Sleep
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SleepPolysomnography1.pptxDisorders of Sleep & Polysomnography
CPSC 4500 Diagnostics & Therapeutics
Chapter 33 in egan’s
Sleep Apnea
Present when patients have at least 30 episodes of apnea over a 6-hour period of sleep
Apneic period may last 20-90 seconds
Two types: Obstructive and Central (may be mixed with combo of the two)
Sleep studies (polysomnography) aid in diagnosing sleep related disorders
Sleep studies can help determine the cause, severity, and effects of the breathing disorder during sleep
Recorded during sleep study: eye movement, brain wave activity, ECG, presence of apneas, chest and abdominal movement, SpO2, limb movement
Sleep Apnea
Obstructive Sleep Apnea (OSA)- estimated to affect 2-4% of the population (equivalent to asthma & diabetes)
Clinical presentations- sleep disruption due to increased airway resistance, daytime sleepiness (hyper- somnolence), severe oxyhemoglobin desaturation, pulmonary hypertension, right heart failure
Treatment decreases morbidity and mortality*
Sleep apnea defined by repeated episodes of complete cessation of airflow for 10 seconds or longer
Obstructive (upper airway closure) or Central (lack of ventilatory effort)
Obstructive Sleep Apnea
Paradoxical movement of the rib cage and abdomen in response to the closed airway occurs.
Strong/intense respiratory effort with absence of airflow*
Ventilatory effort usually increases until a threshold is reached that triggers a brief arousal seen on the EEG, and airway opening occurs.
Oxyhemoglobin desaturation usually accompanies the event
Central Sleep Apnea
Compared with the events of OSA, no movement of the rib cage or abdomen is present, and the airway remains open.
During an apneic event, there is a lack of ventilatory effort.
A brief arousal on the EEG is associated with a maximal ventilatory effort that usually follows the episode of apnea.
Oxyhemoglobin desaturation may be associated with the event.
Central Sleep Apnea
Central sleep apnea (CSA) is not as common as OSA
Only 10-15% of total sleep apnea patients have CSA
Can be caused by: CNS lesions, stroke, CHF, high-altitude hypoxemia
Can have mixed central/obstructive components*
Hypopnea- significant decrease in breathing without complete cessation of airflow; 30% decrease in flow with a 4% oxygen desaturation
Episodes of hypopnea usually result in arousal from sleep
Absence of inspiratory effort with no diaphragmatic movement
Obstructive Hypopnea
Defined as a reduction of airflow by 30% to 50% for 10 seconds or longer.
Paradoxical movement of the rib cage and abdomen in response to the narrowed airway occurs.
Ventilatory effort usually increases until a threshold is reached that triggers a brief arousal seen on the EEG and complete airway opening occurs.
Oxyhemoglobin desaturation usually accompanies the event and usually is of a lesser degree than occurs with apnea.
Sleep Apnea
Obstructive
Loud snoring
Hyper somnolence*
Morning headache
Nausea
Personality changes
Patient has strong respiratory effort but cannot due to obstruction
Central
Insomnia
Mild snoring
Depression
Fatigue during day
Patient has absence of inspiratory effort with no diaphragmatic movement
CNS disorders
Sleep Apnea
The primary cause of OSA is a small or unstable pharyngeal airway (obesity, small chin, etc.)
