Saturday, November 28, 2020

Sleep Apnea Diagnosis, Causes & Treatment


Sleep apnea is when soft tissue in the back of the throat becomes soft and collapses into the airway to narrow the channel and block oxygen flow. The brain alerts the sleeper to this sleep-breathing problem by interrupting sleep, so that the sleeper can gasp for air. This brief partial arousal completes a cycle which may continue hundreds of times a night. An estimated 20 million Americans have apnea with half of those cases, 10 million people, having undiagnosed apnea.

During these abnormal pauses in breathing or recurrent hypoxia, the upper airway continues to collapse, the sleeper does not get enough oxygen and sleep is disrupted. Intermittent hypoxia (IH, oxygen desaturation and re-oxygenation) or a recurrent lack of oxygen catches the sleeper in a cycle of oxygen deprivation and fitful sleep architecture. Spending the night gasping for air, the sufferer spends his days tired and irritable from lack of sleep.

Chronic Condition

Apnea is a common disorder, not a disease or an event, but a chronic condition that requires long-term management. Sleep apnea is a non-communicable disorder, meaning that it does travel from one person to another. It is a physical and biological or physiological disorder, not a disease.

The affliction is a chronic illness, not an isolated event or acute occurrence. Some medical conditions may cause apnea, while apnea may cause other medical conditions to develop. Usually overweight adults, children with large tonsils, heart and thyroid patients are likely to suffer from apnea. Physicians attempt to find the underlying reason for apnea first.

Sleep apnea is difficult to detect as some common symptoms like concentration problems and headaches are often misdiagnosed. Primary care physicians are not as trained to recognize symptoms as sleep specialists are. A partner disturbed by violent snoring may be the one to discover it before the physician. Some people have conditions like enlarged tonsils that when standing upright, present no problem. But when in the supine position or lying down position, the tonsils press down on the airway, causing sleep apnea.

To measure the severity of sleep apnea, physicians and researchers use the Apnea-Hypopnea Index (AHI). The number of times that the oxygen de-saturates in the blood and the number of awakenings is divided by the number of hours slept. An apnea-hypopnea index of 15 episodes per hour or one event every 4 minutes, meets a formal diagnosis of sleep apnea to a patient. An AHI index of 20 is considered moderate to severe sleep apnea.


Much worse than snoring are the major health problems likely to result from untreated sleep apnea. Researchers have found that apnea sufferers who have both apnea and excessive daytime sleepiness are twice as likely to die. Those with severe apnea have a 40 percent increased risk of death. Undiscovered and untreated sleep apnea can cause:

  • Early mortality – poor sleep from any sleep disorder is associated with a significant risk of mortality.
  • Immunosuppression – oxidative stress and inflammation influence the damage repairing process.
  • Heart failure – coronary artery disease (CAD), irregular heartbeat, heart attacks, stroke, and arrhythmias. Intermittent hypoxia (IH) causes endothelial cell dysfunction which triggers atherosclerosis.
  • Blood Pressure – diastolic blood pressure increases causing a risk for other cardiovascular diseases, such as heart attacks, stroke, and heart failure.
  • Depression – a mood disorder may develop with apnea; depression and apnea share several symptoms including fatigue and sleepiness.
  • Cancer – changes in oxygenation influence increased tumor growth and melanoma cancer cells.
  • Obesity – systemic inflammation may cause significant weight gain.
  • Diabetes – insulin resistance and diabetes type 2 is found in apnea patients.
  • Organ damage – elevated blood pressure during apnea episodes can damage internal organs, including the heart.

Socioeconomic Costs

In one study, researchers showed a significantly lower quality of life in apnea patients, as well as twice as high health costs. Sleep apnea patients had a 30% higher unemployment rate and when they did work, they earned 30% lower amount of money than their colleagues. Visits to the doctor, hospital visits and medication costs were much higher in this group, even up to eight years before the apnea was diagnosed.

Health and safety consequences for apnea sufferers include more motor vehicle crashes, industrial accidents, household accidents, and negligence in areas like work and school. One study found that people with apnea are two times more likely to have a car accident. Serious accidents with personal injury happened three to five times more often to apnea patients. Even people with only mild sleep apnea were prone to more car crashes.

Researchers also found no self-reported feeling of sleepiness, suggesting that the apnea patient was not aware of performance deficiencies. Neurocognitive deficits affect work and academic achievements. Poor achievement or underperformance can be seen in children and adults with sleep apnea.

