The Effects of Provent® on Obstructive Sleep Apnea During Continuous Positive Airway Pressure Therapy Withdrawal

Randomised, placebo-controlled trial of Provent® versus Placebo-Provent® versus continuous positive airway pressure therapy (CPAP) to define the effects of Provent® on the severity of obstructive sleep apnea, daytime symptoms as well as on measures of cardiovascular risk in patients with obstructive sleep apnea.

Patients successfully treated with CPAP will be randomised to one of three arms for a duration of 2 weeks:

• Withdraw CPAP and use Provent®
• Withdraw CPAP and use Placebo-Provent®
• Continue treatment with CPAP

Inclusion criteria

• Objectively confirmed obstructive sleep apnoea (at the time of original diagnosis) with an oxygen desaturation index (ODI, >4% dips) of between 10 and 50/h and an ESS of >10 (these thresholds will exclude subjects with borderline and very severe forms of OSA in whom there may be a disproportionate treatment effect).
• Currently >10/h oxygen desaturations (>4% dips) during an ambulatory nocturnal pulse oximetry performed at the end of a 4-night period without CPAP.
• Treated with NCPAP for more than 12 months, minimum compliance 4h per night.
• Current ESS < 10.
• Written informed consent.

Exclusion criteria

• Previous ventilatory failure (awake resting arterial oxygen saturation <93% or arterial PCO2 > 6kPa).
• Unstable, untreated coronary or peripheral artery disease, severe arterial hypertension (>180/110mmHg).
• Previously diagnosed with Cheyne-Stokes breathing.
• Current professional driver.
• Any sleep related accident.
• Age <20 or >75 years at trial entry.
• History of chronic nasal obstruction.
• Mental or physical disability precluding informed consent or compliance with the protocol .
• Non-feasible trial follow-up (for example, distance from follow-up centre, physical inability).