Give honey for button battery ingestion? The tale of two anesthetised pigs…

Believe it or not, UpToDate recommends honey as first aid for button battery ingestions.

Perhaps we should look at the evidence.

We know button batteries can cause nasty and sometimes lethal caustic oesophageal injury.

This study was a cadaver and live American Yorkshire piglet model looking at potential pH neutralizing agents prior to definitive endoscopy.

In vitro, they tested the final tissue pH of cadaver oesophagus after installation of various products. They included different kinds of honey, Carafate, apple juice, orange juice, Powerade, Gatorade, maple syrup, simulated saliva and 0.9% sodium chloride control.

In the lab, the honey and Carafate seemed to work the best and underwent further study.

Bring on the live pigs!

9 anaesthetised pigs had a button battery placed in their oesophagus for an hour. (Poor creatures.) Serial irrigations of study solution occurred every ten minutes starting at the five-minute mark.

2 pigs got honey, 3 got Carafate, and 4 got saline control.

On day 7, the unfortunate piglets were euthanized and histology obtained.

Results?

Honey was the big winner! They had much less depth of injury. Half  of the saline piglets had delayed oesophageal rupture.

This little piggy went to market… to get honey! Give honey for button battery ingestion.

Really??!!?

This recommendation is based on TWO anesthetised pigs that got honey.

This is extremely low-quality evidence.

One should only change practice based on such low-quality evidence if the treatment or therapy was considered to be extremely low risk.

Perhaps honey is extremely low risk. But are we certain?

Would care get delayed in finding and administering honey? Does honey impair endoscopy? What about aspiration or honey induced mediastinitis? Will kids get nasal-oesophageal tubes to administer honey? Would we tend to delay endoscopy because they "got the honey?” 

Perhaps risk may be minimal… But changing practice based on two honey glazed pigs??

(ok… I’d give the honey too… I can’t believe I just said that…)

Covering:

Anfang RR, Jatana KR, Linn RL, et al. pH-Neutralizing Esophageal Irritations as a Novel Mitigation Strategy for Button Battery Injury. Laryngoscope 2018 Jun 11. doi: 10.1002/lary.27312. [Link to article]

Clinical Trial of Fluid Infusion Rates for Pediatric DKA

Dr Annoying Bowtie, RACP

Emergency physicians often get criticised for overhydrating children with DKA. “Too much fluids will cause their heads to explode,” as spoken from an annoying bow tie.

But there has never been good quality evidence to prove fluid administration causes cerebral edema. In fact, a study by Glaser etal. in 2001 showed no association between fluids and bad outcomes.

But as there is no definitive RCT, the debate still rages!

Hopefully this clinical trial will put matters to rest.

After 17 years, Dr Nicole Glaser is back! Now teamed up with the PECARN mega-group, they randomised 1255 children with 1389 DKA episodes to one of 4 treatment arms (please see original paper for further details)

• Fast administration of 0.9% normal saline
• Fast administration of 0.45% normal saline
• Slow administration of 0.9% normal saline
• Slow administration of 0.45% normal saline

(Just to give an idea of what is fast vs. slow, a 50 kg child would get an infusion started of 300ml/hour vs. 140ml/hour.)

The primary outcome was a decline in mental status (measured by GCS) during treatment. Secondary outcomes included clinically apparent brain injury during treatment and some measures of memory.

Results?

No difference. Neither the rate of administration nor the sodium chloride content of the IV fluids resulted in bad outcomes. 

So the debate is over?

Unfortunately, no.

98% of the children recruited in this study started out at GCS 14-15.  We know it is the sickest cohort of DKA that develop bad complications. This study was never going to show a difference. The clear majority were going to get better with any reasonable management... regardless of fluid protocols.

What about the child with a pH of 6.9 and GCS 6? Does the rate of fluid administration matter?

Hmmmmmm....

Unfortunately, an adequately powered RCT of severe DKA will never happen. It is simply not feasible. 

Alas, the annoying bow ties will continue...


Covering

Kupperman N, Ghetti S, Schunk J, et al. Clinical Trial of Fluid Infusion Rates for Pediatric Diabetic Ketoacidosis. N Engl J Med 2018;378:2275-87. [link to original full text article]

Change the guidelines! An RCT of Epinephrine in Out-of-Hospital Cardiac Arrest; the PARAMEDIC2 Trial

Should we still be giving adrenalin in cardiac arrest?

Despite decades of tradition and guidelines, there has never been any good evidence showing adrenalin improves meaningful outcomes.

