Obstructive Sleep Apnea In The Perioperative Setting. Christopher Karcher, MD Diplomate, ABPN Medical Director The Neuroscience Sleep Center

Transcription

1 Obstructive Sleep Apnea In The Perioperative Setting Christopher Karcher, MD Diplomate, ABPN Medical Director The Neuroscience Sleep Center

2 Obstructive Sleep Apnea Cyclic collapse of upper airway tissues Constellation of: Daytime symptoms from disruption of sleep: somnolence, poor concentration/memory issues, mood Signs of sleep disturbance: snoring, gasping, restlessness Relevance: Risk for poor neurocognitive performance Adverse medical outcomes Increased all-cause mortality and cardiovascular mortality

3 Obstructive Sleep Apnea Common Disorder 9% to24% of middle aged adults 24%-62% in those >65 years old 22% Adults undergoing elective surgery Frequently undiagnosed In up to 80% of patients with moderate/severe OSA Often encountered in undiagnosed and untreated perioperative patients Young, Dempsy, et al. WMJ 2009; 108:246. Peppard, Young, Barnet, et al. AJE 2013; 177:1006 Young, et al. N Engl J Med 1993; 328:1230-5

4 OSA Can increase risk of respiratory, cardiac, and infectious complications following surgical procedures May require: Additional monitoring Unplanned escalations of care Prolonged hospitalization

5 OSA Important to identify patients at risk for OSA in pre-operative setting Appropriate anesthesia Post-surgical monitoring Pain Control Objectives: Review of data regarding perioperative outcomes in patients with OSA Methods for quick identification of patients at high risk for OSA Implementation of clinical strategies to minimize OSA associated complications

6 Obstructive Sleep Apnea Cyclic collapse of the upper airway tissues during sleep: Apneas (cessation of breathing for 10 seconds) Hypopneas (Significantly reduced airflow with>3% desaturation Common disorder that is often undiagnosed in patients in the pre-operative or inpatient setting (up to 80% of patients with moderate/severe OSA are undiagnosed) Prevalence in general inpatient population has not been studied well, but likely higher than general population due to strong association with co-morbid conditions Young, et al. Sleep 1997;20: Kapur, et al. Sleep Breath 2002;6:49-54

7 General Health Consequences Immediate Oxygen desaturation Hypercapnia Arousal mediated sympathetic surges Development/worsening of hypertension Delayed Myocardial infarction Development of atrial arrhythmia (four fold) Independent risk factor for stroke (three fold in men) Somers, et al. Circulation 2008;118: Mehra, et al. Am J Respir Crit Care Med 2006;173: Redline, et al. Am J Respir Crit Care Med 2010;

8 Increased Inpatient Prevalence Post-stroke patients Cardiac Care Unit Admissions Acute Decompensated Heart Failure Acute Coronary Syndromes Elective Surgery

9 Adverse Inpatient Outcomes Worse short term outcomes in post-operative and post-stroke settings Two large database studies have found worse inpatient outcomes in patients who carry a diagnosis of OSA (based on billing codes) compared with those without OSA Study with 55 million pregnancy-related discharges from Nationwide Inpatient Sample Database: Preclampsia OR 2.5 Eclampsia OR 5.4 Cardiomyopathy OR 9.0 Pulmonary Embolism OR 4.5 Louis, et al. Sleep 2014;37:843 Lindenauer, et al. Chest 2014; 145: 1032

10 New Diagnosis of OSA During Hospital Admission Higher Readmission and Mortality at 14 months following CHF admission ODI >5 HR 2.9 Increased Mortality at 3 years following CHF admission (OR 1.5) Worse composite cardiovascular outcomes after MI admission AHI >30 HR 5.4 Ohmura, et al. Am J Cardiol 2014;113:697 Khayat, et al. Eur Heart J 2015; 36:1463 Lee, et al. J Clin Sleep Med 2011;7:616

11 Perioperative Complications Associated with OSA Lipford, et al. Hosp Pract, 2014;43(1):56-63

12 Pathophysiology of Apnea

13 Pathophysiology of Sleep Apnea Awake: typically upright position + neuromuscular compensation Loss of neuromuscular compensation + Decreased activity of airway dilator musculature Sleep Onset Hyperventilate: correct hypoxia & hypercapnia Airway opens Airway collapses Pharyngeal muscle activity restored Apnea (negative intrathoracic pressure) Hypoxia (pulmonary vasoconstriction) & Hypercapnia Increased respiratory effort/sympathetic tone Arousal from sleep

