Impact of unilateral vocal immobility on voice and airway physiology
Research type
Research Study
Full title
The Selective Inspiratory Loading used as Vocal Examination Record (SILVER) study: an investigation of the impact of unilateral vocal fold mobility impairment on voice and airway physiology
IRAS ID
174370
Contact name
Hesham Kaddour
Contact email
Sponsor organisation
Barking Havering and Redbridge NHS Trust
Duration of Study in the UK
1 years, 7 months, 1 days
Research summary
We aim to prospectively study the impact of vocal fold paralysis/immobility on voice and airway physiology through a multi-centred observational study. The larynx is the gateway to the respiratory system and at the same time, it is the sound-source for voice generation. These functions are achieved by vocal adduction (coming together) to create a vibrating "flutter-valve", and pushing apart (abduction) to allow air to get through. The impact of unilateral (one-sided) vocal fold paralysis on voice production has been extensively studied. By contrast, and although the larynx accounts for 25% of the total respiratory resistance, the respiratory manifestations of unilateral vocal fold immobility have been sparsely studied.
We recently published a preliminary study, identifying a pattern of airflow obstruction, manifested in flow-volume loops, that seems highly sensitive and specific for unilateral vocal fold immobility. We aim to validate these findings in a large-scale study of patients with unilateral vocal fold immobility. This will advance our understanding of laryngopulmonary physiology and how voice and airway physiology interact.
Our principal aim however is clinical and is to assess whether non-invasive physiological airway examination (flow-volume loops) can be used for laryngeal functional surveillance: Every year in the UK >12000 patients undergo thyroid and parathyroid surgery, which put the laryngeal nerves at risk. This is the main risk associated with this surgery. Despite this, fewer than 20% of patients have postoperative laryngeal examination. As such, surgical quality-assurance is very patchy and this inconsistency in turn makes vocal weakness rate unsuitable for outcome management at this time. Flow-volume loops are objective, non-invasive, and available in every lung function laboratory. By creating and validating quantitative indices of airway physiology associated with unilateral vocal fold immobility, we intend to investigate the possibility of a "shared" physiological language for outcome assessment and documentation.
REC name
North West - Haydock Research Ethics Committee
REC reference
15/NW/0220
Date of REC Opinion
13 Mar 2015
REC opinion
Favourable Opinion