Thursday, 2 September 2021

Utilization of Prophylactic Antibiotics After Nasal Packing for Epistaxis


When I trained, I was told I needed to prescribe prophylactic antibiotics after I placed nasal packing. It was thought this reduced the potential for toxic shock syndrome or sinusitis. Is this recommendation evidence based?

Hmmmm…

This single ED in Manhattan retrospectively reviewed 275 cases of anterior nasal packing and determined the rates of antibiotics given and evidence of benefit.

Most patients that got non-absorbable packs (Merocel, RapidRhino) got antibiotics. Those with absorbable packs (Surgicel, Gelfoam) did not.  Although this aspect of the study is robust, it is hardly important… I just don’t care.

I want to know how many patients got benefit from antibiotics.

Out of the 275 cases, there was one episode of sinusitis in each group. Looks like it doesn’t matter?

But there is a fatal flaw.

They didn’t really look for outcomes.

Only 40% of the patients had documented follow up! In addition, this would have been poor quality retrospective data.

If you don’t look for something, you will not find it. Interesting that this study got published.

Probably the best thing to come out of this “study” is their review of the literature.  In a nutshell, there is moderate evidence to show that antibiotics are not needed after nasal packing.

Good enough for me.

 

Covering:

Hu L, Gordon SA, Swaminathan A, et al. Utilization of Prophylactic Antibiotics after Nasal Packing for Epistaxis. J Emerg Med. 2021;60:140-149. [link to article]

 

Elevated blood pressures are common in the ED, but are they important?


No.

You can stop reading now if you want…

This was an electronic medical record review of 30,278 adults treated and released from the University of Alberta ED in 2016.

They identified those that had elevated BP’s at triage and cross-referenced them with multiple data bases to see if they developed cardiovascular events by 2 years(Databases included hospital EDIS, Pyxis, Pharmaceutical Information Network, administrative data holdings, National Ambulatory Care Reporting systems, outpatient billing claims etc.)

Of the 30,278 that were treated and released, about half had elevated BP’s at triage. 70% had no prior history of hypertension and eventually about a quarter of those subsequently received a diagnosis of chronic hypertension.

After adjusting for confounders, high BP at triage was not associated with adverse cardiovascular outcomes within 2 years of the ED visit.

I’m willing to believe this is true… but there are many methodologic limitations.

Don’t be mesmerized by the huge number of patients… this does not guarantee quality. Nor do large numbers reduce bias.

I’m concerned about a potential “garbage in & garbage out” phenomenon. The veracity of this study is predicated on the quality of the information in many large databases. (For example, a large database in the USA shows the rate of virgin births at 0.5%)

There were a lot of other issues; retrospective design, residual confounding, use of triage BP’s, lack of follow up, possible non-differential misclassification, etc.

So, are elevated BP’s in the ED important?

I still say no, but not necessarily due to this study. Heck, at least hypertension is better than hypotension. 

 

Covering:

McAlister FA, Youngson E, Rowe B. Elevated Blood Pressures are Common in the Emergency Department but Are they Important? A Retrospective Cohrt Study of 30,278 Adults. Ann Emerg Med. 2021;77:425-432. [link to article]

  

Accuracy of OMI ECG findings vs traditional STEMI criteria for diagnosis of acute coronary occlusion MI... the OMI manifesto?


I’ve heard of many manifestos.

There’s the Communist Manifesto, the US Declaration of Independence, the Unabomber Manifesto and now we’ve got the OMI Manifesto.

(Ok… it’s not a freakin manifesto. But good to know about anyway.)

The charge is being led by the master sensei Dr Stephen Smith (of ECG blog fame) and his student Dr Pendell Meyers. They’ve published quite a few articles looking at additional ECG criteria to identify patients that may benefit from emergent reperfusion of an acute coronary occlusion.

They hypothesized that blinded interpretation of their new OMI criteria would be more accurate than the traditional STEMI criteria.

OMI criteria?

OMI (occlusion MI) is basically STEMI criteria plus some STEMI equivalents including:

Subtle STE not meeting criteria, hyperacute T waves, reciprocal ST depression and/or negative hyperacute T waves, STD worrisome for posterior MI, suspected new Q waves, terminal QRS distortion, positive Sgarbossa criteria, any inferior STE with SZTD or T wave inversion in aVL

Without going into any details of the study, they thought the OMI criteria were great. Sensitivity went up from about 40% to 85%. Specificity remained around 90%.

Unfortunately, the manuscript as published in the open access journal IJC Heart & Vasculature is quite difficult to follow. It is poorly presented and would have benefited from substantial revision. Either way, you don’t need to read it… the message is rather simple and has a degree of face validity (albeit with many limitations).

What are we to conclude?

If you are an expert at ECG interpretation, you can probably identify more patients with acute coronary occlusion MI by using OMI criteria (which most of us are already doing to some extent). Whether additional patients genuinely benefit from an aggressive intervention is officially not known.

 

Covering:

Meyers P, Bracey A, Lee D, et al. Accuracy of OMI ECG findings versus STEMI criteria for diagnosis of acute coronary occlusion myocardial infarction. IJC Heart & Vasc. 2021:33; 100767 [link to full text article]

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.

Results?

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 clinicaltrials.gov 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 ?)



Covering:

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.)

Results?

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.


Covering:

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.

Results?

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…

 

Covering:

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 12.mg 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.

Results?

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.


Covering:

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]