Vocal Cord Dysfunction Induced by Methacholine Challenge Testing

摘要: Study objectives To determine whether methacholine challenge testing (MCT) provokes vocal cord dysfunction (VCD), as evidenced by inspiratory closure on direct laryngoscopy, and spirometry flow-volume loops (FVLs) demonstrate any changes that are suggestive of VCD. Design Prospective, controlled study. Setting Army medical center. Patients Thirty-four subjects all with normal baseline spirometry. Ten had documented evidence VCD, 12 exercise-induced asthma (EIA) reactive MCT, served healthy asymptomatic control subjects. Methods Measurement FVLs laryngoscopy the cords performed immediately before after undergone MCT. Results Evidence adduction was found in four VCD patients. Two patients adducted at baseline, their conditions were unchanged undergoing other demonstrated acute None EIA or groups Truncation limb FVL MCT noted five patients, which correlated 60% these One patient truncation no group. A comparison between without during showed significant differences. Conclusions The findings suggest may cause an episode positive results not reflect underlying airways disease. However, a flattening undergoes is diagnostic for presence adduction.