Obstructive Sleep Apnea Perioperative Implications From Mechanisms to Risk Modification

1. Obstructive Sleep Apnea Perioperative ImplicationsFrom Mechanisms to Risk Modification Satya Krishna Ramachandran MD FRCA Assistant Professor of Anesthesiology University of Michigan Medical School, Ann Arbor rsatyak@med.umich.edu

2. Disclosures • Paid scientific advisory consultant • Galleon Pharmaceuticals • Merck, Sharp & Dohme • Funding • PSA with MSD for 2014 • MiCHR CTSA PGP UL1TR000433 for 2014 The material of this talk is independent of these disclosures This is a confidential Quality Improvement and Assurance/peer review document of the University of Michigan Hospitals and Health Centers. Unauthorized disclosure or duplication is absolutely prohibited. This document is protected from disclosure pursuant to the provisions of MCL 333.20175; MCL 333.21515; MCL 331.531; MCL 331.533 or such other statutes that may be applicable

3. Goals & Objectives • To describe the relationship between OSA and early postoperative respiratory failure • To review mechanisms of unanticipated early postoperative respiratory failure • To critically evaluate methods of risk-modification of early postoperative respiratory failure

4. Obstructive Sleep Apnea and Respiratory Failure

5. Evidence in the surgical population • Retrospective studies: associations • Gupta – more complications, ICU admissions • Hwang – more morbidity • Memtsoudis – independent increase in morbidity • Mokhlesi – Increased respiratory failure • Prospective evidence: associations • Chung – more postoperative desaturation episodes • Gali – more morbidity with postoperative episodic desat. • Sudden death – case reports Gupta. Mayo ClinProc. 2001;76:897-905 Hwang. Chest. 2008;133:1128-34 Memtsoudis. Anesth Analg. 2011;112:113-21 Gali B. Anesthesiology 2009;110:869-77 Ostermeier. Anesth Analg. 1997;85:452-60

6. AHI and outcome Gami. N Engl J Med. 2005;352:1206-14.

7. Nocturnal pattern in sudden death Gami. N Engl J Med. 2005;352:1206-14.

8. Severity of OSA and nocturnal variation in sudden death Gami. N Engl J Med. 2005;352:1206-14.

9. If they are prone to sudden death during sleep, is the risk of postoperative sudden deathincreased in patients with OSA?

10. Nocturnal Variation In Outcome Of ARE Postoperative ARE from RM database 35 cases – 5 deaths / 6 years History or known risk factors for OSA present in ~40% cases Ramachandran SK. J Clin Anesth 2011;23:207-13

11. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity Somers et al. Circulation. 2008;118:1080-1111

12. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity

13. Hypoxia and Arrhythmia/Conduction • Nocturnal ventricular arrhythmias • Min SpO2<60% • AHI >65.hr-1 • QRS prolongation • Min SpO2<90% • AHI >30.hr-1 • Heart Block • Min SpO2<90% • Obesity Sheppard. Chest. 1985 Sep;88(3):335-40 Valencia-Flores. ObesRes. 2000 May;8(3):262-9. Ramachandran – unpublished data

14. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity

15. MSNA and OSA Somers et al. J Clin Invest. 1995;96:1897-904

16. MSNA and Sleep Stage Somers et al. J Clin Invest. 1995;96:1897-904

17. MSNA In Awake State Somers et al. J Clin Invest. 1995;96:1897-904

18. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity

19. Cardiovascular variability Narkiewicz et al. Circulation. 1998;98:1071-1077

20. Intrathoracic Pressure Changes • Repeated Mueller maneuvers during OSA • Intrathoracic pressures approach -65 mmHg • ?Increased risk of postoperative pulmonary edema • Increased transmural gradient across atria and ventricles • Increased wall stress and afterload • Diastolic dysfunction • Atrial remodeling

21. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity

22. OSA and Inflammation • Selective activation of inflammatory pathways • Hypoxemia • Sleep deprivation/fragmentation • Increased levels in OSA • Cytokines, adhesion molecules, serum amyloid • C-reactive protein - ?obesity related • TNF • May influence postoperative mortality and morbidity

23. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity

24. Unanticipated Postoperative Respiratory Failure • Prediction model in 222,094 patients from the NSQIP dataset. • Overall, 49.4% unanticipated tracheal intubations occurred within first three days after surgery. • The incidence of unanticipated early postoperative intubation (UEPI) was 0.83-0.9% Ramachandran SK et al. Anesthesiology2011;115:44-53