The PARAMEDIC2 trial was a very well conducted RCT of 8014 patients in the UK with out-of-hospital cardiac arrest. Patients were properly randomised to getting either adrenalin 1mg q3-5 minutes or matching placebo.

Primary outcome in this study was rate of survival at 30 days. But we all know the real outcome of interest is hospital discharge with a favourable neurologic outcome.

Results?

The adrenalin group had more patients with ROSC, transport to hospital and ICU resources. Rate of survival at 30 days was marginally better at 3.2% vs. 2.4%. (NNT 112)

Yes, the rates of survival were abysmal.  But remember the patients included in the study did not respond to initial resuscitative efforts (CPR and defibrillation). They were only enrolled when they got down the pathway requiring adrenalin.

But the real outcome of interest; neurologically intact survival?

No difference.

In the end, adrenalin increases resource utilization and increases survival of the neurologically devastated.

Sounds pretty bad to me. Sounds pretty bad to the consumer groups too.

Will this change the guidelines?

Old habits die hard. But there will never be a trial more definitive than this one. It would have been unethical to start this trial if the authorities (in the UK at least) were not prepared to change practice.

But adrenalin may be worse. Ask yourself; does giving a worthless treatment distract the focus from more important resuscitative efforts? This study didn't address this question but I think I know the answer.

Yes, change the guidelines!

Covering:

Perkins GD, Deakin CD, Quinn T, et al. A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest. N Engl J Med 2018 Jul 18. doi:10.1056/NEJMoa1806842 [full text]

Paper critiqued at Emergency Tasmania 2018. Special thanks to Dr Mark Reeves, FANZCA and audience for feedback.

Fake News: Intraosseous vascular access is associated with lower survival and neurologic recovery among patients with out-of-hospital cardiac arrest

Prior observational studies have challenged the widely held belief that IO access is just as good as IV. This paper further explored the association between IO access and poor outcomes compared to IV.

The authors performed a secondary analysis of a large trial of patients with out-of-hospital cardiac arrest. They were able to identify patients that got IV vs. IO as their means of access.

They excluded patients who had any failed attempts at either route of vascular access or who had both performed.

The primary outcome was favourable neurologic outcome on hospital discharge (mRS <3 i.e. patients could at least walk without assistance).

Results?

13,155 were included in the analysis. 5% had IO access and 95% had IV (obviously patients were not randomised to this intervention)

For all outcomes, the IV access was far superior. 7.6% of patients with IV access had favourable neurologic outcome vs. 1.5% with IO.

This is astounding! A huge difference… let’s throw away the IO’s!!!

But there is no way this is true.

No amount of fancy statistics can make up for systematic bias and residual confounding that is present in this cohort study. There is clearly a reason why paramedics went directly to IO rather than IV. The IO group was obviously a “sicker” cohort to start with and had worse outcomes.

Not all cardiac arrest is the same. We know those with witnessed arrest, bystander CPR and shockable rhythms do better. There are also many other factors that influence outcomes.

Capturing all potential confounders in a resuscitation is problematic. When under duress, data is hard to measure accurately. In addition, there are always the unknown confounders that go unmeasured and unadjusted. No statistics can truly fix bad or absent data.

Futhermore, what was the magic medicine they used to account for this five fold increase in favorable outcomes? No drugs have really been shown to work in ALS. 

In the same context of “fake news” sometimes bad evidence is worse that no evidence at all. This study has the very unfortunate possibility to mislead and cause harm. At best, it is hypothesis generating for future prospective study.

For now, reject the fake news and keep drilling your IO’s. 

 

Paper critiqued at Emergency Tasmania 2018. Special thanks to Dr Mark Reeves, FANZCA and audience for feedback.

Covering:

Kawano T, Grunau B, Scheuemeyer FX, et al. Intraosseous Vascular Access is Associated with Lower Survival and Neurologic Recover Among Patients with Out-of-Hospital Cardiac Arrest. Ann Emerg Med. 2018;71:588-596.

Association of Preprocedural Fasting with Outcomes of Emergency Department Sedation in Children

Many guidelines still call for patients to be properly fasted prior to ED procedural sedation. Although this is steeped in consensus and tradition, is this really beneficial?

No.

This was a planned secondary analysis of a multicentre prospective cohort study of 6183 children who received parenteral procedural sedation in one of 6 Canadian ED’s.

They compared fasted and non-fasted children with the occurrence of pulmonary aspiration, adverse events, serious adverse events and vomiting.

Results?

