The Crashing Asthmatic

I had prepared this before the 3MG trial came out and hat tip to simon carley and his post for alerting me to it.

UPDATE: have since read the 3MG trial and here’s my thoughts on that

In my current dept, there’s a monthly joint ICU/ED meeting. I recently presented on some of the evidence base and strategies for managing life-threatening asthma. The 15 people there seemed to enjoy it so now i’m sharing it with the rest of the #FOAMed community.


I’ve included some references below from some of the papers cited in the talk.

Two talks in particular deserve mention.

One on EM:RAP by Mel Herbert himself back in 2007 [subscription needed] and the other from EMCrit.

Lim, Wei Jie, Redhuan Mohammed Akram, Kristin V Carson, Satya Mysore, Nadina A Labiszewski, Jadwiga A Wedzicha, Brian H Rowe, and Brian J Smith. “Non-Invasive Positive Pressure Ventilation for Treatment of Respiratory Failure Due to Severe Acute Exacerbations of Asthma..” Cochrane Database of Systematic Reviews (Online) 12 (2012): CD004360. doi:10.1002/14651858.CD004360.pub4.

Mohammed, S, and S Goodacre. “Intravenous and Nebulised Magnesium Sulphate for Acute Asthma: Systematic Review and Meta-Analysis..” Emergency Medicine Journal 24, no. 12 (December 2007): 823–830. doi:10.1136/emj.2007.052050.

Nair, Parameswaran, Stephen J Milan, and Brian H Rowe. “Addition of Intravenous Aminophylline to Inhaled Beta(2)-Agonists in Adults with Acute Asthma..” Cochrane Database of Systematic Reviews (Online) 12 (2012): CD002742. doi:10.1002/14651858.CD002742.pub2.

Rowe, B H, J A Bretzlaff, C Bourdon, G W Bota, and C A Camargo. “Magnesium Sulfate for Treating Exacerbations of Acute Asthma in the Emergency Department..” Cochrane Database of Systematic Reviews (Online) no. 2 (2000): CD001490. doi:10.1002/14651858.CD001490.

Tobin, A. “Intravenous Salbutamol: Too Much of a Good Thing?.” Critical Care and Resuscitation : Journal of the Australasian Academy of Critical Care Medicine 7, no. 2 (June 2005): 119–127.

“British Guideline on the Management of Asthma” (February 2, 2012): 1–151.

UPDATE:

I had some correspondence from the author of this paper [free full text] regarding the ‘atrial calming’ effect of magnesium. I certainly gave lots of IV magnesium for patients in fast AF. Usually not for the ‘lone AF’ patients, but the sickies with pneumonias and deranged electrolytes. I’d never considered that the supposed rate control effect of magnesium might be useful in the asthmatic to help control the slightly ridiculous tachycardia you get if you’re doing it right.

As mentioned, the paper is free and well worth a read and a good reference.

 

Ketamine use in TBI – the ICP goes down not up.

click for source

H/T Rob Bryant for tweeting the paper.

[blackbirdpie url="https://twitter.com/RobJBryant13/status/271116807195217920"]

We all love ketamine, or at least Minh does. But there has always been the bogey man stories, that if you use ketamine in someone with a head injury, there brain will explode and you’ll get covered in lots of brain goo which is never  a good luck. As a result, I rarely see people reach for ketamine as an induction agent for these people.

There is increasing evidence that the ICP rise attributed to ketamine is likely a bit of a myth based on faulty early data and even faultier interpretation (a bit like lignocaine/adrenaline is bad for fingers…)

This study provides a little bit more ammo that ketamine is safe for ICP. It’s not gold standard, bullet proof evidence but the case is building.

Bar-Joseph, Gad, Yoav Guilburd, Ada Tamir, and Joseph N Guilburd. “Effectiveness of Ketamine in Decreasing Intracranial Pressure in Children with Intracranial Hypertension..” Journal of Neurosurgery. Pediatrics 4, no. 1: 40–46. doi:10.3171/2009.1.PEDS08319. PMID 19569909

METHODS

  • single centre in Israel in the PICU with kids with TBI
  • two groups, 
    • one who got ketamine for a procedure
    • the other who got ketamine for the ICP specifically
  • ketamine was 1-1.5mg/kg
  • all were on midaz and morphine as sedation
  • some had propofol as well
  • a bunch got mannitol or hypertonic saline or thiopental and some even had decompressive craniectomy

RESULTS

  • 30 patients, 82 episods of ketamine administration, most for treatment of raised ICP
  • it worked, it lowered the ICP by about 5mmHg in both groups of patients

Their only concern is that some of the prior studies showed ICP rises in those who were probably inadequately anaesthetised. This bunch of kids were doped up to the max and they say maybe that’s why the ketamine is safer.

