Sleep apnea overview

Jump to navigation Jump to search

Sleep Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Sleep apnea from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Criteria

History and Symptoms

Physical Examination

Laboratory Findings

Polysomnography

Home Oximetry

CT

MRI

Ultrasound

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Sleep apnea overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Sleep apnea overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Sleep apnea overview

CDC on Sleep apnea overview

Sleep apnea overview in the news

Blogs on Sleep apnea overview

Directions to Hospitals Treating Sleep apnea

Risk calculators and risk factors for Sleep apnea overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Saarah T. Alkhairy, M.D.

Overview

Historical Perspective

Sleep apnea was first described in literature in the 19th century. It was often misdiagnosed as either narcolepsy or skepticism. In 1981, Collin Sullivan invented the continuous positive airway pressure (CPAP) for the treatment of sleep apnea. Prior to its recognition as a unique disorder, sleep apnea was viewed as either a type of insomnia or an age-related phenomenon.

Classification

There are three types of sleep apnea: obstructive, central, and mixed. The majority of patients have obstructive sleep apnea (OSA). Individuals of untreated sleep apnea stop breathing repeatedly during the night usually for a minute or longer, during their sleep. Most of the time, these individuals are unaware of these episodes because the episodes don't trigger an awakening. Obstructive sleep apnea results from the narrowing or total blockage of the airway. In central sleep apnea, there is failure of the central nervous system to send appropriate signals to the muscles of respiration. These signals control the individual's breathing. It is also possible for an individual to have a combination of these two types, referred to as mixed apnea.

Pathophysiology

The pathogenesis of obstructive sleep apnea includes upper airway anatomy defects, the inability of the upper airway dilator muscles to respond to respiratory challenge during sleep, inadequate arousal threshold, loop gain, and potential for state-related changes in lung volume. The pathogenesis of central sleep apnea involves chemoreceptors that modulate ventilation.

Causes

Sleep apnea may be commonly caused by a large neck/abodminal circumference (e.g. obese individuals), administration of medications, diseases that narrow the respiratory airways (e.g. enlarged adenoids, enlarged tonsils), diseases that affect the central nervous system (e.g. cerebrovascular accident, spinal cord injury), or infectious diseases (e.g. polio).

Differential Diagnosis

Sleep apnea must be differentiated from other diseases that cause loud snoring, fatigue, choking, coughing, and daytime sleepiness. To differentiate obstructive sleep apnea (OSA) and central sleep apnea, a polysomnogram should be performed. OSA will demonstrate evidence of thoracoabdominal effort, whereas central sleep apnea will not.

Epidemiology and Demographics

Sleep apnea must be differentiated from other diseases that cause loud snoring, fatigue, choking, coughing, and daytime sleepiness. To differentiate obstructive sleep apnea (OSA) and central sleep apnea, a polysomnogram should be performed. OSA will demonstrate evidence of thoracoabdominal effort, whereas central sleep apnea will not.

Risk Factors

The most common risk factor for the development of sleep apnea is large neck circumference. Other risk factors of sleep apnea include smoking, alcohol, sedatives, tranquilizers, males, a positive family history, certain ethnic backgrounds such as African Americans, and individuals over 60-65 years. Continuous positive airway pressure (CPAP) is a risk factor for complex sleep apnea (also known as mixed sleep apnea).

Screening

There are no guidelines to screen for either obstructive or central sleep apnea among the general population. However, commercial drivers, operators of heavy equipment, pilots, and other occupations at risk of diurnal sleepiness should be screened by history and physical exam using standardizes questionnaires.

Natural History, Complications, and Prognosis

Sleep apnea can begin with loud snoring and eventually lead to serious complications. Common symptoms include somnolence, depression, and headaches. More serious complications include cardiovascular diseases, stroke, and hypertension. If sleep apnea is adequately treated, the prognosis is very good. If it is left untreated, patients can develop serious complications and have a poor prognosis.

Diagnosis

The diagnosis of sleep apnea is listed in the DSM-V guidelines using either either the Apnea Hyponea Index (AHI) or the Respiratory Disturbance Index (RDI).

History and Symptoms

Common symptoms in patients with sleep apnea include loud, chronic snoring, interruptions in breathing while sleeping, and somnolence. There are many non-specific symptoms that include morning headaches, mood changes, lack of concentration, and history of diseases such as CHF. Children have specific symptoms such as hyperactivity and behavior problems.

Physical Examination

Generally, the most common signs of sleep apnea are a large waist/neck circumference and facial deformities. If sleep apnea is left untreated, signs of for pulmonale, stroke, hypoxemia, and pulmonary hypertension are evident.

Diagnostic Studies

Laboratory Findings

Laboratory tests are not diagnostic of sleep apnea. Occasionally evidence of anemia, polycythemia, proteinuria, hypercapnia, or low T4 may be found.

Polysomnography

Polysomnography is diagnostic of sleep apnea and is recommended among all patients who are suspected to have sleep apnea during history-taking.

Oximetry

Home oximetry is a portable monitor that records similar information to a polysomnogram. The results of home oximetry are not diagnostic, but may determine the need for polysomnography to either confirm or rule out sleep apnea.

CT

Computed tomography (CT) is not diagnostic of sleep apnea, but can help visualize abnormal airway structures and crania-facial anomalies.

MRI

Magnetic Resonance Imagine (MRI) is not diagnostic of sleep apnea, but can be used to identify anatomical structures that may be associated with the development of sleep apnea.

Ultrasound

Ultrasound is not diagnostic of sleep apnea. Cor pulmonale and pulmonary hypertension may be evident among patients with severe sleep apnea on echocardiography.

Other Diagnostic Studies

Other tests for sleep apnea include EEG, EMG, EOG, ECG, a nasal airflow sensor, and a snore microphone.

Medical Therapy

If left untreated, sleep apnea can have serious and life-threatening consequences such heart disease, hypertension, automobile accidents due to somnolence, and many other ailments. Treatment often starts with behavioral therapy. Medical treatment involves the treatment of the underlying cause and somnolence. Medications, such as acetazolamide and oxygen are not routinely used for the treatment of sleep apnea. The most effective treatments help open the airway such as continuous positive airway pressure (CPAP) and oral appliances.

Surgery

Surgery, usually the second line of treatment, is usually very effective in treating snoring. It could either be an inpatient or an outpatient procedure. Several surgical options exist depending on the site of the obstruction in the airway.

Primary Prevention

Primary prevention of sleep apnea involves lifestyle changes such as weight loss and smoking cessation, reconstruction of facial anomalies, and treatment of underlying medical causes.

Secondary Prevention

Secondary prevention of sleep apnea involves lifestyle changes. These methods reduce the severity of sleep apnea on the patient.


References


Template:WikiDoc Sources