Perioperative Management of
Obstructive Sleep Apnea
BY
AHMAD YOUNES
PROFESSOR OF THORACIC MEDICINE
Mansoura Faculty of Medicine
SLEEP DISORDERED BREATHING
• The standard parameters used to record sleep
and wake are electroencephalography (EEG),
electro-oculography (EOG), electromyography
(EMG), airflow measurement, respiratory effort
measurement, electrocardiography (ECG),
oxygen saturation, snoring monitor, and sleep
position evaluation.
• All these parameters are recorded in
polysomnography which is the gold standard
for diagnosis of Sleep disordered breathing .
Types of Sleep disordered breathing includes :
1-Obstructive sleep apnea syndrome in which
inadequate ventilation occurs despite continued
efforts to breath due to upper airway
obstruction.
2- Central sleep apnea syndrome in which
inadequate ventilation occurs resulting from
absent or diminished respiratory effort.
3-Sleep hypoventilation syndrome in which > 10
mm Hg increase in PaCO2 during sleep in
comparison with an awake supine value.
Apnea: is defined as the drop in peak airflow by >90% of baseline for
10 seconds or longer and at least 90% of the event duration meet the
amplitude reduction.
• An obstructive apnea occurs when airflow is
absent or nearly absent, but ventilatory effort
persists. It is caused by complete, or near
complete, upper airway obstruction
A central apnea occurs when both airflow and ventilatory
effort are absent.
During a mixed apnea, there is an interval during which there is no
respiratory effort (ie, central apnea pattern) and an interval during
which there are obstructed respiratory efforts .
Hypopnea
• Hypopnea be scored when all of the following four
criteria are met:
• Airflow decreases at least 30 percent from baseline
• There is diminished airflow lasting at least 10 seconds
• at least 4 percent oxyhemoglobin desaturation .
or
• Airflow decreases at least 50 percent from
baseline
• There is diminished airflow lasting at least 10 seconds
• 3 percent oxyhemoglobin desaturation or an arousal
Apnea-hypopnea index (AHI) is the total number of
apneas and hypopneas per hour of sleep.
SLEEP DISORDERED BREATHING SYNDROMES
1- Obstructive sleep apnea syndrome (OSA) in adults is defined as either
• More than 15 apneas, hypopneas, per hour of sleep ( AHI
>15 events/hr) in an asymptomatic patient
OR
• More than 5 apneas, hypopneas, per hour of sleep (AHI >5
events per hour) in a patient with symptoms (eg,
sleepiness, fatigue and inattention) or signs of disturbed
sleep (snoring, restless sleep, and respiratory pauses).
2- Central sleep apnea syndrome (CSAS) can defined as:
a. Study showing AHI > 5 events/hr. and
b. Central AHI > 50% of the total AHI, and
c. Central apneas or hypopneas >=5/hr., and
d. Symptoms of either excessive sleepiness or
disrupted sleep.
3- Sleep Hypoventilation Syndrome
Score hypoventilation during sleep if there is a
≥10 mm Hg increase in PaCO2 during sleep in
comparison with an awake supine value
OSA is the most prevalent sleep disorder in the adult population.
• OSA is more common than bronchial asthma in adults
,affecting approximately 4% of men and 2% of women.
• The prevalence of OSA is higher in patients presenting
for surgery than in the general population e.g. moderate
or severe OSA is prevalent in at least 50% of patients
subjected to bariatric surgery , and a significant
proportion of OSA patients remain undiagnosed when
they present for surgery.
• The presence of OSA is known to increase the
occurrence of comorbid conditions ( hypertension ,
ischemic heart disease , diabetes melitus and stroke )
and postoperative complications .
• It is the opinion of the American Society of
Anesthesiologists Task Force that the perioperative risk
to patients increases in proportion to the severity of sleep
apnea.
OSA and postoperative complications
• In a recent retrospective study of elective non-cardiac
procedures, the occurrence of postoperative complications
was observed in 44% of patients with OSA versus 28% in
patients with no OSA.
• Patients with OSA undergoing hip or knee replacement were
at an increased risk of developing perioperative complications
(24% versus 9%, respectively).
• An increased risk of postoperative complications was also
observed in OSA patients undergoing upper airway and
cardiac procedures .
• The most commonly observed complication was oxygen
desaturation (17% in patients with OSA versus 8% with no
OSA).