Sleep Architecture

Sleep hygiene and meeting sleep requirements, is a vital part of health and vitality for all age groups. The upper airway, consisting of nose, mouth, throat, windpipe, and tongue, collapses and leads to shallow breathing. The blocked airway reduces oxygen levels, slows the heart rate and ultimately disrupts sleep architecture. With no air flowing, the low oxygen condition wakes you up to as many as 100 times an hour. Episodes can last for minutes or seconds.

Sleep disorders of any kind that adversely affect sleep architecture can lead to long-term permanent damage. Positive events that sleep triggers are delayed like vital hormone replenishment and neuron synthesis. Negative conditions are initiated like inflammation of tissues and internal organs, leading to other medical problems. Poor sleep from any sleep disorder can cause excessive daytime sleepiness, irritability, and making bad choices, including bad food choices.

Types of Apnea

Obstructive sleep apnea is the most common type of sleep apnea. The throat muscles relax and cause gasping for air and snoring, or intermittent interruption of breathing. Central Sleep Apnea is when the brain does not communicate well with the muscles that control breathing. Complex Sleep Apnea is a combination of the other two types. 84 percent of apnea cases are obstructive sleep apnea, 0.4 percent are central sleep apnea while complex sleep apnea is seen in 15 percent of all sleep apnea patients.

Common apnea occurs with moderate to severe disease symptoms in 4 to 9% women and 9 to 24% of men. Some patient populations have an even greater risk including people with medical conditions, those who take certain medicines, the elderly, heart patients, surgery patients, people with brain tumors or infections, and the obese.

Risk Factors

Anyone, at any age, can be affected by sleep apnea, even children. However, some people under certain conditions are more susceptible. The risk factors for the disorder:

  • obesity – 70% of obstructive apnea cases are found in overweight people.
  • male gender – men are twice as likely as women to have apnea.
  • race – apnea risk is higher in black, Hispanic, and Asian populations.
  • family history – having a close relative with apnea, mother/father/sibling.
  • physical abnormalities – large tonsils and adenoids, large uvula, a large tongue, a small jaw bone, large neck size (men=17+ inches, women=16+ inches), and head or facial abnormalities increase the risk. Nasal obstructions, sinus problems, and deviated septum are risk factors, too.
  • certain medicines – sedatives or hypnotic drugs may cause problems.
  • alcohol before bed – breathing problems may arise under the influence of alcohol.
  • sleep on your back – the tongue may collapse into the airway when sleeping on your back.
  • being over the age of forty – normal aging can affect sleep patterns for everyone, and middle aged people are more likely to have apnea.
  • gastroesophageal reflux, or GERD – acid reflux affects the vocal cords and apnea.

Testing and Measurement

Apnea Index (AI) – Apnea is measured during sleep by dividing the total number of apneas by the number of hours slept. Severity of the disorder is indicated by a greater AI number. The higher the number, the worse the apnea.

Hypopnea Index (HI) – A hypopnea also disrupts sleep but not as severely as apnea. A 4% decrease in oxygen in the blood leads to a definition of hypopnea. The index is calculated by taking the number of hypopneas and dividing by the number of hours slept.

Apnea-Hypopnea (AHI) – This index is the most commonly used as it takes both apneas and hypopneas into account and gives an indication of the severity of the sleep disruption. The number of apneas and hypopneas are divided by the number of hours of sleep.

Disturbance index (RDI) – All disturbances are measured in this index, including episodes that do not meet the level of apnea or hypopnea.

Holter Oximetry Home Test – testing and measuring at home is easier with this small and portable device. The device is fairly new and users report comfortable conditions for use. Researchers find the device gives reliable results.

The Berlin Questionnaire – a simple screening questionnaire can adequately show who may be at risk. Persons who report major symptoms in any two of these three areas are considered to be at high risk for sleep apnea: snoring, daytime sleepiness, and history of obesity or hypertension. The Berlin Questionnaire is increasingly used in clinical practice and in the absence of a physician encounter.

Epworth Sleepiness Scale – This test measures the likelihood that a person will fall asleep in some situations like reading, watching television, and driving. The level of a person’s daytime sleepiness is quantified. Since daytime sleepiness is a significant factor in early mortality and accidents, the test is a useful assessment.


