Measurement of Critical Closing Pressure (Pcrit) During Drug-Induced Sleep Endoscopy (DISE)

Study Overview
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Brief Summary
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This study intends to test the feasibility of measurement of the critical closing pressure (Pcrit) during drug-induced sleep endoscopy (DISE) for use in future studies, which are aimed at finding an alternative method for patient selection and response prediction before implementation of non-CPAP therapies.Twenty patients diagnosed with OSA and eligible for non-CPAP treatments are going to be included into this study and undergo these measurements. Drug-induced sleep endoscopy (DISE) is part of the standard clinical care for OSA patients that are eligible for non-CPAP therapies. We aim to expand this procedure with measurement of Pcrit, oesophageal pressure, airflow, EEG, EOG, respiratory effort, SpO2 and chin EMG during this study.

Detailed Description
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Patients from the ENT department will be recruited and informed about the study. After obtaining informed consent, the patients will undergo DISE according to the normal clinical care.The study will be performed during this clinical DISE, using a standard polysomnographic set-up (Alice 6 LDx, Philips Respironics) expanded with pressure and flow measurements. After measurements and evaluations are done, the most suitable treatment option based on the DISE and PSG findings, as defined in the standard clinical care, will be advised to the patient. The treatment and its further choice are not part of the current study protocol.

Official Title
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Measurement of Critical Closing Pressure (Pcrit) During Drug-Induced Sleep Endoscopy (DISE)

Conditions
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Obstructive Sleep Apnea

Intervention / Treatment
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* Diagnostic Test: Drug induced sleep endoscopy
* Diagnostic Test: Measurement of critical closing pressure of the uppper airway


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Diagnosis with OSA (AHI ≥15/hour sleep) Eligible for DISE as the next step in the clinical path for OSA. Capable of giving informed consent Exclusion Criteria: Medication use related to sleeping disorders. Central sleep apnea syndrome. Medical history of known causes of tiredness or severe sleep disruption other than OSA (insomnia, PLMS, Narcolepsy). Seizure disorder. Known medical history of intellectual disability, memory disorders or current psychiatric disorders (psychotic illness, major depression, or acute anxiety attacks as mentioned by the patient). Inability to provide informed consent. Simultaneous use of other treatment modalities to treat OSA Esophageal ulceration, tumors, diverticulitis, bleeding varices, sinusitis, epistaxis, recent nasopharyngeal surgery Pregnancy or willing to become pregnant Excessive alcohol or drug use (> 20 alcohol units/week or any use of hard drugs)

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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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| OSA Pcrit-DISE<br>Patients diagnosed with OSA and eligible for non-CPAP treatments | Diagnostic Test: Drug induced sleep endoscopy<br>* DISE is performed in a semi-dark, silent operating theatre, starting with the patient in supine position. To first induce sleep, an IV bolus of midazolam (1.5 mg) is administered. Then, a flexible fiberoptic nasopharyngoscope (Olympus END-GP, 3.7 mm diameter, Olympus Europe GmbH, Hamburg, Germany) is inserted through one of the nostrils. Either at the start of the examination or while holding the scope at the level of the palate, propofol (2.0-3.0 µg/ml) will be administered via a target-controlled infusion (TCI) pump. Sleep occurrence is confirmed using the additional EEG measurement.<br>* Other names: DISE;Diagnostic Test: Measurement of critical closing pressure of the uppper airway<br>* After sleep onset, the CPAP pressure well be increased until no flow limitations are observed. This pressure is called the holding pressure and is used as a base for all the following measurements for that individual OSA patient. After observing sleep stage 2 or 3, the holding pressure is reduced abruptly by 1 cmH2O during expiration for 5 breaths. Then the pressure is set back to the holding pressure for the duration of 1 minute. This procedure is repeated until obstructive sleep apnea is noted.<br>* Other names: Pcrit measurement;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Critical closing pressure of the upper airway (Pcrit) | The pressure at which the upper airway collpases measured in cm H2O. | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Airflow | By using a pneumotachometer attached to a transducer the inspiratory and expiratory airflow (l/s) will be measured. | 1 hour | 
| EEG | Using electroencephalogram electrodes C3, C4, O1, F4 to evaluate sleep and wake stages and ground and system reference electrodes (volt) | 1 hour | 
| Esophageal pressure | The pressure of the esophagus measured in cmH2O using an esophageal ballooon catheter. | 1 hour | 
| SpO2 | using a pulse oximetry device, to non-invasively measure arterial oxygen saturation level (%). | 1 hour | 
| EMG | Using electromyogram electrodes to evaluate muscular activity (volt) | 1 hour | 
| EOG | electrooculogram electrodes to evaluate rapid eye movements (volt) | 1 hour |