They were surprised that the ketmaine actually lowered the ICP not just didn’t increase it.

This is, of course, a tiny little study and with all the different interventions going on you could make the argument that we can’t tell if it was the ketamine that lowered the ICP. None the less it’s still encouraging that the bogey man of raised ICP is a little bit mythical.

Ketamine IV versus IM

Roback MG, Wathen JE, MacKenzie T, Bajaj L. A randomized, controlled trial of i.v. versus i.m. ketamine for sedation of pediatric patients receiving emergency department orthopedic procedures. Ann Emerg Med. 2006 Nov.;48(5):605–612. PMID 17052563

This is (apparently) the first prospective IV v IM trial of ketamine for sedation. I have never given it IM, though it was previously on the CEM guideline as IM 4mg/kg. They now recommend 1mg/kg IV or 2.5mg/kg IM.

Anyhow to the trial.

METHODS

  • paeds childrens ED
  • sedation for fracture reduction
  • randomised but unblinded
  • 1mg/kg IV v 4mg/kg IM
  • everyone got glycopyrolate
  • tried to blind but gave up when it didn’t work

RESULTS

  • n = 208
  • missed a whole bunch of eligible pts and not clear why
  • 100 each group
  • everyone did great
  • there were a couple of minor desaturations in the IV group
  • 35% vomiting IM; 18% vomiting IV
  • IM had a much longer period of sedation 130 mins v 80 mins
  • had to stop the study at nursing request cause they could tell which was which because of the performance characteristics

MY THOUGHTS

There was a much higher rate of vomiting than most studies. It’s usually reported about 5-10%. Their numbers seem pretty high.

As always it’s good to see that this is a remarkably safe thing for us to do in the ED.

I imagine a 35% vomiting rate wouldn’t be the most acceptable if you were an a gas man/woman working in an OT setting but in the ED we’re trying to balance all kinds of spinning plates and safety and ease are pretty important factors.

I think I’ll stick to giving IV ketamine for now.

Morphine and Ketamine for pre-hosp analgesia

Jennings PA, Cameron P, Bernard S, Walker T, Jolley D, Fitzgerald M, et al. Morphine and Ketamine Is Superior to Morphine Alone for Out-of-Hospital Trauma Analgesia: A Randomized Controlled Trial. Ann Emerg Med. 2012 Jan. 11. PMID 22243959

Back where I used to work, or should I say when I used to work… I’m hoping to be back in an ED full time come July so I’ll feel a bit less of a fraud then…

Anyhow, back where I used to work we used to occasionally receive trauma pts where folk from BASICS had been on scene. The patients were always beautifully trussed up and in a remarkably calm and comfortable state despite the fact their femur had been wrapped round there elbow a few minutes before. This was invariably because of the cocktail of ketamine and morphine that the BASICS guys used during the extrication.

This paper is a study of just that type of scenario

METHODS

  • big open label RCT in aus
  • adults with trauma pain who were conscious
  • got 5mg morph and their little methoxyflurane thingy before they were eligible for enrolment.
  • dosing was at discretion of paramedic which is a problem as maybe they were less aggressive with the ketamine and more with the morphine or even vice versa.
  • verbal number pain scale, not VAS
  • primary outcome was decrease in verbal pain scale
  • they didn’t do a power calculation to begin with (or at least they don’t say they did) and had to do it ad hoc when recruitment was slow and they wanted to know whether the interim results would be valid.

RESULTS

  • 135 pts total
  • baseline pain scores of 7
  • delta pain was 5.6 v 3.2 favouring ketamine
  • adverse effects overall 14 % v 39% favouring morphine though they described high BP, tachy, enhanced skeletal tone and disorientation as adverse effects while I’m not sure these matter
  • emergence was rare enough (4/70) and we’re not really sure how bad it was. None received treatment for it

So it seems ketamine is a useful adjunct to morphine in trauma pts. And seems to be safely given without any significant side effects. I imagine the pts are a bit altered after some ketamine and might concern you if you were worried about neurological deterioration.

This is something I’d consider doing as an adjunct in the ED itself. Especially in situations like putting on a thomas splint for femur fracture (in addition to femoral nerve block of course).