Copyright © 2006 by Mosby, Inc. Slide 1 Chapter 31 Sleep Apnea Figure Obstructive sleep apnea. When the genioglossus muscle fails to oppose the force that tends to collapse the airway passage during inspiration, the tongue moves into the oropharyngeal area and obstructs the airway.
Copyright © 2006 by Mosby, Inc. Slide 2 Sleep Apnea Despite the fact that the clinical manifestations of sleep apnea have be described for centuries, it was not until the early 1980s that it became acknowledged by the medical community
Copyright © 2006 by Mosby, Inc. Slide 3 Stages of Sleep and Characteristic Cardiopulmonary Patterns Two major sleep stages during normal sleep Non–rapid eye movement (non-REM) sleep Quiet or slow-wave sleep Quiet or slow-wave sleep Rapid eye movement (REM) sleep Active or dreaming sleep Active or dreaming sleep
Copyright © 2006 by Mosby, Inc. Slide 4 Non-REM Sleep Usually begins immediately after dozing off Four stages of non-REM sleep Each progressing into a deeper sleep
Copyright © 2006 by Mosby, Inc. Slide 5 Stages 1 and 2 The ventilatory rate and tidal volume continually increase and decrease—brief periods of apnea may occur The ECG shows increased slow-wave activity and loss of alpha rhythm Cheyne-Stokes respiration is common in older adult males, especially at high altitudes
Copyright © 2006 by Mosby, Inc. Slide 6 Stages 3 and 4 Ventilation becomes slow and regular Minute ventilation is commonly 1 to 2 L/min less than during the quiet wakeful state Typically the: PaCO 2 levels are higher (4-8 mm Hg) PaO 2 levels are lower (3-10 mm Hg) pH is lower ( unit)
Copyright © 2006 by Mosby, Inc. Slide 7 Stages 3 and 4 Normally, non-REM sleep lasts 60 to 90 minutes Typically, an individual moves in and out of all 4 stages during non-REM sleep Most of the time is spent in stage 2
Copyright © 2006 by Mosby, Inc. Slide 8 Stages 3 and 4 An individual may move into REM sleep, at any time, directly, from any of the 4 non-REM sleep stages The lighter 1 and 2 stages, however, are the most common levels just before REM sleep
Copyright © 2006 by Mosby, Inc. Slide 9 REM Sleep During this period, sudden burst of fast alpha rhythms Ventilatory rate becomes rapid and shallow Sleep-related hypoventilation and apnea are commonly seen during this period
Copyright © 2006 by Mosby, Inc. Slide 10 REM Sleep In normal adults, apneic periods occur as often a five times per hour These apneic periods may last 15 to 20 seconds with no discernible effects In normal infants: Apneas are shorter—about 10 seconds long
Copyright © 2006 by Mosby, Inc. Slide 11 REM Sleep A marked reduction occurs in the: Hypoxic ventilatory response Hypercapnic ventilatory response The heart rate becomes irregular The eyes move rapidly and dreaming occurs
Copyright © 2006 by Mosby, Inc. Slide 12 REM Sleep Paralysis of the skeletal muscles occurs Arms Legs Intercostal and upper airway muscles The diaphragm is NOT affected
Copyright © 2006 by Mosby, Inc. Slide 13 Muscle Paralysis during REM Sleep Affects Ventilation in Two Ways 1.Paradoxical motion of the rib cage Causes in tissue to move inward during inspiration This causes the FRC to decrease 2.Loss of muscle tone in the: Posterior muscles of the pharynx Genioglossus—protrudes the tongue Posterior cricoarytenoid—abducts the vocal cords
Copyright © 2006 by Mosby, Inc. Slide 14 Loss of Muscle Tone in the Upper Airway May Result in Airway Obstruction The negative pharyngeal pressure produced when the diaphragm contracts during inspiration tends to: Bring the vocal cords together Collapse the pharyngeal wall Suck the tongue back into the oral pharyngeal cavity
Copyright © 2006 by Mosby, Inc. Slide 15 REM Sleep REM sleep lasts about 5 to 40 seconds Recurs about every 60 to 90 minutes REM sleep lengthens and becomes more frequent toward the end of a sleep period
Copyright © 2006 by Mosby, Inc. Slide 16 REM Sleep REM sleep constitutes about 20% to 25% of sleep time It is usually more difficult to awaken a subject during REM sleep
Copyright © 2006 by Mosby, Inc. Slide 17 Types of Sleep Apnea
Copyright © 2006 by Mosby, Inc. Slide 18 Types of Sleep Apnea Apnea—the cessation of breathing for 10 seconds or longer Sleep apnea—more than five episodes of apnea per hour May occur in either or both non-REM and REM sleep, over a 6-hour period
Copyright © 2006 by Mosby, Inc. Slide 19 Types of Sleep Apnea Generally, the episodes of apnea are more frequent and severe during REM sleep and in the supine body position Apnea periods last more than 10 seconds and occasionally exceed 100 seconds in length In severe cases, as many as 500 apnea periods per night may occur
