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Perioperative care of OSA Patient

Case Studies

45 yo male 320 lbs / 5’11” Rotator cuff repair under general anesthesia Admitted to ward for overnight pain control

Case Studies

IV pain medication 3 hours post-op Repeated 4 hours later when pain prevented sleep

Case Studies

Two hours later on routine check, nurse found him in full arrest Internist pre-op history and physical mentions that patient has been diagnosed with OSA

Case Studies

A 32-year-old male 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 (patient-controlled analgesia) with a 25 mcg bolus, 12-minute delay, and 25 mcg 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 http://www.apsf.org/newsletters/html/2002/summer/04sleepapnea.htm

Case Studies

SETTLED $ 1,000,000 Medical Malpractice - Young woman suffering from sleep apnea and seizures was not properly monitored in hospital and overmedicated resulting in respiratory arrest and death.

Sleep apnea patient dies from anoxic brain injury following surgery - $2,000,000 settlement Several hours after undergoing a laparoscopic cholecystectomy, the patient, a 33 year old man, who suffered from sleep apnea, was found apneic, with his CPAP not affixed to his face. The patient was unable to be resuscitated and ultimately died. The plaintiff’s allegations included, among other things, failure to provide proper post surgical care to a sleep apnea patient, failure to adequately monitor the patient, and failure to timely and adequately resuscitate the patient.

Case was settled for $2 million (with a medical malpractice cap in Virginia of $2 million).

Irv Cantor and Stephanie Grana represented the plaintiff.

Case Studies

• • Undiagnosed Obstructive Sleep Apnea Causes Post-operative Death Hallberg & McClain obtained a $ 475,000 settlement for a widow when her 46-year-old husband died following kidney surgery. It was alleged that the hospital staff was negligent in failing to recognize that the patient suffered from obstructive sleep apnea (OSA) and, therefore, failed to provide adequate monitoring and airway management during the first post-operative day. Expert medical opinion established that the combination of OSA and narcotic pain medication in the immediate post-operative period exposed the patient to increased risk of airway obstruction leading to cardiopulmonary arrest. Settlement Amount: Settlement Date: Attorney: $ 7,000,000.00

7/2004 Howard D. Mishkind Description of Case: Plaintiff, a 45-year-old male, presented to Defendant ABC Hospital for treatment of abdominal pain. During the postoperative period he exhibited signs and symptoms of sleep apnea with abnormalities in his heart rhythm. Despite his clinical course, John Doe was transferred from the PACU to an unmonitored medical floor without an EKG monitor, without pulse oximetry monitoring and without continuous blood pressure monitoring. Less than four hours later he was found in cardiopulmonary arrest. John Doe experienced a cardiorespiratory arrest that has resulted in anoxic encephalopathy. He is described as being in a persistent vegetative state.

Pathophysiology

cessation of breathing > 10 seconds Hypopnea/Apnea Microarousals in an attempt to restore upper airway patency Adesanya et a

OSA Manifestations

Snoring Daytime somnolence Morning headaches Chung et. al

Physiologic changes

arterial hypoxemia arterial hypercarbia polycythemia systemic hypertension pulmonary hypertension right heart failure Anesthesia and coexisting diseases

Prevalence

2% in women 4% in men Changing demographics increasing this number Vastly undiagnosed (80 - 90 %) Gross et. al

Prevalence - risk factors

Male Smoking Diabetes Treatment-resistant hypertension Increasing BMI (>35) Increasing age (>60) Hypothyroid Alcoholism Head and neck cancers Chung et. al

Prevalence surgical patients

No epidemiological studies Studies used PSG in general surgery patients Significantly higher Most cases not diagnosed Chung et. al

OSA frequency in surgical populations

Chung et. al

Diagnosis

Gold standard is polysomnography in sleep lab Not feasible to screen everyone Not practical

Sleep study

EEG ECG Chin and leg electromyograms Pulse oximetry Nasal and oral airflow Chest and abdominal efforts Gross et. al

Sleep Study

For each hour of sleep: Number of apneas Number of Hyponeas (>50 drop in flow) At least 4% drop in O2 saturation for > 10 seconds • http://s3.amazonaws.com/publicASMBS/GuidelinesStatements/PositionStatement/PERI-OP_MANAGEMENT_OF_OSA-FINAL-EC-APPROVED_3.5.12_forPub.pdf

POLYSOMNOGRAPHY

http://www.thoracic.org/clinical/sleep/sleep-fragment/pages/iatrogenic-artifact-during-polysomnography.php

Sleep Study

Number quantified to generate Apnea Hypopnea Index Normal - AHI < 5 Mild OSA - AHI 5 - 15 Moderate OSA > 15 Severe OSA > 30 http://s3.amazonaws.com/publicASMBS/GuidelinesStatements/PositionStatement/PERI-OP_MANAGEMENT_OF_OSA-FINAL-EC-APPROVED_3.5.12_forPub.pdf

Sleep Study

United States Centers for Medicare and Medicaid Services provides coverage for treatment of adult patients with OSA when the AHI > 15, or when the AHI > 5 and is accompanied by comorbidities such as excessive daytime sleepiness, impaired cognition, mood disorders, insomnia, hypertension, ischemic heart disease, or history of stroke.

