anaphylaxis Flashcards
Type 1 Hypersensitivity Reaction
Immediate Anaphylaxis -
mast cell activation which releases histamines.
Type 2 Hypersensitivity Reaction
Antibody targeting antigens on the cell surface.
AUTOIMMUNE REACTIONS or INCORRECT BLOOD TRANSFUSION
Type 3 Hypersensitivity Reaction
Immune Complex Reaction -
antigen-antibody complex which lodges in a vessel wall and activates a complement system.
(e.g: rheumatoid arthritis)
Type 4 Hypersensitivity Reaction
Antigen-specific activated T cells - contact dermatitis.
What is a uniphasic reaction?
A reaction with rapid onset and symptoms get rapidly worse
Once treated, symptoms don’t return.
What is a biphasic reaction?
Mild-severe reactions followed by a period of time when there are no symptoms before increasing symptoms with breathing and blood pressure problems.
What is a biphasic reaction?
Mild-severe reactions followed by a period of time when there are no symptoms before increasing symptoms with breathing and blood-pressure problems.
How long should patients be monitored following anaphylaxis?
6-12 hours
Symptoms of Anaphylaxis
- Skin changes - redness and itching.
- Mucosal changes - swelling below the skin surface.
- Swallowing and breathing difficulties due to swollen mouth, throat or tongue.
- wheezing
- tachypnoea (quick breathing)
- tachycardia
- hypotension
4 causes of anaphylaxis in the dental practice.
- Antibiotics
- Chlorhexidine
- Local Anaesthetic
- Iodoform
Airway assessment for anaphylaxis:
- Swollen tongue.
- Difficulty swallowing/speaking.
- Throat tightness.
- Hoarse voice.
- Stridor.
Breathing assessment for anaphylaxis:
- Difficult or noisy breathing.
- Chest tightness.
- Persistent coughing.
- Wheezing.
- Tachypnoea (increased respiratory rate).
Circulation assessment for anaphylaxis:
- Hypotension
- Tachycardia
- Pallor (sweaty)
Disability assessment for anaphylaxis:
- Feeling dizzy or faint.
- Confusion
- Agitation
- Syncope
- Loss of consciousness.
Exposure assessment for anaphylaxis:
- Skin changes or rashes?
- Abdominal pain and cramps.
- Nausea or vomiting.
- Diarrhoea
- Sense of impending doom.
How would you manage anaphylaxis in the dental setting?
Adrenaline (ASAP)
What does adrenaline do in the event of anaphylaxis?
- Reverses peripheral vasodilation.
- Reduces oedema.
- Dilates the airways.
- Increases myocardial contractility.
- Suppresses histamine and leukotriene release.
Dose of adrenaline for a person over 12?
0.5ml
Dose of adrenaline for a child aged 6-12?
0.3 ml
Dose of adrenaline for a child under 6?
0.15 ml
How frequently should adrenaline dose be readministered?
Every 5 mins until there has been an adequate response.
What is the angle of injection?
90 degrees
Positioning of a patient with anaphylaxis?
In a comfortable position - upright may be better for breathing difficulties but those with hypotension will benefit from lying down with legs raised.
Resuscitation Council Response to Anaphylaxis
- Call for help and request emergency drugs and resuscitation kit.
- Assess with ABCDE.
- Call 999 and state anaphylaxis.
- Stop dental procedure, clear airway and remove potential triggers.
- Administer oxygen 15 litres through non-rebreathe mask.
- Administer adrenaline.
- Monitor using ABCDE.
- Repeat adrenaline at 5 min intervals.
