1. The Perioperative Evaluation of Obstructive Sleep Apnea Shelley Hershner, MD University of Michigan

2. Conflict of Interest Disclosures for Speakers
1. I do not have any relationships with any entities producing, marketing, re-selling, or distributing health care goods or services consumed by, or used on, patients, OR
2. I have the following relationships with entities producing, marketing, re-selling, or distributing health care goods or services consumed by, or used on, patients. Xx
Type of Potential Conflict
Details of Potential Conflict
Grant/Research Support
Consultant
Speakers’ Bureaus
Financial support
Other
Intellectual Property Rights- Sleep to Stay Awake, a free online sleep education intervention owned by the Regents at the University of Michigan x
3. The material presented in this lecture has no relationship with any of these potential conflicts, OR
4. This talk presexnts material that is related to one or more of these potential conflicts, and the following objective references are provided as support for this lecture:

3. Nocturnal pattern in sudden death
Gami. N Engl J Med. 2005;352:

4. Severity of OSA and nocturnal variation in sudden death
Gami. N Engl J Med. 2005;352:

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

6. 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

7. OSA – chronic pain? Untreated OSA increases pain sensitivity
May result in need for higher doses of opioid

8. OSA and Respiratory depression
It is estimated that up to 20% of patients develop respiratory depression postoperatively.
Blake et al showed that patients with significant postoperative OSA received 3-times greater doses of morphine

9. Outcomes measures relevant to OSA
The first 72 hours following surgery have direct implications for respiratory morbidity
Respiratory failure caused by narcotic use peaks in the first 24 hours after surgery
Significant postoperative hypoxemia and sleep-related breathing abnormalities peaks on the 3rd postop night.
Respiratory complications are associated with a 12-fold increase in patient care costs and 9-fold increase in death
Ramachandran SK. J Clin Anesth 2011;23:207-13
Rosenberg J. Br J Anaesth 2008;100:45-9
Taylor S. Am J Surg 2005;190:752-6
Rosenberg J. Br J Anaesth 1994;72:145-50
Rosenberg J. Eur J Surg 1994;160:137-43
Dimick JB. J Am Coll Surg 2004;199:531-7

10. OSA and Postoperative RD?
Limited adult data
Postoperative ARE outcomes unrelated to dose
Opioid consumption lower in patients who died
Postoperative ARE from RM database
35 cases – 5 deaths / 6 years
History or known risk factors for OSA present in ~40% cases
Ramachandran SK et al. J Clin Anesth 2011;23:207-13

11. OSA = Reduced Therapeutic Margin
May have elevated PRE-operative opioid requirements
May have increased POST-operative pain
May have greater risk of RD from opioid analgesia
Dose equivalence difficult to determine/establish

12. OSA and Surgery

13. 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
Mokhlesi endotracheal intubation (OR = 4.35p < 0.001), noninvasive ventilation (OR = 14.12p < 0.001),and atrial fibrillation (OR = 1.25, p < 0.001).
Prospective evidence: associations
Chung – more postoperative desaturation episodes
Gali – more morbidity with postoperative episodic desat.
Sudden death – case reports
ndotracheal intubation (OR = 4.35, 95% CI =  , p < 0.001), noninvasive ventilation (OR = 14.12, 95% CI =  , p < 0.001), and atrial fibrillation (OR = 1.25, 95% CI =  , p < 0.001).
Gupta. Mayo Clin Proc. 2001;76:
Hwang. Chest. 2008;133:
Memtsoudis. Anesth Analg. 2011;112:113-21
Gali B. Anesthesiology 2009;110:869-77
Ostermeier. Anesth Analg. 1997;85:452-60
Obes Surg Nov;23(11):