You may notice warning signs include physical distress of headaches, chest pain, swelling in the legs, and heartburn. You might have nocturia or getting up during the night to urinate. You may feel sensations like a sour taste in your mouth and sweating. Your personality may change with memory and concentration difficulties and irritability. You may have an unrefreshed or tired feeling when waking or all day long.

Others may notice your loud snoring as all apnea patients snore to varying degrees of loudness. They may observe you choking, gasping and other displays of not breathing. You may be observed tossing and turning at night.

Children with sleep apnea always snore, but they may not show excessive daytime sleepiness as adults do. Normal development and physical growth may be depressed and serve to warn parents and physicians. Sleep apnea may cause the heart to fail on the right side, blood pressure may be elevated which leads to high blood pressure later in life. Warning signs include snoring, restlessness, bedwetting, mouth breathing, short attention span, hyperactivity and performance problems in school.

Key Symptoms – Obstructive Sleep Apnea

A diagnosis of obstructive sleep apnea (OSA) is suspected by the physician under the following key warning signs: obesity, male sex, jaw and tongue abnormalities, snoring, headaches and excessive daytime sleepiness.

Related Factors – Obstructive Sleep Apnea

Further indicators are numerous and include a history of dental problems, motor vehicle accidents, nocturia or erectile dysfunction, heartburn, dry mouth, sweating, recent weight gain, endocrine disorders and mood disorders.

Testing – Obstructive Sleep Apnea

Polysomnography (PSG) is the first test commonly ordered. A sleep study is conducted under controlled conditions in a laboratory. You may be asked to sleep overnight at the facility for one or more days. All apnea like disturbances, hypopneas and apneas are measured and scored with the AHI or RDI index. A nasal pressure sensor signal is used to record and score the results.

During that procedure, or in a separate effort, other tests for air flow and respiratory assessment may be part of the testing phase, including pulse oximetry which measures oxygenation of a patient’s blood, and capnography which provides information on carbon dioxide production. These tests are commonly performed:

  • EEG (Electroencephalography) – determines sleep stages and states.
  • EMG (Electromyography) – measures arms and legs movement and sleep states.
  • ECG (Electrocardiography) – detects cardiac dysrhythmias.
  • Endoscopy – awake or sedated visual inspection of the throat.

A cine MRI may be ordered which visualizes sites and patterns of any obstructions. This test is performed with the patient sedated. The test is growing in use and shows movement of the cerebrospinal fluid (CSF).

Diagnosis – Obstructive Sleep Apnea

Severe – more than 30 episodes/hour.
Moderate – more than 15 but less than 30 episodes/hour.
Mild – more than 5 but less than 14 episodes/hour.
Normal – less than 5 episodes/hour.

Additionally, complicating factors may be included the diagnosis and determine proper treatment 1) with concurrent obesity 2) with persistent hypersomnolence or excessive sleepiness 3) with positional component or types of sleeping positions 4) anatomical lesions.

Key Symptoms – Central Sleep Apnea

The presence of risk factors is the first sign that a physician will look for. In addition, insomnia, daytime sleepiness and poor concentration will alert the physician. Snoring, breathing pauses, and headaches are commonly found to be key symptoms of central sleep apnea.

Related Factors – Central Sleep Apnea

In addition, underlying conditions are often the cause of this type of apnea. Abnormal heart rhythm indicating chronic heart failure and an abnormal neurological examination suggesting brain lesions may further inform the physician. A history of endocrine disorders and neuromuscular weakness is also a related factor.

Testing – Central Sleep Apnea

An overnight PSG, polysomnography sleep study is the only sure way to find out whether you have central sleep apnea. An observation of REM (rapid eye movement) and non-REM sleep in both lying on the back position or supine and non-supine position, is important as central sleep apnea features disturbances dependent on these factors. Other physiological diagnostic tests similar to the aforementioned tests, may be ordered.

Diagnosis – Central Sleep Apnea

Central sleep apnea is a rare condition and not well understood. A central sleep apnea is diagnosed when respiratory flow stops for of at least 10 seconds and is not accompanied by any chest or abdominal respiratory movements, with episodes of five or more apneas or hypopneas per hour of sleep. Additionally, Cheyne-Stokes breathing pattern, indicated with congestive heart failure, renal failure, stroke, may be diagnosed and treatment adjusted accordingly.


Treatment consists of adding a steady supply of air with an oxygen delivery system called Continuous Positive Airway Pressure (CPAP). This breathing device, worn at night, is the most accepted treatment for common apnea. Lifestyle changes like losing weight or surgery is indicated in some cases. Some cases are due to medications which can be discontinued.

