Developing a Perioperative Sleep Apnea Safety Program

Transcription

1 Developing a Perioperative Sleep Apnea Safety Program Wm. Charles Sherrill, Jr M.D. Sleep Program Medical Director Presbyterian Sleep Health Novant Carolina Sleep Society May 5, 2012

2 Conflict of Interest: None

3 Clinical Scenario A 32 year old presented for an open reduction and internal fixation of an arm fracture, which was satisfactorily performed under general anesthesia. He was discharged to the ward on a fentanyl PCA (pt controlled analgesia) with a 25mcg bolus, 12-minute delay, and 25mcg hourly rate. At night, the nurses heard him snoring loudly. One hour after his last normal vital signs, he was found in respiratory arrest. He was resuscitated, but displayed signs of anoxic brain damage. By questioning the patient s wife, a consultant was able to elicit the husband s history of heavy snoring and nocturnal apneic spells that were felt to be clinically consistent with a diagnosis of sleep apnea. Ann Lofsky, M.D. Sleep Apnea and Narcotic Postoperative Pain Medication: A Morbidity and Mortality Risk

4 Clinical Scenario 45 year old male, 320 lbs and 5 11 had a rotator cuff repair under general anesthesia. The intraoperative course was uneventful. He was admitted to the ward for overnight pain control. Four hours after surgery, he received an intramuscular injection of Meperidine 100 mg with Phenergan 25 mg. This was repeated 3 hours later when severe pain prevented him from sleeping. Two hours later, nurses making a routine check found him to be in full arrest. He could not be resuscitated. The internist s history and physical mentioned his having been diagnosed with sleep apnea. Ann Lofsky. M.D. Sleep Apnea and Narcotic Postoperative Pain Medication: A Morbidity and Mortality Risk

5 Malpractice cases involving Obstructive Sleep Apnea in Hospitalized Patients Intubation complications (20%) Extubation difficulties (10%) Post operative catastrophes (70%) Drug induced respiratory arrest resulting in death/brain damage Patients with OSA with inadequate monitoring

6 Postoperative catastrophes ( Dead in bed ) Severe OSA Morbid obesity Isolated ward room No monitoring Receiving narcotics Off O2/PAP Jonathan L. Benumof, M.D.

7 The pharynx is a hollow potentially collapsible tube without rigid fixed bony structures for support and surrounded entirely by soft tissue. Patency is dependent on Intrinsic mechanical stiffness of the airway Upper airway muscle activity Extraluminal pressure Lung volume The imbalance of these forces is critical to the development of upper airway obstruction

8 The Balance of Forces (Malhotra & White, 2002)

9 Individuals with OSA are primarily dependent on the activity of the pharyngeal dilator muscles for airway patency. OSA patients demonstrate increased EMG activity in the pharyngeal dilator muscles (Genioglossus muscle) during wakefulness. The reduction in EMG activity in these muscles at sleep onset is greater in OSA patients than normals. OSA patients have a reduced ability to compensate for factors that predispose them for upper airway collapse Increased negative pharyngeal pressures during inspiration Reductions in upper airway muscle tone

10 Physiologic factors in OSA which could result in increased perioperative complications Anatomical imbalance Lung volume reduction (Decreased FRC and ERV) Sympathetic nervous system activation Ventilatory instability (loop gain)

11 Impact of sedatives, anesthetics, and analgesics (opioids) on respiratory function Dose dependent depression of muscle activity of the upper airway muscles Depression of central respiratory output/upper airway reflexes» Increased collapsibility of the upper airway Direct action (peripheral) on hypoglossal (tongue) and phrenic (diaphragm) nerves» Phrenic nerve depression decreases in lung volume Alterations in apneic threshold/hypoxic sensitivity Alterations in the chemical/metabolic/behavioral control of breathing

12 Increase in sympathetic nervous system activation (catecholamine excess) Surgical stress Hpoxemia/Hypercarbia Arousals Related to an increased risk of cardiac arrhythmias, cardiac ischemia and hypertension. Majority of unexpected and unexplained postoperative deaths occur at night and within 7 days of surgery. Rosenberg, J. et al British Journal of Surgery 1992.

