TBS Top papers 2025 (part 1)

This week, I’m back in Zermatt at The Big Sick (TBS) Conference—one of my absolute favourite meetings. It’s small, it’s focused, and it’s all about the sickest patients we see in practice. I was here last year, and if you’re interested, you can check out last year’s papers here.

Despite a packed schedule, this post is all about the first session—a look at some key papers from the last 12 months. I was lucky to share the session with Brian Burns (Sydney HEMS) and Rob McSweeney (Critical Care Reviews). I’ll come back to their picks later, but for now, here’s my list.

I wasn’t aiming for the biggest, most methodologically robust trials. Instead, I picked papers that might change what we do in practice—or at the very least, make us think.

Non-invasive versus arterial pressure monitoring in the pre-hospital critical care environment

We covered this paper on the blog earlier in the year and you can see the full review here. IN essence this trial was a retrospective review from Thames Valley Air Ambulance where they compared blood pressures from an invasive arterial line (IBP) vs. NIBP. They looked for agreement as defined as within 20mmHg od SBP/DBP, or 10mmHg of MAP. Personally I think this is a very generous definiition of agreement. In the criticually unwell there is a big difference between an SBP of 90 vs. 71mmHg, but that would be defined as agreement here.

What they actually found is that there is poor agreement between NIBP and IBP, especially so for MAP where there is agreement in about 50% of cases. In addition the data shows that NIBP performs less well when the patient is hypotensive (SBP is reported as higher than IBP), and when the patient is hypertensive it underestimates.it. So in those patients in whom a difference really matters, the readings are more likely to be wrong.

We need to stop thinking about resuscitation as just doing CPR—we need to know if it’s actually working. And without an arterial line, how do we know? Maybe new non-invasive tech will fill the gap, but for now, if I think a patient has a shot at survival, I’m putting in an art line.

The association between intra-arrest arterial blood pressure and return of spontaneous circulation in OOHCA

So if NIBP is not great, does it matter? Well I think so and this paper makes a good argument for this. There is a lot of animal data that demonstrates that you need adequate coronary perfusion to get ROSC in cardiac arrest. That work suggests that you need a DBP ot above 30-40mmHg to achieve this (as coronary perfusion is largely determined by diastolic blood pressure), but what about humans.

In this study from a UK air ambulance they looked at those patients where they had placed a femoral arterial line intra-arrest. What they found backs up the animal data. Those patients who got ROSC had a DBP of >35mmHg.

What this means is that we arguably need to be targeting the ‘impact’ of resuscitation in physiological terms as opposed to just the process. So, it’s not enough to just do CPR, we need to know whether that CPR is having an impact. Can you do that without an arterial line? I suspect not. However, that skill is not universally available and perhaps we need a different, maybe non-invasive, technology to do this. I understand there may be devices on the horizon so let’s hope so. For now, I’ll keep putting art lines in my cardiac arrest patients who I think have got the possibility of a good outcome.

Serratus anterior plane blocks for early rib fracture management. SABRE trial.

Although this multicentre Australian trial of enrve blocks for chest wall trauma is quite small, I think it has some really interesting outcoems that may really change practice. You can read the full review here, but in essence this was an RCT of serratus anterior plane blocks (SAPBs) vs standard care with the primary outcomes being pain.

The bottom line is that SAPBs reduced pain scores and the need for opiates. This is important to me as it’s a group of patients I commonly meet on our major trauma ward, where chest wall trauma is a significant cause of morbidity and sometimes mortality. Whilst our preferred block there is an ESP block, that’s not easily achievable in the ED, but an SAPB is.

It’s also worth noting that the group of patients who benefited the most had posterior rib fractures, a site that is traditionally considered beyond the reach of the SAPB. That’s not the case here and so we need to challenge that thinking.

I increasingly like to think of the SAPB as the fascia iliaca block of the chest, and I’m going to predict that it may eventually become a standard of care for those patients with significant chest wall trauma and pain.