Medicare National Coverage Determinations Manual: Continuous Positive Airway Pressure (CPAP) 1986

Treatment

PAP is the mainstay Short and long term benefits

PAP short-term benefits

Improvements in gas exchange Improved sleep disorder breathing

Chau et al.

Chau et al.

PAP long-term benefits

Improved gas exchanged Improved pulmonary mechanics Central respiratory drive Improvement in hypertension Decreased number of apnea-related arrhythmias ? decreased mortality Chau et. al

Chau et al.

Perioperative Care

Identifying at-risk patients

Screening questionnaires too many questions complicated scoring

STOP-BANG

S: Do you snore loudly T: Do you feel tired during the day O: Anyone observed you stop breathing during sleep P: Do you have a history of high blood pressure

STOP-BANG

Sensitivity AHI > 5 = 66% AHI > 15 = 74% AHI > 30 = 79%

STOP-BANG

B: BMI > 35 kg/m2 A: Age > 50 N: Neck circumference > 40 cm G: Male gender

STOP-BANG

Sensitivity AHI > 5 = 84% AHI > 15 = 93% AHI > 30 = 100% Chung et. al

STOP-BANG

Validity examined in a study of 177 surgical patients STOP-BANG and PSG concurrent AHI > 5 = 66% AHI > 15 = 74% AHI > 30 = 80% Chung et. al

Increased risk for perioperative complications?

Most studies retrospective, case reports, observational Varied findings amongst studies No level one or level two evidence

Increased risk for perioperative complications?

higher reintubation rates hypercapnia oxygen desaturation arrhythmias myocardial injury delirium unplanned ICU admission Chung et al.

Perioperative complications

Respiratory complications Sustained Arrhythmias Hypertension More severe OSA = tendency towards more complications

Medication effects

Apnea results from collapse of pharyngeal airway decrease lumen of airway/collapse = obstruction Prevented by dilator muscles This muscle tone is decreased in sleep Greatly potentiated by anesthetics/sedatives/pain medications Anesthesia and coexisting disease

Medication effects

Decreased ventilatory response to hypoxia and hypercapnia Decreased peripheral drive from chemoreceptors/carotid bodies

Anesthetic Management

Anesthetic effects

“Exacerbates the upper airway anatomic alterations that result in pharyngeal collapse” Abolish arousal from sleep REM rebound after anesthesia

Practice Guidelines

Practice guidelines for the perioperative management of patient with OSA

Report by American Society of Anesthesiologists 2006 Not intended as standards or absolute guidelines Basic recommendations supported by analysis of current literature and by a synthesis of expert opinion Goal of reducing adverse outcomes

Practice guidelines for the perioperative management of patient with OSA

Perioperative risk is a function of severity of OSA invasiveness of procedure requirements for post-procedure analgesic

Scoring OSA risk

• A: Severity of sleep apnea based on sleep study (ie, AHI) or clinical indicators if sleep study not available: None = 0; Mild OSA = 1; Moderate OSA = 2; Severe OSA = 3. Subtract 1 point in patients using CPAP or bilevel pressure ventilation preoperatively and postoperatively, and add 1 point in a patient with Paco2 > 50 mm Hg.

• B Invasiveness of surgery and anesthesia: Superficial surgery under local or peripheral nerve block anesthesia without sedation = 0; Superficial surgery with moderate sedation or general anesthesia or peripheral surgery under spinal or epidural anesthesia (with no more than moderate sedation) = 1; Peripheral surgery with general anesthesia or airway surgery with moderate sedation = 2; Major surgery or airway surgery under general anesthesia = 3.

• C: Requirement for postoperative opioid: None = 0; Low-dose oral opioids = 1; High-dose oral opioids or parenteral or neuraxial opioids = 3.

• D: Estimation of perioperative risk: Overall score = score of A + greater score of either B or C. Patients with overall score ≥ 4 may be at increased perioperative risk from OSA. Patients with a score ≥ 5 may be at significantly increased perioperative risk from OSA.

Practice guidelines for the perioperative management of patient with OSA

Preoperative Preparation improve or optimize physical status - CPAP, NIPPV, BiPAP Inpatient vs. outpatient basis Identification of possible comorbidities

Comorbidities Associated with OSA

http://anesthesiaandsleep.org/wp content/uploads/2011/05/OSA-Web-Final.pdf

Practice guidelines for the perioperative management of patient with OSA

Intraoperative Management - No randomized studies anesthetic technique - general, local, nerve block airway management - deep sedation, ETT patient monitoring

Postoperative Management

Analgesia Oxygenation Patient positioning Monitoring

Postoperative analgesia

Opiods should be used sparingly Multi-modal No background infusions Caution with concurrent use of sedatives

Opioids and OSA

Brown et found that the total analgesic opiate dose in patients with OSA and recurrent hypoxemia was half that required in patients without such a history and attributed this finding to upregulation of central opioid receptors due to recurrent hypoxemia