13 Postoperative factors which may contribute to complications in OSA Use of neuraxial / parenteral opioids Positioning Sleep fragmentation / REM rebound (?) Comorbid medical conditions

14 What is the scope of the problem? How does the surgical process affect individuals with obstructive sleep apnea? Does OSA result in postoperative complications more frequently than the non- OSA surgical population?

15 What is the prevalence of obstructive sleep apnea in the general surgical population? Data obtained primarily from screening questionnaires. Results would suggest that 25%-30% of patients presenting for elective general surgery would screen positive for OSA. Is this going to be less of a problem or more of a problem in the future?

16 Obesity Trends* Among U.S. Adults BRFSS, 1990, 1998, 2007 (*BMI 30, or about 30 lbs. overweight for 5 4 person) No Data <10% 10% 14% 15% 19% 20% 24% 25% 29% 30%

17 Critical points of the NHANES data Prevalence of clinically severe obesity is increasing much faster than that of moderate obesity. Strum, R. Increase in morbid obesity in the USA. Public Health 2007, 121(7), Data from BMI > 40 kg/m2 has increased fivefold 1:200 adults to 1:33 adults BMI > 50kg/m2 has increased tenfold 1:2,000 adults to 1:200 adults More not less of these individuals will be showing up for surgical intervention.

18 The STOP-BANG Questionnaire Identified the Patients with Significant Exacerbations of Sleep Disordered Breathing during the Perioperative Period. P. Liao et al. 67 patients: STOP-BANG + limited channel testing 20 low risk (SB < 3); 47 high risk (SB >3) High Risk patients Pre operative AHI 10.2/hr. PON 1 AHI 13.2/hr. PON 3 AHI 23.2/hr. PON 5 AHI 17.9/hr. PON 7 AHI 16.0/hr. STOP-BANG 6-8 predictive of patients with higher AHI

19 Does the presence of obstructive sleep apnea place patients at increased risk for postoperative complications? Respiratory or cardiovascular difficulties Transfer to higher level of care acuity Increased length of hospital stay Mortality

20 Kaw, R. et al. AJRCCM 183; 2011: A3147 IM preop assessment and PSG databases crossmatched to identify patients underwent both PSG and non cardiac surgery pts, 471 pts eligible for study: 269 (57%) had OSA Presence of OSA associated with: Increased incidence of significant hypoxia (p=0.02) Reintubation (p=0.048) Unplanned ICU transfer (OR=7.6) Overall complications (OR=9.9) Longer length of hospital stay (OR=1.9)

21 Postoperative complications Higher reintubation rates (+)/(-) Hypoxemia / Hypercarbia (+) Arrhythmias Myocardial ischemia Increased transfers to higher level of care (+)/(-) Increased length of hospitalization (+)/(-) Delirium Reationship to severity of OSA (AHI) (+) / (-)

22 Prevalence of obstructive sleep apnea appears to be increasing in association with the increase in obesity. The prevalence of both known and unknown obstructive sleep apnea in the surgical population will be increasing in the future. These patients are at increased risk for postoperative complications and death that may be reduced with appropriate screening and post operative monitoring.

23 OSA patients will present for surgery in one of three ways: Known OSA compliant with therapy Known OSA Mild OSA therapy not recommended Refused therapy or non compliant Therapy instituted weight loss, surgery, dental appliance: status unknown Unrecognized OSA Goal: Minimize the number of these patients presenting for surgery Goal: Provide appropriate monitoring and access to post operative evaluation; if needed longitundinal care.

