Impact of unilateral vocal fold mobility impairment on laryngopulmonary physiology

Objective: To examine the impact of unilateral vocal fold mobility impairment (UVFMI) on airway physiology.

Study design: Cross-sectional observational study.

Participants: There were 21 patients with UVFMI and 53 controls.

Main outcome measures: All patients and patient controls underwent a maximum-effort flow-volume loop examination. Forced expiratory flow in one second (FEV1 ), forced expiratory volume (FVC), peak inspiratory flow rate and peak expiratory flow rate (PIFR and PEFR, respectively) and area under the inspiratory and expiratory flow-volume loops (AUCI nspiratory and AUCE xpiratory, respectively) were measured. The ratio of PEFR to PIFR and AUCE xpiratory to AUCI nspiratory was derived.

Results: There were 48 males and 26 females. Mean age at measurement was 39 ± 11 years. Patients and controls were matched for age, sex, height and weight. None of the expiratory variables were significantly different between the groups. PIFR was significantly lower in UVFMI patients compared with controls (3.4 ± 1.2 versus 5.3 ± 1.8; P < 0.0001), as was AUCI nspiratory (11.5 ± 6.3 versus 17.5 ± 8.5; P = 0.0002). PEFR/PIFR provided the best differentiation between patients with UVFMI and controls with an area under the Receiver Operating Characteristic (ROC) curve of 0.96 and at a threshold of 1.9, and PEFR/PIFR had sensitivity and specificity of 95.2% and 90.6%, respectively.

Conclusions: Flow-volume loops are a non-invasive method of studying vocal abduction and could compliment voice assessment and laryngoscopy in UVFMI. With further research, they could provide an outcome measure for laryngeal rehabilitative procedures, and a shared physiological language for screening and surgical quality assurance.