Most children were very healthy at baseline. 80% of the procedures were for orthopaedic reductions and laceration repairs. Two thirds of children got ketamine alone. (This is obviously a different cohort from those patients that get treated in the operating theatre.)

How many children were not properly fasted?

About 50% for solids and 5% for liquids.

In the end, there was no association between fasting and any bad outcomes. This is concordant with all of the previous studies on this subject.

Naysayers can complain about the limitations of this study; not huge enough to make definitive claims about safety, ketamine is airway protective, conducted in tertiary centres, and it was not randomised.

The excellent accompanying editorial by Steve Green (Dr Ketamine) shreds these arguments with further evidence. In addition, he emphasises many of the potential harms of fasting.

Even before this study was published, the American Collegeof Emergency Physicians (ACEP) 2014 clinical policy recommended not to delay procedures solely on fasting time.  

Outside the USA, I would imagine most of us have quietly changed our practice anyway and don’t consider fasting to be a mandatory requirement. Perhaps is time to formally change our policies.  

Covering: 

Bhatt M, Johnson DW, Taljaard M, et al. Association of Preprocedural Fasting with Outcomes of Emergency Department Sedation in Children. JAMA Peiatr. 2018. 172(7):678-685. 

Bougie vs Endotracheal Tube with Stylet for ED Intubations: an RCT

“…use of a bougie compared with an endotracheal tube + stylet resulted in significantly higher first-attempt intubation success among patients undergoing emergency endotracheal intubation.”

Should we all go bougie first?

As is often the case, the devil is in the details…

This was a single centre clinical trial randomised 757 adult patients to the two arms (bougie vs. stylet) using mostly a C-MAC Macintosh blade.

The primary outcome was first-attempt success in patients with at least one difficult airway characteristics (obesity, short neck, cervical spine immobilisation etc.)

They had a ridiculously high 96% first attempt success rate with the bougie but only an 82% with the stylet. (To put this in perspective, the first attempt success rate in the ANZEDAR registry was 84%)

Before you jump on the gum elastic bougie train, consider a few things.

This study was conducted in an ED where the tradition was to use a bougie first. They would have obviously been more comfortable with this technique and the stylet was new to them.

The vast majority of the intubations were done by less experienced PGY 2 - 4 emergency residents and fellows. Emergency medicine faculty only performed 3% of the procedures.

The incidence of hypoxemia (13% vs. 14%) did not differ between the groups. This is a more relevant patient oriented outcome. This study did not report any patient harms from the lower first-attempt success of the stylet (but to be fair, was not powered for safety).

In the end, I don’t think this study will be overly practice changing. Most clinicians will stick with what they know best. But a 96% first pass success rate is extremely high and hard to ignore.

Covering:

Driver, BE, Prekker ME, Klein LR, et al. Effect of Use of a Bougie vs Endotracheal Tube adn Stylet of First-Attempt Intbuation Success Among Patients with Difficult Airways Undergoing Intubation; A Randomized Clinical Trial. JAMA. 2018;319(21):2179-2189.

Early application of continuous femoral nerve block for neck of femur fractures: an RCT

Many patients with neck of femur fractures get some form of a nerve block in the Emergency Department. This is most often a single injection and wears off in several hours. Would a continuous block via infusion be better?

This UK single centre trial randomised patients to standard care vs. a continuous infusion of 0.2% ropivacaine at 5ml/hour for 48 hours. The medication was delivered by perineural catheter placed by experienced anaesthesia doctors.

Included patients had to be >70 years old, without cognitive impairment, live at home and independently mobilise. Yikes! This obviously limited the number of eligible patients and made this study less feasible to undertake.

The two primary outcomes were the Cumulated Ambulation Score and Dynamic Pain Score score over three days. Whatever those are...

111 patients with fractures underwent analysis.

It is no surprise no difference was found. (Other than a secondary outcome of improved pain at rest) With these small numbers, the researchers had low statistical power and could only hope to find a big difference. In addition, there were several issues that may have drawn the conclusion to the null hypothesis.

Many questions remain; did they use the right dose, did they do the correct block, were the primary outcome scores appropriate & relevant, etc.

In the end, the jury is still out. Despite the negative conclusion, the research question really remains unanswered. If there was a longer delay to theatre, one would hope a continuous infusion would be better than standard care… but who knows, there still is clinical equipois

 

Covering:

Rowlands M, van de Walt G, Bradley J, et al. Femoral Nerve Block Intervention in Neck of Femur Fracture (FINOF): a randomised controlled trial. MJ Open 2018;8:e019650. doi: 10.1136/bmjopen-2017-019650