24 Know moderate/severe OSA on therapy: Primary focus: assess status Compliance with therapy Resolution of symptoms Development of comorbid conditions Continue PAP therapy postoperatively Pressure requirements may increase postoperatively Bolden, N. et al. Anesthesia Analgesia 2007, 105;

25 Known OSA no active therapy Asymptomatic or minimally symptomatic May become symptomatic postoperatively Gupta et al. study. Complication rate not related to severity of OSA Unrecognized / Non-compliant These surgical patients are the primary focus of perioperative sleep apnea safety program

26 Clinical management strategy Preoperative Screening (Identification) Monitoring (Keeping the patient safe) Discharge (Longitudinal evaluation and care)

27 Why do we need a mechanism for screening? F. Chung ASA 2010 Oct A pts: 234 pts in lab PSG; 585 pts HST Surgeons/anesthesiologists not informed of PSG results. Clinical diagnosis of OSA noted by record review. 138/819 pts had severe OSA (AHI > 30) (17%) 118/138 (86%) were not identified by surgeons 65/138 (47.1%) were not identified by anesthesia

28 Purpose of OSA Screening (Identification) Eliminate or markedly reduce the unrecognized OSA patient presenting for surgery Heightened awareness of which patients may be at increased postoperative risk Opportunity to identify poorly compliant or inadequately treated patients and intervene Limitation: Screening does not discriminate between mild and moderate/severe OSA. Does not identify true at risk patients.

29 Questions to ask: Perioperative Sleep Apnea Program How do you screen patients preoperatively? What do you do with patients that screen positive? How do you monitor these patients? How and when do you treat patients that screen positive? What happens after discharge?

30 Screening Questionnaires Berlin Questionnaire ASA Checklist STOP and STOP-BANG questionnaire Sleep Apnea Clinical Score (SACS) (Flemons)

31 Screening Tools for OSA Important features: Easy to understand Ease of administration/scoring Limited time requirements Sensitivity/Specificity Validated (PSG) Generalizable to various patient populations Primary care, surgical, medical, sleep clinic

32 Validation of the Berlin Questionnaire and American Anesthesiologists Checklist as Screening Tools for OSA in Surgical Patients. Chung, F. et al. Anesthesiology V 108 No 5 May 2008, Preoperative pts 18 yrs or older and without previously diagnosed OSA. 2,467 patients were screened:

33 Classified as high risk of OSA Berlin Questionnaire 33% ASA Checklist 27% STOP Questionnaire 28% No significant difference in the questionnaires in the ability to identify patients with OSA. Approximately 30% of general surgical patients will screen positive for OSA.

34 Sensitivity (STOP-BANG Questionnaire) AHI>5 STOP 65.6% STOP-BANG 83.6% AHI>15 STOP 74.3% STOP-BANG 92.9% AHI>30 STOP 79.5% STOP-BANG 100% Negative Predictive Value (NPV) AHI>5 STOP 44.0% STOP-BANG 60.8% AHI>15 STOP 76.0% STOP-BANG 90.2% AHI>30 STOP 89.3% STOP-BANG 100%

35 Data suggests that the use of screening questionnaires can reliably identify patients at risk for obstructive sleep apnea. Sensitivity and negative predictive value good. Specificity fair False positive rate is 15%-20%. Majority that screen positive will have mild obstructive sleep apnea. Roughly 50% mild OSA; 33% mod/severe OSA; 13% severe OSA Use of any of the screening tools improves the likelihood of identifying obstructive sleep apnea.

36 A Higher Score on STOP-BANG was Associated with a Higher Incidence of Post-Operative Complications. F. Chung, P. Liao STOP-BANG and overnight HST (10 channel) 862 patients completed STOP-BANG/complication STOP-BANG 0-2 postoperative complication 39.9% % % Both cardiac and pulmonary complications increased with increasing score; not neurologic Argues for use of higher STOP-BANG score to assess risk U of Chicago: STOP-BANG greater than or equal 5.

37 Screen positive for Obstructive Sleep Apnea. Now what? Monitor high risk patients perioperatively Intervene with PAP therapy for cardiopulmonary difficulties. Evaluation and definitive therapy after discharge. Evaluate and institute therapy prior to surgery. Who does the consultation? Choice of diagnostic study. Who do you treat? Mode of treatment? Process has to be completed in a timely fashion.

