Accuracy of the Sensory Test Using the Laryngopharyngeal Endoscopic Esthesiometer in Obstructive Sleep Apnea

Study Overview
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Brief Summary
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This is a prospective double blinded randomized crossover controlled trial aiming at validating the measurement of laryngopharyngeal mechanosensitivity in patients with suspected OSA using a recently developed laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER). Subjects will be recruited from patients with suspected OSA referred for baseline polysomnography to a university hospital sleep laboratory. Intra- and inter-rater reliability will be evaluated using the Bland-Altman's limits of agreement plot, the intraclass correlation coefficient, and the Pearson or Spearman correlation coefficient, depending on the distribution of the variables. Diagnostic accuracy will be evaluate plotting Receiver-operating-characteristic-curves (ROC-curves) using as reference standard basal polysomnogram. The sensory threshold values for patients with mild, moderate, and severe OSA, will be determined and compared using ANOVA or Kruskal Wallis test, depending on the distribution of the variables.

Detailed Description
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INTRODUCTION: Obstructive sleep apnea-hypopnea syndrome (OSA) patients might have varying degrees of laryngopharyngeal mechanical hyposensitivity; however, these findings come from studies performed with methods having weak inter-rater reliability and accuracy evidence. The purpose of this study is to validate the measurement of laryngopharyngeal mechanosensitivity in patients with OSA using a recently developed laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER). The LPEER includes an air-pulse generator and an endoscopic laser rangefinder and works coupled to a conventional fiberoptic endoscope. This device generates air-pulses ranging from 0.04 mN to 16.5 mN in order to cover a wide range of laryngopharyngeal reflexes and sensory thresholds. Depending on the reflex or sensory threshold to be explored the LPEER is configured to deliver a sequence of 10 air-pulses of different intensity. METHODS: The study will be prospective, double blinded, and with a randomized and crossover assignment of the raters. Subjects will be recruited from patients with suspected OSA referred for baseline polysomnography to a sleep laboratory of a tertiary care university hospital. They will undergo a laryngopharyngeal sensory test using the LPEER, which includes measurement of the thresholds for the velopharyngeal, hypopharyngeal and aryepiglottic fold psychophysical sensitivity. Intra- and inter-rater reliability will be evaluated using the Bland-Altman's limits of agreement plot, the intraclass correlation coefficient, and the Pearson or Spearman correlation coefficient, depending on the distribution of the variables. Diagnostic accuracy will be evaluate plotting ROC-curves using as reference standard basal polysomnogram. The sensory threshold values for patients with mild, moderate, and severe OSA, will be determined and compared using ANOVA or Kruskal Wallis test, depending on the distribution of the variables.The discriminative capacity as well as correlations between laryngopharyngeal sensory thresholds and OSA severity indexes will be explored in subgroups of subjects with normal and abnormal sensation. The relationship between sensory thresholds and OSA severity indexes will be explored by linear equations as well as by second- and higher-order polynomial equations. The laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER), could be a new tool for the evaluation and monitoring of laryngopharyngeal sensory involvement in patients with OSA, which, if proved valid, could help to increase the knowledge about the pathophysiological mechanisms of this condition and potentially help finding new therapeutic interventions for OSA. ETHICS: This study will follow the Declaration of Helsinki principles and national legal regulations about research in human subjects. The protocol was approved by the Institutional Review Board of Fundacion Neumologica Colombiana and all recruited subjects will provided a signed informed consent. DISSEMINATION: The results will be disseminated through conference presentations and peer-reviewed publication.

Official Title
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Accuracy of the Sensory Test Performed Using the Laryngopharyngeal Endoscopic Esthesiometer and Rangefinder in Patients With Suspected Obstructive Sleep Apnoea Hypopnea (OSA): a Prospective Double-blinded, Randomised, Pilot Study

Conditions
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Larynx, Sleep Apnea, Obstructive, Sensory Disorder