25. UEPI Independent Predictors • Surgical Type • Current Ethanol Use • Current Smoker • Dyspnea • COPD • Diabetes Mellitus • Active Congestive Heart Failure • Hypertension Requiring Medication • Abnormal Liver Function • Cancer • Prolonged Hospitalization • Recent Weight Loss • Body Mass Index < 18.5 Or ≥ 40 Kg/m2 • Sepsis Ramachandran SK et al. Anesthesiology2011;115:44-53

26. UEPI Independent Predictors • Surgical Type • Current Ethanol Use • Current Smoker • Dyspnea • COPD • Diabetes Mellitus • Active Congestive Heart Failure • Hypertension Requiring Medication • Abnormal Liver Function • Cancer • Prolonged Hospitalization • Recent Weight Loss • Body Mass Index < 18.5 Or ≥ 40 Kg/m2 • Sepsis Ramachandran SK et al. Anesthesiology2011;115:44-53

27. Mechanisms of Perioperative AE? • Hypoxia • Sympathetic activation • Cardiovascular variability • Inflammation • Comorbid disease • Chemoceptor hypersensitivity

28. OSA and chemoreceptor sensitivity • Limited adult data • Postoperative ARE outcomes unrelated to dose • Opioid consumption lower in patients who died Ramachandran SK et al. J Clin Anesth 2011;23:207-13

29. Metabolic Disease and RD?

30. Risk Modification

31. Baseline Risk Reduction Strategies • Preoperative CPAP • Opioid sparing techniques • Regional anesthesia/analgesia • Non-opioid adjuncts • Minimal access surgery • Continuous pulse oximetry monitoring • Postoperative CPAP • Expert Opinion

32. PREoperativeCPAP • No RCT guided evidence of perioperative benefit • Possible mechanisms: • Less severe nocturnal desaturation • More dependable postoperative CPAP usage • Challenges: • Majority of patients are undiagnosed • Adherence with therapy is low • Timely preoperative testing/fitting

33. Preop CPAP Benefit - MSNA, MAP Somers et al. J Clin Invest. 1995;96:1897-904

34. CPAP and QTc Dispersion • Longitudinal 6-month study of CPAP • 12-lead ECG data analysis Dursunoglu et al. Sleep Medicine 2007;8:478–483

35. CPAP and Arrhythmia in CHF Ryan et al. Thorax 2005;60:781–785

36. Cessation of CPAP and MSNA Somers et al. J Clin Invest. 1995;96:1897-904

37. UM Model for Fast Track PSG

38. MSQC study • Introduced a new concept – Preoperative PAP treatment for OSA • Implies diagnosis of OSA • Compliance generally ~50% • MSQC nurse abstractors collect data from 56 hospitals in Michigan • Risk adjusted for surgery, comorbid conditions and intraoperative characteristics

39. Frequency Tables

40. MSQC Analysis

41. Multivariate Analysis

42. Baseline Risk Reduction Strategies • Preoperative CPAP • Opioid sparing techniques • Regional anesthesia/analgesia • Non-opioid adjuncts • Minimal access surgery • Continuous pulse oximetry monitoring • Postoperative CPAP • Expert Opinion

43. Baseline Risk Reduction Caveats • Opioid sparing techniques • Reduce opioid consumption • May not modify respiratory risk Blake et al. AnesthesInt Care. 2009;37:720-725

44. Baseline Risk Reduction Strategies • Preoperative CPAP • Opioid sparing techniques • Regional anesthesia/analgesia • Non-opioid adjuncts • Minimal access surgery • Postoperative CPAP • Continuous pulse oximetry monitoring • Expert Opinion

45. UM model for Postop CPAP

46. Risk Modification – Postop CPAP • Robust evidence for early treatment of hypoxia • Randomized Controlled Trial of CPAP vs. O2 • Major elective abdominal surgery • CPAP associated with • lower intubation rate (1% vs 10%) • lower occurrence rate of pneumonia (2% vs 10%), infection (3% vs 10%), and sepsis (2% vs 9%). • No RCT evidence of benefit of postoperative CPAP in OSA patients Squadrone V. JAMA 2005;293:589-595

47. Baseline Risk Reduction Strategies • Preoperative CPAP • Opioid sparing techniques • Regional anesthesia/analgesia • Non-opioid adjuncts • Minimal access surgery • Postoperative CPAP • Continuous pulse oximetry monitoring • Expert Opinion

48. Postoperative Monitoring Overview • Outcome studies – monitoring success is limited to recent, small single center studies, majority evidence points to no benefit. • Limitations of current state of alarm technology • Why universal monitoring may be a problem

49. Outcome Studies • 3 tiers of monitoring conceptually: • Spot monitoring • Continuous bedside monitoring • Integrated monitoring /surveillance systems • Largest studies are of bedside devices • Majority of current evidence around IM/SS • Direct comparative effectiveness trials are impossible in the current climate