38 Consultation: Sleep physician Physician extender Super nurse Antic, N.A. Am J Respir Crit Care Med vol 179. p , 2009 Sleep technician/respiratory therapist/ Sleep navigator Template: symptoms, comorbid conditions, physical exam

39 Diagnostic testing: In lab polysomnography Limited channel testing (portable sleep testing) Autonomic measures of sleep disordered breathing Peripheral arterial tone (PAT) Cardiopulmonary coupling (CPC)

40 Decision if made to treat who do you treat: Level of AHI / ODI Increased risk of complications with increasing AHI. (not seen in all studies) Invasiveness of surgery / post operative narcotic requirements (used to determine risk in ASA guidelines) Patients that experience arrhythmias, ischemia, oxgen desaturation postoperatively (PACU) Presence and severity of comorbid conditions

41 Treatment Preoperatively CPAP/Bilevel based on titration study Auto-titrating pressure therapy Time constraints for compliance Potential benefit of preoperative PAP therapy Reduction in upper airway edema Improved PAP compliance during hospitalization? Mayo experience: APAP use in high risk patients POD 1 median APAP use 396 minutes Length of stay median APAP use 213 minutes

42 Postoperative monitoring Who should be monitored? What level of monitoring is appropriate? Where should the monitoring take place? How long should monitoring be continued?

43 Monitoring based on: Level of AHI / ODI / SpO2 nadir Invasiveness of surgery and postoperative narcotic requirements Clinical course in PACU Presence of comorbid conditions

44 Sleep-Disordered Breathing in Hospital Patients: Identifying and Treating Ptients at Risk. Gay, P. Use of Sleep Apnea Clincal Score (SACS) to screen 693 patients non cardiac surgery Likelihood of postoperative respiratory events High SACS: OR 3.5 Recurrent events in PACU: OR 21 Course in PACU apppears to be most predictive of subsequent postoperative respiratory events.

45 Monitoring Postoperatively Level of care (ward, step down unit, ICU) Monitoring in room and central Type of monitoring Oximetry, ECG Oximetry, ECG plus capnography Duration of monitoring Time: First 24 hours During use of narcotics postoperatively Ability to maintain SaO2 > 90 % room air (with sleep?)

46 Monitoring in the postoperative period with oximetry alone or oximetry with capnography No studies which have demonstrated superiority of either monitoring strategy in: Reduction in postoperative complications Reduced length of stay Reduction in transfers to higher level of acuity of care. Nonrandomized studies in individual institutions have suggested reductions in complications and reductions in transfers to higher levels of care with monitoring.

47 Recommendations for monitoring Use of oximetry in high risk patients Continuation of monitoring until able to maintain oxygen saturation > 90% on room air including a period of sleep (definition of sleep) Role of capnography needs to be defined Action plan / protocol for response to alarms Future: Integrated monitoring systems

48 Post operative management Multimodality pain management NSAID s Acetominophen Tramadol Ketamine Gabapentin/Pregabalin Clonidine Dexamethasone Dexmedetomidine (Precedex) Alpha 2 agonist Post operative oxygen desaturation times more likely in OSA patients receiving opioid analgesia compared with nonopioid analgesia. Bolden, N. et al. Anesth Analg 2008; 105:

49 Law of unintended consequences: Monitoring capability / Costs Logistics/flow process Increased utilization and costs of PAP therapy Increased demand for RCP services Education New technology i.e. capnography New terms: AHI, ODI etc New skill sets False alarms: alarm fatigue False sense of security

50 CoMorbidities: should they be considered in the assessment of level of monitoring? Higher Risk: Atrial fibrillation* Congestive heart failure* Severe COPD Coronary artery disease* Obesity Hypoventilation Syndrome Pulmonary Hypertension Kaw, R. Respiratory Medicine 2011, 105, Uncontrolled Hypertension* Lower Risk: Mild COPD Hypertension Diabetes Mellitus Cerebrovascular disease* Obesity BMI > 35 kg/m2*

51 What should you do? Minimum: Screen preoperatively Those that screen positive special identification Notification to primary care physician upon discharge of positive screen.

