Sleep Study
Hatem Ezz eldin Hassen MD
Consultant of Phoniatrics KFHJ
Obstructive episodes
Arousals /nocturnal choking
Excessive daytime sleepiness
Abnormal motor movements
Morning headaches
Nasal obstruction
Weight gain
Drugs: alcohol intake
Cardiovascular symptoms
Respiratory symptoms
Thyroid symptoms
Social history
General appearance
Blood pressure
Craniofacial morphology
Nasal airway
Tongue size,
Soft palate/uvula/tonsils
Nasopharynx - adenoids / polyps / cyst / tumor
Hypopharynx-lingual tonsils/vallecula, epiglottic or
supra-glottic cysts / tumour
Larynx-vocal folds mobility
To assess the patient's general condition
To differentiate between simple snoring and
sleep apnea and determine the presence, type
and severity of any apneas or hypopneas and,
To assess the site of
airway obstruction
 Lateral cephalometry
 Naso-optic fibroscopy (Muller’s maneuver)
Sleep nasendoscopy
 Computed tomography (CT)
 Magnetic resonance imaging (MRI)
 Acoustic reflection technique
 Pharyngeal manometry
 Acoustic analysis of snoring sounds
*is the gold standard investigation in the
diagnosis of OSAS and other forms of sleep
related disorders.
*multiple simultaneous recording of physiologic
measures during sleep.
Normal sleep entails a cyclical progression from non rapid eye
movement sleep (N-REM) to rapid eye movement sleep (REM)
with a periodicity of 90-120 minutes.
During N-REM sleep, subjects pass through 4 stages which
represent progressively deeper sleep states.
During REM sleep, increased movements and EEG activity
occurs with characteristic eye movements. Dreaming &
Obstructive episodes are likely to occur during REM sleep
A normal young adult would spend 5 % of the night in stage 1, 45
% in stage 2, 15 % in stage 3, 10 % in stage 4, and 25 % in REM
sleep (Baker, 1986).
Electroencephalogram (EEG).
Submental electromyogram (EMG).
Electro – oculogram (EOG) : These three measurement are needed for
sleep staging and allow differentiation between sleep and wakefulness.
Oxygen saturation (PO2): by Modern pulse oximeters
Electrocardiogram (ECG) : To monitor apnea associated arrhythmias.
 Nasal and oral airflow: airflow is usually detected using heat sensitive thermoisters. These are not able to
quantify airflow but simply detect its presence or absence. Absence of airflow for greater than 10 sec. Will be
counted as an apnea.
Chest and abdominal movement: patients wear an elasticized belt around the chest and abdomen into witch are
incorporated strain gauges that measure changes in circumference. This information allows differentiation
between central and obstructive apnea.
Anterior tibialis EMG: Allows the diagnosis of “periodic movements during sleep”
Sleeping position detector :
Sleep Lab
A: Central apnea B: Obstructive apnea
Sleep Related Breathing Disorders - Definitions
Snoring: is a noise generated from the upper airway due to partial airway
An apnea: is the cessation of airflow at the nostrils and mouth for at least 10
The apnea index (AI): is the number of apneas per hour of sleep.
Hypopnea: a decrease in airflow associated with oxygen desaturation
The apnea Hypopnea index (AHI): apneas + Hpopneas per hour of sleep
The respiratory disturbance index (RDI): the total number of obstructive apneas,
hypopneas, and central apneas per hour.
The sleep apnea syndrome (SAS): 30 or more apneic episodes during a 7-hour
period of sleep or an apnea index equals to or greater than 5.
The American sleep association grades sleep apnea as follows:
Mild: (AHI 5-15)
Moderate: (AHI 5-30)
Severe: (AHI >30)
Sleep Related Breathing Disorders - Definitions
Obstructive sleep apnea: The cessation of airflow in the presence of
continued respiratory effort . Due to Upper airway obst.
Central sleep apnea: No flow of air at the nose or mouth associated with
a cessation of all respiratory effort. These patients may or may not snore.
Heart failure, frontal lobe damage or brain- stem lesions. Often no
apparent cause, and it is thought to be related to instability of the
respiratory control mechanisms.
Mixed apnea: this usually begins as a central apnea with no airflow or
respiratory effort followed by increasingly forceful respiratory efforts
again with no airflow until airway clears.
Obstructive apnea is more common than central apnea though any
individual may demonstrate one or more of the above forms of apneas
during a night's sleep.
Upper Airway Resistance Syndrome
Episodes of marked partial upper airway obstruction but, no
complete obst. of the airway. They are able to maintain their
oxygen saturation but need so much respiratory effort to
overcome the partial obstruction that they induce frequent
micro arousals
They usually have symptoms similar to those with OSA.
Treatment of UARS is similar to that of OSA; the use of CPAP
usually is effective.
Main difference between UARS and OSA is the there is no
hypoxia related to UARS.
