Monday 11 December 2023

Emergency department versus operating room intubation of patients undergoing immediate hemorrhage control surgery

There are theoretical reasons why endotracheal intubation can make trauma patients worse. Induction agents can cause hypotension. Positive pressure ventilation decreases venous return and can decrease cardiac output. This is not to mention the potential complications of the procedure itself. 

Of course, all of this must be balanced with the possible need for a definitive airway and to ensure oxygenation & ventilation.

So… for trauma patients requiring surgery, is it better to intubate in the ED or wait to go to the operating theatre?

This study looked at the National Trauma Data Bank (registry data… beware) and identified 9,667 patients at 253 trauma centers who underwent hemorrhage control surgery within 60 minutes of ED arrival. To attempt to minimize confounding, they excluded patients with GCS <8, dead on arrival, ED thoracotomy, or those “with clinical indications for intubation.”

The primary outcome was mortality when comparing ED intubation vs. in theatre.

The unadjusted mortality for those intubated in the ED was 17% vs. 7% in theatre. Absolute increase of 10% or a number needed to kill (NNK) of 10.

Intubating in the ED is lethal!?

Wait a minute…

Of course, the sicker patients are more likely to get intubated in the ED!

This study was no exception. ED patients had markedly higher injury severity scales. They had lower GCS, more chest, lung, heart, thoracic vascular and liver injury. They were more tachycardic and twice as likely to get a thoracotomy for hemorrhage control.  

The authors tried the usual fancy statistical adjustments that we often see with observational study design, but this is far from a perfect science. Studies like this invariably have some residual confounding which makes the interpretation difficult.

To be fair, the authors do a good job of mentioning the study limitations but unfortunately overstate their conclusion.

There is an association between ED intubation and worse outcomes. Yes, but is this a causal relationship? That is the big question which can only be answered with a randomized clinical trial.



Dunton Z, Seamon MJ, Subramanian M, et al. Emergency department versus operating room intubation of patients undergoing immediate hemorrhage control surgery. J Trauma Acute Care Surg. 2023;95:69-77. [link to article]



“Diagnostic accuracy of clinical examination to identify life-and limb-threatening injuries in trauma patients”

How good is the physical examination
for finding life threatening stuff in trauma patients?

This study sought to answer this question but the title is somewhat misleading. It should have been a bit longer as below:

Diagnostic accuracy of the single pre-hospital physical examination to identify life and limb threatening injuries performed by a doctor in the field around London, UK without using adjuncts who had no idea they were going to participate in a study and may or may not have collected or written down information as sought by the investigative team.

It’s clear that I was not involved in the peer review process of this paper.

Since the methods employed never really had a hope of answering the research question, I’m not going to go into much details of the paper. Nevertheless, I still think their conclusion is correct! “Clinical examination… has only a moderate ability to detect life and limb threatening injuries.”

Even a broken clock is correct twice a day.

Just to reiterate, this was a retrospective study of a single physical exam. It was performed pre-hospital, possibly in an austere environment with no ultrasound or other adjuncts. The doctor very likely had other significant priorities; i.e. scoop and run. It cannot speak to the utility of serial examinations or those performed a bit later as things evolve.

My fear is someone may pull this paper out of their pocket to suggest that we need to do away with physical exam and perform full body CT scans in all trauma patients. This could likely cause harm, especially in lower risk trauma patients or pediatrics.



Wohlgermut JM, Marsden ME, Stoner RS, et al. Diagnostic accuracy of clinical examination to identify life- and limb-threatening injuries in trauma patients. Scand J Trauma Resusc Emerg Med. 2023;31:18 [link to free full text article]



Emergency Department REBOA in trauma patients with exsanguinating hemorrhage- Finally an RCT!

Resuscitative Endovascular Balloon Occlusion of the Aorta has had lots of exciting coverage over the past few years. But despite the hype, we don’t really know if it helps or harms patients.

Huh… Why don’t we know if it works?

Existing data has exclusively been observational. Researchers have passively sat back and looked to see if there are outcome differences between those who got REBOA and those who didn’t. The problem is these are two VERY different groups. Despite all the fancy statistical analysis, it is impossible to properly adjust for all the between group confounding.

What is the best way to get rid of confounding?


The process of randomization ensures that there are equal amounts of known and unknown confounders in each group. Problems solved… theoretically.

So here is the first randomized clinical trial of REBOA in trauma!

The UK-REBOA RCT was conducted in 16 major trauma centers in the UK. Patients with exsanguinating hemorrhage were enrolled over 4+ years.

The primary outcome was all-cause mortality at 90 days. There were lots of secondary outcomes.


90 patients were enrolled almost all (97%) with blunt trauma. As expected, they were super sick with a median injury severity score (ISS) of 41.

