1. Obstructive Sleep Apnea: A Serious Epidemic Obstructive Sleep Apnea A Serious Epidemic M.A.Hamadeh,M.D,FCCP,FAAM Assoc. Clinical Professor, Med. University of Illinois School of Medicine Director, Sleep Disorders Centers, Christ Hospital & Medical Center

2. Sleep Apnea

3. Sleep Apnea is: Common Common Dangerous Dangerous Easily recognized Easily recognized Treatable Treatable

4. Types of Sleep Disordered Breathing Apnea Apnea –Cessation of airflow > 10 seconds Hypopnea Hypopnea –Decreased airflow  30% from baseline lasting > 10 seconds associated with > 4% oxyhemoglobin desaturation

5. Apnea Patterns Obstructive Mixed MixedCentral Airflow Respiratory effort

6. Obstructive Apnea

7. Central Apnea

8. Mixed Apnea

9. Obstructive Hypopnea

10. Respiratory Effort-related Arousals

11. RERA: Respiratory Effort-related Arousal (Guilleminault, 1993) A sequence of breaths characterized by increasing respiratory effort leading to an arousal from sleep which does not meet criteria for an apnea or hypopnea. These events must fulfill both of the following criteria: 1. Pattern of progressively more negative esophageal pressure, terminated by a sudden change in pressure to a less negative level and an arousal 1. Pattern of progressively more negative esophageal pressure, terminated by a sudden change in pressure to a less negative level and an arousal 2. The event lasts 10 seconds or longer. 2. The event lasts 10 seconds or longer. UARS (Upper Airway Resistance Syndrome): > 5 RERA’s per hour of sleep

12. What About “Simple Snoring?” Snoring in pregnancy is associated with increased hypertension and growth retardation, controlling for weight, age, smoking (Franklin, Chest, 2000) Snoring in pregnancy is associated with increased hypertension and growth retardation, controlling for weight, age, smoking (Franklin, Chest, 2000) Snoring is associated with cognitive decline (Quesnot, J Am Geriatric Soc, 1999) Snoring is associated with cognitive decline (Quesnot, J Am Geriatric Soc, 1999) Snoring medical students are more likely to fail exams, controlling for BMI, age, sex (Ficker, Sleep, 1999). Snoring medical students are more likely to fail exams, controlling for BMI, age, sex (Ficker, Sleep, 1999). Snoring is a risk factor for cardiovascular disease in women. (Hu, J Am Coll Cardiol 2000). Snoring is a risk factor for cardiovascular disease in women. (Hu, J Am Coll Cardiol 2000). Snoring is a risk for type II diabetes (Al-Delaimy, Am J Epidemiol 2002). Snoring is a risk for type II diabetes (Al-Delaimy, Am J Epidemiol 2002). Snoring women have faster progression of CAD ( Leineweber C. Sleep 2004) Snoring women have faster progression of CAD ( Leineweber C. Sleep 2004)

13. Measures of Sleep Apnea Frequency Apnea Index Apnea Index –# apneas per hour of sleep Apnea / Hypopnea Index (AHI) Apnea / Hypopnea Index (AHI) –# apneas + hypopneas per hour of sleep Respiratory Disturbance Index Respiratory Disturbance Index –# apneas + hypopneas + RERAs per hour of sleep

14. Severity Criteria Based on PSG From the American Academy of Sleep Medicine (Sleep, 1999) “Mild” sleep apnea is 5-15 events/hr “Mild” sleep apnea is 5-15 events/hr “Moderate” sleep apnea is 15-30 events/hr “Moderate” sleep apnea is 15-30 events/hr “Severe” sleep apnea is over 30 events/hr “Severe” sleep apnea is over 30 events/hr (“Events” includes apneas, hypopneas, and RERA’s) (“Events” includes apneas, hypopneas, and RERA’s)

15. One Definition of Obstructive Sleep Apnea (OSA) CPAP will be covered for adults with sleep- disordered breathing if: – AHI (or RDI) > 15 OR – AHI (or RDI) > 5 with (“mild, symptomatic”) Hypertension Hypertension Stroke Stroke Sleepiness Sleepiness Ischemic heart disease Ischemic heart disease Insomnia Insomnia Mood disorders Mood disorders