52 What should you do? Maximum Screen preoperatively Those that screen positive: evaluation and those with moderate/severe OSA: treatment. Evaluation: consultation; in lab and/or limited channel testing Treatment: in lab titration and/or APAP. Monitoring post operatively with use of PAP with sleep Discharge: Notification of primary care physician Follow up with sleep physician for longitudinal care

53 STOP-BANG > 5 Screen OHS Known OSA (AHI >15) Known Mild OSA (AHI 5-15) Suspected OSA (+ Screen) PAP Post-Op PACU (-) PACU (+) PACU (+) PACU (-) Monitor Usual Care Monitor APAP Monitor D/C Monitor SpO2 > 90% during Sleep Usual Care Monitor Usual Care D/C Home on PAP Discharge D/C on APAP Discharge PACU (+) Desaturation Apnea Hypoventilation Higher Level of Acuity Moderate/Severe OSA PACU (+) Co-morbid Conditions Sleep Consultation

54 Intolerant/Noncompliant with PAP therapy Behavioral therapy Elevate Head of bed / Minimize supine position Minimize narcotics / sedatives O2 with sleep to maintain oxygen saturation > 90% Discharge on O2 Follow up sleep consultation (out-patient) Evaluation / Diagnostic testing CPAP Clinic Desensitization therapy Discussion of alternative therapies for OSA

55 Discharge recommendations Establishment of protocols which ensure that individuals identified at high risk for OSA are referred for appropriate evaluation, treatment, and longitudinal care when appropriate. Patients discharged on APAP if used during hospitalization. Expedited referral for patients in which PAP therapy was initiated during hospitalization.

56 Things to come? Case Western Reserve University Dennis Auckley, M.D. 311 in-patients admitted to general medicine floor during 4 month period. Assessed both STOP-BANG and Berlin Questionnaire» 60.2 % positive both screens» 81.8 % no diagnosis of OSA» 40.2 % received IV narcotics» No orders for respiratory monitoring

57 Things to come? Continuous Positive Airway Pressure: Evaluation of a Novel Therapy for Patients with Acute Ischemic Stroke. Bravata, D. et al. Sleep Vol 34 No 9, 2011, Pts with acute ischemic stroke use of APAP to diagnose and treat OSA compared with control group. Improvements in Stroke Scale in CPAP group compared with controls. Utilization in high risk medical patients.

58 Sleep Management Center Inpatient Sleep Apnea Consultation Opportunity to identify previously undiagnosed patients with OSA Reduce postoperative complications/death Establish longitudinal care to reduce long term cardiovascular risk. Patients with comorbidities most often will require in lab diagnosis and treatment.

59 Future Challenges Identification of true at risk patients Higher cutoff for positive questionnaires Presence of co-morbid conditions: OHS / pulmonary HTN Optimum and prudent monitoring strategy Threshold alarms Improvement in compliance with therapy during hospitalization Process to improve patients evaluation and institution of therapy. (50% rule). Expansion of program to other high risk hospitalized medical patients In patient sleep consultative services Questions: wcsherrill@novanthealth.org

60 Algorithms Sleep and Sleep-Disordered Breathing in the Hospitalized Patient. Peter Gay, M.D. Respiratory Care Sept 2010, Vol 55, No 9, Management of Sleep Apnea in Adults-Functional Algorithm for the Perioperative Period. Chung, F. M.D. Can J Anesthesia 2010, 57: Perioperative Management of OSA Patients: Practical Solutions and Care Strategies. UCSD/University of Toronto. Perioperative Management of Obstructive Sleep Apnea. Adesanya, A. et. al. Chest 2010; 138(6) Advoiding Adverse Outcomes in Patients with Obstructive Sleep Apnea (OSA): Development and Implementation of a Perioperative OSA Protocol. Bolden, N. et. al. Jr Clin Anesthesia 2009, 21,