OSA and postoperative complications
• Proposed guidelines from the Adult OSA Task
Force of the American Academy of Sleep
Medicine suggest that :
1- Questions regarding OSA should be included in
routine health screenings.
2- If OSA is suspected, a comprehensive sleep
evaluation should be conducted.
• Interestingly, it was observed that OSA patients
undergoing surgery had higher AHI and oxygendesaturation index scores on the third
postoperative night compared to the first
postoperative night or preoperatively .
Perioperative Management Plan
• Anesthesiologists should work with surgeons to develop a
protocol whereby patients in whom the possibility of OSA
is suspected on clinical grounds are evaluated long
enough before the day of surgery to allow preparation of a
perioperative management plan.
• This evaluation may be initiated in a preanesthesia clinic
(if available) or by direct consultation from the operating
surgeon to the anesthesiologist.
• The perioperative management of patients with OSA
begins with preoperative identification ,after which plans
are made to tailor specific preoperative ,intraoperative and
postoperative care.
OSA symptoms
OSA signs
Screening for OSA prior to surgery
• It is estimated that 82% of men and 92% of women
with moderate-to-severe sleep apnea have not
been diagnosed.
• A substantial proportion of these patients present
for surgery and may have an increased risk of
perioperative complications.
• The screening tools may assist in the diagnosis of
OSA when associated with a high index of clinical
suspicion.
• Snoring is a prime symptom of OSA and is almost
100% sensitive, however it lacks specificity and
has a low positive predictive value.
Screening for OSA prior to surgery
• A study screening preoperative patients using the Berlin
Questionnaire determined that it had a sensitivity of 69%
and a specificity of 56% in surgical patients.
• Although validated in primary care settings, the Berlin
Questionnaire is a complicated scoring system with a
large number of questions.
• The American Society of Anesthesiologists developed a
tool in 2006 to help assist anesthesiologists in identifying
patients with OSA.
• It comprises a 14-item checklist categorized into history
of airway obstruction during sleep , physical
characteristics, and complaints of somnolence .
American Society of Anesthesiologists Checklist
High risk of OSA if 2 or more categories scored as positive.
Low risk of OSA if 1 or no categories scored as positive
Screening for OSA prior to surgery
• The sensitivity of the American Society of
Anesthesiologists checklist was 79% at AHI of > 15
and 87% at AHI > 30.
• A significant step forward in the screening of
patients for OSA was the development of a more
concise and easy-to-use bedside screening tool
abbreviated as the STOP Questionnaire
• The sensitivity of the STOP questionnaire with AHI
> 15 and > 30 as cut-offs were 74% and 80%
respectively.
• The specificity at similar AHI levels was 53% and
49% respectively.
The STOP questionnaire
Screening for OSA prior to surgery
• When combined with BMI, age, neck
circumference, and gender, the STOP
Questionnaire had a high sensitivity, especially
for patients with moderate to severe OSA.
• This combined version is commonly referred to as
the STOP-Bang Questionnaire .
• The use of the STOP-Bang Questionnaire
improved the sensitivity to 93%, and 100% at AHI
cut-offs of >15 and >30 respectively, making it an
ideal screening tool with a high sensitivity level.
• The specificity of the STOP-Bang Questionnaire at
similar AHI levels was 43% and 37% respectively.
•
The STOP-Bang scoring model.
Screening for OSA prior to surgery
• Various other screening modalities including the modified
Mallampatti score of 3 or 4, or a waist circumference of >
105 cm, have been correlated well with an increased AHI .
• With analyzing the accuracy of clinical screening methods
in the diagnosis of OSA (26 different clinical prediction tests
with 8 in the form of questionnaires, and 18 algorithms,
regression models or neural networks ), STOP-Bang
Questionnaire was described as a user-friendly and
excellent method to predict severe OSA (AHI >30).
• The linear scale and the simple acronym make the STOPBang Questionnaire practical and easy-to-use in the
preoperative setting.
• STOP-Bang is now widely adopted as a screening tool for
OSA in primary care settings, preoperative clinics and sleep
clinics.
In the Mallampati maneuver, patients are instructed not to emit sounds but to open
the mouth as wide as possible and protrude the tongue as far as possible.
In the modified Mallampati, the patient is instructed to open the mouth as wide as
possible without emitting sounds.
