|
Adeno-tonsillar
Adenoid and tonsillar tissue.
Apnea
The cessation of airflow at the nostrils and mouth for at
least 10 seconds. Literally means "no breath".
Apnea Index (AI)
A measure of the severity of sleep apnea; the number of all
types of apnea events per hour.
Apnea/Hypopnea Index (AHI)
The number of apneas and hypopneas per hour. Also known as
the Respiratory Disturbance Index (RDI).
Arousal
Abrupt change from sleep to wakefulness or from a "deeper"
stage of non-REM sleep to a "lighter" stage. These
often correlate with changes in heart rate.
Arrhythmia
A deviation in the normal pattern of the heartbeat.
Autonomic Arousal Index
Alterations in heart rate by >10 beats/minute for at least
five seconds, separated by >10 seconds in duration.
Basic Sleep Cycle
Progression through orderly succession of sleep states and
stages. For the healthy adult, the first cycle begins in going
from wakefulness to non-REM sleep. The initial REM period
follows the first period of non-REM sleep, and the two sleep
states alternate throughout the night with an average period
of about 90 minutes. A night of normal human sleep usually
consists of 4-6 non-REM/REM sleep cycles.
Bi-Level
Two level pressure device used to treat sleep apnea. A lower
pressure is used during exhalation and a higher pressure during
inhalation. Bi-Level machines are more expensive than a standard
CPAP device, but some patients tolerate it better because
they can exhale more comfortably against the constant inhalation
pressure. (Sometimes called Bi-PAP, but that is a trademark
name of one system).
Biological Clock
The brain process causing us to have 24-hour fluctuations
in body temperature, hormone secretion, and other bodily activities.
The most important function provides for the daily alternation
of sleep and wakefulness.
Body Mass Index (BMI)
Abbreviation for body mass index, the most popular tool for
defining what are healthy weight, overweight, and obesity
in an individual.
Body Position
Positions in which the patient is sleeping. Often quantitated
into supine (back), and non-supine categories. The percentage
of time spent sleeping in each position is measured.
Bradycardia
Heart rhythm with a rate lower than 60 beats per minute in
an adult.
Bruxism
The compulsive, unconscious grinding of teeth, especially
during sleep.
Central Apnea
Absence of airflow caused by a complete cessation of all respiratory
effort to breathe. Abnormalities of respiratory control in
the brain or elsewhere can produce central apnea.
Cheyne-Stokes Respiration
A breathing pattern typified by regular "crescendo-decrescendo"
or waxing and waning fluctuations in tidal volume. Often seen
in the setting of neurologic disease, congestive heart failure,
and high altitute.
Circadian Rhythm
The inherent daily fluctuation of behavioral and physiological
functions including the sleep/wake cycle, generally tied to
the 24 hour day-night cycle but sometimes to a different periodicity
especially when light/dark and other time cues are removed.
Continuous Positive
Airway Pressure (CPAP)
Application of positive air pressure at a constant level to
help keep an airway open by acting as a pneumatic "splint",
thus preventing the airway from collapsing during sleep. Measured
in cm of H2O pressure.
Desaturation
A reduction of the value of the oxygen saturation (SaO2).
Electrocardiograph (EKG)
A device used in measuring the electrical activity of the
heart.
Epworth Sleepiness Scale
An index of sleep propensity (tendency) during the day as
perceived by a patient, and derived from the answers to 8
standardized questions.
Excessive Daytime Sleepiness or Hypersomnolence
(EDS)
A subjective report of difficulty in staying awake, accompanied
by a ready entrance into sleep or diminished consciousness
when an individual is sedentary.
Fragmentation (Pertaining
to Sleep Architecture)
The interruption of a sleep stage as a result of the appearance
of a lighter stage, or to the occurrence of wakefulness, which
leads to a disrupted non-REM to REM sleep cycle.
Gastroesophageal Reflux Disease (GERD)
The abnormal flow of stomach acid upwards into the esophagus
that can cause arousals and disrupt sleep.
Humidification
Adding moisture to the airflow as an adjunct to Continuous
Positive Airway Pressure (CPAP) therapy in the treatment of
obstructive sleep apnea syndrome (OSAS). Humidification can
be added to the CPAP by diverting the airflow over or through
a cool or heated water reservoir (humidifier) to prevent the
upper airway from drying out.
Hypersomnia
Sleep of excessive depth or abnormal duration often characterized
by a state of confusion upon awakening. Usually caused by
psychological rather than physical causes.
Hypertension (HTN)
A persistent elevated blood pressure that is often asymptomatic.
