Monday 5 July 2021

Effectiveness and safety of small-bore chest tubes (20 Fr) for chest trauma patients

The optimal chest tube size for the relief of traumatic haemo/pneumothorax is not known. Traditionally, garden hoses up to 36 to 40 Fr in size have been recommended. The outer diameter of one of these tubes is up to 13mm… ouch!

A more recent observational study caused ATLS/EMST to recommend tubes a bit small at 28-32 Fr. This is still something I don’t think I would want hanging out of my chest.

Not based on any high-quality evidence, these authors from Kobe, Japan decided that 20 Fr or an 8 Fr pigtail was good enough. After some time, they decided to describe their results. Yes… this was their methods.


Over 5 years, they put in 107 chest tubes. About 90% were 20 Fr and the rest were pigtail catheters. The mean Injury Severity Scale (ISS) was 17.8.

There were 8 (7.8%) tube related complications, and none were due to tube obstruction. There were 4 retained haemothoraxes and 4 unresolved pneuomothoraxes.

The authors conclude that it might be reasonable to safely manage chest trauma patients with small-bore chest tubes.

This retrospective observational study is of low-quality evidence and should not change practice. But it may provide some clinical equipoise to support a proper randomized trial. This should definitively answer the research question.

After all these years, I’m quite surprised a large RCT has not been conducted. It strikes me that it should be feasible and ethical to perform. These are usually the major challenges in conducting experimental trials. A review of shows only one small study out of Egypt but it is not yet recruiting.

What are we waiting for? (There must be something I’m missing…Bueller... Bueller ?)


Maezawa T, Yanai M, Young Huh J, et al. Effectiveness and safety of small-bore tube thoracostomy (<20 Fr) for chest trauma patients: A retrospective observational study. Am J Emerg Med. 2020;38:2658-2660. [link to article]


A randomized, noninferiority trial of two doses of IV ketamine for analgesia in the ED

This study aimed to determine if a low dose of ketamine (0.15mg/kg) was just as good (or bad) as a higher dose (0.3mg/kg).

This single ED in Chicago conducted a double-blind RCT that included adult patients with acute pain (flank, abdo, back, musculoskeletal or headache) and had a >5 on their initial NRS.

There were several exclusion criteria including patients that had chronic pain or currently taking opioids. This is arguably the patient population who would likely be best targeted for ketamine… but I digress.

Ketamine was given as initial therapy without co-administration of any other analgesics. Yikes!

Oh… and the ketamine was given as a slow IV infusion over 15 minutes (to decrease side effects and increase nursing hassle).

The primary outcome, NRS, was measured at 30 minutes. They also measured adverse events with the Richmond Agitation Sedation Scale (RASS) the Side Effect Rating Scale of Dissociative Anaesthetics (SERSDA). (Ketamine is so special, it even comes with its own measure tool for side effects.)


98 patients were enrolled and there was no statistical difference in the primary outcome nor side effects at 30 minutes. The authors conclude a lower dose is fine.

I disagree.

As a surrogate of patient satisfaction, the authors asked the patients, “would you take this medication again for similar pain?An astounding number said no; 25% vs. 40% in the low and high dose respectively. This is arguably the most important outcome of this study… patients really didn’t like this stuff (even when given slowly to minimize side effects).

Let’s face it, we would never use ketamine this way. It is not first line therapy. Would never use it in isolation. We would target our patient population differently. And logistically, we probably would not give an infusion.

So, what can we conclude? Don’t use ketamine this way.

Generally speaking, the hype and enthusiasm for subdissociative ketamine for pain is ridiculous. Yes, it has its place. But bang-for-buck, it’s a dirty drug; it doesn’t work that well and comes with many side effects.


Lovett S, Reed T, Riggs R, et al. A randomized, noninferiority, controlled trial of two doses of intravenous subdissociative ketamine for analgesia in the emergency department. Acad Emerg Med. 2021;00:1-8. DOI:10.1111/acem.14200 [link to article]

Thursday 1 July 2021

The ED-AWARENESS Study: A prospective cohort study of awareness with paralysis in patients intubated in the ED

Evidently, awareness with paralysis rather bad. Some studies indicate it is associated with PTSD, depression, and other psychological sequelae. I'll take their word for it...

But how often do patients have awareness after intubation in the emergency department?

This single centre prospective cohort study of 383 patients was conducted in Washington University in St. Louis.

After eventual extubation, patients were questioned about their experiences. Three independent reviewers independently adjudicated whether there was awareness with paralysis.


2.6% (10/383) of patients reported awareness. Exposure to rocuronium in the ED was found to be an associated risk factor.

There are many challenges to this type of study. There is no blood test for awareness. Measurement of the outcome was self reported. As such, it relies on the accurate memories of patients after major illness and complicated hospital stays.

Nevertheless, some of the descriptions on Table 2 of the manuscript are worrisome. One such case of a patient getting fiberoptic nasotracheal intubation after angioedema is below:

“I came to the ED because my tongue was swollen. I remember them putting the breathing tube down, but I could not move. I remember the breathing tube actually going in and being panicked. It was terrible and traumatic. I was panicking inside…”

This paper is not high-quality science, but it does have a simple message. A small number of ED patients may have awareness after intubation. Longer acting paralytics may not provide the clinicians a visual cue that patients are waking up.

Others might argue that small rates of awareness are the price of business in trying to save lives in the ED. Do we really want to heavily sedate that hypotensive trauma patient? Hmmm…



Pappal RD, Roberts BW, Mohr NM, et al. The ED-AWARENESS Study: A Prospective Observational Cohort Study of Awareness With Paralysis in Mechanically Ventilated Patients Admitted From the Emergency Department. Ann Emerg Med. 2021;775:32-544. [link to article]

A double blind RCT of IV chlorpromazine vs prochlorperazine for the treatment of acute migraine in the ED

This single centre study out of the ED at Austin Health, enrolled patients with migraine to either IV chlorpromazine (Largactil/Thorazine) vs 12.5mg IV prochorperazine (Stemetil/Compazine).

The primary outcome was a reduction in pain at 60 minutes as reported on a 11 point (0-10) Numerical Rating Scale (NRS). They also recorded some secondary outcomes and safety measures.


65 patients were included.

It doesn't take a statistical genius to understand this study was only powered to find a large treatment difference. So, it is no surprise they didn’t find one in the primary nor secondary outcomes.

The only statistical difference noted was side effects. Chlorpromazine had worse hypotension and syncope.

What does this study add to our knowledge?

Not much.

It was an elegant study design but woefully underpowered to adequately answer the study question. It makes me wonder why they bothered. Such small numbers can only find huge differences (which rarely exist in medicine) and often cannot get rid of baseline difference in study population and confounding; precisely the reason for conducting a randomized trial.


Hodgson SE, Harding AM, Bourke EM, et al. A prospective, randomized, double-blind trial of intravenous chlorpromazine for the treatment of acute migraine in adults presenting to the emergency department. Headache. 2021;61:603-11. [link to article]