Screening for OSA prior to surgery
• Nocturnal oximetry may be a sensitive and
specific tool to detect OSA in surgical patients.
• There was a strong correlation between
nocturnal oximetry and the AHI from
polysomnography .
• The oxygen desaturation index measured by
nocturnal oximetry had a sensitivity of 75-95%
and a specificity of 67-97% as compared to AHI.
• The availability of various screening modalities
and an increasing awareness of the occurrence
of OSA may lead to more patients being
diagnosed with this challenging condition.
Nocturnal oximetry
Screening for OSA prior to surgery
• Preoperative preparation can include the use of home
sleep tests e.g. Apnea Link as a diagnostic tool for OSA.
• The diagnostic gold standard remains polysomnography
carried out overnight in a sleep clinic, often times this is an
expensive, time-consuming option.
• There frequently is not enough time from the date of
scheduled surgery to obtain necessary authorizations and
appointments for a PSG, resulting in the need for
alternative diagnostic methods.
• For the anesthesiologist who first suspects sleep apnea in
a preoperative clinic for surgery scheduled several days in
the future, the patient’s surgery would have to be cancelled
and rescheduled pending the PSG and appropriate
treatment
Apnea Link
Screening for OSA prior to surgery
• Pulse oximetry as a single metric of sleep apnea lacks the
sensitivity and specificity of PSG and multi-channel home
sleep testing .
• If the goal is only to cipher out those with an AHI of 15 or
20 or more, pulse oximetry can be considered.
• Centers for Medicare and Medicaid Services, 2009
reported that the final decision supporting equally
effective testing utilizing PSG and home sleep tests, as
measured by outcomes and patient compliance
.
• While patients with mild OSA may not require preoperative
PAP therapy, patients with moderate and severe OSA who
have been on PAP therapy should continue treatment in the
preoperative period .
• Patients who have been noncompliant with instructions for
CPAP use prior to surgery and are in need of CPAP postsurgery, pose the highest risk of potential complications .
Preoperative optimization of patients with known or
suspected OS A
• There are a substantial percentage of patients diagnosed with OSA
who are often prescribed CPAP or BPAP devices.
• The current use of CPAP or BiPAP should be noted with special care
on compliance to therapy.
• Patients should be advised to bring their CPAP devices to the hospital
on the day of surgery for postoperative use.
• A subset of patients may need reassessment preoperatively,
especially patients with a known diagnosis of OSA but lost on followup, recent exacerbation of OSA symptoms, those who have undergone
OSA-related airway surgery, or have been non-compliant with CPAP .
• Experience suggests that restarting preoperative CPAP may be
beneficial on non-compliant patients.
• The American Society of Anesthesiologists task force on the
management of OSA recommends that patients with moderate and
severe OSA who have been on CPAP therapy should continue with
CPAP in the postoperative period .
Preoperative optimization of patients with known or
suspected OSA
• Precautions should be taken in anticipating the possibility
of having a difficult airway
• Most patients may be obese and appropriate care should
be taken to prevent desaturation .
• It is useful to employ short-acting anesthestic drugs, less
soluble inhalational agents, titrate opioids, and minimize
sedation .
• In patients with anticipated difficult airways, awake
extubation may have to be performed preferably in a 30° to
45° head-up position.
• The routine perioperative care may be adequate for
patients with mild OSA. If patients have any co-morbidities,
they should be optimized.
• Patients may benefit by the modifications of anesthetic
technique such as avoidance of general anesthesia in
favor of a central neuraxial or a peripheral nerve block.
Preoperative optimization of patients with known or
suspected OSA
Intra-operative optimization of patients with known or
suspected OSA
Intra-operative optimization of patients with known or
suspected OSA
• Several issues can arise intraoperatively in the OSA
patient, including difficult intubation, opioid-related
respiratory depression, and excessive sedation;
provides an overview of potential anesthetic concerns
with the OSA patient .
• Two important correlates of difficult intubation are a
higher Mallampati score ≥ 3, neck circumference > 40
cm, or waist circumference > 105 cm ; same for both
genders).
Intra-operative optimization of patients with known or
suspected OSA
• Proper positioning should include supporting the obese
patient behind the upper back and head to achieve an
anatomical position where a horizontal plane between the
sternal notch and the external auditory meatus is
established.