Copyright © 2006 by Mosby, Inc. Slide 20 Types of Sleep Apnea Sleep apneas may appear in all age groups In infants, it may play a role in sudden infant death syndrome (SIDS)
Copyright © 2006 by Mosby, Inc. Slide 21 Obstructive Sleep Apnea (OSA) Obstructive Sleep Apnea (OSA) Most common During periods of OSA, the: Patient, initially, appears quiet and still Followed by an increased effort to inhale
Copyright © 2006 by Mosby, Inc. Slide 22 Obstructive Sleep Apnea Obstructive Sleep Apnea OSA often ends only after an intense struggle Snorting is often heard during periods of OSA Called “fricative breathing” In severe cases, the patient may: Suddenly awaken Sit upright in bed, and Gasp for air
Copyright © 2006 by Mosby, Inc. Slide 23 Obstructive Sleep Apnea Obstructive Sleep Apnea OSA patients usually breathe normally during wakeful periods OSA seen more often in males than females (8:1 ratio) Between 1% and 4% of male population Commonly seen in obese people with short necks
Copyright © 2006 by Mosby, Inc. Slide 24 Pickwickian Syndrome Pickwickian Syndrome Named after a character in Charles Dickens’ The Posthumous Papers of the Pickwick Club (1837) Joe: the fat boy who snored and had excessive daytime sleepiness Charles Dickens’ description of Joe included many of the classic features now recognized as OSA
Copyright © 2006 by Mosby, Inc. Slide 25 Pickwickian Syndrome Pickwickian Syndrome However, many patients with OSA are NOT obese, thus clinical suspicion should not be limited to this group
Copyright © 2006 by Mosby, Inc. Slide 26 Some Clinical Disorders Associated with OSA Some Clinical Disorders Associated with OSA Obesity Anatomic narrowing of the upper airway Excessive pharyngeal tissue Enlarged tonsils or adenoids Deviated nasal septum Laryngeal stenosis
Copyright © 2006 by Mosby, Inc. Slide 27 Some Clinical Disorders Associated with OSA Some Clinical Disorders Associated with OSA Laryngeal web Pharyngeal neoplasms Micrognathia Macroglossia Goiter Hypothyroidism
Copyright © 2006 by Mosby, Inc. Slide 28 Some Clinical Disorders Associated with OSA Some Clinical Disorders Associated with OSA Testosterone administration Myotonic dystrophy Shy-Drager syndrome Down syndrome
Copyright © 2006 by Mosby, Inc. Slide 29 General Clinical Manifestations Associated with OSA Chronic loud snoring Hypertension Morning headaches Systemic hypertension Nausea Dry mouth on awakening Intellectual and personality changes
Copyright © 2006 by Mosby, Inc. Slide 30 General Clinical Manifestations Associated with OSA Depression Sexual impotence Nocturnal enuresis Excessive daytime sleepiness Car accidents or job malperformance related to sleepiness Pulmonary hypertension
Copyright © 2006 by Mosby, Inc. Slide 31 Polysomnographic Monitoring Findings Apnea-related oxygen desaturation More than five obstructive apneas of more than 10 seconds per hour of sleep, and one or more of the following: Frequent arousal from the apneas PVCs Profound bradycardia and/or asystole Shortened sleep latency
Copyright © 2006 by Mosby, Inc. Slide 32 Central Sleep Apnea Occurs when respiratory centers of the medulla fail to send signals to the respiratory muscles Characterized by cessation of airflow at the nose and mouth with absence of diaphragmatic excursions Associated with cardiovascular, metabolic, or central nervous system disorders
Copyright © 2006 by Mosby, Inc. Slide 33 Central Sleep Apnea Diagnosed when the frequency of apnea episodes is more than 30 in a 6-hour period
Copyright © 2006 by Mosby, Inc. Slide 34 Clinical Disorders Associated with Central Sleep Apnea Congestive heart failure Metabolic alkalosis Idiopathic hypoventilation syndrome Encephalitis Brainstem neoplasm Brainstem infarction Bulbar poliomyelitis Cervical cordotomy Spinal surgery Hypothyroidism
Copyright © 2006 by Mosby, Inc. Slide 35 General Noncardiopulmonary Clinical Manifestations Tendency to be of normal weight Mild snoring Insomnia Some of the following may also occur Daytime fatigue Depression Sexual dysfunction
Copyright © 2006 by Mosby, Inc. Slide 36 Mixed Sleep Apnea Combination of obstructive and central sleep apnea Usually begins as central sleep apnea, followed by: Ventilatory efforts without airflow—OSA Clinically, mixed sleep apnea is usually classified and treated as OSA
Copyright © 2006 by Mosby, Inc. Slide 37 Figure Patterns of airflow, respiratory efforts (reflected through the esophageal pressure), and arterial oxygen saturation produced by central, obstructive, and mixed apneas.