In the end, the trial was stopped for harm. Mortality was 54% with REBOA vs. 42% in the standard care arm. Number needed to kill (NNK) is 8. In addition, all the secondary outcomes and bleeding seemed to be worse with REBOA.

Does this signal the death of REBOA?

Probably not.

Unfortunately, this paper has lots of limitations. The biggest of which is only 19 out of 46 patients randomized to REBOA got the device inserted and balloon inflated. It is hard to demonstrate a treatment effect when most patients don’t get the treatment. But perhaps this shows the real-world difficulties of performing REBOA.

Critics of this paper will highlight many other issues: training of providers, time delays, specific device used, small numbers, stopped early, baseline differences favored the control arm, no penetrating trauma, etc.

Despite all the issues, I think there is a big take home point.

REBOA is very hard to study.

These authors went to great efforts. They included 16 centers over 4+ years and still they had major issues. In the end, I doubt we will see much better evidence anytime soon. Nevertheless, I think we will see a shift away from REBOA... don't believe the hype


Jansen, JO, Hudson J, Cochran C, et al. Emergency Department Resuscitative Endovascular Balloon Occlusion of the Aorta in Trauma Patients with Exsanguinating Hemorrhage: The UK-REBOA Randomized Clinical Trail. JAMA. 2023;330(19):1862-1871. [Link to article]




Sunday 10 December 2023

Aspirin vs Enoxaparin for thromboprophylaxis after a fracture

You are sending home a patient from the ED with a broken ankle after you carefully crafted a new plaster. Hmmmm… do you need to worry about DVT prophylaxis?

Guidelines and local practice vary. When you see this variation, it invariably means there is not conclusive evidence to inform practice.

Perhaps this RCT from the New England Journal of Medicine might help?

These researchers from the USA conducted a pragmatic, multicentre, randomized non-inferiority trial. They included patients who had a fracture of an extremity (hip to midfoot or shoulder to wrist) that were treated operatively or who had pelvic or acetabular fracture.

Patients were randomized to aspirin 81mg BD vs. enoxaparin 30mg BD while in hospital but could get whatever after discharge “according to the clinical protocols of each hospital.” (For what it’s worth, BD aspirin is not a typo…)

Primary outcome was death from any cause and secondary outcomes looked at PE’s, DVT’s and bleeding complications.


12,211 patients were included! Mean age 44 years old and 87% had lower extremity fractures. Median BMI was 27. On average, patients received about 9 in-hospital doses of thromboprophylaxis and were prescribed a 21-day supply of whatever upon discharge.

Primary outcomeno difference at 0.7% mortality in both groups. There was statistically more DVT’s in the aspirin group by a whopping 0.8% margin (NNT 125). PE’s were no different and nor were complications.

What should we conclude in the ED?

Yes, this is the tricky. The patients included in this study were not patients discharged from the ED. Extrapolating the findings from this RCT to our population is problematic. Bummer…

In addition, I’m disappointed they did not standardize the take home thromboprophylaxis. This likely made it much more difficult to find differences between the groups as patients were likely to cross-over.

Further, this trial did not restrict enrollment to high-risk patients. These are precisely the patients I want to target… another bummer. It is very possible that enrolling all-comers diluted down the benefits & differences of therapy. Who knows… but it’s common sense.

In the end, I don’t think this should substantially change how we think about ED patients that we send home with fractures. Nevertheless, I anticipate this study will influence the guidelines… we might see some more aspirin being recommended. But I'm not sure if this is for the better or worse.



METRC Consortium, Aspirin or Low-Molecular-Weight Heparin for Thromboprophylaxis after a Fracture. N Engl J Med 2023;338:203-13. [Link to article]




Friday 15 September 2023

Intra-articular Hematoma Block Compared to Procedural Sedation for Closed Reduction of Ankle Fractures

I must have missed this paper originally published in 2018 in Foot and Ankle International… perhaps my subscription has lapsed.

Either way, I’m intrigued.

These researchers sought to compare intra-articular hematoma blocks (IAHB) vs. procedural sedation to aid in the reduction of displaced ankle fractures (fracture subluxations or dislocations).

This was a retrospective chart review without great methods… but what the hell.

They identified 221 patients that underwent IAHB vs. 114 who got PS over 11 years in their single ED in Minnesota. The primary outcome was rate of successful reduction. But they also looked at reduction attempts, time to successful reduction, length of stay in the ED and some adverse events. However, they did not report on adequacy of pain reduction or patient satisfaction.

A hematoma block was performed using 10 to 12ml of 1% lignocaine without adrenalin that was injected into the tibiotalar joint. Ultrasound guidance was not used (but in my opinion can be helpful).


Patients were not randomised and as such, there were some substantial differences between the groups. As you can discern from the numbers, they liked their hematoma blocks twice as much as procedural sedation. However, more patients with complete dislocations got sedation.

