Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Lessons for management of anaphylaxis from a study of fatal reactions – Part I

ResearchBlogging.org

Also posted over at Research Blogging.

What can help us to learn more about what leads up to a bad outcome from anaphylaxis?

it seemed that study of a large number of fatal reactions might give insight into why prevention and treatment had failed.[1]

Most of these patients are old. The young seem to be clustered in exposures to nuts and other food allergens.


Click on images to make them larger.

Only nine of these patients did have epinephrine anaphylaxis kits prescribed. Most were not used. The use/lack of use is documented in this table –

For most of the anaphylaxis that was not due to food, the cause of death was considered to be shock, or a combination of respiratory compromise and shock. For the anaphylaxis related to food, the opposite was true. None were considered to be just due to shock and only 5 out of 37 were considered to be due to a combination of respiratory compromise and shock.

Is this representative of the deaths from anaphylaxis?

It is not clear what fraction of the total number of fatal reactions have been identified; unidentified cases will include those dying from acute asthma due to unrecognized food allergy [13], sudden death from unrecognized insect stings [14] and elderly bronchitics dying at home from unrecognized antibiotic anaphylaxis [15]. [1]

A major problem is the lack of recognition of anaphylaxis, even by paramedics.

The first treatment for noniatrogenic reactions was in some cases given by paramedics. Because all food-related reactions caused dif®culty breathing, the paramedics commonly had difficulty deciding whether to use the protocol for anaphylaxis or for asthma. This led to delayed or inappropriate treatment that may have contributed to the fatality. Paramedic protocols should allow for this difficulty [18]. [1]

For those of us who still might think that all we have to do is follow the protocol, some of these patients were treated by paramedics who followed protocol. Unfortunately, they did not follow the anaphylaxis protocol.

One physician assumed that the patient was just hyperventilating withheld epinephrine (adrenaline) because the doctor assumed that the patient was just having a panic attack – right up until the time of cardiac arrest. Apparently, that was enough of a clue that this was more than just anxiety.

A patient suffocating due to anaphylaxis probably IS having a panic attack.

Especially if people can treat the anaphylaxis, but do not believe it is a real breathing problem. While we should not automatically give epinephrine to patients with panic attacks, we do need to be able to tell the difference between them.

Few of these patients received epinephrine before cardiac arrest.

Waiting for cardiac arrest is waiting a little bit too long to start treatment with epinephrine – we were going to do it anyway as a part of one of the cardiac arrest algorithms.

In order to be less likely to withhold appropriate epinephrine, we should consider titration of epinephrine by infusion –

First, grab 1 mg of epinephrine – any concentration will do, the number work out with either the 1:10 or 1:1000 versions.[2]

Next, put this in 1 liter NS.[2]


Image credit. Further information on dosing is available at the image link.

Assessment and epinephrine – in reasonable doses – are the keys to treating anaphylaxis.

I will discuss the problems with too aggressive treatment of anaphylaxis with epinephrine in Part II.

See also –

Most Common Cause of Death in Anaphylaxis is Failure to Give Epinephrine

What About IV Epinephrine for Patients Who Are Not Dead

[1]

Footnotes:

[1] Lessons for management of anaphylaxis from a study of fatal reactions.
Pumphrey RS.
Clin Exp Allergy. 2000 Aug;30(8):1144-50. Review.
PMID: 10931122 [PubMed – indexed for MEDLINE]

Free Full Text in PDF format from medicina.med.up

[2] Anaphylactic reactions – 5 things.
Sunday, September 4, 2011
Doc Cottle’s Desk
Article

The images following the quotes are from the same article.

Pumphrey RS (2000). Lessons for management of anaphylaxis from a study of fatal reactions. Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology, 30 (8), 1144-50 PMID: 10931122

.

Comments

  1. I find it unacceptable that some Paramedics didnt recognize their pt needed epi.

  2. With a 60gtts/mL set, the 1-20mL/min is pretty tough to administer properly without a pump. With a 10gtts/mL it’d be easier. Our pumps are set for 8 mcg/mL concentration (4mg in 250mL) thru a microdrop set in order to make up for this problem.

    • Christopher,

      With a 60gtts/mL set, the 1-20mL/min is pretty tough to administer properly without a pump. With a 10gtts/mL it’d be easier.

      That is going to depend on the dose that is needed.

      With small children, the 10 gtt set could be dangerous, but with adults, it is a matter of titrating flow to symptoms.

      More vs. Less.

      There is no specific right dose.

      We turn the flow down when the symptoms start to improve. It should not matter how well we can count the drops, but how well we assess the change in symptoms.

      I realize that this is an answer that may not please some lawyers and some QA/QI/CYA people, but this is about what is best for the patient, not what is best for the some lawyers and some QA/QI/CYA people.

      We need to be better at estimating. Estimating is important. Demands for precision lead to inaction. Inaction can be deadly, when action is needed.

      Our pumps are set for 8 mcg/mL concentration (4mg in 250mL) thru a microdrop set in order to make up for this problem.

      I like pumps for some things, but I think they only add to the confusion in life-threatening situations.

      .

      • Technology also has a habit of failing at the precise moment you need it most. And the more complicated the technology, the greater the potential for catastrophic failure.