16. Sleep-Disordered Breathing is a Spectrum

17. Prevalence of Sleep Apnea 30-60 year olds Percent of Population Adapted from Young T et al. N Engl J Med 1993;328.

18. Why Sleep Apnea Isn’t Going Away…..

21. SDB with Aging

22. Sleep Apnea vs Sleep Disorders Prevalence of common sleep disorders Prevalence of common sleep disorders – Insomnia: 10-30% – Sleep Apnea: 5% – RLS: 10% – Narcolepsy: 0.05% Diagnoses of patients presenting to sleep centers (Coleman II, 2000) Diagnoses of patients presenting to sleep centers (Coleman II, 2000) – Sleep apnea: 67.8 – RLS: 4.9% – Narcolepsy 3.2%

23. 1 2 3 4 5 6 7 8 9 The Upper Airway

24. Control of Dilator Muscles Effects On Pharyngeal Muscle Activity Normal Subject Awake OSA Patient NREM Genioglossus EMG Tensor Palatini EMG Airflow Genioglossus EMG Tensor Palatini EMG Airflow

25. Pathophysiology of Apnea Wakefulness Sleep

26. Pathophysiology of Sleep Apnea Awake: Small airway + neuromuscular compensation Loss of neuromuscular compensation + Decreased pharyngeal muscle activity Sleep Onset Hyperventilate: connect hypoxia & hypercapnia Airway opens Airway collapses Pharyngeal muscle activity restored Apnea Arousal from sleep Hypoxia & Hypercapnia Increased ventilatory effort

27. Clinical Consequences Cardiovascular Complications Morbidity Mortality Sleep Fragmentation Hypoxia/ Hypercapnia Excessive Daytime Sleepiness Sleep Apnea

28. Consequences: Excessive Daytime Sleepiness Increased motor vehicle crashes Increased motor vehicle crashes Increased work-related accidents Increased work-related accidents Poor job performance Poor job performance Depression Depression Family discord Family discord Decreased quality of life Decreased quality of life

29. Consequences: Automobile Accidents Sassani, et al., Sleep 2004; 27:453

30. Consequences: Automobile Accidents Odds Ratio 0 2 4 6 8 10 12 NO ETOH+ ETOH ETOH On Day of Accident Risk of Traffic Accident: OSA + ETOH Adapted from Teran-Santos J et al. N Engl J Med 1999;340.

31. Consequences: Cardiovascular Systemic hypertension Systemic hypertension Cardiac arrhythmias Cardiac arrhythmias Cardiovascular disease Cardiovascular disease –Myocardial ischemia –Congestive heart failure Cerebrovascular disease Cerebrovascular disease

32. Consequences: Mortality Marshall et al. Sleep 2008; 31:1079-1085 Young et al. Sleep 2008; 31:1071-1078 Busselton, AustraliaWisconsin Cohort RDI > 15 RDI < 5 RDI 5-15 Years of follow-up

33. Consequences: Hypertension Shepard JW Jr. Med Clin North Am 1985;69.

34. Cardiovascular Consequences: Hypertension Odds Ratio 0 0.5 1 1.5 2 2.5 3 00.1 - 4.95 - 14.9> 15 Apnea / Hypopnea Index (AHI) Prospective Study of Association Between OSA and Hypertension Adjusted for age, sex, BMI, neck circ., cigs., ETOH, baseline Htn Adapted from Peppard PE et al. N Engl J Med 2000;342.

35. Consequences: Arrhythmias

36. Consequences: Cardiovascular Disease Odds Ratio Cross Sectional Study of Association Between OSA and CVD Adjusted for age, sex, race, BMI, Htn, cigs., chol. 0 0.5 1 1.5 2 2.5 CADHFCVA 0 - 1.3 1.4 - 4.4 4.5 - 11.0 > 11.0 AHI Adapted from Shahar E et al. Am J Respir Crit Care Med 2001;163.

