Goodlettsville Dental Services

Sleep Apnea

Sleep apnea (or sleep apnoea in British English) is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called an apnea (Greek: ἄπνοια (ápnoia), from α- (a-), privative, πνέειν (pnéein), to breathe), lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep. The standard definition of any apneic event includes a minimum 10 second interval between breaths, with either a neurological arousal (a 3-second or greater shift in EEG frequency, measured at C3, C4, O1, or O2), a blood oxygen desaturation of 3-4% or greater, or both arousal and desaturation. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram, or a “sleep study”.

Clinically significant levels of sleep apnea are defined as five or more episodes per hour of any type of apnea (from the polysomnogram). There are three distinct forms of sleep apnea: central, obstructive, and complex (i.e., a combination of central and obstructive) constituting 0.4%, 84% and 15% of cases respectively. Breathing is interrupted by the lack of respiratory effort in central sleep apnea; in obstructive sleep apnea, breathing is interrupted by a physical block to airflow despite respiratory effort. In complex (or “mixed”) sleep apnea, there is a transition from central to obstructive features during the events themselves.

Regardless of type, the individual with sleep apnea is rarely aware of having difficulty breathing, even upon awakening. Sleep apnea is recognized as a problem by others witnessing the individual during episodes or is suspected because of its effects on the body (sequelae). Symptoms may be present for years (or even decades) without identification, during which time the sufferer may become conditioned to the daytime sleepiness and fatigue associated with significant levels of sleep disturbance.

Development and discovery of sleep apnea in humans

The first reports in the medical literature of what is now called obstructive sleep apnea date only from 1965, when it was independently described by French and German investigators. However, the clinical picture of this condition has long been recognized as a character trait, without an understanding of the disease process. The term “Pickwickian syndrome” that is sometimes used for the syndrome was coined by the famous early 20th century physician, William Osler, who must have been a reader of Charles Dickens. The description of Joe, “the fat boy” in Dickens’s novel The Pickwick Papers, is an accurate clinical picture of an adult with obstructive sleep apnea syndrome.

The early reports of obstructive sleep apnea in the medical literature described individuals who were very severely affected, often presenting with severe hypoxemia, hypercapnia and congestive heart failure. Tracheostomy was the recommended treatment and, though it could be life-saving, postoperative complications in the stoma were frequent in these very obese and short-necked individuals.

The management of obstructive sleep apnea was revolutionized with the introduction of continuous positive airway pressure (CPAP), first described in 1981 by Colin Sullivan and associates in Sydney, Australia. The first models were bulky and noisy, but the design was rapidly improved and by the late 1980s CPAP was widely adopted. The availability of an effective treatment stimulated an aggressive search for affected individuals and led to the establishment of hundreds of specialized clinics dedicated to the diagnosis and treatment of sleep disorders. Though many types of sleep problems are recognized, the vast majority of patients attending these centers have sleep-disordered breathing.

Prevalence and costs in the USA

It is estimated that 20 million Americans are affected by sleep apnea. That would represent more than 6.5%, or nearly 1 in 15 Americans, making sleep apnea as prevalent as asthma or diabetes. It is also estimated that 85-90 percent of individuals affected are undiagnosed and untreated. The Wisconsin Sleep Cohort Study found that, among the middle-aged, nine percent of women and 24 percent of men had sleep apnea.

The costs of untreated sleep apnea reach further than just health issues. It is estimated that the average untreated sleep apnea patient’s health care costs $1,336 more than an individual without sleep apnea. If approximations are correct, 17 million untreated individuals account for $22,712 million,or almost 23 billion in health care costs.