http://koifishcommunications.com/blog/personal-passions/oral-appliance-for-sleep-apne-0073/

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

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

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

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.

•
•
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:
$
7,000,000.00
Settlement Date:
7/2004
Attorney:
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.

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

Snoring
Daytime somnolence
Morning headaches
Chung et. al

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

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

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

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

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

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

• http://s3.amazonaws.com/publicASMBS/GuidelinesStatements/PositionStatement/PERI-OP_MANAGEMENT_OF_OSA-FINAL-EC-APPROVED_3.5.12_forPub.pdf

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

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

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

PAP is the mainstay
Short and long term benefits

Improvements in gas exchange
Improved sleep disorder breathing

Chau et al.

Chau et al.

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.

Screening questionnaires too many questions complicated scoring

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

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

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

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

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.

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

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

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

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

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

• 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

http://anesthesiaandsleep.org/wpcontent/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

Analgesia
Oxygenation
Patient positioning
Monitoring

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

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

Aim for baseline
CPAP or NIPPV as soon as feasible

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

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

Avoid supine position

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

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

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

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

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

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 .
56

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/wpcontent/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