Morbidly obese patients with obstructive sleep apnoea often results in all except -

Sleep apnea is characterized by paial or complete cessation of breathing during night-time sleep, resulting in repeated arousal from sleep, oxyhemoglobin desaturation, and daytime sleepiness. Apnea is defined as complete cessation of airflow for >10 s (Table I).3 Hypopnea, a paial cessation of airflow, is defined as a 50% to 90% reduction in airflow for >10 s, accompanied by a >3% decrease in oxyhemoglobin saturation (SaO2) and terminated by electroencephalographic arousal.4 The 3 types of apnea are central, obstructive, and mixed. Central sleep apnea (CSA) is characterized by a complete withdrawal of central respiratory drive to the inspiratory muscles, including the diaphragm, and results in the simultaneous absence of naso-oral airflow and thoracoabdominal excursions. In OSA, the thoracic inspiratory muscles, including the diaphragm, are active, so thoracoabdominal excursions are seen. Absence of airflow results from upper-airway occlusion caused by lost pharyngeal dilator muscle tone, with consequent pharyngeal collapse. Mixed apnea has an initial central component followed by an obstructive component. Like apnea, hypopnea can also be obstructive or central. We focus here on obstructive causes. Obstructive sleep apnea is a sleep-related breathing disorder that has a major impact on cardiovascular function. It has been associated with hypeension, coronary aery disease, cardiac arrhythmias, sudden cardiac death, and hea failure. Ref Davidson 23rd edition pg 538