• In patients with OSA, the sitting posture decreases the
frequency of airway obstruction compared to supine, and
the benefits from upright positioning are enhanced in the
obese patient.
• Placing patients into a sitting position for preoxygenation
and anesthetic induction should be considered.
Intra-operative optimization of patients with known or
suspected OSA
• The obese patient has a reduced FRC, and tidal volume
often falls below the closing capacity of the small airways,
leading to atelectasis, increased intrapulmonary shunting,
and impaired oxygenation.
• FRC is further reduced after induction of anesthesia, when
the weight of the anterior chest compresses the thorax.
• At least three minutes of breathing 100% oxygen or five
vital capacity breaths of 100% oxygen are essential.
• For superficial procedures, one should consider the use of
local anesthesia or peripheral nerve blocks, with or without
moderate sedation.
• If moderate sedation is used, ventilation should be
continuously monitored by capnography or another
automated method if feasible because of the increased risk
of undetected airway obstruction in these patients.
Intra-operative optimization of patients with known or
suspected OSA
• One should consider administering CPAP during sedation
to patients previously treated with these modalities.
• General anesthesia with a secure airway is preferable to
deep sedation without a secure airway, particularly for
procedures that may mechanically compromise the
airway.
• Spinal/epidural anaesthesia should be considered for
peripheral procedures.
• Full reversal of neuromuscular block should be verified
before extubation. When possible, extubation and
recovery should be carried out in the lateral, semi-upright,
or other non-supine position.
Intra-operative optimization of patients with known or
suspected OSA
Post-operative optimization of patients with known or
suspected OSA
•
Postoperative concerns in the management of patients
with OSA include:
(1) analgesia,
(2) oxygenation
(3)patient positioning
(4) monitoring.
• Risk factors for respiratory depression include the
systemic and neuraxial administration of opioids,
administration of sedatives, site and invasiveness of
surgical procedure, and severity of the sleep apnea.
•
•
Postoperative residual curarization is common after administration
of neuromuscular blocking agents.
Suggested practices include verification of full neuromuscular
blockade recovery, ensuring the patient is fully conscious prior to
extubation, and placing the patient in a semi-upright recovery
position. Anticipating possible difficult airways, use of short-acting
anesthetic agents, opioid minimization, reversal prior to extubation,
and extubation in a non-supine position.
Post-operative optimization of patients with known or
suspected OSA
• Opioids suppress REM and slow wave sleep .
• REM rebound contribute to haemodynamic instability ,
myocardial ischemia and infarction ,stroke ,mental
confusion and wound breakdown.
•
Exacerbation of respiratory depression may
occur on the third or fourth postoperative day
as sleep patterns are reestablished and “REM
rebound” occurs.
Post-operative optimization of patients with
known or suspected OSA
• Supplemental oxygen should be administered
continuously to all patients who are at increased
perioperative risk from OSA until they are able to
maintain their baseline oxygen saturation while
breathing room air.
• The Task Force cautions that supplemental oxygen may
increase the duration of apneic episodes and may
hinder detection of atelectasis, transient apnea, and
hypoventilation by pulse oximetry.
• CPAP or BiPAP, with or without supplemental oxygen,
should be continuously administered when feasible to
patients who were using these modalities
preoperatively, unless contraindicated by the surgical
procedure.
Post-operative optimization of patients with known or
suspected OSA
• Compliance with CPAP or BiPAP may be
improved if patients bring their own equipment
to the hospital.
• Intermittent pulse oximetry or continuous
bedside oximetry without continuous
observation does not provide the same level of
safety.
• If frequent or severe airway obstruction or
hypoxemia occurs during postoperative
monitoring, initiation of nasal CPAP or BiPAP
should be considered.
Management of patients scheduled for ambulatory surgery
• Due consideration must be given to
1- The type of surgery,
2- Associated co-morbidities,
3-Patient’s age
4- Severity of OSA
5-The treatment status
6-Anticipated use of postoperative opioids
7-The type of anesthesia (local vs general vs nerve blocks
with or without sedation) and
8- Home care .
• The American Society of Anesthesiologists Advisory
Guidelines on the Perioperative management of patients
with OSA suggests that superficial surgeries or minor
orthopedic surgery using local or regional techniques,
and lithotripsy, may be done on an ambulatory basis.
