Principles of Treatment
- Give high doses of oxygen
- Infuse physiologic fluids
- Establish adequate airway
- Monitor heart rate & blood pressure
- No therapeutic role in acute adverse reaction: antihistamines, H2 antagonists, corticosteroids
Vasovagal Reaction
- hypotension (systolic blood pressure <80 mmHg) with sinus bradycardia (pulse <60 bpm)
- dizziness, diaphoresis
- loss of consciousness
- Monitor vital signs
- Leg elevation >60° + Trendelenburg position
- Secure airway + O2 610 L/min
- Secure IV access + rapid IV infusion of isotonic Ringer's lactate / normal saline
if symptoms persist, add:
- atropineslowly IV 0.61.0 mg
- Repeat atropine every 35 min slowly IV up to a total dose of 0.04 mg/kg (3 mg) in adults
[pediatric: 0.02 mg/kg IV; starting dose: min. 0.1 mg, max. 0.6 mg; may repeat to total dose of 2 mg]
Dermal Contrast Reaction
- hives = urticaria
- itching = pruritus
- flushing
- facial angioedema (= nonpruritic SQ edema of eyelid / peroral)
Mild Urticaria
- Discontinue injection if not completed
- No treatment needed in most cases
- H1-antihistamine, ie
diphenhydramine (Benadryl®) PO/IM/IV 2550 mg
or
hydroxyzine (Vistaril®) PO/IM/IV 2550 mg
Severe Urticaria
add H2-antihistamine:
- cimetidine (Tagamet®) 300 mg PO / slowly IV (diluted in 20 mL D5W solution)
[pediatric: 510 mg/kg diluted in 20 mL D5W solution]
or
ranitidine (Zantac®) 50 mg PO / slowly IV (diluted in 20 mL D5W solution)
if widely disseminated:
- IV line started + kept open (with normal saline / Ringer's lactate)
- epinephrine IV (1÷10,000) IV slowly over 25 min 1.0 mL (= 0.1 mg) if no cardiac contraindication
Nausea / Vomiting
may be the 1st signs of a more severe reaction
Respiratory Distress
- wheezing (inconsequential)
- bronchoconstriction (life-threatening)
- laryngeal edema (life-threatening)
Facial / Laryngeal Edema
- epinephrine SQ (1÷1,000) 0.10.2 mL (= 0.10.2 mg)
or if patient hypotensive
epinephrine (1÷10,000) slowly IV 1.0 mL (= 0.1 mg)
Repeat after 15 min up to a maximum of 1.0 mg - O2 610 L/min (via mask)
monitor: ECG; O2 saturation (pulse oximeter); BP
If not responsive to therapy:
- Seek assistance (CODE team)
- Consider intubation
Bronchospasm (isolated)
- O2 610 L/min (by mask, not nasal prongs)
monitor: ECG; O2 saturation (pulse oximeter); BP - β2-agonist metered dose inhaler in 23 deep inhalations: metaproterenol (Alupent®) / terbutaline (Brethaire®) / albuterol (Proventil®)
NOT: diphenhydramine as it thickens secretions
If unrelieved
with normal blood pressure + stable bronchospasm
- epinephrine SQ (1÷1,000) 0.10.2 mL (= 0.10.2 mg); may give 0.3 mg
[pediatric: 0.01 mg/kg up to 0.3 mg max.]
with decreased blood pressure + progressive bronchospasm
- epinephrine IV (1÷10,000) slowly over 25 min IV 1.0 mL (= 0.1 mg)
[pediatric: 0.01 mg/kg IV]
Repeat after 15 min up to a maximum of 1.0 mg
Alternatively
- aminophylline 6 mg/kg IV in D5W over 1520 min (loading dose); then 0.41.0 mg/kg/hr
Cx: hypotension, cardiac arrhythmia
or
terbutaline 0.250.50 mg IM/SQ - 200400 mg hydrocortisone IV
if unsuccessful, may require intubation
if anxiety exacerbates bronchospasm, sedation with 510 mg Demerol IV - Call for assistance (CODE team) for severe bronchospasm / if O2 saturation persists <88%
Outline