Left untreated, a host of problems can ensue including immunosuppression, hypertension, obesity and diabetes. Relationships with others may become difficult as apnea sufferers often have poor concentration and headaches. Snoring is common and may disturb the bed partner. Both lose sleep and become irritable due to one person’s sleep disorder. However, not everyone who snores has apnea.

Treatment of apnea consists of three major efforts. 1) Find the underlying condition 2) Recommend weight loss 3) Use a breathing device at night.

  1. Find the underlying condition – obesity and endocrine disorders are common causes, some medications cause apnea, as well as some conditions like high altitude or a certain sleeping position may induce apnea.
  2. Recommend weight loss – apnea patients who lose weight can realize a significant reduction in symptoms and possibly a complete remission.
  3. Use a breathing device at night – restoring air flow mechanically and automatically is the treatment of choice.

CPAP – Continuous Positive Airway Pressure

During the PSA, polysomnography test or sleep study or in conjunction with the test, a CPAP titration study is performed. This procedure determines the proper therapeutic CPAP pressure. In other words, the right amount of oxygen that the patient needs is determined. Also, the right mouthpiece or interface is fitted, and troubleshooting is performed.

The interface is a mask, often triangular shaped, that fits over the nose and mouth. A variety of mask interfaces is available, depending on the patient. Pressurized oxygen flows from the oxygen tank kept at the bedside, through a tubing channel into the interface mask and down the airway. Straps hug the mask tightly to the head to prevent normal tossing and turning from ripping it off. This oxygen delivery system restores normal airflow and prevents apneas. During the expert mask fitting, the patient and partner are familiarized with the equipment and proper procedures for using it.

Effective treatment is hampered by problems with patients actually using the device as it was designed. Adherence is low in apnea patients as they often have issues with the unit. Early adherence is influential in long-term use, so physicians try to follow-up with troubleshooting to make sure everything goes well. Devices are now more lightweight, not as noisy, and have heat and humidity modifications to prevent congestion and nasal dryness.

Early problems arise as the device may be viewed as uncomfortable, could make one feel claustrophobic, socially disabled, and even induce a panic attack. During the critical initiation phase the patient’s partner may play a critical role in the acceptance and effective use of the device.

The partner can help manage the situation in several ways. 1) Take over management of the treatment 2) Work collaboratively with the patient 3) Let the patient handle the CPAP treatment by himself/herself. In any case, early acceptance of the device is key and the partner’s support may be critical.

Elderly patients highly benefit from CPAP use as a significant risk of mortality is avoided and even possible remission of symptoms. Infants who needs positive airway pressure sometimes need massaging or rubbing the back or stomach to encourage inhalation, however, this sometimes wakes the child, inviting further sleep deprivation.

Avoidance Behaviors

Lifestyle behaviors to avoid are alcohol use, especially at bedtime, smoking cigarettes or other substances and caffeine use from coffee and sodas.

Further or Additional Treatment

Additional treatments can be used in conjunction with CPAP, and repeated or adjusted as necessary. Every person’s situation is different, and only a physician can recommend proper treatment. However, physicians as a rule, will start with the least invasive and most effective treatment first, and move on to more drastic measures as needed.

Treatment for the rare cases of central sleep apnea is not as well known as for constructive sleep apnea, as not as much is known about central sleep apnea and treatment varies widely, however CPAP is generally accepted as the first course of action, after looking for the underlying cause.

Lifestyle changes

  • Weight loss – almost always recommended as most apnea patients are overweight.
  • Positional – changing from being a back sleeper to a side sleeper may help to open the airway. Special shirts and pillows may be obtained commercially that prevent the person from rolling onto their back.

Oral Appliance Therapy

Mouthpieces and/or a procedure called the Pillar Implant can be used. During Pillar Implant procedure, small polyester rods are implanted in the soft palate to stiffen it and reduce vibration. A Mandibular Advancement Splint aligns the jaw to prevent airway blockage and snoring. Many of these procedures can be done on an outpatient basis with local anesthesia.


  • Bariatric – indicated for obese patients to reduce stomach size and induce weight loss.
  • Nasal Somnoplasty – remodeling of nasal passages with low-power radio frequency energy.
  • Airway – shrinking or stiffening tissue, removing obstructions or resetting the lower jaw.