37. OSA and Stroke * * Arzt, et al., AJRCCM 2005; 172:1447.

38. Sleep Apnea Risk Factors Obesity Obesity Increasing age Increasing age Male gender Male gender Anatomic abnormalities of upper airway Anatomic abnormalities of upper airway Family history Family history Alcohol or sedative use Alcohol or sedative use Smoking Smoking Associated conditions Associated conditions

39. Risk Factor: Obesity Davies RJ et al. Eur Respir J 1990;3. >4% Arterial saturation dipa h -1 % Predicted normal neck circumference

40. Risk Factor: Age % with AHI > 5 Adapted from Young T et al. N Engl J Med 1993;328.

41. Risk Factor: Gender Millman RP et al. Chest 1995;107. Apnea/Hypopnea Index Skinfold Sum (mm) Male Female

42. Risk Factor: Anatomic Abnormality Suratt PM et al. Chest 1986;90. Apneas & Hypopneas per hour of sleep 75 6 4 8 5 1 2 7 3

43. Adapted from Redline S et al. Am J Resp Crit Care Med 1995;151. Likelihood of Sleep Apnea as Function of Family Prevalence Risk Factor: Family History (Adjusted for age, race, sex, BMI) Odds Ratio 1 2 3 Relative Relatives Relatives

44. Risk Factor: Sedatives Sanders MH. In: Principles and Practice of Sleep Medicine. Philadelphia: W.B. Saunders Company, 1994. Peak Integrated activity (% control) Minutes after injection Diazepam Injection Hypoglossal Nerve Phrenic Nerve 05153060 150 100 50 0

45. Risk Factor: Alcohol Bonara M et al. Am Rev Respir Dis 1984;130 © American Lung Association. Before Alcohol Blood Alcohol = 83 mg/dl Blood Alcohol = 134 mg/dl Phrenic Hypoglossal Phrenic Hypoglossal Phrenic Hypoglossal

46. Risk Factor: Smoking Adjusted Odds Ratio for Sleep Apnea (AHI > 15) in Former & Current Smokers vs Nonsmokers Adapted from Wetter DW et al. Arch Intern Med 1994:154 ©1994 American Medical Association. Former Current Smokers Smokers (Adjusted for age, race, sex, BMI) Odds Ratio

47. Diagnosis: History Snoring (loud, chronic) Snoring (loud, chronic) Nocturnal gasping and choking Nocturnal gasping and choking –Ask bed partner (witnessed apneas) Automobile or work related accidents Automobile or work related accidents Personality changes or cognitive problems Personality changes or cognitive problems Risk factors Risk factors Excessive daytime sleepiness Excessive daytime sleepiness Sleep Apnea: Is Your Patient at Risk? NIH Publication, No 95-3803.

48. Diagnosis: Assessing Daytime Sleepiness Often unrecognized by patient Often unrecognized by patient –Ask family members Must ask specific questions Must ask specific questions –Fatigue vs. sleepiness –Auto crashes or near misses –Sleep in inappropriate settings Work Work Social situations Social situations

49. Diagnosis: Physical Examination Upper body obesity / thick neck Upper body obesity / thick neck > 17” males > 16” females Hypertension Hypertension Obvious upper airway abnormality Obvious upper airway abnormality

50. Exam: Tonsillar Hypertrophy Shepard JW Jr et al. Mayo Clin Proc 1990;65. Oropharynx With Tonsillar Hypertrophy Normal Oropharynx

51. Exam: Oropharynx Patient With the Crowded Oropharynx

52. Exam: Oropharynx Class I Class III Class II Class IV

53. Physical Examination Guilleminault C et al. Sleep Apnea Syndromes. New York: Alan R. Liss, 1978. Structural Abnormalities

54. Diagnosis: Pediatric Apnea Presentation Presentation –Behavioral problems / irritability –Poor school performance –Enuresis –Snoring Cause Cause –Adenotonsillar hypertrophy –Craniofacial abnormality –Frequently not obese

55. Pediatric Sleep Apnea Child with Sleep Apnea Child’s Enlarged Palatine & Adenoidal Tonsils

56. Why Get a Sleep Study? Signs and symptoms poorly predict disease severity Signs and symptoms poorly predict disease severity Appropriate therapy dependent on severity Appropriate therapy dependent on severity Failure to treat leads to: Failure to treat leads to: –Increased morbidity –Motor vehicle crashes –Mortality Other causes of daytime sleepiness Other causes of daytime sleepiness

57. What Test Should be Used? In-laboratory full night polysomnography In-laboratory full night polysomnography –Split night studies Home diagnostic systems Home diagnostic systems –Oximetry to full polysomnography

58. Polysomnography

59. Polysomnogram

60. Full-Night In-Laboratory Polysomnography Pro Pro –Full set of variables obtained –Equipment problems can be repaired –Technician can address patient problems Con Con –Cost –Accessibility –Patient sleeps away from home

