76 Airway Complications in Angioedema

Abstract

Angioedema is a common and potentially life-threatening diagnosis that results in more than one million emergency department (ED) visits per year. It manifests as localized edema of the deep dermis and subcutaneous tissues secondary to increased vascular permeability. The face, lips, mouth, throat, and extremities are commonly affected. The pathophysiology is complex and the disorder is broadly classified as resulting from histaminergic or bradykinin-mediated mechanisms. Angioedema is a well-known adverse effect of angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitor-induced angioedema (AIAA) affects 0.1% to 0.7% of patients taking ACE inhibitors and accounts for approximately one-third of all ED visits for angioedema in the United States. Early ED provider recognition of the specific type of angioedema is essential to optimize management and patient outcomes. We sought to characterize airway interventions and complications for AIAA versus non-ACE inhibitor induced angioedema (NAIA). We performed a retrospective chart review of patients seen in the ED with a diagnosis of angioedema at Methodist LeBonheur Healthcare facilities in Memphis, TN from 1 January 2006 to 31 August 2016. Adult patients greater than 18 years were included. Among the 1,299 patients diagnosed with angioedema, 954 had AIAA and 345 had NAIA. AIAA patients were older than those with NAIA (59 years vs 55; p=0.01). Approximately 62% were female in both groups. AIAA patients were more likely to be African American (89% vs 76%; p=0.001) and more likely to be current smokers (28% vs 21%; p=0.001). BMI distribution was similar between the two groups. Initial symptoms were similar in the 2 groups except rash (<1% in AIAA group vs. 8% in NAIA group; p<0.0001) and face swelling (42% and 32% respectively; p=0.01). Anaphylaxis and shock on presentation was much more common in the NAIA group (p<0.0001). Patients with AAIA required intubation significantly more frequently (19.8% vs 12.2%; p=0.03) and had a higher likelihood of difficult intubation (50.8% vs 40.4%; p=0.04). One-third of patients who required intubation in the AAIA group required nasotracheal intubation (NAIA, 16%; p=0.02). Patients with AAIA were intubated by Otolaryngology much more frequently as compared to NAIA (30% vs 9%; p=0.002). Rates of emergency cricothyroidotomy and semi elective tracheostomy were similar in both groups. Extubation failure rates were also similar, with approximately 8% failing extubation once and 2.4% failing twice. In multivariate analysis, patients with AAIA were more likely to be African American (OR 3; p=0.007), currently smoke (OR 1.5; p=0.021), and have lip swelling (OR 2.5; p=0.017). They were less likely to have rash (OR 0.089; p=0.0001) and anaphylaxis (OR 0.032; p=0.016). Airway complications occurred more commonly in patients suffering from AAIA. This population is more likely to need intubation, be difficult to intubate, and require advanced airway techniques such as nasotracheal intubation.