Obstructive Sleep Apnea

1. Obstructive Sleep Apnea Babak Saedi .M.D Imam Khomeini Hospital

2. What is OSA? • Disorder of obstructed breathing occurring during sleep • Apnea: cessation of breathing with respiratory effort lasting greater than 10s • Hypopnea refers to a greater than 50% reduction in air flow

3. Epidemiology of OSA • Prevalence - 2% in women, 4% in men • In the elderly, estimates range from 28% to 67% in men and 20% to 54% in women • two thirds are obese

4. Why is it so Important? • Hypertension • 25% of hypertensives have OSA (AI>5) • Sleep Heart Health Study • 6000 patients corrected for bmi, neck, EtOH • Nieto, et al. JAMA 283 (14): 1829-36, April 2000 • SDB (including snoring) and Htn correlate • 1700 patients • Bixler, et al Arch IM 160 (15): 2289-95, 2000 • Sleep 1980; 3: 221-4 • BMJ 1987; 294: 16-19

5. Health Impact • MI • REI >20 independent predictor of MI • 223 German males with angio confirmed CAD • Schafer, et al. Cardiology 92(2): 79-84, 1999 • Increased mortality in CAD patients • 5 y study (Sweden)-62 patients; 19 with OSA (RDI 17) • OSA mortality: 37.5%; Non-osa mortality: 9.3% • Peker, et al. Am J Resp Crit Care 162 (1): 81-6, 7/2000

6. Health Impact • CVA • REI severity is independent predictor of Stroke • 128 patients (UM)- 75 stroke; 53 TIA • 62.5% with AHI >10 with stroke vs 12% controls • Bassetti, C et al. Sleep 22(2): 217-23, 3/1999

7. Health Impact • Death • AI<20, at 8y follow-up: 4% mortality • AI>20, at 8y follow-up: 37% mortality • treatment with trach or CPAP: 0% mortality • Chest 1988; 94: 9-14 • NCSDR 1993 • 38000 CV deaths related to OSA per year

8. Societal Impact

9. 2006 American Academy of Sleep Medicine

10. Societal Impact • Increased Traffic Accidents • simulated driving: SDB ~100x more likely to drive off the road • Acta Otolaryn 1990; 110: 136ff • 7x increased risk of auto accidents • Clin Chest Med 1992; 13: 427-34

12. PATENT Vs COLLAPSED AIRWAY 2006 American Academy of Sleep medicine

13. How’s it Diagnosed? • History, Physical Examination, and Sleep Study • History • Disrupted sleep, restless sleep, awaken with gasping and choking • Loud snoring • Tired, inappropriate falling asleep • Witnessed apneas

14. Who gets it? • Men who snore and who are overweight

15. adenotonsillar hypertrophy nasal obstruction hypothyroidism acromegaly Down syndrome sedative use Alcohol Smoking micrognathia retrognathia Obesity Neck circumference vocal cord paralysis H&N masses Risk factors

16. History • Associated Complaints • Weight changes • Thyroid/Growth Hormone abnormalities • GERD • Habits • sleep schedule • EtOH • PMH/Meds • Hypertension • Sedatives; Antihistamines

17. SITUATION CHANCE OF DOZING Sitting and reading Watching TV Sitting inactive in a public place (e.g a theater or a meeting) As a passenger in a car for an hour without a break Lying down to rest in the afternoon when circumstances permit Sitting and talking to someone Sitting quietly after a lunch without alcohol In a car, while stopped for a few minutes in traffic

18. Physical Exam • Height and Weight (BMI) • BMI=[703.1 x weight(pounds)] / [Height (in)2] • neck size • Face-retrognathia • Nose • Oral cavity- palate, uvula, tonsils/pillars, tongue, occlusion

20. OBESITY • Strongest risk factor for OSA • Present in > 60% of patients referred for a diagnostic sleep evaluation • Wisconsin Sleep Cohort Study • A one standard deviation difference in BMI was associated with a 4-fold increase in disease prevalence

21. Obesity • Alters upper airway mechanics during sleep • Increased parapharyngeal fat deposition: neck circumference: > 17” males > 16” females With subsequent:  smaller upper airway  increase the collapsibility of the pharyngeal airway

22. obesity 2. Changes in neural compensatory mechanisms that maintain airway patency:  diminished protective reflexes which otherwise would increase upper airway dilator muscle activity to maintain airway patency

23. obesity 3. waist circumference Fat deposition around the abdomen produces  reduced lung volumes (functional residual capacity) which can lead to loss of caudal traction on the upper airway  low lung volumes are associated with diminished oxygen stores

25. Physical Examination

26. Evaluation • thyroid function tests • Poly somnography is the gold standard

27. History and physical examination identify only 52% of OSA patients, with a specificity of 70% • Clinic of North America 1999

29. Fiberoptic Nasopharyngolaryngoscopy • Determines level of obstruction • Provides estimate of degree of obstruction • Technique • supine (i.e., in a sleeping position) • at FRC-point of maximal relaxation • snore maneuver • Mueller maneuver- inspire against a closed airway