61. Pro Pro –Reduced cost –Patient may be studied only once –Reduces time to treatment initiation Con Con –Diagnostic time may be inadequate –Treatment time limited –Protocol decisions to start CPAP may be difficult to make during data acquisition Split-Night In-Laboratory Polysomnography

62. Home Study Tracing

63. Home Study Pro Pro –Potentially less expensive –Patient sleeps at home Con Con –Generally fewer signals are recorded –Equipment cannot be adjusted –Technician cannot assist patient

64. Diagnostic Conclusions Signs and symptoms Signs and symptoms –Excessive daytime sleepiness –Hypertension and other cardiovascular sequelae Sleep study results Sleep study results –Apnea / hypopnea frequency –Sleep fragmentation –Oxyhemoglobin desaturation

65. Treatment Objectives Reduce morbidity and mortality Reduce morbidity and mortality –Reduce sleepiness –Decrease cardiovascular consequences Improve quality of life Improve quality of life

66. Therapeutic Approach Risk counseling Risk counseling –Motor vehicle crashes –Job-related hazards –Judgment impairment Apnea and co-morbidity treatment Apnea and co-morbidity treatment –Behavioral –Medical –Surgical

67. The High-Risk Driver Educate patient Educate patient Document warning Document warning Resolve apnea quickly Resolve apnea quickly Follow-up Follow-up –Effectiveness –Compliance

68. Behavioral Interventions Encourage patients to: Encourage patients to: –Lose weight –Avoid alcohol and sedatives –Avoid sleep deprivation –Avoid supine sleep position –Stop smoking

69. Weight Loss Should be prescribed for all obese patients Should be prescribed for all obese patients Can be curative but has low success rate Can be curative but has low success rate Other treatment is required until optimal weight loss is achieved Other treatment is required until optimal weight loss is achieved

70. Weight Loss and Sleep Apnea -4 -20 to <-10% -10 to <- 5% -5% to <+5 +5 to +10% +10% to +20 -3 -2 0 1 2 3 4 5 6 Change in Body Weight Adapted from Peppard PE et al. JAMA 2000;284. Mean Change in AHI, Events/hr

71. Weight Loss and Sleep Apnea Smith PL et al. Ann Intern Med 1985;103. Baseline 20 40 60 80 100 5 10 15 20 40 Weight Loss BaselineWeight Loss Apnea Frequency (EPISODES/HOUR) Mean Fall Sa02 (PERCENT)

72. Sleep-Position Training

73. Medical Interventions Positive airway pressure Positive airway pressure –Continuous positive airway pressure (CPAP) –Bi-level positive airway pressure Oral appliances Oral appliances Other (limited role) Other (limited role) –Medications –Oxygen

74. Positive Airway Pressure

76. Benefits of CPAP: Mortality 96% 91% 86% Campos-Rodriguez, et al., Chest 2005; 128:624

77. Benefits of CPAP: Sleepiness CPAP Treatment Latency to Sleep (min) Adapted from Lamphere J et al. Chest 1989;96.

78. Benefits of CPAP: Performance Obstacles hit in 30 min. Adapted from Findley L et al. Clin Chest Med 1992;13. (n=6) (n=6) (n=12)

79. Positive Airway Pressure: Problems Patient Acceptance Claustrophobia Aerophagia Chest Discomfort Mask Discomfort

80. CPAP for OSA: Benefits Improved cognitive function Improved cognitive function Improved quality of life Improved quality of life Reduced daytime sleepiness Reduced daytime sleepiness Reduced risk of automobile accidents Reduced risk of automobile accidents Reduced health care costs Reduced health care costs Reduced blood pressure Reduced blood pressure Reduced cardiac arrhythmias Reduced cardiac arrhythmias Improved glucose tolerance Improved glucose tolerance Reduced mortality rate Reduced mortality rate Reversal of impotence Reversal of impotence

81. Positive Airway Pressure: Problems

82. CPAP Compliance Patient report: 75% Patient report: 75% Objectively measured use Objectively measured use > 4 hrs for > 5 nights / week: 46% Asthma-medicine compliance: 30% Asthma-medicine compliance: 30%

83. Mean percentage days CPAP used Adapted from Kribbs NB et al. Am Rev Respir Dis 1993;147. CPAP Compliance Time CPAP used