After complete sleep study the following information is scored:
Lights out
Sleep Latency – from lights out to onset of sleep
Sleep Stages
Non-REM – N1, N2, N3
Sleep Efficiency – percentage of time asleep
Respiratory Events
Leg Movements
Heart Rhythms
Snoring intensity
Lights on
Quality of patient’s sleep compared to baseline
Scoring Respiratory Events
Apnea – when all of the following criteria are met
There is a drop in the peak thermal sensor excursion by >90%
of baseline
The duration of the event lasts at least 10 seconds
At least 90% of the event’s duration meets the amplitude
criteria for apnea
Classified as: obstructive, central, or mixed based on
respiratory effort
Hypopnea – when all of the following are met
1) The nasal pressure signal excursion drops by 30% of baseline
The duration of this drop occurs for a period of at least 10
There is a 4% desaturation from pre-event baseline
At least 90% of the event’s duration meets the amplitude
Hypercapnic CSA
Impaired Central Drive ("Won’t Breathe"): 
1-Tumors or trauma-induced lesions to brainstem
2-congenital central hypoventilation syndrome (Ondine curse)
3-opioid-induced CSA
4- OHS
Impaired Respiratory Motor Control ("Can’t Breathe")
1-myasthenia gravis
2-amyotrophic lateral sclerosis
3-post-polio syndrome
5-Chest wall syndromes such as kyphoscoliosis
PSG Indications: Nonrespiratory Disorders
A PSG preceding an MSLT is indicated for evaluation of
suspected narcolepsy or to help differentiate narcolepsy from
idiopathic hypersomnia.
PSG is indicated for evaluation of suspected periodic limb
movement disorder but NOT the restless legs syndrome (RLS; a
clinical diagnosis).
A PSG is indicated to evaluate (1) nocturnal behavior possibly
due to seizures, (2)atypical parasomnia behavior (frequent
episodes each night ,stereotypic behavior, or behavior unusual
for age), (3) nocturnal behavior/parasomnia that has resulted in
injury to the patient or others
Portable Monitoring for OSA in Adults
Types of Monitoring Devices
Type 1 – in sleep center, attended, overnight polysomnogram
Type 2 – record same variables as type 1, unattended (at home)
Type 3 – evaluate four physiologic parameters – not sleep
respiratory movement and airflow
heart rate
arterial oxygen saturations
(snoring), (position)
Type 4 – evaluate one or two parameters (saturation and airflow)
Approach to Reading the PSG
Before the PSG is read, a review of the clinical history with special
attention to symptoms of sleep apnea, narcolepsy, RLS, and
medications is very useful.
The presence of underlying lung disease may help explain a low
awake arterial oxygen saturation (SaO2) or low baseline sleeping
A clinical history of pacemaker insertion or known atrial
fibrillation is also very helpful in providing a useful interpretation of
ECG findings.
All digital PSG systems have a view that shows graphical
summary information of the entire night. It is often useful to look
at the big picture before going through the data in smaller time
Tips for the clinician:
• The clinician should recognize that many patients with
significant OSA do not complain of daytime sleepiness.
• A history of snoring and gasping would suggest a PSG
is indicated.
• It should also be noted that some patients with OSA
complain of insomnia.
• A PSG for PAP titration is the standard procedure to
select a level of pressure for treatment.
• The titration can be performed on a separate night after
a diagnostic PSG or during the second part of the night
during a split (partial night) study.
Indications of Split Study:
(1) AHI > 40 /hr with at least 2 hours of monitoring,
(2) AHI of 20 to 40 with special clinical circumstances such as
severe desaturation or arrhythmia thought due to OSA
(3) at least 3 hours remain for the PSG titration.
Indications of PSG Repeat:
Time for CPAP titration is < 3 hours
If the patient is being treated on CPAP and is NOT doing
well, a repeat PSG study on CPAP is indicated.
PSG is also indicated if a patient on CPAP gains > 10% of
body weight to determine whether the pressure is adequate.
Dyspnea due to pulmonary edema
Idiopathic hypersomnia
Nocturnal panic attacks
Obesity-hypoventilation syndrome (pickwickian syndrome
Simple snoring
Chronic Obstructive Pulmonary Disease
Gastroesophageal Reflux Disease
Periodic Limb Movement Disorder
Classic tetrad of
1- excessive daytime sleepiness (EDS),
2- cataplexy,
3- hypnagogic hallucinations,
4- sleep paralysis.
Narcolepsy is thought to result from genetic predisposition, abnormal
neurotransmitter functioning and sensitivity, and abnormal immune
 Diagnosis
The combination of an overnight polysomnogram (PSG) & a
multiple sleep latency test (MSLT) showing sleep latency 8 minutes or
less and 2 or more sleep-onset random eye movement (REM)
periods strong suggests narcolepsy
An alternative criterion is a cerebrospinal fluid hypocretin level of
110 pg/mL or less.