Medications – modafinil or armodafinil may be prescribed for hypersomnolence or excessive daytime sleepiness. A nasal decongestant may be indicated in some cases.

Supplemental oxygen – oxygen therapy provided through a nasal cannula has been shown to improve the ventilatory response. This domiciliary oxygen helps patients with decreased oxygen concentration in arterial blood.

Adaptive Servoventilation – A proprietary algorithms evaluates ventilation patterns during each breath, and adapts variable pressure to reduce hypoventilation and hyperventilatory overdosing. Pressure is calculated by the machine with a default algorithm, and the machine adjusts the dosage automatically.

Return to lower altitude – sometimes high altitudes with changes in oxygen levels may induce breathing pauses, so returning to sea level may eliminate the oxygen deficit which causes apnea. Supplementing with oxygen may help prior to the return to lower altitude.

Culprit Drug removal – find, eliminate or reduce dose of suspected drug which triggers apnea. Narcotic drugs often induce apnea symptoms.

Related Apnea Problems

Conditions with symptoms similar to sleep apnea include other sleep disorders:

  • Hypothyroidism – the thyroid gland, located in the neck, transmits hormones to control metabolism. An underactive thyroid may produce some symptoms similar to apnea.
  • Narcolepsy – periods of extreme drowsiness or suddenly falling asleep.
  • Restless Legs Syndrome – sensations and unexplained urges to move the legs may keep some up at night, causing daytime sleepiness.
  • Dissomnia – any of the 30 kinds of disorders related to getting to sleep or staying asleep, intermittent wakefulness, and/or early morning awakening.

Emerging Possibilities


Since apnea is found in 60-70% of overweight and obese people, weight loss is often recommended. One study showed that a low energy diet along with psychological and behavioral counseling helped apnea patients to lose weight. 48% of participants no longer needed a breathing apparatus and 10% were completely cured with weight loss. Most participants were able to maintain the weight loss, and those with severe apnea had the most improvement.

The Brain

The search for a pill or drug for apnea is closer as studies have shown that a brain chemical may be useful. Noradrenaline is released in the brain to help the person cope with apnea. Artificial manipulation of noradrenaline may help the brain become even more flexible and assist in adapting and improving apnea episodes.

The Nerves

The diaphragm is stimulated by the phrenic nerve. Stimulation of the nerve has been shown to almost eliminate central sleep apnea. The pacemaker for the nerve reduced or stopped the incidence of paused breathing, improved blood oxygen and heart rate.

Nasal Spray

A fluticasone furoate nasal spray reduced development of cell proteins marked for an inflammatory response. This intranasal corticosteroid treatment reduced proliferation of a pro inflammatory cytokine which regulates cell growth and differentiation, and reduced likelihood of apnea development.

Sound Test

Analysis of breathing during wakefulness may be an accurate new test for obstructive apnea. Apnea produces several distinct sound features present while the person is awake. This new test predicted apnea in 84% of cases. Negative pharyngeal pressure sounds can also be used to predict the severity of apnea. This test may be a less costly and less time consuming alternative to overnight polysomnography, a sleep study.


Repetitive decreases of oxygen open the door to a fight-or-flight response in the body. Short-term blood pressure and heart rate increases cause a long-term systemic cascade of negative physiological changes. Most or half of all cases are undiagnosed and untreated. The toll on the individual in terms of quality of life and the toll on the health care system is broad and deep.

Simple questionaires found online and in the physician’s office are very effective at ferretting out individuals with problems. Also, expensive overnight sleep tests can be substituted for by inexpensive home machines. These devices are comfortable for the user and give reliable results to the physician.

Once a diagnosis is made, simple steps may correct the problem. However, many apnea sufferers may have to use the CPAP machine for the rest of their lives. Compliance with using the machine is low, as apnea sufferers may have found it uncomfortable or socially stigmatizing. More work needs to be done at the beginning of device usage, and involve the partner of the apnea sufferer.

Since, apnea sufferers, from mild to severe, experience many more accidents than others, more care is needed when in the general public and in moving vehicles. Since many apnea sufferers don’t know they have the disorder, it is impossible to say with certainty just how many people are on the roads in varying degrees of incapacity. General practitioners are being advised by sleep specialists and researchers to routinely screen everyone for apnea and related disorders.


Medically trained in the UK. Writes on the subjects of injuries, healthcare and medicine. Contact me

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