84. CPAP Compliance: Predictors Predict Good Compliance Predict Good Compliance –Increased AHI –Increased daytime sleepiness –Perception of benefit Predict Poor Compliance Predict Poor Compliance –Lack of EDS –Lack of perceived benefit –Nasal obstruction –Side effects –Claustrophobia

85. Strategies to Improve Compliance Patient Education Patient Education Frequent and early follow-up Frequent and early follow-up Machine-patient interfaces Machine-patient interfaces –Masks –Nasal pillows –Chin straps Humidifiers Humidifiers Ramp Ramp Desensitization Desensitization Pressure relief CPAP or Bi-level pressure Pressure relief CPAP or Bi-level pressure

86. CPAP Masks

87. CPAP Ramping Pressman MR et al. Am J Respir Crit Care 1995;151 © American Lung Association. Effect of Recurrent Use of Ramping on Nocturnal Saturation

88. Bi-level Positive Airway Pressure Positive Pressure Therapy 15 CPAPBi-level 10 5 0 Pressure Flow Insp Exp

89. Compliance: CPAP Vs. Bi-Level PAP Reeves-Hoché MK et al. Am J Respir Crit Care Med 1995;151 © American Lung Association. Compliance: CPAP vs Bi-level Positive Pressure CPAP Bi-level Mean hours of use 87654328765432 Visit 1 2 weeks Visit 2 4-8 weeks Visit 4 24-28 weeks Visit 3 8-12 weeks Visit 5 52 weeks

90. Monitoring Compliance Most PAP units measure ‘mask-on’ times Most PAP units measure ‘mask-on’ times Adherence data can be downloaded into compliance reports Adherence data can be downloaded into compliance reports Objective monitoring recommended in treatment guidelines Objective monitoring recommended in treatment guidelines Objective monitoring required by CMS Objective monitoring required by CMS

91. Monitoring Compliance

92. Oral Appliances Indications Indications –Snoring and apnea (not severe) Efficacy Efficacy –Variable with 52% of patients with AHI<10/hr on treatment Side effects Side effects –TMJ discomfort, dental misalignment, and salivation

93. Oral Appliances Variables that Effect Efficacy Severity of OSA: higher success with mild to moderate disease (AHI <30-40) Severity of OSA: higher success with mild to moderate disease (AHI <30-40) Degree of protrusion: more effective with increased protrusion Degree of protrusion: more effective with increased protrusion Positionality of SDB: more effective in patients with supine-dependent OSA Positionality of SDB: more effective in patients with supine-dependent OSA BMI: more effective in patients with lower BMI BMI: more effective in patients with lower BMI Sleep 2006;29:244

94. Oral Appliance: Mechanics

95. Supplemental Oxygen Not a primary treatment for sleep apnea Not a primary treatment for sleep apnea Does not improve daytime sleepiness Does not improve daytime sleepiness May prolong apneas May prolong apneas Reduces oxygen desaturation during apneas Reduces oxygen desaturation during apneas Reduces arrhythmias Reduces arrhythmias

96. Pharmacologic Treatment Limited Role Limited Role –Protriptyline or fluoxetine –Decongestants –Nasal steroids –Antihistamines –Other

97. Surgical Alternatives Reconstruct upper airway Reconstruct upper airway –Uvulopalatopharyngoplasty (UPPP) –Radiofrequency tissue volume reduction –Genioglossal advancement –Nasal reconstruction –Tonsillectomy Bypass upper airway Bypass upper airway –Tracheostomy

98. Sites of Airway Narrowing Adapted from Morrison DL et al. Am Rev Respir Dis 1993;148. 18% 82%

99. Uvulopalatopharyngoplasty (UPPP) Usually eliminates snoring Usually eliminates snoring 41% chance of achieving AHI < 20 41% chance of achieving AHI < 20 No accurate method to predict surgical success No accurate method to predict surgical success Follow-up sleep study required Follow-up sleep study required

100. Uvulopalatopharyngoplasty (UPPP)

101. Primary Care Management Risk counseling Risk counseling Behavior modification Behavior modification Monitor symptoms and compliance Monitor symptoms and compliance –Monitor weight and blood pressure –Ask about recurrence of symptoms –Evaluate CPAP use and side effects Sleep Apnea: Is Your Patient at Risk? NIH Publication No.95-3803.

