Anaphylaxis Training

1
Anaphylaxis Training
Understanding, Recognising and Managing Major
Allergic Reactions
Dr Aaron Pennell MBBS MSc Medical Advisor
(emergency care) Essex Police
2
Objectives

• Review the epidemiology of major allergic
  reactions
• Understand the definitions of such reactions
• Briefly review the structure of the immune
  system and response
• Review the pathogenesis of allergy and major
  reactions
• Briefly review the approach to investigating
  allergies
• Describe the clinical spectrums of major
  allergic reactions
• Describe the clinical presentation
• Be confident in skills to rapidly assess the
  patient
• Be confident in the immediate management
• Review the main drugs used in the immediate
  management
• Epinephrine
• Chlorpheniramine
• Hydrocortisone

Anaphylaxis Training
3
Epidemiology

• Hardly any reliable data exists on the subject !
• One study in Cambridge 1 in 1996 showed
• Of 1500 patients brought to AE with
  anaphylaxis only 1 had symptoms of
• loss of consciousness with respiratory
  compromise
• This is equivalent to 110000 a year in the
  population
• The rate almost trebled when symptoms of
  respiratory difficulty were included
• A study from the USA 2 in 1999 showed that
• There were 84000 cases of anaphylaxis in one
  year with 1 fatality
• It is also known that
• Anaphylaxis is more common in children than
  adults 3
• Food allergy accounts for the vast majority of
  reactions 4
• Another anaphylaxis study 4 in 2000 showed that

Anaphylaxis Training
4
Epidemiology - Definitions
No universally Accepted definition
Anaphylaxis Training
Poor availability of reliable data
Broad spectrum of the disease
5
Definition

• Need to recognise the spectrum of disease and
  presentation

• Erythema
• Pruritis
• Urticaria
• Angioedema
• Asthma / respiratory insult
• Laryngeal oedema
• Rhinitis
• Conjunctivitis
• Itching of the palate or external auditory
  meatus
• Nausea, vomiting and abdominal pain
• Palpitations
• Overwhelming anxiety
• Severe headache
• Fainting, collapse
• Loss of consciousness
• Death !

Anaphylaxis Training
6
Definition

• Need to recognise the spectrum of disease and
  presentation

Anaphylaxis Training

• Involves one or both of the following
• Respiratory compromise
• Cardiovascular compromise
• plus or minus any other signs or symptoms

7
Spectrum of disease 7

• Atopy
• Allergy
• Hypersensitivity reaction
• Type I (Anaphylaxis)
• Minor
• Moderate
• Severe
• Life threatening
• Fatal
• Type II (Cell mediated)
• Type III (Immune complex mediated)
• Type IV (Delayed T Cell mediated)
• Contact dermatitis

Anaphylaxis Training
8
Immune system and response
INNATE
ADAPTIVE

• Self v Non-self
• Antigen recognition molecules
• Clonal selection
• Memory

• Barriers to primary infection
• Phagocytosis
• Complement
• Inflammatory mediators

Anaphylaxis Training
IMMUNE SYSTEM ASSOCIATIONS

• Success
• Failure

9
Immune system and response
Pre B Cell
B Cell
Plasma Cell
Lymphoblast
T H Cell (CD4)
Pre T Cell
T S Cell (CD8)
PP Stem Cell
Myeloblast
Anaphylaxis Training
Monocytes
Macrophages
Proerythroblast
Myeloblast
Megakaryocyte
Neutrophills, Basophills, Eosinophills
Platelets
RBCs
10
Antibodies (Immunoglobulins)

• Glycoproteins produced by plasma cells
• IgM, IgA, IgD, IgG, IgE
• Have the same basic structure

Anaphylaxis Training

• IgE is normally present in very low levels in
  plasma
• Most is specifically bound to MAST cells and
  Basophills
• Associated with Type I hypersensitivity
  reactions - Anaphylaxis

11
Objectives
Anaphylaxis Training

• The chemical mediators released
• are either preformed or newly synthesised
• Preformed ones include
• Histamine
• Chemokines
• Heparin
• Newly synthesised include
• Prostaglandins
• Leukotrienes

12
Triggers

• Common causes
• Foods
• Bee and wasp stings
• Drugs
• Latex rubber
• Foods reported as triggers
• Peanuts 8
• Fish
• Shellfish
• Eggs
• Milk
• Sesame, Pulses etc Note
• Others Anaphylaxis may be worse in
• those on beta blockers 9

• Drugs causing anaphylaxis
• Antibiotics (especially penicillin)
• Anaesthetic agents
• Aspirin
• NSAIDS
• IV Contrast media
• Opioid analgesics

Anaphylaxis Training

• Rare Causes
• Exercise
• Semen
• Vaccines

13
The result of all of this.

• Massive vasodilation
• Bronchoconstriction
• Mucosal oedema
• Distributive Shock
• Anaphylactoid reactions
• Involve the same mediators (histamine etc) but
  are NOT triggered by
• IgE
• Certain specific drugs act directly on mast
  cells and this is one trigger

Anaphylaxis Training
IMPORTAINT POINT There is no way of
differentiating the two in clinical practice
therefore both are Treated the same in the
immediate period
14
How are they investigated

• Difficult after the event !
• A sample of venous blood taken about 1 hour
  after the onset of symptoms can be
• assessed for mast cell tryptase but it is
  unreliable
• IgE immunoassays are also difficult to assess
• Following the reaction prick testing may be
  performed

