Diagnosis of laryngotracheal stenosis from routine pulmonary physiology using the expiratory disproportion index

Abstract

EDI can reliably diagnose LTS using routine lung function data. Its simplicity and clinical utility, first recognized by Duncan Empey, are underpinned by a unique physiology whereby PEFR, being determined by total tracheobronchial tree resistance, falls disproportionately compared with FEV1 , which is determined within small intrathoracic airways. EDI provides valuable information about the presence and extent of LTS particularly in nonspecialist clinical settings and its routine inclusion within standard lung function reports could prevent the prolonged morbidity and mortality that currently result from missed and delayed diagnoses.