The rate of successful reduction was about the same in both groups. About 70% were reduced with one attempt and 25% more by the second. Overall, there was a 90% success rate.

As for safety, one patient in the procedural sedation group got intubated… yikes!

This study has many limitations and is not high-quality evidence. Nevertheless, it is yet another paper demonstrating the utility and uptake of hematoma blocks for displaced ankle fractures. Even the New England Journal of Medicine has jumped on board with these blocks for ankles.

The beauty of a haematoma block is no need for a resuscitation room and lots of resources. It can quickly be performed by a single provider. In addition, a further reduction attempts can easily take place as the block will last for a while.



MacCormick LM, Baynard T, Williams B, et al. Intra-articular Hematoma Block Compared to Procedural Sedation for Closed Reduction of Ankle Fractures. Foot & Ankle Int. 2018;39:1162-8. [Link to article]

Thursday 14 September 2023

Have you heard about the HEAR score?

We’ve all heart about the HEART score for risk stratification of patients with chest pain in the ED. Take away the troponin and you’ve got the HEAR score!

Yes, the HEAR score tries to identify patients at very low risk of ACS that don’t even need a troponin. The thought is this will decrease resource utilisation and improve patient flow.

The original “derivation” of the HEAR score was in 2020 by Smith LM, et al. These subsequent researchers from Calgary (go stampede!) sought to externally validate this strategy.

They conducted a secondary analysis of a prospective cohort study of patients with chest pain that got a troponin to exclude MI in their single ED.

They enrolled 1150 patients. Of those, 8% had index MI and 11% with MACE by 30 days. HEAR score <1 identified 202 (17.6%) of patients at very low risk of adverse events with a 99% sensitivity (95% CI 95.6-99.9%). Only one patient out of 202 was missed. 

As with most screening tools that are highly sensitive, it often means they are terribly non-specific. The HEAR score is no exception. As such, it should only be used as a one-way decision instrument

The authors of this study appropriately conclude that this very low risk cohort of HEAR <1 is unlikely to benefit from troponin testing and will lead to significant resource savings.

This is not exactly ground-breaking. A young patient with a low-risk story, a normal ECG, and no risk factors is very unlikely to have a problem.

Sure, it’s probably fine to skip the troponin. I think a lot of us have been doing this over the years via gestalt. But at least this study quantifies the risk and provides support for those clinicians who want to avoid troponin testing in very low risk patients.

Perhaps the greatest use of HEAR score is to allow you sleep at night… perhaps a bit of medico-legal defense when you document the score and send that low risk patient home without blood tests.


O'Rielly CM, Andruchow JE, McRae AD. External validation of a low HEAR score to identify emergency department patients at very low risk of major adverse cardiac events without troponin testing. CJEM. 2022;24:68-74. [link to article]

Wednesday 10 August 2022

Not so FAST? How a study on lung ultrasound got it wrong…

This study out of UC San Diego set out to determine the accuracy of lung ultrasound vs. supine portable chest x-ray for the detection of traumatic pneumothorax.

Yes, I also thought this research questions had been suitably answered.

In 2020, a CochraneReview included 13 prospective paired comparative accuracy studies and concluded that ultrasound was about 90% sensitive vs. 50% for a chest x-ray. Both are highly specific.

Regardless of the consistent evidence, let’s consider face validity. Anyone who is competent in lung ultrasound knows that ultrasound is much better at finding pneumothorax. There is no planet in the solar system where a supine portable chest x-ray is going to be more sensitive than ultrasound.

But this study concludes the opposite… chest x-ray was better!

Huh? How could this be?

This was a retrospective registry review. Retrospective data is often poor quality. Registry data is even worse. Garbage in... garbage out. Ironically, this study would never have been included in the Cochrane review.

What is the probability that this single study with worse quality evidence is correct and all the consistent higher quality studies are wrong?

Yes, the probability is close to zero.

But where did this study really go wrong?

I think the authors answered the question themselves, “… in a non-study environment, such as ours, the pleural views were not universally performed with the same rigor as in a prospective study designed specifically to detect pneumothorax.”

I think this is probably the answer.

There are many other problems with this study, but I’m limited by word count. So briefly, the  methods for assessment of diagnostic accuracy of a test were performed backwards. They used the wrong probes for lung ultrasound. They used the wrong clinicians to perform and interpret the ultrasound. That was only to name a few...

As expected, there were many concerned letters to the editor. Even one from Dr Giovanni Volpicelli who is the world leader and pioneer of lung ultrasound. But the authors stuck with the strategy of “never admit you are wrong” and doubled-down in their conclusions.

A bit sad really...


Santorelli JE, Chau H, Godat L, et al. Not so FAST- Chest ultrasound underdiagnoses traumatic pneumothorax. J Trauma Acute Care Surg.2022;92:44-8.[link to article]