14. OSA and Perioperative Outcomes
NIS: 2,610,441 entries for orthopedic and 3,441,262 for general surgical procedures performed between 1998 and 2007
Perioperative outcomes research relevant to OSA suggests several important facts. OSA diagnosis is independently associated with a 2-6 fold increase in risk of adverse cardio-pulmonary outcomes. High risk features of OSA namely morbid obesity (BMI ≥40 kg.m-2) diabetes and hypertension are also independently associated with postoperative pulmonary outcomes
Memtsoudis et al. Anesth Analg 2011;112:113–21

15. OSA and Perioperative Outcomes
NIS: 2,610,441 entries for orthopedic and 3,441,262 for general surgical procedures performed between 1998 and 2007
Memtsoudis et al. Anesth Analg 2011;112:113–21

16. Systematic Review 413,304 OSA and 8,556,279 control patients
Does Obstructive Sleep Apnea Influence Perioperative Outcome? A Qualitative Systematic Review for the Society of Anesthesia and Sleep Medicine Task Force on Preoperative Preparation of Patients with Sleep-Disordered Breathing.
Anesthesia & Analgesia. 122(5): , May 2016.
DOI: /ANE

17. With known or high risk to have OSA were not
55% of patients
With known or high risk to have OSA were not
receiving PAP therapy prior to their surgery
Measurements and Results: Of 26,842 patients, 2,646 (9.9%) had a diagnosis or suspicion of OSA. Of those, 1,465 (55.4%) were untreated.
Patient and procedural risk factors were evenly balanced between treated and untreated groups. Compared with treated OSA, untreated OSA
was independently associated with more cardiopulmonary complications (risk-adjusted rates 6.7% versus 4.0%; adjusted odds ratio [aOR] = 1.8,
P = 0.001), particularly unplanned reintubations (aOR = 2.5, P = 0.003) and myocardial infarction (aOR = 2.6, P = 0.031).
Conclusions: Patients with obstructive sleep apnea (OSA) who are not treated with positive airway pressure preoperatively are at increased risks
for cardiopulmonary complications after general and vascular surgery. Improving the recognition of OSA and ensuring adequate treatment may
be a strategy to reduce risk for surgical patients with OSA.
Abdelsattar et al. SLEEP, Vol. 38, No. 8, 2015

18. Frequency Tables Entire Cohort Sleep Apnea Freq. (%) None 32,148 90.91
Untreated
1,769 5
Treated
1,446
4.09
Total
35,363
100
General Surgery
20,873
90.31
1,226
5.3
1,013
4.38
23,112

19. Postoperative Complications in Patients With Obstructive Sleep Apnea Syndrome Undergoing Hip or Knee Replacement: A Case-Control Study
Serious complications occurred in 24 patients (24%) in the OSAS group compared with 9 patients (9%) in the control group (P=.004). Hospital stay was significantly longer for the OSAS patients at a mean ± SD of 6.8±2.8 days compared with 5.1±4.1 days for the control patients (P<.007).
Group 1A undiagnosed obstructive sleep apnea syndrome
group 1B patients with OSAS that had been diagnosed at the time of operation.
Objective: To identify and assess the impact of postoperative complications in patients with unrecognized or known obstructive sleep apnea syndrome (OSAS) undergoing hip replacement or knee replacement compared with control patients undergoing similar operations. Although OSAS is a risk factor for perioperative morbidity, data quantifying the magnitude of the problem in patients undergoing non-upper airway operations are limited.
Patients and Methods: This retrospective, case-control study from a single academic medical institution included patients diagnosed as having OSAS between January 1995 and December 1998 and undergoing hip or knee replacement within 3 years before or anytime after their OSAS diagnosis. Patients with OSAS were subcategorized as having the diagnosis either before or after the surgery and also, regardless of time of diagnosis, by whether they were using continuous positive airway pressure (CPAP) prior to hospitalization. Matched controls were patients without OSAS undergoing the same operation. Interventions were defined specifically as administration of a particular treatment in the context of each complication, eg, supplemental oxygen, implementation of additional monitoring such as oximetry for hypoxemia, or transfer to the intensive care unit (ICU) for cardiac ischemia concerns. Postoperative complications were assessed for all patients in the different categories and included respiratory events such as hypoxemia, acute hypercapnia, and episodes of delirium. Serious complications were noted separately, including unplanned ICU days, reintubations, and cardiac events. The length of hospital stay was also tabulated.
Results: There were 101 patients with the diagnosis of OSAS in this study and 101 matched controls. Thirty-six patients had their joint replacement before OSAS was diagnosed, and 65 had surgery after OSAS was diagnosed. Of the latter 65 patients, only 33 were using CPAP at home preoperatively. Complications were noted in 39 patients (39%) in the OSAS group and 18 patients (18%) in the control group (P=.001). Serious complications occurred in 24 patients (24%) in the OSAS group compared with 9 patients (9%) in the control group (P=.004). Hospital stay was significantly longer for the OSAS patients at a mean ± SD of 6.8±2.8 days compared with 5.1±4.1 days for the control patients (P<.007).
Conclusion: Adverse postoperative outcomes occurred at a higher rate in patients with a diagnosis of OSAS undergoing hip or knee replacement compared with a group of matched control patients.
Postoperative Complications in Patients With Obstructive Sleep Apnea Syndrome Undergoing Hip or Knee Replacement: A Case-Control Study.
Gupta, Rakesh; Parvizi, Javad; Hanssen, Arlen; Gay, Peter
Mayo Clinic Proceedings. 76(9): , September 2001.

