Snoring

Snoring, sleepiness and sleep apnea
Snoring is a common complaint related to sleep. Almost all patients with obstructive sleep apnea (OSA) snore, but only a small proportion of all snorers have OSA.

Obstructive sleep apnea is a sleep disorder that is characterized by repetitive collapse of the upper airway during sleep. This results in obstructive apneas (temporary cessation of breathing) or hypopneas (overly shallow breathing) which causes intermittent hypoxemia and arousals leading to excessive daytime sleepiness among a multitude of symptoms listed below.

Who develops sleep apnea?
Sleep apnoea is much more common than was previously thought. It is the second most common treatable respiratory illness after asthma. People at risk of suffering from sleep apnea are male, obese and of advancing age.

Obesity remains the strongest risk factor for OSA. In Ireland, there is an alarming lack of awareness of appropriate body size. A person is overweight if their BMI is more than 25, and obese if their BMI is more than 30. The prevalence of OSA in obese patients is as high as 45%. A neck circumference or shirt size greater than 17 inches in a male or 16 inches in a female complements obesity as a risk factor for OSA.

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Craniofacial or upper airway soft tissue abnormalities is an important risk factor which does not fit the stereotypical obese snoring adult. This issue is well characterized in Asian patients who can demonstrate similar OSA severity at lower BMIs due to differences in craniofacial features including shorter cranial base and a more acute cranial base flexure.

Do you have sleep apnea?
Snoring occurs in 95% of patients with obstructive sleep apnea. The snoring is usually accompanied with periods of silence which suggest apneic episodes (temporary cessation of breathing)

Excessive daytime sleepiness and fatigue also suggest OSA. There is a range of screening tools for OSA. A recent meta-analysis confirmed the STOP-BANG questionnaire is preferred in both specificity and sensitivity in detecting OSA to the more traditional Epworth Sleepiness Score and the Berlin Questionnaire.

The following table summarizes the symptoms of OSA
Daytime symptoms Night time symptoms Excessive daytime sleepiness Snoring Fatigue Witnessed apneas (lack of breathing) Asymptomatic but reported by bed partner Gasping/choking at night Morning headache Insomnia Morning dry mouth Nocturia (2 episodes or more per night) Impotence or reduced libido Nocturnal waking

How is obstructive sleep apnea (OSA) diagnosed?
There are 4 different levels of sleep testing. In Type 1 and Type 2, apneas and hypopneas are identified, and the number of events per hour is translated into the apnea-hypopnea index (AHI). Type 3 and 4 sleep testing give you a respiratory disturbance index.

The commonest objective assessment for OSA in Ireland is currently the limited sleep study. This is a Type 3 sleep test using a portable monitor which is usually not attended by a technician. It incorporates at least 3 signals from the patient including respiratory movement (thoracic and abdominal movements), oro-nasal airflow, ECG or pulse rate and continuous oxygen saturation. A popular example in Ireland includes the Phillips’ Stardust monitor. Most systems available also include relevant variables like body position and event monitors.

An attended inpatient sleep laboratory polysomnography (PSG) or attended inpatient sleep study is the gold standard for diagnosis of OSA (Type 1 sleep test). The PSG is commonly performed as an unattended study (Type 2 sleep test). A PSG incorporates the minimum 3 signals above along with monitoring EEG (electroencephalography), EOG (electrooculography), and EMG (electromyography).

What is the limitations of a limited sleep study compared to a polysomnogram?
A limited sleep study is valuable in diagnosing suspected OSA in patients with a high pre-test probability of having moderate to severe OSA. Patients should not have comorbid medical or suspected sleep disorders. Comorbid medical conditions include COPD patients with heart failure which predisposes patients to central sleep apnea and patients with hypoventilation syndromes. Patients at risk of suspected sleep disorders like narcolepsy, parasomnias, periodic limb movement disorder should be referred for a PSG.
Limited sleep studies do not detect arousals from sleep because of lack of EEG monitoring. Hence a limited sleep study cannot detect sleep time or detect respiratory effort related arousals. This may lead to an underestimation of the respiratory disturbance or projected AHI.

Pulse oximetry or a Type 4 sleep test should not be used alone for the diagnosis of OSA.

Driving and OSA
Road traffic accidents are 10 times more common in patients with OSA. Patients with diagnosed OSA must notify the National Driver License Service (NDLS).
The Road Safety Authority guidelines in Ireland state that driving must cease until satisfactory control of symptoms have been attained with ongoing compliance with CPAP treatment confirmed by a respiratory specialist.
Periodic medical review will suffice every 1 to 3 years depending on the NDLS.

Current available treatment for OSA.