This is a really interewsting trial published in the NEJM this year. It caught my eye as I work in a system where we are more ECNO than ECMO, and where ECPR is simply not available. Let’s imagine a case that I see not uncommonly. A man in his 40s has a witnessed cardiac arrest, bystander CPR, early defibrillation and early access to great post ROSC care and with an ECG showing a massive anterior STEMI. Cases like this are clearly terrible for the patient and family, but when I meet them in prehospital care or the ED I am actually quite hopeful as I think that a really positive outcome. However, on this (hypothetical) occasion he gets to PCI and is stentedm but sadly he develops profound cardiogenic shock on the ICU. Despite cardiovascular suppoty with a variety of inotropes and even consideration of LVADs and balloon pumps he died.

Now for some people will say that the solution here is ECMO, for the vast majority of the world that is simply not an option. So are there altertnatives. The DanGer shock trial looked at patients like this and supported them with an impella device. Think of this as a pump placed in the left ventricle that supports it’s function. Unlike ECMO this is a device that can be used by any competent PCI cardiology centre. I’ve personally seen them used and they are quite remarkable.

This trial took sick patients with the following characteristics and randomised them to standard care or the insertion of an impella device.

STEMI
SBP <100mmHg
On vasopressors
LActate >2.5mmol
LVEF <45%

So basically a really sick cohort.

What they found is that at 180 days 58.5% of impella patients survived as compared to 45.8% of standard care. That’s a remarkable NNT of about 8.

There are problems with this study though. It took them ages to recruit and so it’s unlikley that representative a cohort. However, I’d like to see more on this as either a bridge to ECMO or as analternative for teh 99%+ of the world who don’t live within 60 minutes from arrest to an ECMO centre.

The impact of double sequential external defibrillation timing on outcomes during refractory out-of-hospital cardiac arrest

Thius is the first of two sub-analyses of the DOSE-VF trial which `I think expand our underrstanding of how we might optimise defibrillation. In this study the authors went back and interrogated the defibrillators to determine whether there was an association between the shocks in dual sequence defibrillation. The trial protocol was for the shocks to be one second apart, but this was done manual and so there was a natural variation when done in practice.

Why was it a one second pause anyway? Well that was probablym because of fears of damage to the defibrillators if they were used simultaneously (which is what I used to do in the past!).

What they found is that the shorter the duration between shocks then the more likley for VF/VT to be terminated, with a 48% success rate if less than 75msecs as compared to roughly 25% if after this. That’s really interesting and poterntially important, but it is a secondary analysis and perhaps we need to be cautious as a result.

We also anoither secon dary analysis of the DOSE-VF trial trhat looked at whether failure to defibrillate is due to a true failure (they never came out of VF), vs. recurrent where they may go into a perfusing rhythm, but then rapidly revert to VT/VF. In my head I’ve always felt that one needs more electricity (failure) and the other needs drugs (recurrent). In this paper the research team were able to interrogate the defibs in DOSE-VF and demonstrate that there really is a difference between with 17% of patients having true refractory (not recurrent). The bottom line for us is that DSED is better for both, and especially so for refractory. This is then further evidence that DSED is a great technique, but again this is a secondary analysis and we should be cautious of over interpreting this finding.

Summary

None of these statements are definitive, but they should get you thinking.

NIBP is unreliable for sick patients—if BP matters, use an art line.
DBP >35mmHg predicts ROSC in cardiac arrest—we need to measure CPR effectiveness.
SAPBs reduce rib fracture pain and opioid use—potential new standard of care.
Impella improves survival in cardiogenic shock—a possible ECMO alternative?
DSED shock timing matters—faster = better defibrillation success.

This was the TBS audience and so I;’ve selected cases that ask people to think differently rather than the biggest/best/most cited. My aim was to get people thinking and if the number of convereations I’ve had since then it worked. There are some great minds here at this amazing conference and if time/funds/family/jobs work for. you and you can make it here one year then please do so. You’ll have a great time in a wonderful environment.

References and further reading.

