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Sleep Apnea Syndrome Sung Chul Hwang, M.D. Department of Pulmonary and Critical Care Medicine Ajou...
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Transcript of Sleep Apnea Syndrome Sung Chul Hwang, M.D. Department of Pulmonary and Critical Care Medicine Ajou...
Sleep Apnea Syndrome
Sung Chul Hwang, M.D.
Department of Pulmonary and Critical Care Medicine
Ajou University School of Medicine
Obstructive Sleep Apnea
• A disorder characterized by collapse of pharyngeal airway during sleep accompanied by arousal from sleep.
• In OSA continued ventilatory effort is present . But in Central Sleep Apnea both the ventilatory effort and air flow is absent.
Definitions ( 1 )• Apnea : complete cessation of air flow
for at least 10 seconds
• Hypopnea : reduction in air flow of more than 50 % accompanied by desaturation of at least 4% or an arousal from sleep
Definitions ( 2 )
• Apnea Index : the Average number of apneas per hour of sleep
• Apnea/hypopnea index(Resp. Disturbance Index) : Number of Apneas + hypopneas per hour of sleep
• Sleep Apnea Hypopnea Syndrome(SAHS) : patients who have sleep study based diagnosis of sleep apneas and hypopneas associated with the clinical symptoms of the disorder
• Severe SAHS : > 50 AHI
• Mild & Moderate SAHS : AHI 10 - 30
Definitions ( 3 )
Classifications
• Cerntral Apnea : No effort to breat
• Obstructive Apnea : Ventilatoey effort is presebt but no air flow because the Upper airway is closed
Epidemiology of OSA
• 9.1% of men and 4.0 % of women if AHI > 15 is used
• 3 million men and 1.5 million women with OSA ( AHI > 5 with complaint of day time sleepiness)
Pathogenesis
• Parynx is abormal in size and easy collapsibility in OSA• Changes during sleep : • Reduced tonic input to upper airway muscles• Diminished protective pharyngeal reflexes• Reduced load compensation• “set point” to increased sensitivity to hypocapnea indu
ced apneic threshold• Site of the obst. : anywhere from nose to glottis
Clinical Manifestations
During Sleep Behavioral Cardio-
respiratory
Snoring Daytime sleepiness
Nocturnal asphyxia
Nocturnal asphyxia
Traffic Accidents 2-3 tines
Tachyarryhthmia
VT, Bradycardia
Repeated
Arousal during sleep
Intellect change
Personality change
Impotence
Pul.Hypertension
RV failure
LV failure ]
Polycythemia
Increased PaCO2
Increased HCO3, Decreased Cl -
Clinical Features
Decreased pH Central Vasodilatation
Morning Headache
Decreased PaO2Arousal from sleep
Day time Somonolence
Hb desaturation Cyanosis
Polycythemia
Pulmonary Vasospasm
Cor Pulmonale
Pul. HiBP
OthersNocturnal choking episodesArousalInsomia/ sleep disruptionNocturiaG-E refluxAtypical chest painNight sweatingDecreased libidoConcentration and memory defect
Physical Examinations
• Hypertensive• Obese• Middle aged• Large thick neck “ crowded” Upper airway• Nasal Obstruction• Low hanging palate• Retrognathia• Micrognathia
Diagnosis of OSA
• History
• Physical Exam
• Routine Lab : X-rays , ABG, EKG, CBC
• Polysomnography
• Overnight Oxymetry
Polysomnography
Obstructive Sleep Apnea
Treatment (1)
• General Measures Weight control
Stop smoking
Alcohol withdrawal
Treat coexisting disease
Avoid driving motor vehicles
Treatment (2)
• Correct Anatomic Airway obstruction• Enlarged tonsils or adenoids
• Skeletal abnormalities involving craniofacial configurations
• Nasal obstructions
Treatment (3)
• Nasal CPAP• Treatment of choice for OSA
• Well tolerated in 80 % of patients
• Nasal masks, nasal Prongs, Oronasal masks
CPAP inObstructive Sleep Apnea
Treatment (4)
• Surgical Procedures• Tracheostomy• Uvulopalatopharyngoplasty (UPPP)• Maxillofscial surgery combined with UPPP• Laser Assissted Uvulopalatoplasty(LAUP)• Consider in those CPAP is not an option• Effective in Snoring but tend to recur
Treatment (5)
• Oral Appliances• Mandibular advancement prostheses
• Improve upper airway patency
• Hold the tongue foward
Mandibular Advancement Splint
Maxillofacial Advancement Surgery for OSA
Cardiac Ischemia During Apneic Episode
Obstructive Sleep Apnea
Central Sleep Apneas
Sung Chul Hwang, M.D.