20. Preoperative Evaluation Surgery status --Inpatient versus outpatient
Intraoperative Management
Postoperative Management
Postoperative Analgesia
Discharge to Unmonitored Settings
Anesthesiology, V 120 • No 2 1 February 2014

22. 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

23. Baseline Risk Reduction Caveats
Opioid sparing techniques
Reduce opioid consumption
May not modify respiratory risk
Opioid/IV paracetamol +/- NSAID/tramadol
Blake et al. Anesthes Int Care. 2009;37:

24. 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%).
Squadrone V. JAMA 2005;293:

25. Does PAP prevent complications? Not known yet…
no major complications occurred in this study. No difference in the incidence of postoperative complications was found between the two groups.
Compliance was 45%
Background: Obstructive sleep apnea (OSA) may worsen postoperatively. The objective of this randomized open-label trial is to determine whether perioperative auto-titrated continuous positive airway pressure (APAP) treatment decreases postoperative apnea hypopnea index (AHI) and improves oxygenation in patients with moderate and severe OSA. Methods: The consented patients with AHI of more than 15 events/h on preoperative polysomnography were randomized into the APAP or control group (receiving routine care). The APAP patients received APAP for 2 or 3 preoperative, and 5 postoperative nights. All patients were monitored with oximetry for 7 to 8 nights (N) and underwent polysomnography on postoperative N3. The primary outcome was AHI on the postoperative N3. Results: One hundred seventy-seven OSA patients undergoing orthopedic and other surgeries were enrolled (APAP: 87 and control: 90). There was no difference between the two groups in baseline data. One hundred six patients (APAP: 40 and control: 66) did polysomnography on postoperative N3, and 100 patients (APAP: 39 and control: 61) completed the study. The compliance rate of APAP was 45%. The APAP usage was 2.4–4.6h/night. In the APAP group, AHI decreased from preoperative baseline: 30.1 (22.1, 42.5) events/h (median [25th, 75th percentile]) to 3.0 (1.0, 12.5) events/h on postoperative N3 (P < 0.001), whereas, in the control group, AHI increased from 30.4 (23.2, 41.9) events/h to 31.9 (13.5, 50.2) events/h, P = No significant change occurred in the central apnea index. Conclusions: The trial showed the feasibility of perioperative APAP for OSA patients. Perioperative APAP treatment significantly reduced postoperative AHI and improved oxygen saturation in the patients with moderate and severe OSA. OBSTRUCTIVE sleep apnea (OSA) is a comm
Liao et al. Anesthesiology 2013; 119:837-47

