Dexamethasone use in anaphylaxis
Question# 822
Why is Dexamethasone not indicated for severe allergic reaction in the pre-hospital setting?
Answer:
Prehospitally, the primary treatment for anaphylaxis is intramuscular (IM) epinephrine (1:1000). This crucial medication is lifesaving, and we should have a low index of suspicion to treat anaphylaxis. As you’re aware, it should be given IM in the lateral thigh, 0.01 mg/kg to a max of 0.5 mg q 5 minutes, with a max of 2 doses.
When given promptly, most patients will respond to 1 dose of IM epi, and the vast majority of patients don’t require a 2nd dose of epi. In fact, refractory anaphylaxis, is quite rare. If patients aren’t responding to the epi, we need to consider other causes to their symptoms.
Mechanistically, the epinephrine should relieve all of the anaphylactic side effects, but there is a role for some adjunct medications such as fluids, antihistamines, and bronchodilators.
With respect to steroids, these can in turn stabilize the mast calls, but they take hours to work. Therefore, these medications do not relieve the initial symptoms and signs of anaphylaxis.
Historically, the theoretical rationale has been that the administration of steroids has been to prevent biphasic reactions, but this has since been debunked. While you might see steroids given hospitably, it is unlikely to be given for an isolated anaphylaxis presentation and likely as part of a broader treatment plan for a more complex patient.
In our pediatric patients, the guidelines also align with this approach, and steroids are only given for patients with persistent shock, asthma, or upper airway complications. The TREKK bottom line recommendations further add that “they do not reduce reaction severity, and in children, may increase the risk of biphasic anaphylaxis”. Thus, the routine use of systemic corticosteroids is discouraged.
If you’d like to learn more about anaphylaxis and it’s treatment, we encourage you to check out the Critical Levels podcast episode/elective CME (2023) about this topic.
When given promptly, most patients will respond to 1 dose of IM epi, and the vast majority of patients don’t require a 2nd dose of epi. In fact, refractory anaphylaxis, is quite rare. If patients aren’t responding to the epi, we need to consider other causes to their symptoms.
Mechanistically, the epinephrine should relieve all of the anaphylactic side effects, but there is a role for some adjunct medications such as fluids, antihistamines, and bronchodilators.
With respect to steroids, these can in turn stabilize the mast calls, but they take hours to work. Therefore, these medications do not relieve the initial symptoms and signs of anaphylaxis.
Historically, the theoretical rationale has been that the administration of steroids has been to prevent biphasic reactions, but this has since been debunked. While you might see steroids given hospitably, it is unlikely to be given for an isolated anaphylaxis presentation and likely as part of a broader treatment plan for a more complex patient.
In our pediatric patients, the guidelines also align with this approach, and steroids are only given for patients with persistent shock, asthma, or upper airway complications. The TREKK bottom line recommendations further add that “they do not reduce reaction severity, and in children, may increase the risk of biphasic anaphylaxis”. Thus, the routine use of systemic corticosteroids is discouraged.
If you’d like to learn more about anaphylaxis and it’s treatment, we encourage you to check out the Critical Levels podcast episode/elective CME (2023) about this topic.
References
ALS PCS
Critical Levels Podcast Episode 34 - Anaphylaxis
TREKK Anaphylaxis Bottom Line Recommendations
UpToDate - Anaphylaxis: Emergency treatment