Anaphylaxis

A Welcome Tour De Force in Anaphylaxis: Putting All The Competencies into Action

Gregory W. Rutecki, MD

The American Journal of Medicine kicked off 2014 with a provocative collection of papers as a supplemental edition on what is characterized as an underdiagnosed, undertreated, and potentially fatal disease: anaphylaxis. More so, it covered all the competencies required by healthcare professionals to appreciate the protean ramifications of this serious pathology. 

Medical Knowledge

“The level of under-diagnosis of anaphylaxis and the resultant shortcomings in the US are of concern.1” Practitioners need to know that this disease can be missed and the consequences thereof can be fatal.

For treatment,2,3 there is no convincing data for either antihistamines or steroids. Antihistamines take more than 80 minutes to work and block only 50% of histamine production—but none of the other mediators are affected (eg, mast cells). The drug of choice is epinephrine (see below for critical administration recommendations).

NIAID/FAAN, data-driven criteria, have a 96.7% sensitivity and 82.4% specificity for the diagnosis.3 They incorporate the organ targets for anaphylaxis and include: skin (hives, angioedema, pruritus, flushing), lungs (dyspnea, wheezing, bronchospasm, stridor O2), and blood pressure which can decrease or result in circulatory collapse. 

It is essential to realize that an anaphylactic reaction can be uniphasic, biphasic, or protracted. If it is biphasic and patients leave the site of medical care, they may suffer consequences before they have obtained a prescription for ambulatory epinephrine. Eight foods—fin fish, shell fish, peanuts, tree nuts, milk, eggs, wheat, and soy—lead the list for ingested products that cause anaphylactic reactions.3

Patient Care

Treatment is timely (translation: as soon as possible) with epinephrine administration via intramuscular injection into the lateral thigh—not subcutaneously.  This is useful since half of the patients who die do so in the first hour.3 The epinephrine auto-injector is popular because it has a preset dose, is easy to carry, and use (no mixing), but the needle may not reach muscle tissue in obese individuals. 

Conversely, the needle length is not a problem when epinephrine is drawn out of an ampule, but dose calculation errors can become a serious issue.3 The person drawing up the epinephrine must have a specific competency as well.

Biphasic anaphylactic reactions comprise 20% of all episodes.3 Note: The second episode of anaphylaxis may follow in 6 to 8 hours.

In one study, only 2.9% of emergency responders could recognize an atypical case of anaphylaxis when it presented without skin findings or known exposure to an allergen.2 As primary care practitioners, it is our job to be comfortable with diagnosis in unusual settings and educate others. If you are suspicious, but not convinced, a serum tryptase may help.

Practice-Based Improvement

A protocol-driven care and follow-up plan is important.1 When your patients with anaphylaxis leave the emergency department, they should have: 

• An epinephrine prescription for 2 injections. 

• Specific instructions on how to avoid the offending agent (if identified). 

• A referral to an allergist. 

• An emergency action plan if the pathology reoccurs despite the best preventive efforts.

Primary care practitioners need to prescribe and follow this protocol in its entirety. Expired epinephrine supplies must be monitored as well. 

Systems-Based Practice 

The direct costs for anaphylaxis total $1.2 billion year. Patients and third-party payers pay $294 million for epinephrine alone. In 2007, it cost the system $225 million when anaphylaxis was a consequence of a food allergy. 

Auto-injectors for administering epinephrine have increased in cost from $35.59 per single dose in 1986 to $87.92 in 2011—or a 147% increase in cost.1 For patients and families, the copay portion itself may preclude the purchase of 1 or 2 syringes. Remember, the guidelines recommend 2 epinephrine syringes at all times. 

 My personal knowledge in the area of anaphylaxis needed an update. The intramuscular versus subcutaneous epinephrine injection, as well as the protocol overview, was very important to my practice. This month’s collection of “Top Papers” included timely and informative manuscripts and the varying perspective that addressed multiple competencies was much appreciated. 

And as a closing thought for those movie buffs among you, Alex Hitchens, played by Will Smith in the movie “Hitch,” did not receive appropriate therapy for his anaphylaxis. ■

Gregory W. Rutecki, MD, is a physician at the National Consult Service at the Cleveland Clinic. He is also a member of the editorial board of Consultant. Dr Rutecki reports that he has no relevant financial relationships to disclose.

ReferenceS:

1. Dunn JD, Sclar DA. Anaphylaxis: a payer’s perspective on epinephrine autoinjectors. Am J Med. 2014;127(1 suppl):S45-S50.

2. Nowak RM, Macias CG. Anaphylaxis on the other front line: perspectives from the emergency department. Am J Med. 2014;127(1 suppl):S34-S44.

3.) Lieberman PL. Recognition and first-line treatment of anaphylaxis. Am J Med. 2014;127(1 suppl):S6-S11.