Copyright © 2006 by Mosby, Inc. Slide 38 Diagnosis Begins with a careful history Noting presence of snoring, sleep disturbance, and daytime sleepiness Followed by examination of upper airway and PFT to determine presence of upper airway obstruction Blood evaluation Polycythemia Thyroid function ABGs
Copyright © 2006 by Mosby, Inc. Slide 39 Diagnosis Chest radiograph Electrocardiogram to determine: Presence of pulmonary hypertension State of right and left ventricular compensation Presence of any other cardiopulmonary disease
Copyright © 2006 by Mosby, Inc. Slide 40 Diagnosis and Type of Apnea Confirmed with the following: Polysomnographic sleep studies, which include: EEG and EOG—to identify sleep stages Airflow monitor ECG Monitor of patient’s ventilatory rate and effort Oximetry CT scan
Copyright © 2006 by Mosby, Inc. Slide 41 Overview of the Cardiopulmonary Clinical Manifestations Associated with SLEEP APNEA
Copyright © 2006 by Mosby, Inc. Slide 42 Clinical Data Obtained at the Patient’s Bedside Clinical Data Obtained at the Patient’s Bedside Cyanosis
Copyright © 2006 by Mosby, Inc. Slide 43 Pulmonary Function Study: Lung Volume and Capacity Findings
Copyright © 2006 by Mosby, Inc. Slide 44 Arterial Blood Gases Severe Sleep Apnea Chronic ventilatory failure with hypoxemia pH Pa CO 2 HCO 3 - Pa O 2 Normal (Significantly) Normal (Significantly)
Copyright © 2006 by Mosby, Inc. Slide 45 Figure 4-7. PaO 2 and PaCO 2 trends during acute ventilatory failure. Time and Progression of Disease Pa O Alveolar Hyperventilation Point at which PaO 2 declines enough to stimulate peripheral oxygen receptors Pa CO 2 Chronic Ventilatory Failure Disease Onset Point at which disease becomes severe and patient begins to become fatigued Pa 0 2 or Pa C0 2
Copyright © 2006 by Mosby, Inc. Slide 46 Acute Ventilatory Changes on Chronic Ventilatory Failure Acute alveolar hyperventilation on chronic ventilatory failure Acute ventilatory failure on chronic ventilatory failure
Copyright © 2006 by Mosby, Inc. Slide 47 Oxygenation Indices Q S /Q T D O 2 V O 2 C(a-v) O 2 Normal Normal O 2 ER Sv O 2 Q S /Q T D O 2 V O 2 C(a-v) O 2 Normal Normal O 2 ER Sv O 2
Copyright © 2006 by Mosby, Inc. Slide 48 Hemodynamic Indices (Severe) CVP RAPPAPCWP COSVSVICI RVSWILVSWIPVRSVR
Copyright © 2006 by Mosby, Inc. Slide 49 Radiologic Findings Chest radiograph Right- or left-sided heart failure
Copyright © 2006 by Mosby, Inc. Slide 50 Cardiac Arrhythmias Sinus arrhythmia Sinus bradycardia Sinus pauses Atrioventricular block Premature ventricular contractions Ventricular tachycardia
Copyright © 2006 by Mosby, Inc. Slide 51 General Management of Sleep Apnea Weight reduction Sleep position Oxygen therapy Drug therapy REM inhibitors Protriptyline (Vivactil) Protriptyline (Vivactil) Acetazolamide (Diamox) Protriptyline hydrochloride
Copyright © 2006 by Mosby, Inc. Slide 52 General Management of Sleep Apnea Surgery Uvulopalatopharyngoplasty Laser-assisted uvulopalatoplasty Nasal surgery Tracheostomy Mandibular advancement
Copyright © 2006 by Mosby, Inc. Slide 53 General Management of Sleep Apnea Mechanical ventilation Continuous positive airway pressure Continuous mechanical ventilation Negative-pressure ventilation
Copyright © 2006 by Mosby, Inc. Slide 54 Figure A, Normal airway. B, Obstructed airway during sleep. C, Nasal CPAP generates a positive pressure and holds the airway open during sleep.
Copyright © 2006 by Mosby, Inc. Slide 55 General Management of Sleep Apnea Phrenic nerve pacemaker
Copyright © 2006 by Mosby, Inc. Slide 56 General Management of Sleep Apnea Medical devices Neck collar
Copyright © 2006 by Mosby, Inc. Slide 57 Classroom Discussion Case Study: Obstructive Sleep Apnea