Anaphylaxis to Intravenous Agents

Clinical Presentation and Management

The American Academy of Otolaryngology-Head and Neck Surgery confirms that cardiovascular involvement with hypotension or cardiovascular collapse requires immediate epinephrine administration, with a recommended dose of 50 mcg IV (0.5 mL of 1:10,000 solution) given the presence of IV access and cardiovascular collapse 1, 2, 4
The American Heart Association, as published in Circulation, recommends administering epinephrine immediately, with repeat doses every 5-15 minutes if hypotension or bronchospasm persists, and considering starting an epinephrine infusion if multiple doses are required 1, 2, 4
Aggressive fluid resuscitation with 0.9% saline or lactated Ringer's solution at a high rate through a large-bore IV catheter is necessary, with large volumes potentially required due to massive vasodilation 1, 2
Airway management includes administering 100% oxygen, preparing for intubation given bilateral wheezing and potential for laryngeal edema, and immediate referral to someone with expertise in surgical airway management if oropharyngeal edema develops 1, 2, 4

Obtaining mast cell tryptase levels at specific time points, including an initial sample as soon as feasible, a second sample at 1-2 hours after symptom onset, and a third sample at 24 hours or in convalescence for baseline comparison, can aid in diagnostic confirmation 1, 2, 4
Never delay epinephrine administration while giving antihistamines or corticosteroids, as these do not prevent biphasic reactions and are not first-line therapy, according to the American Heart Association 4
Monitor for biphasic anaphylaxis, which occurs in 1-7% of patients, with risk factors including severe initial presentation and requiring >1 dose of epinephrine, as noted by the American Academy of Otolaryngology-Head and Neck Surgery 3