26. Does PAP prevent complications? Not known yet…

27. Multivariate Analysis
Entire Cohort
Adjusted Odds Ratio
p Value
[95% Conf. Interval]
Morbidity
Sleep Apnea
None
1.00
(ref)
Untreated
1.26
0.008
1.06 -
1.50
Treated
0.87
0.115
0.72
1.04
Pulmonary Occurence
1.14
0.334
1.48
0.60
0.007
0.42
Mortality
1.11
0.692
0.66
1.86
0.69
0.237
0.37
1.28
Abdelsattar et al. SLEEP, Vol. 38, No. 8, 2015

28. RESULTS: Twenty-four cases met the inclusion criteria
RESULTS: Twenty-four cases met the inclusion criteria. The majority (83%) occurred in or after Patients were young (average age, 41.7 years), male (63%), and had a known diagnosis of OSA (96%). Ninety-two percent of cases were elective with 33.3% considered general procedures, 37.5% were ears, nose and throat procedures for the treatment of OSA, and 29.1% were considered miscellaneous interventions. Complications occurred intraoperatively (21%), in the postanesthesia care unit (33%), and on the surgical floors (46%). The most common complications were respiratory arrest in an unmonitored setting and difficulty in airway management. Immediate adverse outcomes included death (45.6%), anoxic brain injury (45.6%), and upper airway complications (8%). Overall, 71% of the patients died, with 6 of the 11 who suffered anoxic brain injury dying at an average of 113 days later. The use of opioids and general anesthetics was believed to play a role in 38% and 58% of cases, respectively. Verdicts favored the plaintiffs in 58% of cases and the defendants in 42%. In cases favoring the plaintiff, the average financial penalty was $2.5 million (±$2.3 million; range, $650,000––$7.7 million). CONCLUSIONS: Perioperative complications related to OSA are increasingly being reported as the central contention of malpractice suits. These cases can be associated with severe financial penalties. These data likely underestimate the actual medicolegal burden, given that most such cases are settled out of court and are not accounted for in the legal literature.
Fouladpour et al. January 2016 • Volume 122 • Number 1

29. The Fast-Track Pre-Surgical Clinic

30. Current System 1 to 4 months 2 to 8 weeks Sleep Study
Refer to Clinic
Sleep Study
Sleep Clinic Appt
1 to 4 months
2 to 8 weeks
1 to 6 weeks
Current System
7 weeks to 7 months
Treatment

31. STOP-BANG STOP-BANG of ≥4 Known OSA a. Not using CPAP/BIPAPOr
Known OSA
a. Not using CPAP/BIPAP
b. Does not have equipment

32. STOP-BANG

34. Patient related challenges:
Overwhelmed patient
Must have “buy in” from the referring pre-operative provider
Patient not perceiving that they have a sleep issue
Education is key. Nurse Educator calls and counsels patient and try's to link sleep to patient’s health issues.
Timeliness and Patient Convenience
Availability of HSAT, clinic appointment,
Linking DME and Clinic Visit
Education of pre-operative provider
Follow up

35. System-related challenges
“Open Spots” in clinic schedule
Timing of Surgery
Timeliness of clinic appointment
Type of Sleep Study
“Flexible” Order Forms
DME Authorization
DME location
Authorization
RT and nursing support
Equipment Issues
Hospital
environment
Coordinating and Expediting

36. Fast Track Order

37. Current Statistics Average AHI 52 = severe OSA Average BMI 36
Average O2 Sat 84
STOP-BANG 4.18

38. Future Directions:
Larger RCT to determines if PAP reduces perioperative complications
Education: Patients and all perioperative providers
Insurance Authorization:
Could shorter length of stays and lower complication rates were “entice” insurance companies to forgo authorization or consider a bundled payment

39. UM model for Postop CPAP