OSA Recurrence in CPAP Withdrawal

Pathophysiology of Obstructive Sleep Apnoea Recurrence During Continuous Positive Airway Pressure Therapy Withdrawal

Continuous positive airway pressure (CPAP) therapy is the most effective Treatment for obstructive sleep apnoea (OSA ). However, adherence to CPAP is often limited. There are established and emerging treatment alternatives to CPAP available, however, they are usually less effective than CPAP. To develop novel treatment methods and to predict who will respond to which treatment, the mechanism underlying obstructive sleep apnoea and different patient types should be described. Especially the contribution of the upper airway function and central respiratory control should be studied for this purpose. In a prospective interventional study, patients with OSA effectively treated with CPAP will undergo physiologic measurements during a two week period off CPAP to define the pathophysiological mechanisms associated with OSA recurrence. This knowledge could facilitate individually tailored treatment and improve therapy adherence and patient outcomes.

Study Overview

• Status: Completed
• Conditions: OSA
• Intervention / Treatment: Other: CPAP withdrawal

Detailed Description

Obstructive sleep apnoea (OSA) is a highly prevalent sleep-related breathing disorder characterised by a repetitive collapse of the pharynx during sleep, which results in apnoea or hypopnoea associated with oxygen desaturations and arousal from sleep. Continuous positive airway pressure (CPAP) is the gold standard treatment. Treatment success depends on regular CPAP usage. However, low adherence to CPAP is a frequent problem. It has recently been shown that OSA does not re-occur immediately in all OSA patients upon CPAP therapy withdrawal and that there are different patterns of recurrence of OSA as indicated by repeated sleep studies. So far, the mechanisms of OSA recurrence upon CPAP therapy withdrawal are incompletely understood. Upper airway collapsibility and neuromuscular tone, pharyngeal oedema and inflammation, neural respiratory drive, sleep stage and position may play a role.

In a prospective interventional study, patients with OSA effectively treated with CPAP will undergo physiologic measurements during a two week period off CPAP to define the pathophysiological mechanisms associated with OSA recurrence. In particular, we will investigate the effects of CPAP withdrawal on neural respiratory drive and upper airway function. Inpatient sleep studies and assessments will be performed at baseline (day 0) on CPAP and at follow-up upon CPAP withdrawal (day 14). At the end of the trial patients will return to their established CPAP therapy.

We hypothesise that CPAP withdrawal results in different patterns of OSA recurrence defined by neural respiratory drive and upper airway function. The aim of the proposed project is to study the mechanisms of OSA recurrence by using a validated CPAP withdrawal model. Knowledge on recurrence patterns and different phenotypes of OSA could facilitate individually tailored treatment of OSA and improved therapy adherence and patient outcomes.

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SE1 7EH
    • Guys and St Thomas Nhs Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion criteria:

• Age ≥18-80 years. Objectively confirmed OSA with an apnoea-hypopnoea- index (AHI) or an oxygen desaturation index (ODI) of ≥20/h at the time of diagnosis (obstructive events).
• Effectively treated with CPAP for > 6 months (AHI on CPAP < 5/h, CPAP usage > 4 hours/night > 70% of the days).

Exclusion criteria:

• Moderate to severe obstructive (FEV1/FVC < lower limit of normal and FEV1 < 70% predicted) or restrictive lung disease (FVC < 60% predicted).
• Daytime pCO2 > 6 kPa (45 mmHg).
• Central Sleep Apnoea/Cheyne Stokes Respiration. Unstable heart failure, untreated coronary artery disease, severe arterial hypertension (resting blood pressure >180/110 mmHg).
• Co-existing non-respiratory sleep disorder (by history).
• Opioid or sedative use. Alcohol abuse.
• Current professional driver or comparable profession.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: DIAGNOSTIC
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: CPAP withdrawal; Short-term withdrawal of CPAP therapy in moderate to severe OSA (intervention)	Other: CPAP withdrawal; Short-term withdrawal of CPAP therapy in moderate to severe OSA

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in neural respiratory drive (NRD) during sleep upon CPAP therapy withdrawal	Electromyography of respiratory muscles as measure of neural respiratory drive	2 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pharyngeal critical occlusion pressure during sleep (Pcrit)	Measures of upper airway collapsibility (cmH2O)	2 weeks
Forced oscillation technique (FOT)	Measure of (upper) airway resistance	2 weeks
Negative expiratory pressure (NEP)	Measure of (upper) airway resistance and collapsibility (cmH2O)	2 weeks
Pharyngeal oedema	Transcervical ultrasound (mm)	2 weeks
Forced expiratory volume in 1 second	Spirometry	2 weeks
Forced vital capacity	Spirometry	2 weeks
Recurrence pattern of OSA defined by the nightly obstructive respiratory events (apnoea-hypopnoea-index)	Polysomnography (events/hour)	2 weeks
Recurrence pattern of OSA defined by the nightly obstructive respiratory events (oxygen desaturation index)	Nightly home pulse oximetry (events/hour)	2 weeks
Home and office blood pressure	Blood pressure (mmHg)	2 weeks
Home and office heart rate	Heart rate (bpm)	2 weeks
Epworth Sleepiness Scale Score (ESS)	Questionnaire for subjective sleepiness (Points)	2 weeks
Fatigue Severity Sclae (FSS)	Questionnaire for subjective sleepiness (Points)	2 weeks
Stanford Sleepiness Scale (SSS)	Questionnaire for subjective sleepiness (Points)	2 weeks
Functional Outcomes of Sleep Questionnaire (FOSQ)	Quality of life questionnaire	2 weeks
Association between ODI (recurrence pattern of OSA) and neural respiratory drive (NRD)	Multivariate Regression modelling with ODI as dependent variable	2 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Association between different measures of (upper) airway function, namely Pcrit, FOT, NEP and FEV1/FVC	Correlation analyses	2 weeks

Collaborators and Investigators

• Sponsor: Guy's and St Thomas' NHS Foundation Trust
• Investigators: Principal Investigator: Joerg Steier, MD Ph, Guy's and St Thomas' NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start (ACTUAL): April 9, 2018
• Primary Completion (ACTUAL): June 30, 2019
• Study Completion (ACTUAL): October 1, 2019

Study Registration Dates

• First Submitted: March 7, 2018
• First Submitted That Met QC Criteria: March 14, 2018
• First Posted (ACTUAL): March 21, 2018

Study Record Updates

• Last Update Posted (ACTUAL): March 15, 2022
• Last Update Submitted That Met QC Criteria: March 14, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: OSA; CPAP; neural respiratory drive; upper airway collapse
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Recurrence
• Other Study ID Numbers: 237921

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No