJ Military Health 2018;164:103-106.

Paper 5. How old is your emergency physician?

We;ve done several posts on St Emlyn’s about the need for life long learning that works. Personally I am a great advocate of peer review and reflection to keep people at the top of their game, but does it matter and does it work. This study won’t tell us whether it works, but it’s certainly food for thought amongst those who are getting a little older (and feeling it). The authors looked at medicare records in the US and in fact put over 2.5Million records up for an analysis against the age of the treating emergency physician. The outcome was 7-day mortality for patients aged 65-89. The headline result is that mortality rose steadily as the physician got older. It was not a huge difference, but it was a linear increase suggesting a dose response effect. This effect has been found in other specialities so it’s perhaps not a surprise.

Sadly we cannot make people younger physically, but perhaps we can work even harder to keep clinicians up to date as their careers progress.

Miyawaki A, Jena AB, Burke LG, Figueroa JF, Tsugawa Y. Association Between Emergency Physician’s Age and Mortality of Medicare Patients Aged 65 to 89 Years After Emergency Department Visit. Ann Emerg Med. 2023 Sep;82(3):301-312. doi: 10.1016/j.annemergmed.2023.02.010. Epub 2023 Mar 23. PMID: 36964007.

Paper 6. Fentanyl for RSI. FAKT study.

I regularly use fentanyl as part of my RSI ‘recipe’. The perceived wisdom is that it reduces hypertension spike, adds to the sedative effect and relieves pain. All are laudable benefits, but it comes at the risk of cardiovascular instability and in particular hypotension. Hypotension is something we definitely want to avoid and so in my service we avoid using it in patients where cardiovascular instability and hypotension are particularly risky. This RCT compared fentanyl or 0.9% saline just before ketamine/rocuronium. Non-invasive BP measurements were recorded every 2 min for 10 min after induction. They tried to keep the SBP in the 100-150mmHg range. Arguably giving the fentanyl so close to induction was a bit close to get its benefits (as ideally it’s best given earlier), but I do see this sequence done in practice.

Primary outcome data were available for 270 of 290 participants. In the fentanyl group, 66% of patients had an SBP outside of the target range post-induction, compared with 65% of the control group (95% CI=−10% to 12%, p=0.86). However, 29% of patients in the fentanyl group had ≥1 low SBP measurement compared with 16% in the placebo group (difference 13%, 95% CI=3% to 23%), and 69% of the placebo group had ≥1 high SBP measurement compared with 55% of the fentanyl group (difference=14%, 95% CI=3% to 24%). There was no difference in the rates of intubation success. This study is limited by differences in baseline characteristics (twice the number of females in the placebo group, and different underlying pathologies), selection bias due to daytime-only recruitment and inaccuracy of non-invasive BP measurements. In addition, the majority of patients had medical indications for RSI (13% trauma).

The data shows that the addition of fentanyl has cardiovascular effects and as a result can lead to fewer episodes of hypertension but increases the rates of hypotension. Whether we give it should therefore be a mindful decision rather than simply following a protocol. As clinicians we must ask what we are trying to prevent, and what risks are acceptable for our patient.

Fentanyl versus placebo with ketamine and rocuronium for patients undergoing rapid sequence intubation in the emergency department: the FAKT study-A randomized clinical trial. Acad Emerg Med 2022;29:719–28.doi:10.1111/acem.14446 pmid: http://www.ncbi.nlm.nih.gov/pubmed/35064992 

Paper 7. Thrombectomy alone or thrombectomy after alteplase in stroke patients.

Following the stroke literature is challenging with many widely held views about the effectiveness of interventions such as thrombolysis. That said there is increasingly consensus and evidence to support the use of thrombectomy for the right patients and a number of studies have shown the effectiveness of this. However, there has been uncertainty about whether patients should be thrombolysed as. abridging therapy prior to thrombectomy. In this study researchers in Canadian and European endovascular centres performed a non-inferiority trial to look at this. They enrolled patients within 4.5 hours of their stroke and who had the opportunity for thrombectomy within 75 mins of randomisation. Of 423 patietns randomised Successful reperfusion occurred in significantly fewer patients assigned to thrombectomy alone 182 (91%) than alteplase plus thrombectomy 199 (96%), risk difference −5.1% (95% CI −10.2% to –0.0%). Complications between groups were similar.

