With an increase in the number of obesity cases in the urban population, the symptom of snoring has become a common complaint that many medical specialists like physicians, pulmonologists and otolaryngologists have come across. An individual may oscillate within a spectrum of sleep — disordered breathing from intermittent simple snoring to severe obstructive sleep apnoea (OSA) and obesity hypoventilation syndrome. (Flowchart: Simple Snoring --> Chronic Heavy Snoring --> Upper Airway Resistance Syndrome --> Mild OSA --> Moderate OSA --> Severe OSA --> Obesity Hypo Ventilation Syndrome).
OSA is characterised by complete breath holds — apnoeas and partial breath holds-hypopnoea. Approximately 5 per cent of the population has obstructive sleep apnoea hypopnoea syndrome (OSAHS). It is more common in males.
What happens in OSA?
Obstruction in the upper airway (structural or due to increase in bulk)
Reduction in muscle tone during sleep increases obstruction
Increased effort of breathing proportionate to the reduction in airway size
Total block in airway and cessation of breathing
Decrease in blood oxygen level
Stimulation of brain and arousal from sleep to restart breathing
The symptoms of sleep apnoea are:
Snoring and fatigue
Witnessed breath holds
Gasping and choking
Excessive Daytime Sleepiness (EDS),
Nocturia and decreased alertness
Unfortunately just history and clinical findings cannot diagnose OSA. It can predict OSAHS in about 50 per cent of patients. Objective measurement of sleep apnoea can be done by a test called polysomnography or sleep study. Subjective assessment of EDS is with different subjective questionnaires. The severity of OSA has been arbitrarily categorised based on the apnoea hypopnoea index (AHI). AHI is the number of apnoeas and hypopnoeas averaged per hour of sleep (check box).
When does OSA require treatment?
■ Mild OSA with out EDS and or other comorbidities just requires change in life style, weight reduction and treatment of nasal conditions like rhinitis.
■ Mild OSA with EDS and or other comorbidities, Moderate and Severe OSA with or wihout EDS and comorbidities are managed with CPAP (Central positive airway pressure devise). This devise supplies air at a higher pressure for breathing so that the excessive resistance is overcome. Though CPAP is the mainstay of medical treatment for sleep apnoea, it has side effects like those related to the face/nasal mask like claustrophobia, skin abrasions, nasal stuffiness and air swallowing. Poor tolerance is a common problem faced by CPAP users.
■ Management of OSA starts with weight loss, change in life style which includes tackling aggravating factors like smoking (active and passive), gastric reflux other than obesity. Male gender and advancing age are other aggravating factors.
Once OSA has been diagnosed the site of airway obstruction has to be ascertained by tests like sleep nasal endoscopy and imaging studies like cephalometry, 3-D CT, Dynamic MRI. Surgical correction of the airway obstruction is recommended in:
1. Severe antisocial snoring without OSA
2. OSAS with severe antisocial snoring
3. Those with failed and inadequate response to CPAP
4. Those with localised obstruction at palatal level
5. Those with Multisegmental obstruction causing severe OSA
Common surgical procedures done for OSA in adults are UP3 (uvulopalatopharyngoplasty — where a strip of the soft palate, the tonsils and uvula are removed), LASER assisted uvulopalatoplasty, Radiofrequency assisted tissue volume reduction and corrective nasal surgeries. A few of the occasional procedures include tracheostomy, tongue base reduction, maxillo mandidular advancement and epiglottectomy. Snoring is a common complaint, but one must be aware that all snoring is not simple snoring. One has to seek medical advice in case of symptoms of OSA since OSAS can lead to life threatening complications if left unattended.
Dr Bathi Reddy, ENT consultant