Transcript Sleep Apnea
Everything You Never Wanted to Know About… Sleep Apnea By: John J. Beneck MSPA, PA-C 1 Case 1 • 35 year old male with loud snoring. Spouse states she can’t sleep in the same room with him. 2 Case 2 • 46 year old obese male in for annual CPE observed by you to appear sleepy during the medical interview. 3 Case 3 • In Hospital: Call at 0025 from RN that 42 year old female diabetic in with lower extremity cellulitis has oxygen saturation in the low 80s when checking vital signs. Awoke when stimulated and SaO2 improved. 4 Objectives • Understand OSAH and CSAS in terms of the following: – – – – – – – Definition Epidemiology Pt. Presentation Dx Prevention Tx Prognosis 5 Abbreviations • • • • • • • • • • • • CO2 – Carbon dioxide CPAP – Continuous positive airway pressure CPE – Comprehensive Physical Exam CSAS – Central sleep apnea syndrome CV – Cardiovascular D/t – due to Dx – Diagnosis Dz - Disease EEG – Electroencephalogram HF – Heart failure HTN – Hypertension LVEF – Left ventricular ejection fraction • • • • • • • • • • • MVC – Motor vehicle crash N-CPAP – Nasal CPAP O2 - Oxygen OSAH – Obstructive sleep apnea hypopnea syndrome pCO2 – partial pressure of carbon dioxide pO2 – Partial pressure of oxygen REM – Rapid eye movement RN – Registered Nurse SaO2 – Oxygen saturation Tx – Treatment W/ - With 6 Neuronal Respiratory Control • Neuronal Control – Rhythmic cycle of breath regulated by medullary neuron interaction – Efferent activity • Cranial nerves of upper airway • Chest wall muscle innervation 7 Neuronal Control (cont.) • Medullary groups influenced by pontine & suprapontine descending pathways • These pathways influenced by sleep-wake cycle, particularly Reticular Activating System activity 8 Obstructive Sleep Apnea Hypopnea - Definition • Episodes of airway obstruction during sleep resulting in recurrent arousals associated with: – Otherwise unexplained excessive daytime sleepiness AND... 9 Definition (cont.) • …AND > 2 of the following • • • • • • Loud disruptive snoring Nocturnal choking/gasping/snort Recurrent nocturnal awakening Unrefreshed sleep Daytime fatique Impaired concentration • ...AND... • Documented overnight sleep monitoring • >5 episodes hypopnea and apnea per hour 10 More Definitions • Apnea – <20% baseline airflow for 10 seconds in adults • Hypopnea – – – – 30% baseline airflow 10 seconds 90% of duration of airflow 30% baseline flow airflow accompanied by 4% oxygen saturation 11 Epidemiology • Overall 2-20% depending on sex and symptoms • Estimated 3 million men and 1.5 million women • M:F 2-4:1 • Daytime sleepiness 2-4% – (narcolepsy 0.02-0.06%) • Up to 85% in obese persons 12 History • Charles Dickens - “The Postumous Papers of the Pickwick Club” – Pickwickian Syndrome – (Obesity Hypoventilation Syndrome) • • • • • Obesity Hypersomnolence Signs of Chronic Alveolar Hypoventilation Polycythemia Sleep apnea 1 - UpToDate, 2006 13 Practical Predictors • HTN • History of habitual snoring • Observed reports of nocturnal choking or gasping • Neck size > 17 inches 14 Airway Patency • Airway size - flow resistance – Anatomic traits • Neck size • Obesity • Crowded upper airway – Large tongue – Small chin • Nasopharyngeal tumors 15 16 OSAH Etiology • Sleep affects respiratory control system – Reduced tonic input to upper airway muscles – Diminished reflexes that protect against airway collapse 17 Etiology (cont) • Exaggerated inspiratory effort • Decreased gas exchange • Resolves with arousal or change in sleep state 18 Recurrent Apnea • Instability of feedback control • Ventilation cycles instead of being maintained at a constant level 19 Mechanism • Sleep… • Upper airway tone... • Obstruction... • Apnea… • pO2, pCO2… 20 Mechanism (cont.) • • • • • • • …Arousal… Upper airway tone… Resumption of breathing… Hyperventilation… Return to sleep… Upper airway tone… This occurs HUNDREDS of times each night 21 Etiology (cont) • Upper airway is destablilized • Partial or complete obstruction of nasopharynx, oropharynx, or both 22 Presentation • Primarily relate to effects on pt’s sleep – Typically overweight men – Awaken unrested – Daytime somnolence – Disruptive snoring • 45% men & 30% women >65 yrs old snore 23 Sleepiness (Of course we need to define sleepiness) • Mild – Sleep during times of rest – Incidental functional impairment • Moderate – Sleep during activities requiring some attention • Concerts • Meetings • Presentations 24 Sleepiness (cont.) • Severe – Sleep during activities requiring at least moderate attention • • • • Eating Conversation Walking Driving – Marked functional impairment 25 Differential Diagnosis of Sleepiness • • • • Sleep restriction Narcolepsy Restless leg syndrome Cardiovascular, respiratory, metabolic disturbances • Drug addiction • Depression 26 OSAH Diagnosis-suspicion • Presentation as above • Witnessed apneic periods, nocturnal gasping or choking – >10 events per hr typical for symptomatic pts • Body habitus • HTN 27 Diagnosis-definitive • Nocturnal Polysomnograph – EEG – Electromyelograph • Chin – activity during REM • Limbs – checks non-respiratory causes of arousal – Electro-oculogram • Detects REM 28 DDx (cont.) – Nasal/oral airflow – Thoracic/abdominal movement – Oxygen saturation – Cardiac rate & rhythm – Body position 29 Split studies • Part 1 – Definitive diagnosis • Part 2 – Optimal CPAP level 30 Terms of OSA Quantification – Apnea-hypopnea index (AHI) – Apnea Index (AI) – Respiratory Disturbance Index (RDI) – Respiratory Arousal Index (RAI) 31 Apnea-Hypopnea Index (AHI) • # episodes apnea & hypopnea / # hrs sleep OSAH = AHI > 15 / hr 32 Apnea Index • # apneic episodes / # hrs sleep 33 Respiratory Disturbance Index (RDI) • # times per hour SaO2 drops > 3% – <5 - No OSA – 5-15 - Mild OSA – 16-30 - Moderate OSA – >30 - Severe OSA 34 Respiratory Arousal Index (RAI) • Computed with EEG measurement • # inspiratory associated arousals per hour of sleep 35 OSAH Complications • Sleepiness – Somnolence during activities – Impaired concentration • Systemic hypertension • Vascular disease 36 OSAH and CV Disease • Arousals – bursts of sympathetic activity – Not good • SaO2 / SaO2 causes ischemia then reperfusion – Oxydative stress • Subsequent – HTN – Insulin resistance – Inflammation • Ultimately leading to… – CV endothelial dysfunction 37 Other Potential Complications • Stroke • Cardiac arrhythmia • Pulmonary HTN • Morning head ache • Peri-operative complications – Impaired intubation – Impaired arousal from sedatives 38 Prevention • Modifiable risk factors: – Obesity – Exacerbative medications – Inadequate sleep • Modifiable complications: – Machinery/motor vehicle operation – Inform Anesthesiologist before elective procedures 39 Treatment - General • Depends on severity of disease – No Tx for < 15 events per hour • Behavioral Modifications 40 Treatment - General (Cont.) • Weight loss – 5-10% body weight may be effective • Nasal CPAP • Oral appliances 41 Treatment - Medical • • • • Vasoconstrictive sprays Weight loss meds Oxygen (select patients) Chemical avoidance – Sedative hypnotics – Alchohol – Antihistamines 42 Treatment - Surgical • Hyoplasty • Linguloplasty • Mandibular advancement • Uvulopalatopharyngoplasty • Tracheostomy 43 Treatment - Surgical • For loud snoring: – Laser-assisted uvuloplasty – Radiofrequency tissue ablation – May apnea and/or delay definitive treatment 44 Prognosis • Natural history largely unknown • IF dz progresses, it does so slowly • Implications with death: – ? in-hospital mortality d/t: • Cardiorespiratory failure • Pulmonary embolus • Case reports complications of anesthesia – Accidents • 2-7 times greater chance of MVC • Equipment operation 45 Central Sleep Apnea Syndrome • > 10 second cessation of breathing in the absence of respiratory effort. 46 Central Sleep Apnea Syndrome • Airflow stops without obstruction • Interruption of central respiratory drive • Airflow AND respiratory effort are absent • Disorder of Apneic Threshold • Relation to OSA (Mixed Apnea) 47 CSAS - Etiology • Complication of OSAH • Narcotic induced CSAS • High altitude induced periodic breathing • Neural disorders – Poliomyelitis – Posterior fossa tumors – Idiopathic failure of central breathing control 48 CSAS – Etiology (Cont.) • Heart Failure – 37% of Pts with HF & LVEF < 45% have CSAS – 12% have OSAH 49 CSAS - Presentation • Insomnia • Nocturnal awakenings • Nocturnal polysomnograph – No evidence of obstruction – No respiratory movement 50 CSAS – Definitive Dx • Pleural pressure monitoring • Airflow Both recorded and at least one shown to be abnormal during events monitoring 51 CSAS - Treatment • Tx underlying cause • Inspired CO2 • Acetazolamide • O2 for non-HF pts • N-CPAP (? w/ CO2) • Phrenic nerve • CV med optimization stimulation 52 In Review… • 3 types of sleep apnea – Obstructive (common) – Central (less common) – Mixed (very common) • Possibly serious implications • Multiple effective tx options • Awareness is key 53 Remember the Cases? • 35 year old male with loud snoring. Spouse states she can’t sleep in the same room with him. • 46 year old obese male in for annual CPE observed by you to appear sleepy during the medical interview. • In Hospital: Call at 0025 from RN that 42 year old female diabetic in with lower extremity cellulitis has oxygen saturation in the low 80s when checking vital signs. Awoke when stimulated and SaO2 improved. 54 References • • • • Westbrook, PR. An overview of Obstructive Sleep Apnea: Epidemiology, Pathophysiology, Clinical Presentation, and Treatment in Adults. In UpToDate, Rose, BD (Ed), UpToDate, Waltham, MA, 2006. Kingman, PS. Sleep Disordered Breathing in Adults – Definitions. In UpToDate, Rose, BD (Ed), UpToDate, Waltham, MA, 2008. Eckert DJ, Jordan AS, Mercha P, Malhotra A. Central Sleep Apnea: Pathophysiology and Treatment. Chest 2007 Feb: 131(2): 595-607 Douglas NJ. Harrison’s online. http://www.merckmedicus.com/pp/us/hcp/frame_textbooks.jsp?pg=http://www.accessmedicine.com/ content.aspx?aid=2869600. Accessed 8/12/08 55