Hyperventilation
An increased rate and/or depth of breathing.
Hypopnea
A decrease in breathing in which the airflow in and out of
the airway is less than half of normal--usually associated
with oxygen desaturation and commonly caused by partial airway
obstruction. The presence of some airflow distinguishes this
event from apneic episodes.
Hypoventilation
A reduced rate and/or depth of breathing.
Hypoxemia
Reduced oxygen tension in arterial blood.
Hypoxia
The condition in which an inadequate amount of oxygen reaches
the tissues of the body. The tissues most sensitive to hypoxia
are the brain, heart, pulmonary vessels and liver.
Idiopathic Dilated
Cardiomyopathy
Disorder in which the heart muscle is weakened and cannot
pump blood efficiently from an unknown cause.
Impotence
The inability of the adult male to achieve penile erection.
Insomnia
The chronic inability to fall asleep or remain asleep during
the night.
Laser Assisted Uvulopalatoplasty
(LAUP)
Laser removal of soft palate tissue which can eliminate or
decrease snoring but has not been shown to be effective in
the treatment of severe sleep apnea.
Lingual
Pertaining to the tongue.
Maxillo-mandibular Anomalies
Developmental abnormalities of the upper and lower jaws.
Micro-arousal
A partial awakening from sleep of short duration.
Mixed Apnea
An interruption in breathing during sleep beginning as a central
apnea then becoming an obstructive apnea.
Multiple Sleep Latency Test (MSLT)
A test utilized to assess excessive daytime sleepiness by
having a patient take a series of naps during the day.
Myoclonus
Muscle contractions in the form of spasms or twitches.
Narcolepsy
A sleep disorder often characterized by sudden sleep attacks
and an abnormal tendency to pass directly from wakefulness
into REM sleep in a short time.
Nares
The pairs of openings in the nose that allows passage of air
from the nose to the pharynx during breathing.
Nasopharyngeal
Pathway through the nose and throat .
Nocturia
Urination, often frequent or excessive, during the night.
Nocturnal
"Of the night" pertaining or occurring during the
hours of darkness, which is considered the normal time for
sleep to occur.
Obesity-Hypoventilation Syndrome
The term applied to obese individuals who hypoventilate during
sleep and wakefulness causing abnormal blood gas values. Known
as Pickwickian syndrome when accompanied by erythrocytosis
and cor pulmonale.
Obstructive Apnea
The cessation of airflow for at least 10 seconds in the presence
of continued inspiratory effort. In sleep these are often
caused by a mechanical obstruction, such as a semi-collapsed
airway, a tongue relaxing in the back of the throat, or large
tissue in the uvula area.
Obstructive Sleep Apnea Syndrome
(OSAS)
A clinical spectrum of chronic disease caused by repeated
apneic or hypopneic events during sleep.
Oral Dental Devices
Oral appliances, available from dentists specializing in treating
dental sleep medicine, may be used in selected patients alone
or in combination with other means to treat OSA. These devices
work by bringing the lower jaw forward, and/or elevating the
soft palette, and/or retaining the tongue from falling back
into the airway.
Oxygen Desaturation
A decreased amount of oxygen carried by hemoglobin in the
arterial blood.
Oxygen Saturation (SaO2)
A measure of oxygen carried by hemoglobin in the arterial
blood. It is expressed as a ratio of the oxygenated hemoglobin
molecules to all of the hemoglobin molecules (oxygenated and
non-oxygenated). Values of arterial oxygen saturation in a
young healthy adult are typically above 95%.
Oximeter (Pulse)
An instrument that gives estimates of arterial oxyhemoglobin
saturation (SaO2) by measuring absorption of selected wavelengths
of light in blood non-invasively. It is usually measured in
peripheral tissues such as the fingers or earlobes.
Pedal Edema
A swelling of the lower extremities resulting from the excessive
accumulation of fluid in the tissues typically seen in heart
failure.
Periodic Breathing
These are repetitive apneic pauses or repetitive patterns
of inconsistent tidal volumes. They are common in premature
infants.
Periodic Limb Movement Disorder (PLMD)
A syndrome also known as periodic leg movements or nocturnal
myoclonus. Characterized by periodic episodes of repetitive
and highly stereotyped limb movements occurring during sleep.
The movements are often associated with a partial arousal
or awakening; however, the patient is usually unaware of the
limb movements or frequent sleep disruption. Between the episodes,
the legs are still. There can be marked night-to-night variability
in the number of movements or in the existence of movements.
