Nasopharyngolaryngoscopy as a Triage Tool for Airway Compromise in Angioedema: A Retrospective Cohort Study

Background Airway compromise and respiratory failure are feared complications of angioedema leading to intensive care unit (ICU) admission. However, few of these patients decompensate. There is a paucity of tools that predict airway compromise in patients with angioedema, and it is unclear if automatic triage to the ICU is warranted. We analyzed patients admitted to our tertiary center ICU with angioedema for "airway watch" to find a way to triage those at greatest risk of respiratory decompensation. Methods We performed a retrospective review of patients with angioedema admitted to our ICU between 2017 and 2020. Data collected included demographics, comorbidities, nasopharyngolaryngoscopy (NPL) findings, need for intubation, and length of stay. Descriptive analysis and subsequent ANOVA or T-test statistical analysis was performed to determine the relationships between individual variables and outcomes. Categorical variables were compared using Pearson's Chi-squared test or Fisher's exact test where applicable. Continuous variables were compared using a Mann-Whitney U test. Results Of 134 patients admitted to our ICU, 63 (47%) required intubation, primarily in the emergency department (92.1%). Of those who required intubation, 61.9% had abnormal NPL findings in contrast to 25.35% of patients who did not require intubation (p<0.0001). Normal NPL findings had a negative predictive value for requiring intubation of 86.5%. Abnormal NPL findings had a positive predictive value for requiring intubation of 68.4%. Conclusion While airway compromise is a serious complication of angioedema, there is scant evidence to support triage to the ICU for those not intubated immediately. The majority of patients with angioedema who required intubation had abnormal NPL findings, and the majority of those with normal NPL findings did not require intubation. This suggests that NPL findings in patients with angioedema can help with triage to the ICU.