Dept. of Pulmonary and Critical Care Medicine
Ajou University School of Medicine
Central Sleep Apneas
• Central apneas reflect unstable breathing control
• Decreased resp. drive : Hypoventilation during sleep --> Hypercapneic CSA
• Increased resp. drive : Hyperventilation during wake and sleep --> Hypocapneic CSA
Mechanisms
• Result of abolished ventilatory motor out-put
• Hypocapnea during NREM sleep is the major cause of reduced ventilatory motor out put
Pathogenesis• Instability often occurs at sleep onset : PaCO2 d
uring awake is less than required for rhythm generation in sleep
• Enhanced by chronic hyperventilation during wakefulness and hypocapnea below threshold
• Hypoxia, Aggravation of cardiorespiratory disease, Hyperventilation, Pulmonary congestion
• Circulatory slowing due to cardiac failure lead to ventilatory instability
Clinical Features• CSA is an alveolar hypoventilation syndro
me• Daytime hypercapnea and hypoxemia• Recurrent resp. failure, polycythemia, Pul.
hypertension, Rt. heart Failure• Poor sleep, morning headaches, daytime fat
igue, somnolence, nocturnal awakenings, etc
Diagnosis
• Clinical features
• Definitive Dx : Polysomnography
• Measurement of transcutaneous PaCO2
• Defect in Resp. control or NM function : elevated Ps CO2 that tend to increased during night esp. REM sleep
Central Sleep Apnea
Treatment• Nocturnal O2 to correct Hypoxemia• Acetazolamide -> Acidosis -> increase venti
lation• Nasal CPAP : increasePaCO2 as the added
expiratory mechanical load • Nasal CPAP is particularly effective in CS
A secondary to CHF in improving sleep quality and daytime cardiac condition
Disoders of Ventilation
Sung Chul Hwang, M.D.
Dept. of Pulmonary and Critical Care Medicine
Ajou University School of Medicine
Chemoreceptor
• Central• Medulla
Oblongata• pH, PaCO2, PaO2• fall in pH of ECF
and Carotid body• Fine regulation
• Peripheral• Aortic and Carotid
body• PaO2• dominant during
Chronic hypoxia• Coarse regulation
Alveolar Hypoventilation• Increased PACO2 & PaCO2 above normal• Impaired respiratory drive: brain stem, car
otid body trauma• Reduction in over all minute ventilation: re
sp. muscles, spinal cord, peripheral nerves • Impaired respiratory apparatus : chest wal
l, airways and lung
Neuromuscular Disorders
• Spinal cord, peripheral nerves, respiratory muscle disease
• orthopnea, paradocxical movement of abdomen and diaphragm
• Dx : Rapid deterioration of MVV, reduced PImax, PEmax, reduced transdiaphragmatic pressures and response to phrenic nerve stimulations
Pathophysiology• Increased PACO2 & PaCO2• Respiratpory Acidosis• Metabolic compensation -- increase in HCO3 --• Decrease in Cl -• Decrease in PAO2 & PaO2• Pulmonary vasoconstriction, Pulmonary hypert
ension, RV hypertrophy, CHF (Cor pulmonale)
Mechanoreceptor• Stretch receptor : smooth muscle of
trachea and main bronchus• Irritant receptor : beneath the epithelium
of larynx, trachea, bronchi• J- receptor : periphery of lung • C- receptor : pulmonary interstitial space
near pulmonary and bronchial circulation
Clinical features
• Hypoxemia, cyanosis, polycythemia• chronic hypoxemia , hypercapnea, pulmonary
HTN, CHF• ABG abnormality esp. in sleep and sleep distur
bances• Sx : morning headache, fatigue, daytime somnol
ence, mental confusion, intellectual impairment• specific features of underlying diseases
Diagnosis
• Defect in Control System : impaired response to chemical stimuli, able to hyperventilate voluntarily
• Defects in N-M System : Unable to hyperventilate, abnormal static and dynamic lung measurements
• Defects in Chest wall, Lungs, Airways : normal airway resistance and compliance, widened (A-a) DO2
Treatment
• Treat individual underlying disease• Correction of Metabolic Alkalosis• O2 supplements• Respiratory Stimulants (medroxyprogesteron
e)• Mechanical Ventilation : especially during sle
ep• Diaphragmatic pacing
Primary Alveolar Hypoventilation(Ondine’s Curse)
• Chronic hypoxemia and hypercapnea without identifiable cause
• defect in metabolic respiratory control• 20 - 50 yrs of age males• Sx and Signs of alveolar hypoventilation • treatment : general supportive care for hy
poventilation
Obesity-Hypoventilation SD (Pickwickian SD)
• Massive obesity • Reduced FRC• Underventilation of Lung base and widening of (A-
a)PO2• Chronic hypercapnia, hypoxemia, polycythemia, p
ulmonary HTN, Right heart failure• Sx : OSA, sleep induced hypoventilation• Tx : stop smoking, weight reduction, correct OSA,
medroxy progesterone
“Panda-Eye” Sign
“” Sign