Anaphylaxis Training
Skin prick test for type I Patch test for
type IV
15

• Clinical presentation
• A useful triad

History
Anaphylaxis Training
Shock or Respiratory compromise
Presence of Any other signs Or symptoms

• Presentation can be evolving (consider IM versus
  IV drug administration)
• Presentation can be rapid
• Presentation is NOT delayed

16
Clinical presentation - Anaphylaxis

• Headache
• Urticaria (/- angioedema)
• Dizziness
• Tachpnoea
• Wheezing later stridor
• Tachycardia
• Hypotension 6
• Loss of consciousness
• Do not waste time measuring blood pressure
  initially
• Use radial pulse as a good indicator of
  perfusion pressure

Anaphylaxis Training
17
Anaphylaxis Training
18
Anaphylaxis Training
19

• Assessment of the patient 5
• Immediately stop administration of any drug etc
• Keep the drug / syringes etc

Anaphylaxis Training

• Establish level of consciousness
• Assess the airway
• Assess breathing GIVE OXYGEN at high flow
• Assess circulation
• If not fully conscious place the patient on
  their side
• If practical elevate legs if patient conscious
• Get help 999 / call for AED / doctor /
  advanced medic / ambulance
• If no signs of breathing immediately give 30
  chest compressions
• Follow this with 2 ventilations
• Continue at a ratio of 230

20
Drug therapy for anaphylaxis

• Epinephrine
• Chlorpheniramine
• Hydrocortisone

Anaphylaxis Training
21
Epinephrine 6

• Is an alpha and beta receptor agonist
• Alpha effects cause vasoconstriction
• Beta effects cause bronchodilation (can also use
  B2A as an adjunct)
• Reverses the 2 severe manifestations of
  anaphylaxis
• Less effective for patients taking alpha or beta
  blocking drugs
• Dose should be halved for those taking MAOI or
  TCA or known cocaine users
• Can be nebulised 10 as a bronchodilator
• Very safe drug to administer exempt from POM
  legislation on administration
• Note

Anaphylaxis Training

• Side effects
• Arrhythmias
• Hypertension
• Thirst

22
Epinephrine Dose

• Adults 0.5 1 mg IM repeated at 5 min
  intervals if no improvement
• Children
•   gt 12 years up to 500 micrograms IM (0.5 mL
  11000 solution) 250 micrograms if child is
  small or prepubertal
• 6 - 12 years 250 micrograms IM (0.25 mL 11000
  solution)
• gt 6 months - 6 years 120 micrograms IM (0.12 mL
  1 1000 solution)
• lt 6 months 50 micrograms IM (0.05 mL, absolute
  accuracy not essential)
• Note
• IV use is hazardous and should only be used by
  those trained in full resuscitation
• IM means deep IM (thigh, buttock or deltoid)

Anaphylaxis Training
23
Chlorpheniramine

• H1 blockers should be used in all anaphylactic
  reactions
• They counteract the histamine release from mast
  cells
• Their use should come after epinephrine or if
  reaction is not life threatening
• Dose
• Adult 10-20 mg IM or IV

Anaphylaxis Training

• Side effects
• Sedative effect

24
Hydrocortisone

• Still some discussion as to its usefulness
  still recommended however
• Effects are not useful until about 3-4 hours
  after administration
• May help prevent biphasic or protracted attacks
• Useful in anaphylaxis in those with asthma
• Dose 100 - 500mg IM or IV

Anaphylaxis Training
25

• Important points to note
• Adrenaline is underused
• Adrenaline reverses nearly all anaphylactic
  reactions
• Other supportive measures include
• Oxygen
• Salbutamol 10
• IV Fluids
• Monitoring

Anaphylaxis Training
26
Risk screening for vaccination programmes
PATCH screen
Anaphylaxis Training

• Previous reaction to agent
• Atopy Allergies (asthma, eczema, hay-fever)
• Triggers for allergy (if applicable)
• Check what medications the person is taking (B
  Blockers etc)
• Have they had this drug before

27
Anaphylaxis Training
Any Questions ?
28
References

• Stewart AG, Ewan PW (1996) The incidence,
  aetiology and management of anaphylaxis
  presenting to
• an AE department. Q J Med 89 859-64
• Yokum MW, Butterfield JH, Kleis JS et al (1999)
  Epidemiology of anaphylaxis in Olmsted county a
• population based study. J Allergy Clinical
  Immunology. 104 452-456
• Simmons FER, Peterson S, Black CD (2002)
  Epinephrine dispensing patterns for an out of
  hospital
• population A novel approach to studying the
  epidemiology of anaphylaxis. Journal of Allergy
  and
• clinical immunology. 110. 647-651
• Lee JM, Greenes DS (2000) Biphasic anaphylactic
  reactions in paediatrics. Paediatrics 106.
  762-766
• Ewan PW. Treatment of anaphylactic reactions.
  prescribers Journal 199737125-32
• Fisher M. Treatment of acute anaphylaxis. Br Med
  J 1995311731-3
• Douglas DM, Sukenick E, Andrade WP, Brown JS.
  Biphasic systemic anaphylaxis an inpatient
• and outpatient study. J Allergy Clin Immunol
  199493977-985.
• Ewan PW. Clinical study of peanut and nut allergy
  in 62 consecutive patients new
• features and associations. Br Med J
  19963121074-8.
• Toogood JH. Risk of anaphylaxis in patients
  receiving beta-blocker drugs.J Allergy Clin
  Immunol 1988811-5
• Turpeinen M, Kuokkanen J, Backman A. Adrenaline
  and nebulised salbutamol in acute asthma.Arch
  Dis Child 198459666-8

Anaphylaxis Training