Vocal cord dysfunction (VCD) in hospitalised exacerbations of asthma and chronic obstructive pulmonary disease (COPD)

Abstract

Introduction: Vocal cord dysfunction (VCD) causes vocal cord narrowing during inspiration resulting in airflow obstruction and breathlessness. In asthma VCD can be found in up to 20% of stable asthmatics but few studies have examined coexisting VCD in exacerbated asthma and none in COPD. We hypothesised that VCD may occur frequently during acute asthma and COPD exacerbations. Method: Overall 34 patients with asthma exacerbations and 37 patients with exacerbations of COPD were studied in the emergency department (ED). All patients had a previous diagnosis of asthma or COPD confirmed by lung function. Asthma chronic disease severity was based on GINA and exacerbation severity based on a validated score. COPD chronic disease severity was based on GOLD criteria and exacerbation severity was based on BAP-65. Dynamic computerised tomography (CT) imaging was done as soon as possible after ED admission and VCD was diagnosed using 320-slice CT of the larynx. Results: In the overall group (n=71) VCD was detected in 20 cases (28%). Patients with COPD had VCD more often (14/37, 37.8%) than asthmatics (6/34, 17.6%, p=0.03). There were no associations between asthma or COPD, acute disease severity and presence of VCD. Patients with COPD had more VCD if they had severe/very severe chronic COPD (10/14, 71%) as opposed to mild/moderate (4/14, 31%). Conclusion: Surprisingly VCD was more frequently detected in COPD than in asthma. VCD should be considered a contributing factor during exacerbations of both diseases. Further studies are needed to determine how much VCD contributes to acute symptoms and to examine effective treatments for VCD in these clinical contexts.