APHA Emergency Response to Reactions 2 — Questions and Answers
Question 1: A patient develops urticaria and facial angioedema 10 minutes after receiving an influenza vaccine. What is the most appropriate initial intervention?
- Administer diphenhydramine IM and observe
- Administer epinephrine 1:1000 IM into the anterolateral thigh (Correct answer)
- Apply ice to the injection site and monitor blood pressure
- Administer oral antihistamines and discharge after 15 minutes
Correct answer: Administer epinephrine 1:1000 IM into the anterolateral thigh
Angioedema combined with urticaria following vaccination indicates anaphylaxis, requiring immediate IM epinephrine as first-line treatment.
Question 2: Which of the following best describes the correct epinephrine dose for anaphylaxis in an adult weighing 80 kg?
- 0.15 mg IM of 1:1000 solution
- 0.3 mg IM of 1:1000 solution (Correct answer)
- 0.5 mg IV of 1:10,000 solution
- 0.1 mg subcutaneous of 1:1000 solution
Correct answer: 0.3 mg IM of 1:1000 solution
Adults and children over 30 kg receive 0.3 mg (0.3 mL) of epinephrine 1:1000 administered intramuscularly.
Question 3: After administering epinephrine for anaphylaxis during vaccination, how long should the patient be monitored before considering discharge?
- 15 minutes
- 30 minutes
- At least 4 hours or until fully stable (Correct answer)
- 1 hour
Correct answer: At least 4 hours or until fully stable
Biphasic anaphylaxis can occur hours after the initial reaction, so patients must be monitored for at least 4 hours or until clinically stable.
Question 4: A 4-year-old child (18 kg) receives a vaccine and develops anaphylaxis. What is the correct epinephrine dose?
- 0.3 mg IM of 1:1000
- 0.15 mg IM of 1:1000
- 0.01 mg/kg IM of 1:1000, max 0.5 mg (Correct answer)
- 0.1 mg IV of 1:10,000
Correct answer: 0.01 mg/kg IM of 1:1000, max 0.5 mg
Pediatric epinephrine dosing is 0.01 mg/kg IM of the 1:1000 solution, not exceeding 0.5 mg per dose.
Question 5: Which vaccine reaction is characterized by fever, seizures, and hypotonic-hyporesponsive episode (HHE) and is most commonly associated with which vaccine?
- MMR vaccine
- Varicella vaccine
- DTaP vaccine (Correct answer)
- Hepatitis B vaccine
Correct answer: DTaP vaccine
HHE (sudden hypotonia, pallor, and unresponsiveness) is most commonly reported after whole-cell pertussis-containing vaccines, including DTaP.
Question 6: When a patient loses consciousness immediately after vaccination, what is the first priority action?
- Call 911 immediately before assessing the patient
- Assess airway, breathing, and circulation and determine if the cause is vasovagal or anaphylactic (Correct answer)
- Administer epinephrine preemptively
- Place the patient in Trendelenburg position and administer IV fluids
Correct answer: Assess airway, breathing, and circulation and determine if the cause is vasovagal or anaphylactic
Rapid assessment of airway, breathing, and circulation distinguishes a vasovagal syncope from anaphylaxis, which guides definitive treatment.
Question 7: A vaccinee begins wheezing and complaining of throat tightness 5 minutes post-injection. What ACIP-recommended action takes priority over all others?
- Administer supplemental oxygen via face mask
- Inject epinephrine IM into the anterolateral thigh immediately (Correct answer)
- Place an IV line and prepare normal saline bolus
- Contact the vaccine manufacturer to report the event
Correct answer: Inject epinephrine IM into the anterolateral thigh immediately
Respiratory symptoms (wheezing, throat tightness) following vaccination indicate anaphylaxis, and IM epinephrine is the singular priority intervention.
APHA Emergency Response to Reactions 2
A patient develops urticaria and facial angioedema 10 minutes after receiving an influenza vaccine.
What is the most appropriate initial intervention?