#Horizon Lt 8001 Manual plus#

Sleep assessment: Overnight diagnostic polysomnography(PSG) will be performed at PWH for every subject on the first night recording electroencephalogram, electro-oculogram, submental electromyogram, bilateral anterior tibial electromyogram, electrocardiogram, chest and abdominal wall movement by inductance plethysmography, airflow measured by a nasal pressure transducer and supplemented by oronasal airflow thermister, and finger pulse oximetry as in our previous studies.2,3 Sleep stages will be scored according to standard criteria by Rechtshaffen and Kales.4 Apnoea is defined as cessation of airflow for > 10 seconds and hypopnea as a reduction of airflow of  50% for > 10 seconds plus an oxygen desaturation of > 3% or an arousal.Īmbulatory Blood Pressure Monitoring (ABPM):Īll patients with OSAS will be fitted with the Ultralite ABPM (Spacelabs Medical, Redmond, WA) via an arm cuff as out-patients during normal activities and monitored for 48 hrs prior to commencement of CPAP or conservative treatment. Subjects and Methods: We propose to carry out a prospective, randomized controlled study on 100 consecutive patients newly diagnosed with OSAS, as defined by overnight sleep study showing Apnoea- hypopnoea index (AHI) ≥ 5 per hour of sleep plus Epworth sleepiness scale (ESS) ≥10.1 The patients will be recruited from the Respiratory Clinic, Prince of Wales Hospital (PWH), Shatin. This randomized controlled study aims to assess the long-term effects of nasal CPAP on 1) 24 hr systemic BP 2) Coagulation state and 3) Carotid artery IMT.Īims: This study aims to assess the long-term effects of nasal CPAP on patients with OSAS with reference to: 1) 24 hr systemic mean BP 2) Coagulation state and 3) Carotid artery intima-media thickness. Recently, carotid artery IMT has been shown to have positive correlations with the severity of SDB.ĭespite robust evidence showing improvement of symptoms, cognitive function and quality of life in patients with OSA treated with nasal CPAP, there are conflicting short-term data whether CPAP can reduce BP in patients with OSA. Common carotid artery intima-media thickness (IMT) has been shown to correlate with traditional vascular risk factors and may predict the likelihood of acute coronary events and stroke. Numerous studies have found a hypercoagulable state in terms of increased clotting factor and platelet activities, and impaired fibrinolysis in coronary artery disease, ischaemic stroke, and SDB. The increased levels of muscle sympathetic nerve activity are diminished by nasal continuous positive airway pressure (CPAP) therapy. The mechanisms for the linkage between SDB and cardiovascular diseases are not fully determined but surges in sympathetic nerve activity are seen at the end of each apnoeic episode accompanied by large rises in systemic arterial blood pressure (BP). Several major epidemiological studies have shown that SDB is not only an independent risk factor for systemic hypertension but it is also associated with cardiovascular complications such as heart failure, stroke, and sudden death.

SDB affects 9 to 24% of the middle-aged and overall 4% of the middle-aged males suffers from Obstructive sleep apnoea syndrome (OSAS) i.e. Sleep-disordered breathing (SDB) briefly means cessation of breathing during sleep at least 5 times per hour.

Horizon Lt 8001 Manual