      • I realize this drip is more like an dopamine drip, but given the 1mcg/mL concentration a microdrip set gets pretty tough to count after about a rate of ~4-5 mcg/min (X mcg/min = X gtts/sec). Beyond that I don’t think you get much better than 200-250 mL/hr flow rate (or 2-3mcg/min) out of a microdrip set.

        Regardless of the choice in adults, I second the caution in peds.

        • The engineer in me demanded I look this up rather than ballpark it, and the recommendation I found was 1 mg in 250 mL (4mcg/mL) with a microdrip set. This allows reasonable flow rates that most medics are familiar with (the lido wheel comes to mind).

          The diagnosis and management of anaphylaxis: An updated practice parameter. J Allergy Clin Immunol 2005;115:S483-523.

          • One emergency doc I know starts all hypertensive CHF patients on the same dose of IV nitroglycerin – “wide open.” Not the max setting on the pump – just “wide open.” I think you can guess where this doc stands on “precision versus inaction!”

            I think the simplicity of the “1 mg in 1 liter” approach has the virtue of simplicity, and will prevent iatrogenic overdoses – it’s hard to OD someone with epi if you are able to see individual drops in the the drip chamber, either micro- or macro-drip!

            For those “panic” times, when the symptoms are worsening, and the macro (10 gtts/ml) set is maxed out, you may have to squeeze the bag, and run the epinephrine in “wide open.” Hopefully its a short-term issue.

            In a similar vein (!), you don’t have to give high-dose IV nitro to a CHF patient for long, and you find yourself down-titrating quickly as the patient improves.

            • Brooks Walsh,

              One emergency doc I know starts all hypertensive CHF patients on the same dose of IV nitroglycerin – “wide open.” Not the max setting on the pump – just “wide open.” I think you can guess where this doc stands on “precision versus inaction!”

              Or we could giver boluses of IV NTG. Only 1 mg at a time so that we are not too aggressive. 😉

              It is even more simple than carrying a pump around and the bolus tends to produce more afterload reduction than the infusion by pump.

              Bolus intravenous nitroglycerin predominantly reduces afterload in patients with excessive arterial elastance.
              Haber HL, Simek CL, Bergin JD, Sadun A, Gimple LW, Powers ER, Feldman MD.
              J Am Coll Cardiol. 1993 Jul;22(1):251-7.
              PMID: 8509548 [PubMed – indexed for MEDLINE]

              High-dose intravenous isosorbide-dinitrate is safer and better than Bi-PAP ventilation combined with conventional treatment for severe pulmonary edema.
              Sharon A, Shpirer I, Kaluski E, Moshkovitz Y, Milovanov O, Polak R, Blatt A, Simovitz A, Shaham O, Faigenberg Z, Metzger M, Stav D, Yogev R, Golik A, Krakover R, Vered Z, Cotter G.
              J Am Coll Cardiol. 2000 Sep;36(3):832-7.
              PMID: 10987607 [PubMed – indexed for MEDLINE]

              Dr. Weingart posted this abstract at EMCrit several months ago –

              A Protocol of Bolus-Dose Nitroglycerin and Non-Invasive Ventilation to Avert Intubation in Emergency Department Acute Pulmonary Edema – this is in pdf format.

              I think the simplicity of the “1 mg in 1 liter” approach has the virtue of simplicity, and will prevent iatrogenic overdoses – it’s hard to OD someone with epi if you are able to see individual drops in the the drip chamber, either micro- or macro-drip!

              For medics trained to use the 4 per ml “lidocaine clock” method, 1 mg in 250 ml may actually be more familiar and be easier to measure at higher infusion rates with a 60 gtt drip set. Unlike IV bolus NTG for CHF, there may not be a benefit to IV bolus epinephrine in anaphylaxis.

              For those “panic” times, when the symptoms are worsening, and the macro (10 gtts/ml) set is maxed out, you may have to squeeze the bag, and run the epinephrine in “wide open.” Hopefully its a short-term issue.

              It should depend on haw well we assess the patient and how quickly we get an appropriate dose of epinephrine on board (and of course, we keep assessing the patient for recurrent anaphylaxis symptoms).

              In a similar vein (!), you don’t have to give high-dose IV nitro to a CHF patient for long, and you find yourself down-titrating quickly as the patient improves.

              That is one of the benefits of some critically unstable patients. They tend to respond quickly – one way or the other.

              .

            • Also –

              Treatment of severe decompensated heart failure with high-dose intravenous nitroglycerin: a feasibility and outcome analysis.
              Levy P, Compton S, Welch R, Delgado G, Jennett A, Penugonda N, Dunne R, Zalenski R.
              Ann Emerg Med. 2007 Aug;50(2):144-52. Epub 2007 May 23.
              PMID: 17509731 [PubMed – indexed for MEDLINE]

              High dose nitroglycerin treatment in a patient with cardiac arrest: a case report.
              Guglin M, Postler G.
              J Med Case Reports. 2009 Aug 10;3:8782.
              PMID: 19830240 [PubMed]

              And there is more evidence of the safety of bolus NTG, even with hypotension.

              .

  3. Keep it simple 1:1:2 … 1mg of adrenaline in a 1 litre bag of 0.9% NaCl run initially at 2gtt/s and titrate to patient condition. That’s how it’s done down under.

    We threw away boluses of adrenaline for anaphylaxis, asthma and severe bradycardia two years ago and it’s eleventy billion percent easier. Oh and we’re probably throwing away adrenaline for cardiac arrest in 2013 too so we’ll see