102. Primary Care Management Reasons for lack of improvement Reasons for lack of improvement –Noncompliance –Alcohol and sedative use –Depression –Poor sleep habits –Nonapneic sleep disorder Persistent or recurrent symptoms Persistent or recurrent symptoms –Consider referral to sleep specialist

103. Sleep Medicine in the Future The prevalence and importance of sleep apnea are attracting attention The prevalence and importance of sleep apnea are attracting attention Training and credentialing have changed Training and credentialing have changed Diagnostic approaches are simplifying, and multiplying Diagnostic approaches are simplifying, and multiplying Reimbursement will continue to fall. Reimbursement will continue to fall. Treatment approaches are changing Treatment approaches are changing The field is vulnerable The field is vulnerable

105. Portable Monitoring (or oximetry) is to in-lab PSG as… CXR is to CT scan (lung cancer) CXR is to CT scan (lung cancer) Pre-post spirometry is to methacholine challenge (asthma) Pre-post spirometry is to methacholine challenge (asthma) Fasting glucose is to oral glucose challenge test (diabetes) Fasting glucose is to oral glucose challenge test (diabetes)

106. Outcomes of Home-Based Diagnosis and Treatment of Obstructive Sleep Apnea Chest 2010; 138: 257-263 Home testing and autoCPAP resulted in the same results in sleepiness, adherence, blood pressure and QoL as in-lab testing. Home testing and autoCPAP resulted in the same results in sleepiness, adherence, blood pressure and QoL as in-lab testing. “It is really not about the technology; it is about the initial and then chronic care of the patient….” (Dr N Collop, editorial) “It is really not about the technology; it is about the initial and then chronic care of the patient….” (Dr N Collop, editorial)

107. CPAP as a Therapeutic Trial (Senn O Chest 2006, n= 33) Autotitrating CPAP, 4-15 cm H 2 0, was used as the therapeutic trial Autotitrating CPAP, 4-15 cm H 2 0, was used as the therapeutic trial A successful trial was “yes” to A successful trial was “yes” to –Are you willing to continue CPAP treatment? –Was objective CPAP use > 2 hours/night? All underwent PSG; sleep apnea was considered an AHI of > 10 All underwent PSG; sleep apnea was considered an AHI of > 10 Excluded were those with CHF, OHS, underlying lung disease, prior CPAP Rx, psych or illness, language problems Excluded were those with CHF, OHS, underlying lung disease, prior CPAP Rx, psych or illness, language problems Those who were diagnosed with OSA on basis of TT had same outcomes as in-lab diagnosed. Those who were diagnosed with OSA on basis of TT had same outcomes as in-lab diagnosed.

108. Autotitrating CPAP (Ayas N, Sleep 2004) Most commonly, increases pressure to eliminate vibration of palate and soft tissue. Most commonly, increases pressure to eliminate vibration of palate and soft tissue. Now costs about the same as “straight” CPAP. Now costs about the same as “straight” CPAP. May improve compliance. May improve compliance. Results in lower pressure over all. Results in lower pressure over all. Can obviate the need for in-lab titration, in many cases. Can obviate the need for in-lab titration, in many cases. Is supplanting in-lab titration Is supplanting in-lab titration

109. Oral Appliances (Kushida C, Sleep 2006)  Indicated for patients with mild-to-moderate obstructive sleep apnea who  prefer oral appliances to CPAP  do not respond to CPAP  are not appropriate candidates for CPAP  fail treatment attempts with CPAP ( Kushida Sleep 2006)  Not as effective as CPAP  Lower blood pressure 3-4 mmHg (Otsuka Sleep Breath 2006)  Outperformed surgery in the only head-to-head trial.  Preferred to CPAP in head-to-head trials.

110. Do Oral Appliances Work? Cochrane Database Syst Rev. 2006 Jan 25;(1):CD001106. “CPAP is effective in reducing symptoms of sleepiness and improving quality of life measures in people with moderate and severe obstructive sleep apnoea (OSA). It is more effective than oral appliances in reducing respiratory disturbances in these people but subjective outcomes are more equivocal. Certain people tend to prefer oral appliances to CPAP where both are effective. This could be because they offer a more convenient way of controlling OSA.”

111. Sleep Apnea Questions?