Simon Carley, “Top resuscitation papers for The Big Sick Conference 2024,” in St.Emlyn’s, February 7, 2024, https://www.stemlynsblog.org/top-resus-papers-for-tbs/.
Møller JE, Engstrøm T, Jensen LO, Eiskjær H, Mangner N, Polzin A, Schulze PC, Skurk C, Nordbeck P, Clemmensen P, Panoulas V, Zimmer S, Schäfer A, Werner N, Frydland M, Holmvang L, Kjærgaard J, Sørensen R, Lønborg J, Lindholm MG, Udesen NLJ, Junker A, Schmidt H, Terkelsen CJ, Christensen S, Christiansen EH, Linke A, Woitek FJ, Westenfeld R, Möbius-Winkler S, Wachtell K, Ravn HB, Lassen JF, Boesgaard S, Gerke O, Hassager C; DanGer Shock Investigators. Microaxial Flow Pump or Standard Care in Infarct-Related Cardiogenic Shock. N Engl J Med. 2024 Apr 18;390(15):1382-1393. doi: 10.1056/NEJMoa2312572. Epub 2024 Apr 7. PMID: 38587239.
Simon Carley, “Non-invasive or arterial pressure monitoring in PHEM?,” in St.Emlyn’s, September 29, 2024, https://www.stemlynsblog.org/non-invasive-or-arterial-pressure-monitoring-in-phem/.
Perera, Y., Raitt, J., Poole, K. et al. Non-invasive versus arterial pressure monitoring in the pre-hospital critical care environment: a paired comparison of concurrently recorded measurements. Scand J Trauma Resusc Emerg Med 32, 77 (2024). https://doi.org/10.1186/s13049-024-01240-y
Simon Carley, “Intra-Arrest Arterial Blood Pressure and Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest.,” in St.Emlyn’s, November 22, 2024, https://www.stemlynsblog.org/intra-arrest-arterial-blood-pressure/.
Partyka C, Asha S, Berry M, Ferguson I, Burns B, Tsacalos K, Gaetani D, Oliver M, Luscombe G, Delaney A, Curtis K. Serratus Anterior Plane Blocks for Early Rib Fracture Pain Management: The SABRE Randomized Clinical Trial. JAMA Surg. 2024 Jul 1;159(7):810-817. doi: 10.1001/jamasurg.2024.0969. PMID: 38691350; PMCID: PMC11063926.
Aziz S, Barratt J, Starr Z, Lachowycz K, Major R, Barnard EBG, Rees P. The association between intra-arrest arterial blood pressure and return of spontaneous circulation in out-of-hospital cardiac arrest. Resuscitation. 2024 Dec;205:110426. doi: 10.1016/j.resuscitation.2024.110426. Epub 2024 Nov 6. PMID: 39515601.
The impact of double sequential shock timing on outcomes during refractory out-of-hospital cardiac arrest. Mahbod Rahimi 1, Ian R Drennan 2, Linda Turner 3, Paul Dorian 4, Sheldon Cheskes 5. PMID: 38092182 DOI: 10.1016/j.resuscitation.2023.110082
Simon Carley, “The impact of double sequential external defibrillation timing on outcomes during refractory out-of-hospital cardiac arrest,” in St.Emlyn’s, June 23, 2024, https://www.stemlynsblog.org/double-sequential-external-defibrillation/.
Cheskes S. Verbeek P.R. Drennan I.R. et al. Defibrillation strategies for refractory ventricular fibrillation.New England J. Med. 2022; 387: 1947-1956
Carley S. JC: Alternate defibrillation strategies in refractory VF. The DoseVF trial. St Emlyn’s. Accessed June 10, 2024.
Morgenstern, J. Dose VF: A double sequential defibrillation game changer?, First10EM, November 8, 2022. A
The Bottom Line blog. DOSEVF.
Rahimi M, Drennan IR, Turner L, Dorian P, Cheskes S. The impact of double sequential shock timing on outcomes during refractory out-of-hospital cardiac arrest. Resuscitation. 2024 Jan;194:110082. doi: 10.1016/j.resuscitation.2023.110082. Epub 2023 Dec 11. PMID: 38092182.