Restless Legs Syndrome
Periodic leg movements of sleep [PLMS]). PLMS are
characterized by involuntary, forceful dorsiflexion of
the foot lasting 0.5-5 seconds and occurring every 2040 seconds throughout sleep.
excessive daytime somnolence
sleep disturbances, daytime fatigue, and involuntary,
repetitive, periodic, jerking limb movements (either
while the patient is asleep or while he or she is awake
and at rest). A positive family history also aids in the
diagnosis of RLS, especially in children.
Thank You
 Pulse ox, EEG, EOG, ECG, EMG,
oral/nasal airflow, respiratory effort,
limb/body movements
 Apnea – lack of ventilation for ≥10 sec with
signs of arousal
 Hypopnea – decrease in respiratory
movement with a drop in O2 sat or with
signs of arousal
 AHI or RDI =(Apneas + Hypopneas)/hours
of sleep
Important parameters
 Lowest O2 saturation
 Number of desaturations below 90%
 Length of time below 90%
Medical Management
Pressure must be
individually titrated
 Compliance is as low as
 Air leakage, eustachian
tube dysfunction, noise,
mask discomfort,
The tests are not always performed in the home ;hence,
the terms HST or PM are not ideal but are used in
much of the literature on this subject.
In the past, PM has been used to diagnose OSA in
settings in which access to PSG is limited or delayed.
The original classification used “level I, II, III, and IV”
to refer to different classes of monitoring but currently
the terminology is “type 1, 2, 3, and 4.”
The Centers for Medicare and Medicaid Services (CMS)
has a different classification for monitoring The CMS
terminology defines the respiratory disturbance index
(RDI) as the total number of apneas and hypopneas per
hour of monitoring time. Therefore, the index
determined by PM (no EEG) would be an RDI using
the CMS definition. CMS also refers to PM as HST.
Medical Management
Useful when > 6 cm H2O difference in
inspiratory and expiratory pressures
 No objective evidence demonstrates
improved compliance over CPAP
Portable Monitoring for OSA in Adults
Limitations of Type 3 devices
Apnea Hypopnea Index – abnormal breathing events
by recording time as sleep can not be recorded
Unless the patient was sleeping the entire recording
time, the AHI calculated by a portable monitor will
likely be lower than an attended polysomnogram
Can not distinguish sleep stages
Friedman algorithm for treatment
Mild (AHI 5-15)
Symptomless: behavior modification
 Symptoms: behavior, device, consider surgery
Moderate (AHI 15-30)
Symptomless: behavior, device
 Symptoms: device, consider surgery for device
Severe (AHI >30)
Device, consider surgery as adjunct, refer for
bariatric surgery BMI>40, consider tracheostomy
Sleep disordered breathing (SDB) is characterized by
repetitive episodes of diminished and cessation of breathing
during nocturnal sleep (Block et al, 1980).
The spectrum of SDB ranges from chronic snoring and upper
airway resistance syndrome to obstructive sleep apnea
(Guilleminault et al., 1991).
Grades of Sleep Apnea Severity
The severity of OSA was determined by the
Mild: AHI 5-15
Moderate: AHI 15-30
Severe: AHI greater than 30
Obstructive Sleep Apnea
Respiratory Disturbance Index (RDI) –
no longer used
apneas, hypopneas, respiratory related arousals
Apnea-Hypopnea Index (AHI)
total number of respiratory events / hours of sleep
Severity of OSA defined by the AHI:
5 – 15
15 – 30
> 30
– not sleep apnea
Diagnosis of the site of upper airway
Muller’s Maneuver
 Sleep endoscopy
 Fluoroscopy
 Manometry
 Cephalometrics
 Dynamic CT scanning and MRI scanning
 Mallampati Airway Classification
 Friedman Classification
The report can include a measure of the sleep onset time (latency) and
the proportion of sleep time spent in each of the sleep stages.
Obstructive sleep apnea is characterized by absence of airflow at the
nose and mouth despite the presence of respiratory effort (thoracic and
abdominal). is caused by a structural narrowing of the upper airway that
becomes manifest when muscular tone diminishes during sleep
central sleep apnea, the patient’s airway is normal, but airflow is absent
because of an absence of respiratory effort. Central apnea is caused by a
neurological defect in the control of respiration, such as with bulbar
poliomyelitis, degenerative neurological diseases, intracranial neoplasm,
brain stem infarction, narcotic or sedative overdose, bilateral cervical
Mixed apnea is diagnosed when elements of central control and
obstruction are both found to be contributing to the apnea. It is
generally classified with the predominating element. However, in many
cases of advanced obstructive sleep apnea, a central element is notable
Sleep Disordered Breathing
Primary snoring
Upper airway resistance syndrome (UARS)
RDI < 5
Arousal Index > 5
Obstructive sleep apnea syndrome (OSAS)
RDI < 5
No daytime sleepiness
RDI > 5
O2 desaturation < 90%
Obesity hypoventilation syndrome (Pickwickian)
BMI >30 kg/m2
Daytime hypercapnia w/ PaCO2 ≥ 45mmHg
Sleep disordered breathing

similar documents