At 90 days the patients had a Modified Rankin Scale score assessment, with a score of of 0–2 (good scores) of 114 (57%) vs 135 (67%) of the thrombectomy alone group versus alteplase plus thrombectomy, adjusted risk difference −7.3% (95% CI −16.6% to 2.1%). This crossed the lower limit of the the non-inferiority margin suggesting thrombectomy alone was inferior.

Whilst this study tells us that we should prioritise thrombolysis for our patients, it opens up a whole range of questions about bridging therapies that might be applicable to get patients to thrombectomy centres, noting that this study was only in centres that can do thrombectomy, which is pretty uncommon in many health economies.

Thrombectomy alone versus intravenous alteplase plus thrombectomy in patients with stroke: an open-label, blinded-outcome, randomised non-inferiority trial. Lancet 2022;400:104–15.doi:10.1016/S0140-6736(22)00537-2 pmid:http://www.ncbi.nlm.nih.gov/pubmed/35810756 

Paper 8. Do we miss giving TXA to our female patients?

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 two 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.

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

Paper 9. A paradigm shift in extrication techniques.

For years we have been taught that it is vitally important to minimise spinal movement in trauma patients. I remember being told of awful outcomes for patients if they were not handled with the greatest of care and the important of not moving the spine, or allowing the patient to move their own spine as this might cause irrecoverable spinal cord damage. That view has been increasingly challenged with many studies now showing that traditional models of extrication using devices like spine boards may in fact worsen spinal movement. We also have better epidemiological data that shows that truly unstable spinal injury is quite rare, and if it is present the patient usually has significant other injuries as well. The problem then is that techniques that minimise spinal movement are also slow, thus potentially compounding the impact of the other life threatening injury. So perhaps we have emphasised spinal movement at the expense of a global appreciation of the patient’s burden of disease. At it’s extremem level you can imagine a patient bleeding to death whilst a slow and steady extrication takes place to potentially prevent an injury that is in fact pretty unlikely!

The EXIT project let by Tim Nutbeam in the UK has been looking at this for many years, and this year brought. agroup of 60 subject matter experts together in a delphi study. tocollate the evidence, experience and collective wisdom of this group to write a series of important and progressive recommendations. I would recommend reading the full document, but in brief these are some of the key points 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

The biggest impact I have seen in the UK is with regard to recopmmendation one above. That has transformed scene times and thus expedited the care of our trauma patients, some with significant injuries that were truly time critical in nature.

A Delphi study of rescue and clinical subject matter experts on the extrication of patients following a motor vehicle collision. Scand J Trauma Resusc Emerg Med 2022;30:41.doi:10.1186/s13049-022-01029-x pmid:http://www.ncbi.nlm.nih.gov/pubmed/35725580 

Paper 10. ECMO for refractory out of hospital cardiac arrest.

Extracorporeal cardiopulmonary resuscitation (e-CPR) has created a lot of enthusiastic comment in recent years. The data is somewhat variable at the moment, with some trials showing dramatic effects, and others having a rather less convincing impact. The concept of using e-CPR to bridge a patient in refractory cardiac arrest (more than 15 mins in this study) until they can receive definitive treatment is certainly an attractive one. In this study we have an RCT of e-CPR use in the prehospital setting from the Netherlands. 160 patients were randomised to e-CPR or standard care. The study used HEMS platforms across the country to achieve this. The primary outcome was survival with a good neurological outcome.

I was quite hopeful about this study, but the results were not as expected with patients assigned to conventional CPR having similar survival until hospital admission (OR 0.1, 95% CI 0.1 to 0.3). 20% e-CPR vs 16% conventional) survived to hospital discharge, and at 6 months positive neurological outcomes were similar (OR 1.4, 95% CI 0.5 to 3.5). That said only a third of patients in the eCPR group actually got it, and the service was arguably in set up whilst also collecting data with some commentators questioning whether the system was mature enough at the time to truly test the concept.

This study is a good one to remind us that we do need to test new technologies in trials and that excellent concepts do not always translate well into real world practice. For now it seems that prehospital eCPR still needs more research on both outcomes and the systems to deliver it, but I have a feeling that the story is not over yet.

