Management of the airway in patients with angioedema

Abstract
Angiodema can be frequently encountered in clinical practice, and usually represents transient areas of tissue edema and erythema. In general, lesions involve the deep dermis as well as subcutaneous or submucosal sites and can affect multiple organ systems, including the respiratory and gastrointestinal tracts. Although the underlying cause for the angioedema is frequently not known, it can result from atopy, specific antigen sensitivities, physical stimuli, as well as disorders that affect the complement cascade. These latter entities may be congenital or acquired. Pathogenesis for angioedema is generally thought to be activation of mast cells or basophils, with subsequent release of histamine and other mediator products which can induce inflammatory changes. In most patients with physical and allergic causes of angioedema, swelling can usually be treated with epinephrine, antihistamines and/or steroids. Management of the airway in such patients is usually symptomatic, although certain patients require hospitalization for supervised care. On the other hand, patients with hereditary angioedema do not often respond well to these agents. In such patients, we currently add infusions of epsilonaminocaproic acid as well as nembulized racemic epinephrine to our therapeutic regimen, but even this may not be satisfactory. At the National Institute of Allergy and Infectious Disease, endotracheal intubation is usually preferred to tracheostomy for securing a temporary airway, though certain patients may require placement of tracheostomies for better control of the airway. Patients with frequent recurrences of airway obstruction are rarely seen--even among those patients with known hereditary angioedema. However, such patients may require tracheal fenestrations to secure long-term protection of the airway. The Institute's experiences in the management of patients with angioedema are reviewed, and therapies employed are described.