Consultant Opinions Regarding Procedures That May Be
Performed Safely on an Outpatient Basis for Patients at
Increased Perioperative Risk from OSA
Management of patients scheduled for ambulatory surgery
• Patients with regional anesthesia also have elevated AHI
and oxygen desaturation. This may imply that OSA
patients need to be treated with CPAP.
• Regarding ambulatory surgery, short-acting anesthetic
agents and non-invasive surgery typically makes this a
safer option for patients with OSA.
• Severe untreated or undiagnosed OSA requiring
postoperative narcotics after ambulatory surgery may be
unsafe.
• The consultants indicated that monitoring of patients with
OSA should continue for a median of 7 h after the last
episode of hypoxemia while breathing room air in an
unstimulating environment.
Management of patients scheduled for ambulatory surgery
• Patients may be discharged to home provided
that there is no moderate or severe OSA, no
recurrent adverse events in postanesthesia care
unit (PACU) such as apnea or desaturation, and
no requirement of postoperative opioid .
• It is important to realize that ambulatory
surgical facilities managing OSA patients
should have transfer arrangements to an
inpatient facility, and be equipped to handle the
potential problems that may arise while dealing
with OSA patients.
Management of patients scheduled for hospital stay
• The 2006 American Society of Anesthesiologists
guidelines recommend that the postoperative
destination should be based on risk factors and
a weighted scoring system .
• The patient’s risk is determined based on the
severity of OSA, the type of surgery and
anesthesia, and the need for postoperative
opioids.
• The final total risk score will be the guide for
the anticipated requirement for postoperative
monitoring of patients.
The occurrence of recurrent respiratory events in PACU can
be used as a reliable indicator to determine whether the
known or suspected OSA patient requires continuous
postoperative monitoring.
• The PACU respiratory event is defined as either:1- An apnea for ≥ 10 s (1 episode needed for yes),
2-Bradypnea of < 8 breaths per minute (3 episodes needed for yes),
3- Pain-sedation mismatch, or
4-Desaturations to < 90% (3 episodes needed for yes) in one 30-minute
time block.
The event is considered significant when any of one of them occurs in two
separate 30-minute time blocks .
This will make it possible to identify the majority of OSA patients that
require further monitoring.
• It is highly likely that these patients may require CPAP therapy.
• Patients with OSA have a more profound increase in AHI on
postoperative night 3 and return to preoperative levels on night 7 .
Sleep Spindles
Special considerations for postoperative management
Postoperative analgesia
• OSA is one of the major risk factors contributing to the
occurrence of respiratory depression .
• The use of opioids can be a special concern in patients with
OSA, as most opiates including morphine, meperidine,
hydromorphone, and fentanyl cause a dose-dependent
reduction of respiratory drive, respiratory rate, and tidal volume
that in turn can lead to hypoventilation, hypoxemia, and
hypercarbia .
• Sedatives , anesthetics and analgesics may selectively
compromise respiratory function in OSA patients.
• The general recommendation is that opioids and other drugs
with central respiratory and sedating effects should be avoided,
if possible. It is imperative to minimize the use of opioids in
diagnosed or suspected OSA patients.
Postoperative analgesia
• The use of morphine in OSA has been deleterious
with reports of respiratory depression and even
death.
• There may be genetic factors that may play a role in
having differing effects on opioid induced
respiratory effects.
• Oxygen desaturations were 12 to 14 times more
likely to occur in OSA patients receiving oral or
parenteral opioids as opposed to those receiving
non-opioid analgesic agents .
Alternative to opioid therapy
• The use of multimodal analgesia may be more beneficial in
patients with OSA in minimizing the opioid-related side
effects and providing effective analgesia as well.
• There are a plethora of medications that can be used, such
as nonsteroidal anti-inflammatory drugs, acetaminophen,
tramadol, ketamine, gabapentin, and pregabalin .
• Caution should be advocated while using some of these
drugs like gabapentin with the side effect of sedation.
Dexmedetomidine has been particularly beneficial because
of the opioid sparing effect and the lack of respiratory
depression.
Alternative to opioid therapy
•
•
•
•
•
The American Society of Anesthesiologists guidelines
recommend regional anesthesia to reduce the possibility of
negative adverse events associated with systemic opioids.
The use of nonsteroidal anti-inflammatory analgesics is
strongly recommended .
The use of nerve blocks with or without catheters with local
anesthetics obviates the need for systemic opioid analgesics.
