Topic: Respiratory disorders
Conditions
Interventions
Participants will be treated with oxygen or sham (air) whilst off CPAP for 14 days.
Patients are crossed-over, so that they are allocated to either CPAP withdrawal with supplemental ox
Sponsors
University of Oxford
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Objectively confirmed obstructive sleep apnoea (at the time of original diagnosis) with an oxygen desaturation index (ODI, =4% dips) of >20/h or/and an apnoea/ hypopnoea index of >20/h (this threshold will exclude subjects with borderline OSA, in whom there may be little treatment effect). 2. Currently >20/h oxygen desaturations (=4% dips) returning on any night during an ambulatory nocturnal pulse oximetry performed during a 4-night period without CPAP. 3. Treated with CPAP for more than 12 months, minimum compliance 4h per night, AHI <10 with treatment (according to machine download data) and ODI<10 confirmed on CPAP during screening oximetry. 4. Written informed consent 5. Upper Age Limit 75 years, lower Age Limit 20 years
Exclusion criteria
Exclusion criteria: 1. Previous ventilatory failure (awake resting arterial oxygen saturation 6kPa) or severe respiratory disorders other than OSA 2. Unstable, untreated coronary or peripheral artery disease, severe arterial hypertension (>180/110mmHg), severe arterial hypotension (75 years at trial entry. 7. Severe nasal congestion. 8. Mental or physical disability precluding informed consent or compliance with the protocol 9. Nonfeasible trial followup (for example, distance from follow-up centre, physical inability). 10. Current smoker
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Home blood pressure change over 14 days; Timepoint: Home blood pressure measured every morning by the patient | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Home heart rate change over 14 days; Timepoint; home heart rate measured every morning by the patient 2. Change in OSA severity: Timepoint: home sleep study measured before study visits 1, 2, 3, and 4 3. Change in subjective (questionnaire ESS) and objective sleepiness (OSLER test); Timepoint: ESS and OSLER measured at study visits 1,2 3, and 4 4. Change in overnight urinary catecholamine secretion; Timepoint: Overnight urine collection for catecholamines prior to visits 1, 2, 3, and 4 5. Change in gene expression (mRNA and microRNA); Timepoint; Bloods samples at visits 1, 2, 3, and 4 | — |
Countries
United Kingdom
Contacts
Public ContactMagda Laskawiec-Szkonter
Outcome results
None listed