SNORING

SNORING

It is undesirable disturbing sound that occurs during sleep. It is  estimated that 25% of adult females snore. It prevalence increases with age.

Definition of Terms

Sleep apnoea It is  cessation of breathing that last for 10 seconds or more during sleep. Less than five such episodes is normal.

Apnoea index It is number of episodes of apnoea in 1 hour.

Hypopnoea It is reduction of air flow. Some define it as drop of 50% of airflow from the base line associated with an EEG defined arousal or 4% drop in oxygen saturation.

Respiratory disturbance index (RDI) also called apnoea-hypopnoea index. It is the number of apnoea and hypopnoea event per hour. Normally RDI is less than 5. Based on RDI, severity apnoea has been classified as mild, 5-14; moderate, 15-30; and serve > 30

Arousal Transient awakening from sleep as a result of apnoea or respiratory efforts.

Arousal index It is number of arousal events in 1 hour. Less than 4 is normal.

Sleep efficiency Minutes of sleep divided by minutes in bed after lights are turned off.

Multiple sleep latency test Patient undergoes four or five scheduled naps usually in the daytime. Latency period from wakefulness to the onset of sleep and REM sleep are measured. It is performed when narcolepsy is suspected or daytime sleepiness is evaluated objectively.

Mechanism of snoring

Muscles of pharynx are relaxed during sleep and cause partial obstruction. Breathing against obstruction causes vibrations of soft palate, tonsillar pillars and base of tongue producing  sound. Sound as loud as 90dB has been recorded during snoring.

Snoring may be primary, i.e. without association with obstructive sleep apnoea (OSA) or complicated, i.e. associated with OSA. Primary snoring is not associated with excessive daytime sleepiness and has apnoea-hypnoea index less than 5.

Aetiology

In children most common cause is adenotonsillar hypertrophy. In adults cause of snoring could be in the nose or nasopharynx such as septal deviation, turbinate hypertrophy , nasal valve collapse, nasal polypi or tumours; in oral cavity and Oropharynx such as elongated soft palate and uvula, tonsillar enlarement, macroglossia, retrognathia, large base of tongue; or its tumour; in the larynx and laryngopharynx such as laryngeal stenosis or omega-shaped epiglottis. Other cause include obesity and thick neck with collar size exceeding 42cm. Use of alcohol, sedative and hypnotics aggravates snoring due to muscle relaxation.

Sites of Snoring

Site of snoring may be soft palate, tonsillar pillars or hypopharynx. It may vary from patient to patient and even in the same patient thus making surgical correction a difficult decision. Sometimes sites of snoring are multiple even in the same patient.

Symptomatology

Exercise loud snoring is socially disruptive and forms snoring-spouse syndrome and is the cause of marital discord sometimes leading to divorce. In addition, a snorer with obstructive sleep apnoea may manifest with:

-Excessive daytime sleepiness

-Morning headaches

-General fatigue

-Memory Loss

-Irritability and depression

-Decrease libido

-Increased risk of road accidents

Treatment

1. Avoidance of alcohol, sedatives and hypnotics.
2. Reduction of weight
3. Sleeping on the side rather than on the back.
4. Removal of obstructing lesion in nose, nasopharynx, oral cavity, hypopharynx and larynx. Radiofrequency has been used for volumetric reduction of tissues of turbinates, soft palate and base of tongue.
5. Performing uvulopalatoplasty (UPP) surgically with cold knife or assisted with radiofrequency (RAUP) or laser (LAUP).