30. UpToDate

31. How To Treat? • Minimal intervention • Drop the Weight!

32. Continuous Positive Airway Pressure (CPAP) • Continuous Positive Airway Pressure pneumatically splints open the patient’s airway during sleep by delivering pressurized air into the throat • Effective at eliminating apneas and hypopneas • Considered the gold standard in the treatment of OSA

33. CPAP Side Effects • Despite its high efficacy, patients frequently cannot tolerate its usage every night for life and thus long-term acceptance has been found to be low (~50%) • Side effects: • Oronasal dryness • Conjuctivitis from air leak • Noise • Claustrophobia • Mask discomfort • Skin abrasions/rash

34. Appliance Design • Patients find appliances that encroach the tongue space and open the bite uncomfortable • No differences in efficacy between greater or lesser mandibular opening in reducing AHI • No difference in treatment success between 1-piece and 2-piece appliances

35. Oral Appliance Therapy • There are no strict guidelines in the design of oral appliances for OSA management and there is a plethora of them in use • There are 1-piece or 2-piece appliances made from soft elastomeric material or hard acrylic • 2-piece appliances have the advantage of allowing for titratable mandibular advancement

36. Surgical Treatment Options • Septoplasty • Turbinoplasty • Partial turbinectomy • Polypectomy • Excision of nasal tumours • Adenoid tonsils excision • Uvulopalatopharyngoplasty • Tonsillectomy • Uvulectomy • Partial glossectomy/tongue base reduction • Genioglossal advancement • Lingual tonsils excision • Hyoid advancement/suspension • Maxillomandibular advancement • Excision of laryngeal tumours • Tracheotomy

37. Surgery • Tracheotomy • An incision in the trachea • Cures OSA nearly 100% of the time • Prior to 1980, it’s all we had; still useful for severe apneics

38. Which Surgical Treatment Option? • When an obvious anatomical abnormality is detected, the appropriate surgical procedure is performed accordingly • Unfortunately, even with sound imaging modalities, it is still difficult to ascertain the pathophysiology of OSA • It is often a combination of multiple sites affecting the upper airway that contribute to OSA

39. Nasal Reconstruction ? • The Journal of Craniofacial Surgery & Volume 21, Number 6, November 2010

40. Remove Tissue- Uvulopalatopharyngoplasty(UPPP) • First successful alternative to tracheotomy • 12 individuals • preop AI 54 +/- 28 • postop AI 28 +/- 28 • 8/12 with post-op AI<20 • Fujita et al. Otolaryngol HNS 1981; 89:923-34

41. Remove Tissue-Other Surgeries • Laser Midline Glossectomy • Palatal Somnoplasty • LAUP • Radiofrequency tongue base reduction • Woodson, et al, AAO 2000, Washington DC • 18 patients completed protocol, average 15,696 J • REI decreased from 45.3 to 33.3

42. UPPP has been considered to be effective only in approximately 50% of patients with OSA

43. Enlarge the Bony Space-Other Surgeries • Genioglossus Advancement/ Hyoid Repositioning • Success ~80% (11-18mm) • Less effective with RDI >60 • Maxillo-mandibular Advancement • Particularly useful in the setting of hypopharyngeal obstruction (Fujita 2 or 3) • Best results when performed following “Stage 1” surgery

44. Maxillomandibular Advancement

45. Palatal Expansion • RPE treatment widens the maxillary bone via distraction osteogenesis at the midpalatal suture • Increases the volumetric space of the nasal cavity, which helps reduce nasal resistance • Promotes spontaneous repositioning of the tongue to a normal position

46. Which Surgical Treatment Option? • Retropalatal and retroglossal openings are common areas that are obstructed in the upper airway • Maxillomandibular advancement has been shown to be very successful at treating OSA with retropalatal and retroglossal obstructions • However, some believe that maxillomandibular advancement is too invasive and should only be performed following a poor response to a procedure involving uvulopalatopharygoplasty, genioglossal advancement, and hyoid suspension • These clinicians argue that it would be overly aggressive to submit a patient who would have responded to a less invasive surgery to the risks/complications from maxillomandibular advancement

47. What is Successful Treatment? • In surgical studies, the definition of success is mainly based on objective measures • Common objective parameters are the apnea-hypopnea index and lowest oxygen saturation • Current accepted definition for surgical cure: • AHI less than 20 with a reduction greater than 50% • Few desaturations less than 90% • Reason for setting the success less than 20 is that several studies have found that an index >20 translates to increased morbidity and mortality

48. Risks of Surgical Treatment • Surgery in the upper airway results in postoperative edema, which has acute adverse effects on breathing • Several medications used during surgery are respiratory depressants and can remain in the body in low amounts for hours/days • OSA can be dangerously aggravated by these drugs thus these patients need prolonged monitoring following surgery • There is also a concern with postoperative analgesics that are respiratory depressants • Other complications: nerve damage, excessive bleeding

50. Sleep Apnea 2006 American Academy of Sleep Medicine