Treatment of Sleep Apnea

Whom to Treat
There is evidence obtained from robust randomized controlled trials (RCT) that treatment improves symptoms, sleepiness, driving, cognition, mood, quality of life, and blood pressure in patients who have an Epworth score of >11, troublesome sleepiness while driving or working, and >15 apneas + hypopneas per hour of sleep. For those with similar degrees of sleepiness and 5–15 events per hour of sleep, RCTs indicate improvements in symptoms, including subjective sleepiness, with less strong evidence indicating gains in cognition and quality of life. There is no evidence of blood pressure improvements in this group, nor is there is evidence that treating nonsleepy subjects improves their symptoms, function, or blood pressure. Thus, treatment cannot be advocated for this large group.

How to Treat
All patients diagnosed with OSAHS should have the condition and its significance explained to them and to their partner. This should be accompanied by provision of written and/or web-based information and a discussion of the implications of the local regulations for driving. Rectifiable predispositions should be discussed; this often includes weight loss and sometimes reduction of alcohol consumption to reduce caloric intake and because alcohol acutely decreases upper-airway dilating muscle tone, thus predisposing to obstructed breathing. Sedative drugs, which also affect airway tone, should be carefully withdrawn.

Continuous Positive Airway Pressure (CPAP)
CPAP therapy works by blowing the airway open during sleep, usually with pressures of 5–20 cmHg. CPAP has been shown in randomized placebo-controlled trials to improve breathing during sleep, sleep quality, sleepiness, blood pressure, vigilance, cognition, and driving ability, as well as mood and quality of life in patients with OSAHS. However, this is obtrusive therapy, and care must be taken to explain the need for the treatment to the patient and his/her partner, and to support all patients on CPAP intensively, providing access to telephone support and regular follow-up. Initiation should include finding the most comfortable mask from the ranges of several manufacturers and trying the system for at least 30 min during the daytime to prepare for the overnight trial. An overnight monitored trial of CPAP is used to identify the pressure required to keep the patient's airway patent. The development of pressure-varying CPAP machines may make the in-lab CPAP night trial unnecessary, but treatment must be initiated in a supportive environment. Thereafter, patients can be treated with fixed-pressure CPAP machines set at the determined pressure or by a self-adjusting, intelligent CPAP device. The main side effect of CPAP is airway drying, which can be countered using an integral heated humidifier. CPAP use, like that of all therapies, is imperfect, but around 94% of patients with severe OSAHS are still using their therapy after 5 years on objective monitoring.

Mandibular Repositioning Splint (MRS)
Also called oral devices, MRSs work by holding the lower jaw and the tongue forward, thereby widening the pharyngeal airway. MRSs have been shown in RCTs to improve OSAHS patients' breathing during sleep, daytime somnolence, and blood pressure. As there are many devices of differing design with unknown relative efficacy, these results cannot be generalized to all MRSs. Self-reports of the use of devices long-term suggest high dropout rates.

Surgery
Four forms of surgery have a role in OSAHS, although it must always be remembered that these patients have a raised perioperative risk. Bariatric surgery can be curative in the morbidly obese. Tonsillectomy can be highly effective in children but rarely in adults. Tracheostomy is curative but rarely used because of the associated morbidity; nevertheless, it should not be overlooked in extremely advanced cases. Jaw advancement surgery—particularly maxillo-mandibular osteotomy—is effective in those with retrognathia (posterior displacement of the mandible) and should be particularly considered in young and thin patients. There is no robust evidence that pharyngeal surgery, including uvulopalatopharyngoplasty (whether by scalpel, laser, or thermal techniques) helps OSAHS.

Drugs
Unfortunately, no drugs are clinically useful in the prevention or reduction of apneas and hypopneas. A marginal improvement in sleepiness in patients who remain sleepy despite CPAP can be produced by modafinil, but the clinical value is debatable and the financial cost significant.

Choice of Treatment
CPAP and MRS are the two most widely used and best evidence-based therapies. Direct comparisons in RCTs indicate better outcomes with CPAP in terms of apneas and hypopneas, nocturnal oxygenation, symptoms, quality of life, mood, and vigilance. Adherence to CPAP is generally better than to an MRS, and there is evidence that CPAP improves driving, whereas there are no such data on MRSs, Thus, CPAP is the current treatment of choice. However, MRSs are evidence-based second-line therapy in those who fail CPAP. In younger, thinner patients, maxillo-mandibular advancement should be considered.