Pearls:

A patient who receives epinephrine for an allergic reaction in the Urgent Care MUST be discharged with an Epi-Pen.

Strict return precautions are critical and consider how easily and quickly a patient can get back to you when deciding how long to observe.

After giving epinephrine for an anaphylactic reaction, 6 full hours of observation is likely unnecessary and 2-3 hours is probably sufficient.

WHO GETS EPINEPHRINE:

Patients with an allergic reaction that involves any compromise to their ABCs.

CONTRAINDICATIONS TO EPINEPHRINE

This is very, very rare.

Patients who have a reported allergy to epinephrine are allergic to the diluent. There is another form of epinephrine that has an different diluent, but it is never available to you.

Gave epinephrine to patients between 15 and 96 for asthma (before we had beta-agonists). No one had an ischemic event or a lethal dysrhythmia.

Cydulka R, et al. The use of epinephrine in the treatment of older adult asthmatics. Ann Emerg Med. 1988 Apr;17(4):322-6. [PMID: 3354935 ]

However, in patients with anaphylaxis there is no contraindication to epinephrine. If they cannot get oxygen, it does not matter if they have CAD or not. Without oxygen, the heart dies.

OBSERVATION AFTER GIVING EPINEPHRINE

We are traditionally taught that patients need to be observed for 4-6 hours after administration of epinephrine for an anaphylactic reaction.

The observation period is necessary because there is a risk of a rebound anaphylaxis that can occur after the epinephrine has worn off. There is not a lot of evidence to tell us the true time frame and risk of rebound anaphylaxis.

Early studies described a 30% risk of rebound, but they included any recurrent symptoms as rebound, including hives or pruritis.

What we actually care about is which patients had recurrence of shortness of breath, hypotension or airway swelling. These are severe biphasic reactions that are very rare.

Grunau BE, et al. Incidence of clinically important biphasic reactions in emergency department patients with allergic reactions or anaphylaxis. Ann Emerg Med 2014 Jun; 63:736. [PMID 24239340]