Intervention / Treatment
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* Other: Laryngopharyngeal sensory test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients being 18 years old or more referred to the sleep laboratory of a tertiary care university hospital for a baseline polysomnography for suspected OSA. Exclusion Criteria: Anticoagulation (though not a contraindication for the endoscopic laryngopharyngeal sensory test, anticoagulation is an exclusion criteria for this validation study in order to keep it a minimal-risk study). Bleeding diathesis. Basal awake oxygen saturation by pulse oximetry below 88%. Not agree to participate in the study. Glasgow coma scale below of 15 (to avoid confusion with involvement of laryngopharyngeal reflexes due to neurological disease accompanied by decreased level of consciousness). Baseline polysomnography that does not meet validity criteria to be interpreted (according to the American Academy of Sleep Medicine). Baseline polysomnography performed more than 15 days before the sensory testing. Ordinarily, the sensory testing will be performed the same day or the next day of baseline polysomnography. More than 5% of total apnoea events being of central origin. History of maxillofacial or pharyngeal surgery (to avoid confusion with involvement of laryngopharyngeal reflexes due to surgery in this region). Laryngopharyngeal tract malignancies (to avoid confusion with involvement of laryngopharyngeal reflexes due to tumours). Central Nervous System (CNS) surgery in the last three months or that has left neurological sequelae (to avoid confusion with involvement of laryngopharyngeal reflexes due to sequelae of CNS surgery). Traumatic brain injury in the last three months or more than three month with neurological sequelae. History of active neuromuscular disease that affects the muscles of head and neck or with sequels present at the time of the sensory testing (to avoid confusion with involvement of laryngopharyngeal reflexes due to neuromuscular disease). History of cerebrovascular disease (to avoid confusion with dysphagia or sensory compromise secondary to cerebrovascular disease). Diabetes (to avoid confusion with diabetic neuropathy that compromises the laryngopharyngeal region). Chronic use of systemic corticosteroids at a dose greater or equal to 20 mg per day of prednisone or equivalent (to avoid confusion with steroid myopathy that compromises the laryngopharyngeal region). Upper respiratory tract infection within 15 days prior to the testing (to avoid confusion with neuropathy associated with respiratory viral disease that compromises the laryngopharyngeal region). Patient's inability to cooperate during the examination (to avoid measurement error caused by the lack of cooperation of the patient).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Subjects participating in the inter-rater reliability evaluation will be evaluated by two raters, an expert and a non-expert rater, each rater performing two measurements of laryngopharyngeal sensory thresholds (ST) two times at each side (right and left) of the corresponding laryngopharyngeal structure. All other subjects, participating in the accuracy evaluation, will be evaluated by only one expert rater who will perform three measurements of laryngopharyngeal ST per subject. The varying degrees of rater experience aims to reproduce common scenarios when a new technique (like the measurement of laryngopharyngeal mechanosensitivity) is introduced to clinical practice. The two raters will measure the ST sequentially and in a randomized cross-over design in each subject (the order in which each rater intervenes will be randomized) aiming that the sensory tests be started an equal number of times by an expert rater and non-expert rater.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Expert rater<br>Pulmonologist or Otolaryngologist with experience in laryngopharyngeal sensory evaluation: who has made more than 50 laryngopharyngeal sensory tests. | Other: Laryngopharyngeal sensory test<br>* The sensory measurements will include thresholds for psychophysical sensory thresholds at the velopharynx, hypopharynx and aryepiglottic folds<br>|
| Other: Non-expert rater<br>Pulmonologist or Otolaryngologist inexperienced in laryngopharyngeal sensory evaluation: who has made minimum 5 and maximum 50 laryngopharyngeal sensory tests. Pulmonologist fellow who has completed the training provided for a Pulmonologist Fellow in bronchoscopy and who has performed minimum 5 and maximum 50 laryngopharyngeal sensory testing. | Other: Laryngopharyngeal sensory test<br>* The sensory measurements will include thresholds for psychophysical sensory thresholds at the velopharynx, hypopharynx and aryepiglottic folds<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Velopharynx psychophysical sensory threshold | Sensitivity threshold at the velopharynx in millinewtons (mN). | 15 days | 
| Hypopharynx psychophysical sensory threshold | Sensitivity threshold at the hypopharynx in millinewtons (mN). | 15 days | 
| Aryepiglottic fold psychophysical sensory threshold | Sensitivity threshold at the aryepiglottic folds in millinewtons (mN). | 15 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Apnea Hypopnea Index | Number of apneas and hypopneas per hour reported in polysomnography, according to the American Academy of Sleep Medicine criteria. | 15 days | 
| Oxygen desaturation index | Number of desaturation episodes by pulse oximetry (SpO2%) (>3% fall in SpO2%) per hour reported in polysomnography, according to the American Academy of Sleep Medicine criteria. | 15 days | 
| T90 | Time spent at oxygen saturation below 90% by pulse oximetry | 15 days | 
| Adverse Events | Any adverse event potentially related to the laryngopharyngeal sensory test, including pain, gagging, discomfort, laryngospasm, syncope or pre-syncope, epistaxis, need for observation or referral to emergency room or hospitalization. | 15 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Endoscopy, Lasers, Fiber Optic Technology, Bronchoscopy, Esthesiometer, Mechanoreceptors, Diagnosis, Reflex, Reproducibility of Results, Reliability of Results, Validity of Results, Sensory Thresholds