Acute Care Block - Anaphylaxis LearnPro Module Flashcards
An anaphylactic reaction is where the patient is more likely to react to the second or subsequent exposure to the allergen
What is an anaphylactoid reaction?
An anaphylactoid reaction has a different mechanism of action whereby the patient may react on the first exposure to an allergen - however the signs, symptoms and treatment are exactly the same for both
What are the vaccination anaphylactic mostly due to?
Vaccination anaphylactic reactions are mostly due to proteins associated with the vaccination such as egg and gelatin
More rarely anaphylactic reactions to vaccinations can be due to yeast or latex (in vial stoppers or syringe plungers or plugs)
What may be different airway features indicative of anaphylaxis?
- Swelling of lips, tongue and throat
- Difficulty in swalloing or breathing
- Increasing difficulty in talking
- Hoarse voice
- Wheeze (expiratory whirring sound indicating closing of lower airways)
- Stridor (inspiratory high pitched sound indicating closing of upper airways)
What may be different breathing features in somebody having an anapjhylactic reaction?
- Respiratory Rate: likely to increase in the early stages, reduces as the patient becomes fatigued and may be a pre-terminal sign of impending respiratory arrest.
- Depth of breathing: use of accessory muscles (especially shoulders for adults but intercostal and subcostal indrawing and flaring of nostrils and head bobbing may be more obvious in young children).
- Cyanosis: a bluish tinge especially around the lips, nailbeds and mucous membranes.
- Oxygen Saturation may be reduced as the patient becomes more hypoxic.
What may be different circulation features in somebody experiencing an anaphylactic reaction?
- May be tachycardic initially as the patient tries to compensate for the poor blood flow to vital organs. (Note: check central pulses, ideally carotid - as the patient may be peripherally shut down).
- Colour: patient may be pale and clammy.
- Hypotension: the blood pressure drops as the shock develops which may cause patient to collapse.
- Cardiac Arrest if untreated
- DO NOT STAND THE PATIENT UP
What may be different disability features in somebody experiencing an anaphylactic reaction? - what should you rule out in this section fo ABCDE?
- AVPU = Alert / Responds to Voice / Responds to Pain / Unresponsive
- Patient may be anxious or panic and sometimes describe a sense of “impending doom”?
- They may be confused, agitated or become less conscious as they become more exhausted and hypoxia takes its toll
- Check Blood glucose to rule out hypoglycaemia
What may be different features on exposure in somebody experiencing an anaphylactic reaction?
What percentage of patients experiencing an anaphylactic reaction experience skin changes?
- Head to toe examination to ensure nothing has been missed
- Skin changes are present in over 80% of anaphylactic reactions
- There may be a raised urticarial rash which may be itchy (pruritus)
- Patient may be very pale and clammy as the peripheries shut down
- May be abdominal discomfort or pain with or without GI changes (e.g. Loose stool). May be nausea or vomiting
- Swelling may be apparent (sometimes very obvious) throughout body but often apparent on the face around lips and eyes (Angiodema)
- May also have itchy eyes and/or runny nose
- Temperature should be checked
Treatment depends on the severity of a reaction
What is the treatment of a mild reaction? (not involving airway, breathing or circulation)
Treatment for mild reaction -
- Remove allergen
- Observe
- Give oral chloramphenamine (caution recommended following allergic reaction to vaccines)
- Localised treatment of swelling such as a cold pack at the site of an injection may also help the patient more comfortable
What is the treatment of a moderate/ severe reaction? (aka an anaphylactic reaction) - involving airway, breathing or circulation
When can adrenaline be removed?
FOLLOW ANPHYLAXIS ALGORITHM
- Remove allergen
- Lie patient flat with feet raised (if tolerated)
- Assess ABCDE
- Give High Flow O2
- Give IM Adrenaline
- Reassess ABCDE
- Repeat adrenaline after 5 minutes if required
Adrenaline is covered by the Human Medicines Regulation 2012 (also known as the Medicines Act), Schedule 19 referring to regulation 238, and may be given by anyone for anaphylaxis in an Emergency Situation without prescription.
What strength is adrenaline given at and what route in anaphylactic reactions?
When can it be repeated?
All ampoules of adrenaline contain 1 mg (1000 microgram).
- Adrenaline 1:1000 contains 1g in 1000ml = 1 mg in 1000 mL
- whereas adrenaline 1:10 000 contains 1g in 10,000ml = 1 mg in 10 mL (given in IV for cardiac arrest).
In an anaphylactic reaction, adrenaline is given IM at 1 in 1000 (1mg in 1ml) - give 500micrograms in adults = 0.5ml
It can be repeated in 5 minutes if no improvement or patient’s condition worsens
What is the dose of adrenaline in
Up to 6 years?
6 to 12 years?
12 years to Adult?
- Up to 6 years – 150 micrograms (0.15ml of 1 in 1000)
- 6 to12 years – 300 micrograms (0.3ml of 1 in 1000)
- 12 years to ADULT – 500 micrograms (0.5ml of 1 in 1000)
Adrenaline is not given IV unless the patient is severely unwell and by an experienced specialist - IV use is not commonly employed because it can lead to development of fatal arrhythmias.
What is the strength of adrenaline given if IV were to be given?
0.5ml of 1 in 10,000 (1mg in 10ml) = 0.05mg (50micrograms) of adrenaline IV
Once IV access has been secured, we can fluid challenge the patient?
What does is given in a child and what does is given in an adult? - what type of fluid
- 500-1000ml IV bolus of fluid in an adult
- 20ml/kg IV bolus of fluid in a child (unless shock from major trauma, then 10ml/kg IV bolus)
Fluid given is a crystalloid - 0.9% sodium chloride or Hartmann’s
Antihistamines and steroids are then given
Give the example of choice of each?
Are these recommended for the management of anaphylaxis in the vaccination setting?
Can these be given without prescrption like adrenaline?
Antihistamine - IV chlorphenamine
Steroid - IV hydrocortisone
Antihistamines and Steroids are no longer recommended for the management of anaphylaxis in the vaccination setting.
These may only be given when precribed
Adrenaline Auto Injector Pen
- In community areas adrenaline may be available as an auto-injector pen.
- 2 examples currently in use are “epipen” and “emerade”.
Emerade comes in a 500 micograms form
Epipen is only available in 150 micrograms or 300 micrograms, the later being used for patients over 6 years old.
How often can a second epipen IM injection be given?
The manufacturer recommends that subsequent doses of epipen be given only after 20 minutes has elapsed, therefore ampoules of adrenaline 1:1000 should be used for subsequent doses.
