Obstructive Sleep Disordered Breathing

Obstructive Sleep Disordered Breathing

 

Associate Professor Paraya Assanasen, M.D.
Department of Otorhinolaryngology
Faculty of Medicine  Siriraj Hospital 

 

Obstructive sleep disordered breathing (OSDB) is a collective term that encompasses a spectrum of disorders which can range from primary snoring and upper airway resistance syndrome (UARS) to varying severity levels of obstructive sleep apnea syndrome (OSAS) (Figure1). Snoring is a common problem encountered in Thailand.  The actual prevalence of snoring in Thailand is unknown, but it is estimated to be 20% in middle-aged male and 5% in middle-aged female in foreign country.  The percentage of elderly people who snore is higher.  People mostly understand that snoring is normal in daily life, but it actually indicates upper airway obstruction.  It is very annoying to patients’ bed partners since it could deprive them from proper and restful sleep, which is essential to good health.  Snoring most often results from collapse of excess soft tissue in the soft palate, tonsillar pillars, tongue, tongue base, and hypopharyngeal walls (Figure 2).  If the degree of such an obstruction is severe, it can lead to OSAS, which is a life-threatening condition. 

OSAS affects about 4% of middle-aged male and 2% of middle-aged female. OSAS is characterized by periodic collapse of the upper airway during sleep, which leads to either complete (apneas) or partial airway obstruction (hypopneas), or both, resulting in arousal and oxygen desaturation (Figure 3).

 Risk factors for this condition include obesity, anatomical abnormalities, aging, male sex, and family history.  Recognition of OSAS is important since it causes daytime somnolence, neurocognitive defects, chronic fatigue, and depression.  In addition, it can increase the risk of having traffic accident, hypertension, cardiovascular disease, stroke, pulmonary hypertension, and cardiac arrhythmia.

From the clinical point of view, the most important practical points are firstly the differentiation among primary snoring, UARS, and OSAS, and secondly, the quest for point (s) of airway obstruction.  The former can be done by overnight polysomnogram, which remains the gold standard for the diagnosis of OSAS.  The latter can be achieved by rigid and flexible endoscopy of the upper airway.

The treatment options for OSDB include weight loss, positional therapy, oral devices, continuous positive airway pressure (CPAP), and surgery.  Surgery offers a viable alternative to nasal CPAP and/ or oral appliances in patients who are intolerant of them. 

 

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