Pharynx
The area posterior to the nares and the oral cavity. It is
the passageway for air from the nasal cavity or mouth to the
lungs via the larynx and the trachea and also for food and
liquids from the mouth to the esophagus.
Pulmonary Hypertension
High blood pressure in the vessels supplying blood to and
from the lungs.
Radiofrequency Tissue Ablation
A procedure (Somnoplasty) for treating nasal obstruction,
snoring and in some cases, sleep apnea. Uses radiowave energy
to reduce snoring and the size of the soft palate.
REM Sleep
Rapid Eye Movement sleep. Sleep characterized by the most
active brain activity, flitting motions of the eyes, and weakness
of the muscles. Most dreaming occurs in this stage, which
accounts for about 20 - 25% of sleep in adults.
Respiratory Disturbance Index
(RDI)
An index that includes all respiratory events (apneas and
hypopneas) per hour.
Restless Legs Syndrome (RLS)
A sleep disorder characterized by a deep creeping, or crawling
sensation in the legs that manifests itself as unilateral
or bilateral twitches in the legs. Episodes generally last
from five minutes to two hours and can alternate with periods
of normal sleep. Leg movement relieves the sensations.
Restlessness (Referring to Quality of Sleep)
The persistence of recurrent body movements, arousals, and/or
brief awakenings in the course of sleep.
Right Heart Failure
Inability of the right ventricle of the heart to pump blood
at high pressures.
Septoplasty
Surgery on the nasal septum (tissue dividing the nasal passage).
Sleep
A state marked by lessened consciousness, lessened movement
of the skeletal muscles, and depressed metabolism.
Sleep Debt
The result of recurrent sleep deprivation which occurs over
time when an individual does not experience a sufficient amount
of the restorative daily sleep that is required to maintain
a sense of feeling rested and refreshed.
Sleep Disorders
A broad range of illnesses arising from many causes including
dysfunctional sleep mechanisms, abnormalities in physiological
functions during sleep, abnormalities of the biological clock,
and sleep disturbances that are induced by factors extrinsic
to the sleep process.
Sleep Hygiene
The practices that promote effective and restorative sleep,
including regularity of bedtime and wakening time, the obtaining
of adequate amounts of restorative sleep on a daily basis
and the restriction of alcohol and caffeine beverages prior
to bedtime. Avoiding exercise before sleep, proper nutritional
practices, and adjusting environmental factors so that they
enhance, not disturb, restful sleep all contribute to proper
sleep hygiene.
Sleep Pattern (24 hour sleep-wake pattern)
An individual's clock schedule of bedtimes and rise times
as well as nap behavior. This may also include time and duration
of sleep interruptions.
Snoring
The noise produced primarily with inspiratory respiration
during sleep coming from the vibration of the soft palate
and the pillars of the oropharyngeal inlet. Many people having
this symptom have incomplete obstruction of the upper airway,
and may develop obstructive sleep apnea.
Soft Palate
The membranous and muscular fold suspended from the posterior
margin of the hard palate and partially separating the oral
cavity from the pharynx.
Somnoplasty
The common name for radiofrequency ablation of tissues in
certain sleep disorders.
Tachycardia
A sustained rapid heart rate, usually defined by a pulse rate
of over 100 beats per minute (bpm).
Tidal Volume
The volume inhaled or exhaled in a normal breath.
Titration
The progressive, stepwise increase or decrease in CPAP pressure
to find the minimal pressure needed to keep the airway open
in a sleep apnea patient.
Upper Airway
The parts of the respiratory anatomy that include the nose,
nostrils, sinus passages, septum, turbinates, tongue, jaws,
hard and soft palate, muscles of the tongue, and throat.
Upper Airway Resistance Syndrome (UARS)
A part of the spectrum of obstructive sleep-related breathing
disorders in which repetitive increases in resistance to airflow
in the upper airway lead to brief arousals and daytime hypersomnolence.
Apneas and hypopneas may be totally absent. Blood oxygen levels
and peripheral saturations can be in the normal range.
Uvula
A soft tissue structure hanging from the posterior aspect
of the soft palate in the midline at the back of the tongue.
It is frequently enlarged in sleep apnea patients.
Uvulopalatopharyngoplasty
(UPPP)
Also abbreviated as UP3. Surgical resection of soft tissue
of the uvula, soft palate, and posterior tonsillar pillars.
UPPP is an accepted means of treatment for sleep apnea and
has a curative rate of less than 50%. Scientific evidence
suggests that UPPP works best in retropalatal and combination
retropalatal and retrolingual obstruction.
(back
to top)
|
