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.

 

Covering:

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.

 

Covering:

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?

Randomization.

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.

Results?

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. 

Covering:

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]

 

 

 

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.

Results?

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 outcome… no 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.

 

Covering:

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