Caution should be exercised in using neuraxial opioids in
patients with OSA as there are reports of postoperative
respiratory arrest in a case series of three patients .
Patients with OSA may be at an increased risk of
perioperative complications with the use of strong opioids
even after a regional anesthetic.
Respiratory Arrest in the Hospital
• Over 90% of inpatient arrests are brady-asystolic, with
the vast majority of these involving known respiratory or
cardiovascular insufficiency prior to loss of vital signs.
• Approximately half of non-ICU arrests involve acute and
unexpected respiratory insufficiency, most of which
have an identifiable risk factor for apnea.
• These risk factors include a decrease in level of
consciousness combined with a process leading to
mechanical obstruction.
• Level of consciousness may be modified by
medications (sedatives / narcotics), encephalopathy,
anesthetics, or even sleep itself).
Respiratory Arrest in the Hospital
• Mechanical obstruction may be related to obesity, airway
swelling / masses, or placement in the supine position.
• The challenge is to identify patients at risk for inpatient
apnea/ hypopnea with enough sensitivity to prevent
arrests and enough specificity to avoid occupying
monitored beds unnecessarily
• The STOP-Bang questionnaire is applied in the
preoperative clinic, with positive screens leading to multichannel home sleep testing.
• Once a diagnosis of OSA is made, patients undergo a
longer period of observation in the PACU followed by
admission to a designated inpatient bed with capnometry,
continuous pulse oximetry, and ECG monitoring.
Evidence for using perioperative CPAP
• CPAP exerts its beneficial effects by acting as a
pneumatic splint and prevents the obstruction to airflow
during sleep.
• Postoperative CPAP reduces airway obstruction, reduces
major postoperative complications and shortens the
hospital stay.
• The American Society of Anesthesiologists task force
recommends that patients continue with their routine
CPAP through the perioperative period.
• The patients are better advised to get their own CPAP
device to the hospital on the day of surgery.
OSA and Malpractice
•
Adverse outcomes can occur due to intubation difficulties (due to
increased oropharyngeal classification, decreased atlanto-occipital
extension, thick neck and occasionally micrognathia and
retrognathia) and extubation difficulties (due to loss of optimal
airway management position, monitors off the patient, patients not
fully awake, no oropharyngeal airway), and together constitute
approximately 30% of the malpractice OSA cases.
•
The prototypical OSA malpractice case, constituting
approximately 70% of the cases, is finding a postoperative patient
dead in bed.
•
The clinical components of the prototypical OSA malpractice
“dead in bed” case are:
(1) Severe OSA
(2) Morbid obesity
(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.
OSA and Malpractice
• Primary care doctors, sleep doctors, surgeons
and anesthesiologists must have ready access
to all OSA - related information in OSA patients;
it has been suggested that the best way to
ensure this continuity of care is to issue medical
alert bracelets to patients who have severe OSA.
• Even though initial costs may rise due to the
increase in time and equipment needed to screen
and diagnose patients, ultimately, litigations will
decrease due to improved patient care in the
perioperative environment.
•
Custom made Wristbands for Patient Safety By providing hospital caregivers
with a visual notification of risk by using a wristband, specific precautions can be
taken to ensure the patient receives the best care possible.
Conclusion
• The combination of anesthesia and undiagnosed OSA
can be potentially dangerous and places the patients at
an increased risk of perioperative complications and
postoperative morbidity.
• Encouraging clinicians to be cognizant of patients with
specific risk factors for OSA remains an important
aspect of quality health care.
• Screening of patients with the STOP-Bang Questionnaire
will identify patients at risk of OSA.
• Combining preoperative screening of OSA and
identifying recurrent PACU respiratory events will allow
risk stratification of diagnosed or suspected OSA
patients for more focused postoperative care.
Conclusion
• Simplified questionnaires and a myriad of inexpensive,
quick at home sleep tests have provided a necessary first
step in arriving at a solid, evidence-based system for
identifying patients with OSA prior to the operating room
setting, which can only serve to diminish the potentially
negative outcomes associated with surgery and OSA.
• Postoperative management of patients with OSA should
include close monitoring postoperatively .
• Adequacy of postoperative respiratory function may be
documented by observing patients in an unstimulated
environment,preferably while they seem to be asleep, to
establish that they are able to maintain their baseline
oxygen saturation while breathing room air.