Sleep onset is associated with a decrease in the activity of the upper airway dilator muscles resulting in airway narrowing potential closure
Patients with untreated OSA have an increased risk of systemic and pulmonary HTN, stroke, nocturnal arrhythmia, heart failure, and myocardial infarction
An increase in sympathetic tone due to hypoxemia ad hypercapnia may result in pulmonary HTN and right heart failure (cor pulmonale)
Tonsillar hypertrophy is typically the primary cause of OSA in pediatric patients
Sleep Apnea
Obesity has been found to correlate with positively with the presence of OSA; BMI >28 (120% of IBW) should alert the RCP to the possibility of the syndrome
Normal body weight patients with a small or recessed chin or those with a deviated nasal septum may also be predisposed to upper airway closure during sleep
Central sleep apnea have a periodic breathing pattern (an increase and then a decrease in RR and VT)
Cheyne-stokes respirations often occurs in CHF or CVA (crescendo-decrescendo pattern of hyperpnea alternating with apnea)
https://www.youtube.com/watch?v=vKO3INoEks4
Overlap Syndrome
Overlap syndrome is when OSA & COPD occur together
Patients are typically obese with smoking history
Moderate to severe nocturnal desaturation
Tend to have a worse prognosis and more severe ABG abnormalities
May present with COPD exacerbation and decompensated right heart failure
Sleep Apnea
Common clinical manifestations
Male
Age > 40 years
Obesity (neck >16.5 in)
Habitual snoring
Daytime sleepiness
Diurnal hypertension
Bed partner typically observes periods of apnea
Metabolic syndrome
OSA & poor sleep quality are associated with metabolic syndrome (large waist circumference, HTN, impaired glucose tolerance, insulin resistance, elevated triglycerides)
Increased cardiac risks
Polysomnography
When sleep apnea is suspected, an overnight polysomnogram (PSG) should be obtained for confirmation of the clinical diagnosis
Electroencephalogram (EEG)
Electrooculogram (EOG)
Chin electromyogram (EMG)
Airflow (measured at nose and mouth)
Ventilatory effort
Cardiac rhythm (ECG)
O2 saturation (pulse oximetry)
Polysomnography
In OSA, airflow is absent or decreased in the presence of continued ventilatory effort
Paradoxical or asynchronous movement of the abdomen and rib cage can be observed
O2 desaturation depends on the length of the apnea
Nasal pressure is a reliable way to detect hypopnea and is well tolerated by patients undergoing a diagnostic PSG
The sleep tech scores the study by # of apneas and hypopneas per hour of sleep and is reported as the respiratory disturbance index (RDI)
Polysomnography
Osa severity
The American Academy of Sleep Medicine (AASM) has defined the severity of OSA as follows:
RDI 5-15 = mild
RDI 15-30 = moderate
RDI >30 = severe
Apnea/hypopnea index (AHI) is same as RDI
Factors reported
Arousal index
Sleep stage distribution (EEG, EOG, EMG)
Frequency of desaturations
Mean O2 saturations
Nadir (lowest) of O2 saturations
Therapeutic Intervention
Management of OSA should individualized, but can be classified into 3 options:
1. Behavioral: should be pursued by all patients
2. Medical: tailored to individual
3. Surgical: tailored to individual
The likelihood of acceptance of and adherence to the prescribed therapeutic intervention must be considered
Goals of treatment: normalize O2 saturation/ventilation, eliminate apnea, hypopnea, and snoring, and improve sleep architecture and continuity
Therapeutic Intervention
Patients need to be informed of the risks of uncontrolled sleep apnea…educated by RCP!
Behavioral interventions include weight loss if needed, avoidance of alcohol, sedatives, hypnotics, and avoidance of sleep deprivation
Alcohol decreases the arousal threshold and may increase the duration of apneas & reduces upper airway muscle tone making it more prone to closure
Sedatives/hypnotics can suppress certain stages of sleep
Sleeping on one’s side or with the head of the bed elevated can be beneficial if snoring occurs in the supine position
CPAP
Continuous positive airway pressure (CPAP) is the first-line medical therapy for OSA
The level of CPAP required for optimal mgmt. of OSA is best determined with a titration performed in the sleep lab
Can decrease morbidity and mortality
Obstruction of the upper airway is abolished by CPAP pressures between 7.5-12.5 cmH20
Can decrease excessive daytime sleepiness (EDS) & the incidence of pulmonary HTN and RHF
CPAP works by “splinting” the upper airway open and by moving the soft palate up against the tongue
CPAP
Approximately 80% of patients accept CPAP, the others have difficulty with adherence to therapy
Objective compliance- more than 4 hours per night for more than 70% of observed nights (only 46%)
Discomfort with device interface, claustrophobia, etc.
