Contrast medium reaction

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30px This page in a nutshell: In a more severe reaction: Adrenaline shot, 0.3-0.5mg in adults, given intramuscularly. Summon an anesthesiologist

In case of a contrast medium reaction, anaphylaxis is a more severe allergic reaction whose diagnostic criteria generally include low blood pressure and/or respiratory distress. In anaphylaxis, intramuscularly administered adrenaline is the most important initial therapy. Also, an anesthesiologist or corresponding clinician on duty should be summoned. A peripheral venous catheter is needed for the administration of IV fluids. Oxygen saturation, pulse and blood pressure are monitored.

Evaluation

Initial evaluation can be done according to an ABCDE approach:

• Airway: Stridor? Swollen tongue?
• Breathing: Cyanosis? Use pulse oximeter if available.
• Circulation: Palpable pulse over radial, femoral and carotid artery? Heart rate? Blood pressure? Difficulty in taking blood pressure must not delay adrenaline administration.
• Disability: Altered level of consciousness?
• Exposure: Hives?

In severe hives and progressive angioedema

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Angioedema

• 0,3-0,5 mg adrenaline intramuscularly on the anterolateral part of the mid-thigh. It is repeated if needed every 3–5 minutes.
• Corticosteroid (see Table of medications below)
• Observation at least 30 minutes

Anaphylaxis

• 0,3-0,5 mg adrenaline intramuscularly on the anterolateral part of the mid-thigh. It is repeated if needed every 3–5 minutes.
• Summon anesthesiologist or corresponding clinician on duty
• Oxygen, 10 L/min on mask. Attach a pulse oximeter.
• In asthma or bronchospasm: Salbutamol inhalations (see Table of medications below)
• In hypotension: Tilt the table to lower the head of the patient and give volume expander
• Corticosteroid (see Table of medications below)

Cardiac arrest (unconscious and no breathing)

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Chest compressions.

• Start CPR: 100 chest compressions per minute and ventilate x2 every 30 compressions
• Connect a defibrillator
• If ventricular fibrillation or tachycardia: defibrillate at 200 Joule
• If asystole or pulseless electrical activity (PEA): 1 mg adrenaline 0,1 i.v. bolus
• Continue CPR

Itching hives

If ABCDE is otherwise normal:

• Antihistamine (see Table of medications below)
• Observation at least 30 minutes

Table of medications

Symptoms	Medication	Route	Dosage		Time to effect	Repeat
			Adults	Children
Severe hives Respiratory distress Hypotension Altered level of consciousness Severe abdominal pains and vomiting	Injection of adrenaline	Intramuscular in lateral thigh	0.3 - 0.5 mg	0.01 mg/kg, up to 0.5 mg 10-20kg: 0.15 mg ≥20kg: 0.3 mg	Less than 5 min	Every 5-10 min if needed
Asthma	Salbutamol (Ventolin) or own bronchodilator	Inhalation	5 mg Usually 4-6 doses	2-6 doses	Less than 5 min	Every 10 mins if needed
Hypoxia	Oxygen	Mask	>5 l/min		Almost immediate	Continuous
Altered level of consciousness or hypotension	Volume expander such as Ringer's	IV with pressure	20mg/kg		Fast	As needed
All anaphylaxis cases	Antihistamine such as desloratadine (Clarinex/Aerius)	Oral	10mg of desloratadine	<6 years: 2.5mg desloratadine 6 - 12 years: 5 mg desloratadine	Within 30-60 minutes	Usually not
All anaphylaxis cases	Glucocorticoid such as betamethasone	Oral or IV	5-8 mg betamethasone	<6 years: 3-4 mg ≥6 years: 5-8 mg	2-3 hours	Usually not