Angioedema

Red flags

  • Any patient you suspect clinically to have airway compromise

 

IMPENDING AIRWAY DISASTER TRIAD

  • Rapid onset aphagia or severe dysphagia, frequently associated with a severe sore throat
  • Rapid onset laryngeal voice change: hoarse, croaky, husky or no voice
  • Systemically very unwell: pyrexia, tachycardia, tachypnoea

There may be associated trismus or torticollis. Beware of any patient who develops these signs after admission: situations deteriorate rapidly. In the presence of neck trauma, any of the above should be taken very seriously. Stridor is a late sign of airway compromise. 

 

Why is this important?

  • Angioedema is the swelling of deep dermal, subcutaneous or submucosal tissue due to vascular leakage. It commonly affects the lips, tongue, eyes and face but can also affect other parts of the body.
  • Patients with angioedema are at high risk of airway obstruction and hence this can be a medical emergency. 
  • Some patients are at risk of recurrent angioedema and should be investigated (see below).

 

When to involve the ENT registrar

The ENT and Anaesthetic registrars should be informed urgently if you have think the patient’s airway is at risk.

In an emergency situation, because most ENT registrars are off-site out-of-hours, it is prudent to put out an emergency call for the anaesthetist, ODP and emergency team, who are on site.

 

Who to admit

All patients with angioedema should be admitted for 24 hours of observation. It is, however, controversial whose care they come under. Most medical teams would not be keen to accept these patients under their care, hence it is usually up to the discretion of the ITU and ENT team.

We would suggest that any patient who has a stable airway with minimal airway oedema may be observed under the care of ENT team on a specialist ENT ward with suitably trained nurses and critical care outreach support readily available. If, however, there is no specialist ENT ward, a critical care unit may be a more appropriate environment.

 

Assessment and recognition 

  • The patient should be seen in Resus with appropriate monitoring attached
  • Use a methodical ABC approach to the patient as per ALS protocol
  • Take a concise history (including past medical, drug and family) and examine the neck, oral cavity and upper aero digestive tract thoroughly; flexible nasendoscopy is invaluable 
  • Remember, call for help early if there are signs of an impending airway obstruction!

 

Immediate and overnight management

  • Stat dose of dexamethasone 6.6mg to 8mg IV, 4mg of chlorphenamine IV, Heliox (or high flow oxygen if Heliox not available)
  • Adults and children >12 years: 0.5ml of 1: 1000 adrenaline IM (= 500mcg) if there is impending airway obstruction (see Resus Council anaphylaxis management algorithm)
  • Otherwise 1: 1000 adrenaline can be given in nebulised form, usually diluted with 4ml 0.9% saline to a final concentration of 1: 5000
  • Prescribe nebulised adrenaline PRN in case the patient has problems breathing while on the ward
  • After the stat treatment above, dexamethasone 6.6mg to 8mg should be prescribed TDS, along with chlorphenamine 4mg QDS
  • The dexamethasone dose should be tapered if a high dose is given for longer than two or three days

 

Aetiology, risk factors and pathophysiology

  • Idiopathic (40%)
  • Hypersensitivity from external stimuli eg food, drugs, insect stings, pollen, animal dander; patients with known atopic conditions (asthma, eczema, hay fever, urticarial) are at higher risk of this
  • Hereditary – there is usually a strong family history. This is associated with mutations of the C1 inhibitory gene (C1-INH) and is not hypersensitivity-related
  • Autoimmune diseases – eg lupus
  • Malignancies – lymphoma, leukaemia
  • Medication – NSAIDs and ACE inhibitors are common culprits; patients may have been taking these drugs for years 
  • Physical factors – eg cold, heat, pressure, vibration and ultraviolet radiation

 

Further management

These patients should be investigated for the underlying cause. Relevant investigations include:

  • Complement
  • Mast cell tryptase
  • C1-esterase inhibitor levels (for hereditary C1-esterase inhibitor deficiency)
  • ANA (for lupus)
  • Rheumatoid factor
  • Skin prick testing or serum RAST 
  • FBC, U&E, CRP, LFT, coagulation screen

 

Patients at risk for recurrent episodes should be counselled about having an Epipen and should seek treatment/advice from an allergy specialist.

 

 

Page last reviewed: 17 September 2017