Introduction Angio-oedema is characterised by subcutaneous oedema resulting from increased vascular permeability and dilation of venules and capillaries. This response is initiated by the release of vaso-active substances such as histamine, serotonin, bradykinin etc.
Angio-oedema may occur anywhere in the body with facial and oro-pharyngeal tissues most commonly affected (94%).
Aetiology Hereditary angio-oedema is an autosomal dominant disorder due to inherited deficiency of C1-esterase inhibitor. It is characterised by episodic, non-pitting oedema of any part of the body and is usually associated with laryngeal oedema.
There are several mechanisms that may produce angio -oedema, e.g. foods, additives, drugs, transfusions, insect bites and infection. Other causes include stress, contraceptive pills, menstruation, minor trauma such as a dental procedure, etc.
Management As an Emergency physician, I have observed that medications are the most common aetiological factor for this potentially lethal condition. Aspirin, Angiotensin-converting enzyme (ACE) inhibitors and non-steroidal anti-inflammatory drugs (NSAIDS) are commonly incriminated.
Recently, we admitted a patient in the Emergency Department with massive oedema of the lips, tongue and uvula due to injection Diclofenac sodium (VoveranTM) administered by intramuscular route. The patient had no previous history of angio-oedema.
She was treated with: Inj. Adrenaline 1:1000 mixed with 4 ml of Normal saline, administered through a nebuliser, with oxygen at 8 litres per minute. Inj. hydrocortisone 100mg IV bolus Injection Pheniramine Maleate (AvilTM) 25 mg. I.V. She was observed for 12 hours for potential airway obstruction. However she recovered uneventfully.
The primary concern in angio-oedema is laryngeal airway swelling and obstruction, which could be so severe that intubation would be impossible. A few years ago, an elderly lady, on ACE on inhibitors, presented with angio-oedema and required endotracheal intubation which was not feasible, due to massive oedema of the tongue. She was therefore subjected to cricothyroidotomy.
Early, aggressive and optimal management are the keys to success in the treatment of angio-oedema. The sheet-anchor drugs of therapy are adrenaline and corticosteroids. Adrenaline could be administered deep IM/IV or as a nebuliser, as in the case above.
Antihistamines are ancillary drugs in the management of Angio-oedema. As the name suggests, these drugs are administered to combat the effects of histamine and their efficacy is evident, only if administered prior to the episode. Their usefulness is therefore limited to a secondary role and there is no evidence-based literature to suggest multiple doses or high-dose anti-histaminic therapy for angio-oedema.
Prof. Suresh S. David MS(Surg) MPhil FACEM Accident and Emergency Medicine CMC Hospital Vellore 632 004
You have alluded to using Adrenailine in IM, IV or nebulised form. SC Adrenaline has rightly been laid to rest.
Why did you choose to use Adrenaline in its nebulised form rather than IM? Is its bioavailability any better or comparable to that of IM form?
I feel that the use of nebulised salbutamol is more anecdotal. I too have used it several times in the past with good results.
However, I am not aware of any convincing evidence either supporting or refuting its use. There is an e-medicine article suggesting its use (Dreskin S.Anaphylaxis.EMedicine.October,2005.http://www.emedicine.com/med/topic128.htm#section~Treatment)
European Resus council have just published their guidelines for the management of anaphylaxis (not necessarily angiooedema). There is no mention of Adrenaline in its nebulised form. I would like to see any further convincing evidence you have to support its use.
Regards
Raj Maroju