14 Intraoperative Respiratory Complications General Anesthesia Decreases tone of upper airway musculature Collective factors decrease airway caliber and increase compliance of pharyngeal walls Obesity Operative Positioning (supine, neck flexion) Muscle relaxant medications Patients at risk for OSA Higher rates of difficult intubation More complicated intraoperative airway maintenance Hiremath, et al. Br J Anesthesia1998;80:606-11

15 Postoperative Respiratory Complications Need for an oral or nasal airway Hypoxemia Atelectasis Wheezing Postoperative Pneumonia COPD or Obesity Hypoventilation Syndrome Patients Chronic Hypoxemia or Hypercapnia Higher Risk for Cardiopulmonary Complications Hwang, et al. Chest 2008;133:

16 Non-Respiratory Complications Atrial Fibrillation Tachyarrhythmia Bradycardia Cardiac Arrest HTN Encephalopathy Sleepiness interferes with participation Mobilization Activities Physical Therapy Gami, et al. Circulation 2004;110:364-7 Kaw, et al. J Cardiovasc Surg 2006;47:683-9

17 Risk Factors for OSA Age Prevalence increases from adolescence through sixth to seventh decade, then plateaus Gender Male>Female (2-3X until menopause) Obesity Strongest Risk factor BMI >40 Obesity Hypoventilation Syndrome

18 Diagnosis: History Snoring (loud, chronic) Nocturnal gasping and choking Ask bed partner (witnessed apneas) Automobile or work related accidents Personality changes or cognitive problems Short Term Memory Loss/Cognitive Impairment Excessive daytime somnolence Sleep Apnea: Is Your Patient at Risk? NIH Publication, No

19 Physical Examination Findings Craniofacial Abnormalities Retrognathia, micrognathia Macroglossia Tonsillar Hypertrophy Enlarged Uvula Low hanging or narrow soft palate border Neck Circumference Men 17 inch/women 16 inch collar sizes Hypertension 50% of OSA patients (morning elevations/resistant)

20 Exam: Oropharynx Patient With the Crowded Oropharynx

21 Exam: Oropharynx Oropharynx With Tonsillar Hypertrophy Normal Oropharynx Shepard JW Jr et al. Mayo Clin Proc 1990;65.

22 Modified Mallampati Classification Paulose, 2010

23 Pathophysiology of Apnea

24 Screening Questionnaires Sleep Apnea Clinical Score (SACS) Berlin Questionnaire STOP-Bang Questionnaire Chung et al.24 and Chung et al.25

25 STOP-BANG Low Risk (0-2) Medium Risk ( 3-4) High Risk(5-8) Sensitivity 84% and Specificity of 40% Consensus statement issued by the Society for Ambulatory Anesthesia recommends routine use of the STOP-BANG screening tool for preoperative assessment for OSA Chung, et al. Br J Anaesth. 2012;108(5): 768

26 Inpatient Evaluation/Diagnosis Obvious Logistical Challenges Medical Illness Limited Resources Technical Challenges Delaying formal testing until recovery from acute illness: more reflective of chronic disease burden

27 Formal Sleep Diagnostics Polysomnography Attended, In-laboratory Gold Standard Home Sleep Apnea Testing In-home, Unattended Limited monitoring of certain cardiorespiratory parameters Many versions Many have been validated against standard PSG

28 Polysomnography

29 Polysomnography

30 Obstructive Events Apnea Cessation of airflow (90% decrement > 10 seconds) Hypopnea Decreased airflow (at least 30% > 10 seconds) associated with either: Arousal Oxyhemoglobin desaturation (>3% baseline) Respiratory Effort Related Arousal (RERA) Flattening of nasal pressure wave form Evidence of increasing respiratory effort Terminating with an arousal Not meeting criteria for either apnea or hypopnea

31 Obstructive Apnea EEG Airflow Arousal Effort (Rib Cage) Effort (Abdomen) Effort (Pes) SaO 2 10 sec

32 Home Apnea Testing

33 AASM Practice Parameter

34 Home Sleep Apnea Testing (HSAT) Patient selection is key Patients with high pre-test probability of moderate/severe OSA No Medical co-morbidities Heart Failure Severe COPD Neuromuscular Disorder/Stroke Less Variables Assessed: Airflow, Respiratory Effort, Blood Oxygenation, Position Advantages: Access Cost J Clin Sleep Med 2007; 3:737 J Clin Sleep Med 2011; 7:531

