Page 122 - JSOM Spring 2018

level for an hour or more. Intravenous epinephrine should be with a higher incidence in patients who present initially with
reserved for the rare patients with severe hypotension despite severe symptoms. The second onset of symptoms may be de-
IM epinephrine or patients in cardiac arrest. Low dose infusion layed for as long as 72 hours. Patients treated for anaphylaxis
of epinephrine for the treatment of severe anaphylactic shock should be monitored closely for four to six hours with lon-
should be limited to controlled environments with the avail- ger periods of observation warranted for patients with severe
ability of continuous cardiac monitoring. symptoms or those refractory to initial treatment. Patients
with a history of asthma should also be observed closely as
Epinephrine may be administered using an autoinjector (Table most fatalities associated with anaphylaxis occur in patients
IV), or by injecting the dose drawn up from an ampule or vial with reactive airways disease.
and administered using a syringe. Autoinjectors are available
by prescription to deliver 0.3 mg and 0.15 mg, and are pre- Medical follow-up
ferred for patients who will self-administer their own medica-
tions when experiencing symptoms or by lay rescuers assisting Any patient treated for anaphylaxis should undergo a medical
a patient experiencing an anaphylactic reaction. Recent criti- follow-up with their primary care practitioner and consider-
cisms of autoinjectors include their high cost; the dose deliv- ation for referral to an allergist or immunologist. Such refer-
ered is below the currently recommended dose for adults; and rals are associated with a refined diagnosis, establishing the
the needle is too short to deliver the medication intramuscu- cause of the event, and improved outcomes. Follow-up, at a
16
larly. For trained rescuers who are called upon to treat patients minimum, should include: 1) a prescription for an automatic
experiencing an anaphylactic reaction, administering epineph- epinephrine autoinjector and instructions on its use; 2) wear-
rine using a syringe affords a lower cost and a potentially more ing identification acknowledging risk for anaphylaxis (i.e.
effective option than currently available autoinjectors. medic alert bracelet) and 3) being provided an anaphylaxis
action plan should they become re-exposed to an allergen.
TABLE IV Automatic Epinephrine Injectors Available in the
United States 17 Summary
Product name Web Sites
Adrenaclick www.adrenaclick.com Anaphylaxis is a serious allergic reaction that is rapid in onset
Auvi-Q www.auviq.com and may cause death. It can occur at any age and it appears the
Epinephrine Injection, www.epinephrineautoinject.com incidence is increasing. Most cases of anaphylaxis present as
USP Autoinjector (authorized generalized hives, flushed skin and itching, along with respira-
generic of Adrenaclick) tory distress or shock. The mainstay of treatment requires the
EpiPen www.epipen.com early and repeated administration of epinephrine that is best
administered by intramuscular injection into the mid-anterior-
Patients experiencing anaphylaxis may experience distributive lateral thigh. Some patients go on to experience profound
shock from vasodilation and by shifting as much as 35 percent shock and will require the aggressive administration of intra-
of their intravascular fluid into the interstitial space in as little venous treatment. All patients treated for anaphylaxis require
as 10 minutes. Initial treatment includes placing patients with a period of ongoing monitoring for recurrence of symptoms
anaphylaxis supine or recumbent with legs elevated unless oth- and require medical follow up should repeated exposure oc-
erwise contraindicated by dyspnea or vomiting. This facilitates cur. With proper planning and timely treatment, medics en-
the shift of fluids from normally dependent portions to the countering anaphylaxis during a law enforcement operation
central circulation to increase blood pressure. Observational or an executive protection detail are presented with the op-
studies of fatal anaphylactic shock suggest that maintaining an portunity to mitigate a potentially preventable medical death.
upright posture may have contributed to the fatal outcome. 14,15
Patients who remain in shock despite epinephrine should re- Endnotes
ceive the rapid administration of intravenous crystalloid and/ 1. Joint Task Force on Practice Parameters representing the American
or colloids fluids, 10-20 ml/kg, repeated as needed to restore Academy of Allergy, Asthma and Immunology; the American Col-
the circulating blood volume. Large volume intravenous fluid lege of Allergy, Asthma and Immunology; and the Joint Council
resuscitation is unnecessary in patients with primarily respira- of Allergy, Asthma and Immunology. Anaphylaxis—a practice pa-
tory or cutaneous symptoms without shock and who respond rameter update 2015. Annals of Allergy, Asthma, and Immunol-
initially to epinephrine. ogy, 115(2015) 341–384.
2. Sampson HA, Munox-Furlong A, Campbell RL, et al. Second sym-
posium of the definition and management of anaphylaxis: Sum-
Patients taking beta-blockers may experience an increased se- mary report—Second National Institute of Allergy and Infectious
verity to an anaphylactic reaction or fail to respond to usual Disease/Food Allergy and Anaphylaxis Network symposium. J Al-
treatment due to the drugs’ effect on blocking the effects of lergy Clin Immunol 2006;117:391–7.
epinephrine. These patients should receive glucagon. The rec- 3. Estelle F, Simons R. Anaphylaxis. J Allergy Clin Immunol 2010;125:
S161–81.
ommended dose of glucagon is 1 to 5 mg (in children: 20-30 4. Simons FER, Motohiro E, Sanches-Borges M, et al. 2015 update of
mcg/kg, maximum 1 mg) administered over five minutes and the evidence base: World allergy organization anaphylaxis guide-
followed by an infusion of 5-15 mcg/min titrated to clinical lines. World Allergy Organization Journal. (2015) 8:32; 1–16.
response. 5. Lieberman P, Camargo CA Jr. Bohlke K, et al. Epidemiology of
anaphylaxis: Findings of the American College of Allergy, Asthma,
All patients treated for anaphylaxis with epinephrine require and Immunology Epidemiology Working Group. Ann Allergy
observation as symptoms may recur as the epinephrine wears Asthma Immunol, 2006;97:596–602.
off or the patient may experience a biphasic recurrence of 6. Jerschow E, Lin RY, Scaperotti MM, McGinn AP. Fatal anaphylaxis
in the United States, 1999-2010: Temporal patterns and demo-
symptoms. Biphasic reactions in anaphylaxis are reported to graphic associations. J Allergy Clin Immunol. 2014;134:1318–28.
occur in 1 percent to 20 percent of anaphylactic reactions, E7.

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