Which PAP device to which patient?

1. Which PAP device to which patient? Claudio Rabec, MD FCCP Service de Pneumologie et Réanimation Respiratoire Centre Hospitalier Universitaire de Dijon

2. Breathingdisorders in sleep The international classification of sleep disorders ( ASSM, ICSD2, 2005) Otherbreathingdisorders Sleep-relatedhypoxemia/hypoventilation OSA CSA Medicalconditions Idiopathic Cheyne Stokes Drug induced Adult Pediatric • Parenchymal • Neuromuscular • Thoracic cage Congénital: Ondine Course COPD UARS OHS Overlap: COPD + OSA OHS + OSA

3. Normal inspiration SaO2 Flow Thx Abd 1

4. Hypoventilation or SaO2 Flow Thx Abd

5. Rhytmogenesis failure (central apneas) 1) Blunted ventilatory drive SaO2 Flow Thx Abd

6. Rhytmogenesis failure (central apneas) 2) Ventilatory instability SaO2 Flow Thx Abd

7. UA obstruction (obstructive apnea) SaO2 Flow Thx Abd 1

8. SB NIV SB PS SBCPAP SBSB

10. Sleep Apnea Abnormal respiratory events during sleep • Apneas • Hypopneas • RERA • Obstructive, central, mixed + Clinical signs

11. 90 % of sleep apnea patients have an obstructive form (0SA)

12. Normal flow Flow limitation Complete Obstruction

13. OSA: Consequences of upperairwaysintermittentobstruction • Episodic “asphyxia” • Sleepfragmentation • Intermittenthypoxemia Sympathetichyperesponsiveness •  Episodes of intrathoracicdepression • Oxydative stress/endothelialdysfunction • Sleepiness •  Daytime fatigue •  Vascular complications

14. OSA-related morbidity • Cardiovascular morbidity • Neurovascular morbidity • Hypertension • Arrhytmias • Motor vehicle and working accidents

15. Severe OSATherapeutic options • Fixed CPAP • Auto CPAP • Cflex ™ /EPR ™ • “Alter” CPAP • Bilevel devices

16. Severe OSATherapeutic options • Fixed CPAP • Auto CPAP • Cflex™ /EPR ™ • “Alter” CPAP • Bilevel devices

19. CPAPHow it works?

21. CPAP: How do it works? Treat apneas and hypopneas CPAPPneumatic splint • Presurize and stabilize UA • Additionaly increase FRC • obstructive • mixed • some central Sometimes improves hypercapnia Potential mechanisms • Treat respiratory events “reset” ventilatory drive • Increase FRC • Counterbalance AutoPEEP (mainy in COPD) • “Normalize” UA function

22. Immediate effects • Improving sleep architecture • Reducing arousals • Reducing flow limitation • Reducing ou abolishing nocturnal respiratory events

23. Long term effects • Improvement in daytime alertness • Normalization of sleep quality • Reduction of risks of motor vehicles and working accidents • Quality of life improvement • Reduction in risk of cardiovascular and neurovascular accidents • Improving survival?

24. Stradling Thorax 2000

25. 1) Hypertension Before CPAP After CPAP Pepperell Lancet 2002

26. 2) Secondary stroke prevention Martinez Garcia; Chest 2005

27. 3) Cardiovascularmorbidity

28. 4) Sleepiness

29. 5) Traffic accidents Teran Santos, NEJM 1999

30. CPAP effective pressure Goals • Reducing arousals • Normalisingsleep architecture • Normalizing flow • Reducing ou abolishing nocturnal respiratoryevents Tools • Manualtitration • Full or "Split night" • Hoffstein formula • AutoCPAPdevices

31. Severe OSATherapeutic options • Fixed CPAP • Auto CPAP • Cflex™ /EPR ™ • “Alter” CPAP • Bilevel devices

32. What is an autoCPAP? • Auto CPAP machine (APAP) is a device commited to deliver a variable pressure • at a customized, regularly adjusted level • between a pre established rang • Designed to increase pressure in response to predetermined respiratory events • Use sophisticated algorithms to detect pressure requirements

33. Rationale of AutoCPAP An individuals pressure profile varies over time • Over the same night • Body position • Sleep State (REM vs. NREM) • Overdifferentnights • Nasal congestion • Alcohol and sedative use • Sleepdeprivation  Fixed pressure does not accommodate for these changes

34. Overnight

36. … overdifferentnights

37. APAP: some main questions… • Whatis the better signal to detectevents? • The methodused to evaluatethis signal isappropriate? • Is there an interest to reduce pressure levelovernight ?

38. How an APAP works?Two different targets Flow Airwayresistance Pneumotach Forcedoscillationtechnique

40. How an APAP works?1) Flow

41. Estimating airway resistance by FOT Principle: to send high frequency - small pressure oscillation to test airway pattency Symetricpattern: Airways closed Asymetricpattern: Airways open

42. Flow vs combined flow + FOT During partial airway collapsus • PTG (flow target) is able to responde to • Snoring • Flow limitation (then to react only to hypopneas with flow limitation)

43. Flow alone vs combined flow + FOT During complete airway collapsus • There is not flow… how to classify apneas? • Airway resistance  Useful for differenciate central from obstructives apneas APAP devices combining PTG +FOT could apriopratelly respond • To snoring • To “flow limited” hypopneas • Only to obstructive apneas

44. S9 Autoset™ (Resmed)FOT algorhytme Waiting time Exploring airway pattency FOT signal sent (4 Hz, 1 cm H2O)

45. Closed airway Flow Mask pressure “Symetric” pattern

46. Open airway Flow Mask pressure “Asymetric” pattern (cardiacoscillations)

47. APAP: some main questions… • Whatis the better signal to detectevents? • Is the methodused to evaluatethis signal appropriate? • Are all APAP equally effective? • Is there an interest to reduce pressure levelovernight ?

48. Principe : tester les machines sur banc de test boucle fermée

49. APAP: the same concept but different algorhitmes Farré, AJRCCM 2002

50. APAP testing in the clinical setting