CPAP
Continuous positive airway pressure (CPAP) given via a nasal mask is the current treatment of choice for OSA. This works by providing pneumatic splinting of the upper airways overcoming the repetitive collapse of the upper airway during sleep. CPAP has been shown to resolve OSA, reduce excessive daytime sleepiness and improve quality of life.
Treatment is initiated using auto titrating CPAP. This machine sucks air from the bedroom. It blows the air, under pressure down the nose, through a small mask that is worn over the nose.

Weight loss and other lifestyle modifications
Losing weight is key. A 1% reduction in weight can lead to a 3% improvement in OSA. Furthermore, the combination of weight loss and CPAP is more effective than either therapy alone. Bariatric surgery is an acceptable option in achieving weight loss when diet and exercise has not been completely successful. Alcohol and other sedating medications should be avoided.

Oral appliances
Patients who are CPAP intolerant or prefer an alternative treatment to CPAP should be referred to the Dublin Dental Hospital or a dentist preferably trained in dental sleep medicine for a mandibular advancement device (MAD). Customized patient-specific oral appliances are more efficacious to wholesale non-customizable devices.
Oral appliances or MAD are efficacious in reducing a patient’s AHI but are inferior to CPAP therapy.

Positional modification techniques
Positional modification techniques work best for patients with supine OSA. Supine OSA is classified as total AHI occurring at twice the frequency in the supine compared to the non-supine sleeping positions. While positional techniques like vibratory vests, foam backpacks or tennis balls can improve supine OSA, CPAP remains the most effective treatment.

Surgical techniques
There has been no clear evidence to support surgical treatment in patients with OSA. Referral to an ENT or maxillofacial surgeon can be suggested if there are severe, surgically correctable obstructing lesions of the upper airway like tonsillar hypertrophy, adenoid hypertrophy or craniofacial abnormalities.
Currently surgery should be reserved for patients who cannot tolerate CPAP therapy or as an adjunct to CPAP therapy.

How to make the CPAP machine work for the patient.
A multidisciplinary method is important to making CPAP therapy work.
Patients should be encouraged to allow time for CPAP acclimatization. A good relationship with the CPAP device provider can allow technical adjustments including mask/headgear adjustment or noise issues to be resolved. CPAP ramp time can be modified to reduce awakenings. A humidifier is an option for nasal dryness. CPAP devices can be placed on the floor under the bed.

Treatment of nasal obstruction with topical nasal steroids has been shown to improve sleep apnea and improve CPAP compliance.

Among reasons for CPAP nonadherence; device effectiveness, transportability, embarrassment and cost were further highlighted as important considerations for OSA sufferers.

Sleep initiation insomnia and late insomnia has been linked with CPAP failure. The following current ideas when coupled with pharmacotherapy can help reduce early and late insomnia leading to higher likelihood of CPAP success.

Finally, with the explosion of smartphones, it is important to empower patients with web-based or app-based access to their personalized CPAP therapy data. Patient access to their own progress from initiation of CPAP therapy will help motivate them during the acclimatization phase.

Current ideas to improve sleep, reduce snoring
Sleep hygiene incorporates lifestyle changes that can improve your sleep quality without unnecessary pharmacotherapy. Simple changes like not drinking tea (approx. 11mg caffeine per cup) or coffee (40mg caffeine per cup) in the evening can help.

Stimulus control is a validated technique where patients do not go to bed till there are sleepy. If they do not fall asleep within 20 minutes, they should leave the bedroom and indulge in non-stimulating and relaxing activities till they are sufficiently sleepy when they should reattempt falling asleep in their bedroom. Regardless of time they eventually fall asleep, patient should wake up at the same time each morning including the weekends.

In patients with residual sleepiness despite more than 6 hours CPAP use nightly, there is evidence that modafinil and armodafinil can improve alertness and reduce daytime sleepiness.

The future for OSA
The future is bright for OSA with much research going into modifying the pathophysiology behind obstructive sleep apnea.

Hypoglossal nerve stimulation, desipramine and upper airway muscle training has been shown to improve the reduction in dilator muscles seen in affected individuals during sleep in small studies. Desipramine increases genioglossus muscle ( a tongue muscle) activity during sleep.

Supplementary oxygen and acetazolamide also play a theoretical role in reducing instability in nocturnal ventilation.

Over the counter nasal dilators (NoZovent and Breathe Right Strips) have not been shown to improve OSA despite improving nocturnal nasal breathing.

Note none of these emerging therapies above are more efficacious than CPAP therapy in unselected OSA patients. The idea is it can act as an adjunct to CPAP or very carefully phenotyped patients.

There is little published evidence behind most herbal products including chamomile and valerian and melatonin as sleeping aids.