Postoperative oxygenation

Aim for baseline CPAP or NIPPV as soon as feasible

CPAP in post-op period

Data/Evidence limited Theoretical benefits Decreased edema of the upper airway Decreased tongue size Increased upper airway volume and stability Ryan CF, Lowe AA, Li D, Fleetham JA; Magnetic resonance imaging of the upper airway in obstructive sleep apnea before and after chronic nasal continuous positive airway pressure therapy, Am Rev Respir Dis 1991 1444 939-944

CPAP in postop period

Many questions remain Duration of CPAP in newly diagnosed patients Non-compliant patients Alternative therapies

Postoperative positioning

Avoid supine position

Postoperative monitoring

Oximetry vs. full monitoring Continuos vs. intermittent How long to monitor

Discharge criteria

Oxygenation should return to baseline No desaturation or deoxygenation while left undisturbed Monitored for a median of 3 hours longer than non-OSA Continued for a median of 7 hours after last obstructive episode

Outpatient v. Inpatient

Sleep Apnea status Status of coexisting disease Nature of surgery Type of anesthesia Need for post-operative opiods

Outpatient???

Obesity Hypoventilation Syndrome

Obesity Hypoventilation Syndrome

What is it? Separate disease entity?

10-20% of obese OSA patients 8% bariatric patients High mortality - 46% at 50 months without therapy Chau et al.

Obesity Hypoventilation Syndrome

BMI > 30 Daytime awake hypercapnia (PaC02 > 45 mm Hg) Daytime awake hypoxemia (PaCO2 < 70 mm Hg)

Obesity Hypoventilation Syndrome

Severe upper airway obstruction Restrictive chest physiology Blunted central respiratory drive Pulmonary hypertension Increased risk for comorbidites (CAD, CHF, DM) Chau et al.

Obesity Hypoventilation Syndrome

Pathophysiology ? impaired respiratory mechanics ? leptin resistnace ? impaired compensation to acute hypercapnia Chaue et al.

Obesity Hypoventilation Syndrome

Screening Presenting patients with high BMI Serum bicarbonate (compensation of resp. acidosis) Room air hypoxemia

Obesity Hypoventilation Syndrome

Opioid-induced Ventilatory Impairment central respiratory depression decreased consciousness upper airway obstruction

Bottom line

Need to have a system to screen for at risk patients Need to determine if patient is appropriate for outpatient Outpatients should be early in day System in place for perioperative managemet All players must be involved

Typical Malpractice suit

70 % “dead in bed” Severe OSA Morbid Obesity Isolated ward bed No monitoring Receiving narctoics Painful incision Off O2 Off CPAP • • • The importance of the problem of OSA, both in terms of preva- lence and consequences, is driving changes in the way OSA is investigated worldwide . As primary care physicians have become more adept at identifying the problem clinically, these resources have been overwhelmed and lengthy waiting lists have resulted . The expense has also caused access problems for some . This has resulted in increased use of simple home based studies to triage the problem . These are suitable methods to rule in patients with a high pre-test probability on clinical grounds and may prove help- ful to anesthesiologists seeking information quickly in patients presenting for pre-anesthetic assessment .

OSA is a widely prevalent problem and will become an increas- ing preoccupation of anesthesiologists, partly because as knowl (3) patient in an isolated ward room, (4) has no monitoring, (5) is receiving narcotics, (6) has a painful incision, (7) is off oxygen and (8) is off his or her CPAP device .

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Sources

Ryan CF, Lowe AA, Li D, Fleetham JA; Magnetic resonance imaging of the upper airway in obstructive sleep apnea before and after chronic nasal continuous positive airway pressure therapy, Am Rev Respir Dis 1991 1444 939-944 Chung SA, Yuan H, Chung F; A systemic review of obstructive sleep apnea and its implications for anesthesiologists, Anesth Analg 2008 1075 1543 1563 Gross JB, Bachenberg KL, Benumof JL; et al.

American Society of Anesthesiologists Task Force on Perioperative Management

Practice guidelines for the perioperative management of patients with obstructive sleep apnea: a report by the American Society of Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea, Anesthesiology 2006 1045 1081-1093 Chau et al. Obesity Hypoventilation syndrome, Anesthesiology. 2012. 188-205 Adesanya et al. Perioperative Management of Obstructive Sleep Apnea, Chest. 2010;138(6):1489-1498 Chung et. al. Perioperative care of OSA patients. UC San Diego School of Medicine CME. http://anesthesiaandsleep.org/wp content/uploads/2011/05/OSA-Web-Final.pdf

Kushida CA, Littner MR, Morgenthaler T; et al. Practice parameters for the indications for polysomnography and related procedures: an update for 2005, Sleep 2005 284 499-521 Medicare National Coverage Determinations Manual: Continuous Positive Airway Pressure (CPAP) 1986 Cheau et al, Obesity Hyperventilation Syndrome. Anesthesiology 2012 188-205 Brown KA, Laferrière A, Moss IR; Recurrent hypoxemia in young children with obstructive sleep apnea is associated with reduced opioid requirement for analgesia, Anesthesiology 2004 1004 806-810