Sleep Disorders
MODULE F
Types of Sleep Disorders
• Obstructive Sleep Apnea
• Central Sleep Apnea
• Mixed
• Hypopnea
Polysomnography
• Early 1980’s sleep disorders were acknowledged by the medical community.
• Sleep apnea• Apnea during sleep for periods of 10 seconds
or longer with an apnea index of 5/hour.• Patient often has 30 or more episodes over a
4-6 hour period.• Apnea may last 20 – 90 seconds.
Hypopnea
• Decreased rate and depth of breathing.
• Monitor Respiratory Disturbance Index (RDI).• Number of respiratory events per hour of sleep• Includes both apneas and hypopneas.• Usually 10 – 15 events/hour is significant.
Stages of Sleep
• 5 stages of sleep• Non-Rapid eye movement (Non-REM)
• Stages 1-4• Quiet or slow wave sleep
• Rapid eye movement (REM)• Stage 5• Active or dreaming sleep
Stages of Sleep
• Each stage is associated with characteristic:• Electroencephalographic (EEG) Patterns• Electro-oculographic Patterns (EOG)• Electromyographic Patterns• Behavioral Patterns• Breathing Patterns
Non-REM Sleep
• 4 Stages• Each progressing into a deeper sleep• Lasts 60 – 90 minutes• Most of the time is spent in phase 2
REM Sleep – Stage 5
• Burst of fast alpha rhythms in the EEG tracing.
• Respiratory rate decreases and Vt becomes shallow.
• Hypoventilation and apnea.
• Decrease in both the hypoxic and hypercapnic ventilatory response during REM.
• Constitutes 20 – 25% of sleep time.
REM Sleep
• Rapid eye movement.
• HR becomes irregular.
• Dreaming occurs.
• Paralysis of movement.• Arms, legs, intercostal & upper airway
muscles.
• Loss of muscle tone in the upper airway results in airway obstruction.
REM Sleep
• REM lasts 5 – 40 minutes and recurs every 60 –90 minutes.
• More difficult to awake a person in REM.
40 Million People Suffer from Abnormal Sleep
• Narcolepsy
• Parasomnias
• Nocturnal leg cramps (restless leg syndrome)
• REM Behavior Disorders
• Insomnia
• Sleep Apnea
Polysomnography
• Overnight test done in a sleep clinic.• 6 ½ to 7 hours
• Multiple monitors are used to assess the patient.
• Patients are often videotaped.
Monitoring
• Respirations (nasal air-flow) • SpO2
• Respiratory Effort• Inductive plethysmography or esophageal
balloon
• Brain wave activity• Eye movement – electro-oculogram• Heart activity• Body position
Summary of Results
• # of apneas and hypopneas are summed and averaged over the night-time to calculate the average number of respiratory disturbances per hour.• Respiratory Disturbance Index
• SpO2 levels below 85% are indicative of sleep apnea.
Consequences of Sleep Apnea
• Increase MVA’s
• Increase work related accidents
• Poor job performance
• Depression/Inability to concentrate
• Family Discord
• Decreased quality of life
Obstructive Sleep Apnea
• Most common of the sleep apneas.
• Partial or complete obstruction of the upper airway during sleep.
• Absence of airflow at the nose/mouth but inspiratory efforts are present; O2 desaturation.
• Can develop Cor Pulmonale.
Obstructive Sleep Apnea
• Symptoms• Loud habitual snoring,
choking/gasping/snorts • Morning headaches• Daytime sleepiness (hypersomnolence)• Obesity• Hypertension• Nocturnal enuresis• Impotence• Personality changes/depression
Obstructive Sleep Apnea
• Profile• Upper body obesity• Neck size #17 or larger in men• Neck size #16 or larger in women• Hypertension• C/O daytime sleepiness
Pickwickian Syndrome
• Obesity
• Excessive daytime sleepiness
• Sleep apnea
• Decreased pulmonary function
• Chronic ventilatory failure• Hypoxic drive
Central Sleep Apnea
• Respiratory centers of the medulla fail to send signals to the respiratory muscles
• Cessation of airflow at the nose and mouth, no inspiratory efforts & desaturation of Hb
• Associated with CNS disorders
• Accounts for 10% of all sleep apneas
Mixed Apnea
• Combination of Obstructive and Central
• Begins as central apnea followed by obstructive apnea
• Down’s Syndrome
Hypopnea
• No apnea
• Decreased depth and rate of breathing
Screening
• History• Examination of neck
and upper airway• Spirometry – flow
volume loop• ABG• Hb
• Thyroid Function• Chest x-ray• EKG• Sleep Study• CT scan of upper
airway or head
General Management
• Weight Reduction
• Behavior modification• Avoid alcohol, sedation, smoking
• Sleep Posture
• Oxygen therapy
• Oral Appliance
General Management
• Surgical Procedures• Laser-assisted Uvulopalatopharynoplasty
(LAUP) or UPPP• Mandibular advancement• Nasal operation• Tonsillectomy• Tracheostomy
General Management
• Non-invasive Ventilation• CPAP – most frequently prescribed therapy• BiPAP• NPV – Central Apnea
• Continuous mechanical ventilation
• Medication – REM Inhibitors
• Phrenic Nerve Pacemaker – Central Apnea