Early extracorporeal CPR for refractory out-of-hospital cardiac arrest. N Engl J Med 2023;388:299–309. doi:10.1056/NEJMoa2204511 

Final thoughts

It’s great to contribute to SASEM once again. It’s also been fun to find some really interesting papers, and with the exception of the paper on age of emergency physician, I loved reading them all.

vb

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1. Early extracorporeal CPR for refractory out-of-hospital cardiac arrest. N Engl J Med 2023;388:299–309. doi:10.1056/NEJMoa2204511 
2. A Delphi study of rescue and clinical subject matter experts on the extrication of patients following a motor vehicle collision. Scand J Trauma Resusc Emerg Med 2022;30:41.doi:10.1186/s13049-022-01029-x pmid:http://www.ncbi.nlm.nih.gov/pubmed/35725580 
3. 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
4. Thrombectomy alone versus intravenous alteplase plus thrombectomy in patients with stroke: an open-label, blinded-outcome, randomised non-inferiority trial. Lancet 2022;400:104–15.doi:10.1016/S0140-6736(22)00537-2 pmid:http://www.ncbi.nlm.nih.gov/pubmed/35810756 
5. Fentanyl versus placebo with ketamine and rocuronium for patients undergoing rapid sequence intubation in the emergency department: the FAKT study-A randomized clinical trial. Acad Emerg Med 2022;29:719–28.doi:10.1111/acem.14446 pmid: http://www.ncbi.nlm.nih.gov/pubmed/35064992 
6. Miyawaki A, Jena AB, Burke LG, Figueroa JF, Tsugawa Y. Association Between Emergency Physician’s Age and Mortality of Medicare Patients Aged 65 to 89 Years After Emergency Department Visit. Ann Emerg Med. 2023 Sep;82(3):301-312. doi: 10.1016/j.annemergmed.2023.02.010. Epub 2023 Mar 23. PMID: 36964007.
7. Defibrillation Strategies for Refractory Ventricular Fibrillation. Cheskes et al NEJM 2023. https://www.nejm.org/doi/full/10.1056/NEJMoa2207304
8. Prehospital Tranexamic Acid for Severe Trauma. The PATCH-Trauma Investigators and the ANZICS Clinical Trials Group NEJM 2023: June 14, 2023 DOI: 10.1056/NEJMoa2215457 https://www.nejm.org/doi/10.1056/NEJMoa2215457
9. Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults. Prekker et al NEJM 2023 https://www.nejm.org/doi/full/10.1056/NEJMoa2301601
10. Vassallo, J., Cowburn, P., Park, C., Bull, D., Harris, S., Moran, C.G. and Smith, J.E. (2023), Ten second triage: a novel and pragmatic approach to major incident triage, Trauma, available at https://journals.sagepub.com/doi/10.1177/14604086231156219
11. Simon Carley, “JC: The PATCH trial. TXA in major trauma. St Emlyn’s,” in St.Emlyn’s, June 23, 2023, https://www.stemlynsblog.org/jc-the-patch-trial-txa-in-major-trauma-st-emlyns/.
12. Laura Howard, “JC – Video vs Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults,” in St.Emlyn’s, June 25, 2023, https://www.stemlynsblog.org/jc-video-vs-direct-laryngoscopy-for-tracheal-intubation-of-critically-ill-adults/.
13. Simon Carley, “JC: Alternate defibrillation strategies in refractory VF. The DoseVF trial. St Emlyn’s,” in St.Emlyn’s, November 10, 2022, https://www.stemlynsblog.org/jc-alternate-defibrillation-strategies-in-refractory-vf-the-dosevf-trial-st-emlyns/.
14. Simon Carley, “JC: Fentanyl as an adjunct in RSI. Does it affect haemodynamic stability? St Emlyn’s,” in St.Emlyn’s, September 17, 2022, https://www.stemlynsblog.org/jc-fentanyl-as-an-adjunct-in-rsi-does-it-affect-haemodynamic-stability-st-emlyns/.
15. Simon Carley, “The EXIT study extrication consensus statements. St Emlyn’s,” in St.Emlyn’s, July 25, 2022, https://www.stemlynsblog.org/the-exit-study-extrication-consensus-statements-st-emlyns/.
16. Simon Carley, “JC: ECPR for refractory OOHCA. St Emlyn’s,” in St.Emlyn’s, January 30, 2023, https://www.stemlynsblog.org/jc-ecpr-for-refractory-oohca-st-emlyns/.
17. Simon Carley, “Differential prescribing of TXA by gender. St Emlyn’s,” in St.Emlyn’s, May 31, 2022, https://www.stemlynsblog.org/differential-prescribing-of-txa-by-gender-st-emlyn-s/.