Devices available: full face masks, nasal pillows, nasal prongs, nasal masks, oral-nasal masks, chin straps
BiPAP
Bi-level positive airway pressure (BiPAP): different pressure requirements for between inspiration (IPAP) and expiration (EPAP)
Generally more expensive than CPAP devices
IPAP & EPAP are increased together until apnea is eliminated; IPAP is then increased independently to eliminate hypopnea, snoring, and arousals
Auto-titrating CPAP: use a computer algorithm for adjusting the level of CPAP in response to dynamic changes in airflow and airway vibration (snoring)
May be useful in facilitating therapeutic CPAP titrations, but not a replacement for diagnostic testing
Adverse Effects of PAP
Side effects of positive pressure therapy are:
claustrophobia- change interface
nasal congestion- nasal steroids
rhinorrhea- antihistamines
skin irritation-lotions
nasal dryness- saline spray
A humidifier can be used in-line with CPAP or BiPAP; heated humidification has been shown to improve compliance*
If the pressure is too much for the patient, a ramp (gradual increase over 5-45 minutes) system device can be used
Oral Appliances
Oral appliances- devices that enlarge the airway by moving the mandible forward or by keeping the tongue in an anterior position; custom fitted by dentists
Less effective than CPAP, but more cost effective
Second-line intervention for severe OSA, but mild cases and patients who are not compliant may benefit
Oxygen therapy- useful for patients with desaturation who refuse positive pressure therapy; has no significant effect on ventilatory arousals and daytime sleepiness
Should be used with caution in COPD patients that are CO2 retainers
Surgical Intervention
Uvulopalatopharyngoplasty (UPPP)- palatal surgery performed with a standard “cold knife” technique or laser
Portions of the soft palate, the uvula, and any additional tissue are removed; success rate of ~50%
Site of physiologic obstruction cannot be predicted correctly with preoperative imaging
Maxillofacial surgery- shows more promise in patients with COPD than UPPP alone
Phase 1: UPPP + genioglossal advancement
Phase 2: advancement of the maxilla & mandible
Perioperative CPAP helps to reduce upper airway swelling and edema present in OSA, before and after surgery
Role of RT in Sleep Disorders
Prompt diagnostic testing
Directly observe evidence of sleep disordered breathing
Member of sleep lab team
Pursue special certifications in Sleep Technology NBRC: Sleep Disorders Specialty (SDS), Certified or Registered Polysomnographic Technologist (PGST)
Home care
Pre & post op (STOP-Bang Questionnaire)
Snoring, Tired, Observed, Pressure, BMI, Age, Neck size, Gender
Changes in Sleep Practice
Home sleep testing is becoming more prevalent, though is not recommended for everyone
Third party payers request (or demand) what type of test will be covered
Payment for patient outcomes versus payment for procedures
When patient perceives testing as “easier”, may be more likely to get evaluated
Auto adjusting PAP to avoid titration studies
Patients requiring clearance for CDL
More frequent testing of pediatric patients
Screening for OSA preoperatively
Terminology
Sleep bruxism – teeth grinding
Xerostomia– dry mouth
Macroglossia – enlarged tongue which may cause scalloped edges
Micrognathia – undersized jaw (mandibular hypoplasia)
Retrognathia – small recessed lower jaw
Mallampati Classification
Evaluation of the airway predicting the ease of intubation. Class III and IV are considered inadequate exposure of the posterior pharynx and are likely in severe obstructive sleep apnea.
Additional Considerations
Broad mental and physical implications of sleep deficiency
Suicidal behavior
Impairment of cognitive function
Depression
Irritability
Decreased concentration
Increased alcohol, sedative, tobacco use
Neuromuscular disease may be associated with a higher incidence of SDB
Ischemic stroke
Parkinson’s disease
Amyotrophic lateral sclerosis
Pediatrics
OSA prevalence in children 2-3%
Most often associated with adenoid/tonsillar hypertrophy = pharyngeal occlusion
Obesity, ethnicity (African American)
Allergic rhinitis, Asthma
Naso-septal obstruction
Pediatric AHI: 1-5 mild, 6-10 moderate, > 10 severe
May experience neurobehavioral consequences
Poor academic performance, ADD, accidental injuries
Insulin resistance, increased food consumption
Miscellaneous Tests
Maintenance of wakefulness test (MWT)
Measure how alert you are during the day
Ability to stay awake as important as how fast you fall sleep
May limit activities (i.e. driving)
Used to assess efficacy of therapeutic intervention
Multiple Sleep Latency Test (MSLT)
Tests for excessive daytime sleepiness by measuring how quickly you fall asleep in a quiet environment during the day
Sometimes referred to as a daytime nap study
5 scheduled naps, awakened after 15 minutes
Helps to diagnose hypersomnias and narcolepsy