35 Limitations of (HSAT) Obstructive Events Only/Not Validated for evaluation of: Central Sleep Apnea Parasomnias Respiratory Event Index (REI): Excludes Hypopneas and RERAS (require scoring of arousals/eeg monitoring) Smaller numerator Number of Respiratory Events/Hours of Recording Time (rather than hour of scored sleep) Smaller denominator Studies demonstrated need for at least 300 minutes of recording time Quality of Unattended Studies/Repeat Studies Sleep 2014; 37:969

36 HSAT vs PSG Un-blinded Trial 373 patients with suspected moderate/severe OSA In-lab PSG with conventional CPAP Titration HSAT with AutoPAP then CPAP transition No differences in outcomes for AHI >15: Effective titrations Titration pressures Time to treatment Daytime Sleepiness Improved Adherence among HSAT/AutoPAP arm Sleep 2012; 35:757

37 Overnight Oximetry Oxygen Desaturation Index (ODI) 5-10 Desaturations/Hour in patients not on supplemental oxygen OSA CSA Risk Stratifying Tool rather than Diagnostic Tool Not accepted by insurance companies for prescription of pap therapy

38 Overnight Oximetry

39 Preoperative Management Inform anesthesiologist that OSA is suspected Consider baseline overnight oximetry and/or arterial blood gas (ABG) to assess degree of hypoxemia and possibility of hypoventilation If patient already on PAP therapy may consider interrogating data card and consider adjustment of pressure settings if indicated Lipford et al. Hosp Prac. 2014;43(1): 56-63

40 Intraoperative Management Avoid sedative/opiate pre-medications Use short acting general anesthetic agents Consider regional nerve block for conscious sedation if appropriate Extubation only after fully alert and able to protect airway Nasal airway devices or positive airway pressure (PAP) therapy should be available Lipford et al. Hosp Prac. 2014;43(1): 56-63

41 Immediate Postoperative Management Highly monitored environment with continuous pulse oximetry Snoring, observed apneas: Then initiate PAP therapy Consider regional nerve block for pain management rather than use of oral or parenteral opioids Release to floor only after maintaining normal oxygen saturations, fully alert, and following commands Lipford et al. Hosp Prac. 2014;43(1): 56-63

42 Postoperative Recovery If overnight oximetry suggests moderate/severe OSA, initiate auto titrating continuous positive airway pressure (CPAP) empirically Arterial blood gas to assess for hypoxemia, hypercapnia Supplemental oxygen if needed (corrects hypoxemia but not hypercapnia), or if CPAP not available/tolerated Consider elevation of head of bed Minimize opiates, use patient-controlled analgesia (PCA) without basal rate for severe pain

43 Modes of Positive Airway Treatment CPAP (Continuous Positive Airway Pressure) BPAP (Bilevel Positive Airway Pressure) IPAP/EPAP Two different airway pressures during respiratory cycle APAP (Autotitrating Positive Airway Pressure) Change in Airflow, Circuit Pressure, Vibratory Snore ASV (Adaptive Servo-Ventilation) Varying amount of inspiratory pressure superimposed on low level of CPAP (addresses concomitant Central Apneas) Long-acting opioids Stroke/Kidney Disease Caution in Patients with Heart Failure and Cheyne Stokes Breathing Pattern, especially if Left Ventricular Ejection Fraction less than 45%: (higher cardiovascular mortality with ASV use)- SERVE HF Trial N Engl J Med 2015; 373: 1095

44 Positive Airway Pressure

45 CPAP sleepapneadisorder.info

46 Oral Appliance

47 Oral Appliances Mandibular Advancement Splints Patient Assessment: dentition, mandibular mobility Device Titration Long Term follow up Tongue Retaining Devices Suction cavity to pull the tongue out of the mouth Not well studied Option for edentulous patients

48 Oral Appliance Mandibular Advancement Device

49 Oral Appliance Tongue Retaining Device

50 Oral Appliances Outcomes 2006 Meta Analysis of Nine Randomized Trials Compared effects of CPAP to Oral Appliances 440 patients CPAP had superior: Reduction of AHI and oxyhemoglobin desaturations Improved Sleep Efficiency Negligible difference in subjective outcomes: sleepiness/quality of life Strong preference among patients for Oral Appliances Cochrane Database Syst Rev 2006; :CD001106

51 Discharge Management Avoid/minimize outpatient opiate medications Instruct family members to observe for apneic episodes, shallow breathing, or loud snoring Consider lateral positioning or head of bed elevation during sleep May consider discharge on nocturnal supplemental oxygen

52 Discharge Challenges Inpatient screening is starting point Still need to coordinate with outpatient formal diagnosis and treatment plan Non-compliance Lack of patient understanding Consider inpatient sleep medicine consultation Direct Referral to Sleep Center Full PSG HSAT