In people with stable<unk> , the most important treatment is weight loss—by diet, through exercise, with medication, or sometimes weight loss surgery (bariatric surgery). This has been shown to improve the symptoms of<unk>  and resolution of the high carbon dioxide levels. Weight loss may take a long time and is not always successful. If the symptoms are significant, nighttime positive airway pressure (PAP) treatment is tried; this involves the use of a machine to assist with breathing. PAP exists in various forms, and the ideal strategy is uncertain. Some medications have been tried to stimulate breathing or correct underlying abnormalities; their benefit is again uncertain. While many people with<unk>  are cared for on an outpatient basis, some deteriorate suddenly and when admitted to the hospital may show severe abnormalities such as markedly deranged blood acidity (pH<7.25) or depressed level of consciousness due to very high carbon dioxide levels. On occasions, admission to an intensive care unit with intubation and mechanical ventilation is necessary. Otherwise, "bi-level" positive airway pressure (see the next section) is commonly used to stabilize the patient, followed by conventional treatment. Positive airway pressure Positive airway pressure, initially in the form of continuous positive airway pressure (CPAP), is a useful treatment for<unk> , particularly when obstructive sleep apnea coexists. CPAP requires the use during sleep of a machine that delivers a continuous positive pressure to the airways and preventing the collapse of soft tissues in the throat during breathing; it is administered through a mask on either the mouth and nose together or if that is not tolerated on the nose only (nasal CPAP). This relieves the features of obstructive sleep apnea and is often sufficient to remove the resultant accumulation of carbon dioxide. The pressure is increased until the obstructive symptoms (snoring and periods of apnea) have disappeared. CPAP alone is effective in more than 50% of people with<unk> . In some occasions, the oxygen levels are persistently too low (oxygen saturations below 90%). In that case, the<unk>  itself may be improved by switching from CPAP treatment to an alternate device that delivers "bi-level" positive pressure: higher pressure during inspiration (breathing in) and a lower pressure during expiration (breathing out). If this too is ineffective in increasing oxygen levels, the addition of oxygen therapy may be necessary. As a last resort, tracheostomy may be necessary; this involves making a surgical opening in the trachea to bypass<unk> -related airway obstruction in the neck. This may be combined with mechanical ventilation with an assisted breathing device through the opening. Other treatments People who fail first-line treatments or have very severe, life-threatening disease may sometimes be treated with tracheotomy, which is a reversible procedure. Treatments without proven benefit, and concern for harm, include oxygen alone or respiratory stimulant medications. Medroxyprogesterone acetate, a progestin, and acetazolamide are both associated with an increased risk of thrombosis and are not recommended.
Obesity hypoventilation syndrome
Central hypoventilation syndrome
Hyperventilation syndrome
Upper airway resistance syndrome
Reactive airway disease
Sleep apnea
Cardiac asthma
Central sleep apnea