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Obstructive Sleep Apnea - The Silent Killer


Sleep apnea is a chronic potentially serious sleep disorder affecting millions of people both of adults and children [1,2]. It is characterized by repeatedly stop and start breathings during sleep. There are 3 main types of sleep apnea which are Obstructive sleep apnea (OSA), Central Sleep Apnea (CSA), and Complex sleep apnea syndrome. Obstructive sleep apnea happens when upper airway muscles relax during sleep. Central sleep apnea happens when the brain could not send the appropriate signals to the muscles that control breathings. Complex sleep apnea syndrome which also known as treatment-emergent central sleep apnea and the abnormal breathings are obstructive sleep apnea mixed with central sleep apnea.

In these three types of sleep apnea, the more common form is OSA which has repetitive complete or partial of upper airway closure during sleep. The first pathogenesis of these closure is pharyngeal anatomical and functional disorders. There are some certain factors associated with higher incidence of OSA by narrowed air passages in the midface and throat. Nasal block, enlarge tongue, enlargement of adenoid and tonsillar tissues, excess weight, thicker or large neck circumference, hypothyroidism (macroglossia, increase soft tissue mass, myopathy), acromegaly, genetic disorders induce thickness of the lateral pharyngeal walls or craniofacial malformations reducing oral cavity size such as Down syndrome, Pierre Robin syndrome, and Prader-Willi syndrome, upper airway muscle tone reduction in old aging, male, menopause, and alcohol or some sedatives are the example factors to influence OSA. The other pathogeneses are elevated loop gain and sleep instability [3,4].

The symptoms are found in clusters mixed between 3-5 domains [5]. The first domain is sleepiness which Epworth Sleepiness Scale is a subjective evaluation tool evaluates a chance of having dozed off in eight different activities [6]. The other domains are upper airway narrowing, sleepiness and upper airway narrowing, sleep disruption or frequent arousal, and other minimal symptoms such as frequent nocturia, frequent leg movement during sleep, concentration and memory impairment, irritability. The upper airway narrowing symptom examples are snore loudly, witnessed apnea, choking air, breathing instability, woke up with dry mouth and dry throat.

Multiple systemic effects and more serious health consequence are found in prolong courses OSA. Cardiovascular disorder, arrhythmias, coronary artery disease, cor pulmonale (failure of the right side of the heart), increases risk of development of pulmonary hypertension, systemic hypertension, are often seen [7-11]. Stroke [12-16], Neurocognitive function, Alzheimer’s disease [17], Neurodegenerative disorders, Endocrine disorders, increase cancer risk [18,19], and increase mortality are also correlated with OSA.

The objective evaluation often involves overnight monitoring the breathing and other body functions during sleep and in-lab polysomnogram study is a recommendation. In the case of treatment, Continuous Positive Airway Pressure (CPAP) is the most common and reliable method of treating OSA to deliver air pressure through a mask placed over a nose during sleep to keep the upper airway passages open and could induces lateral pharyngeal wall thinning. Other PAPs options are auto-CPAP, Bilevel-PAP. However, oral appliances, mandibular advancement, oropharyngeal surgery, Expiratory positive airway pressure (EPAP), Continuous Negative Airway Pressure (cNEP), and Pharmacotherapeutic, are also the additional treatments or are the alternative treatments in some specific cases.

Niratchada SapAnan, M.D. Diploma board certified in Neurology, Epilepsy, and Sleep medicine Bangkok Hospital Pattaya


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