Obesity, Sleep Apnea,

imminentpoppedAI and Robotics

Feb 23, 2014 (3 years and 8 months ago)

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Obesity, Sleep Apnea,
the Airway, and
Anesthesia




R3
김상영


Obstructive Sleep Apnea (OSA)


4% of men, 2% of women


Obesity : very important independent


causative
-
risk factor


(60~90% of OSA, BMI>29

/

)


Craniofacial and orofacial bony abn., nasal
obx., large tonsil :
주로

소아에서


Excess neck fat


대부분

진단이

이루어지지

않은채

살고있음



마취과

의사가

gatekeeper


Definition of OSA Terms



OSA
정의



Cessation of airflow for more than 10 seconds
despite continuing ventilatory effort,


5 or more times per hour of sleep,


usually associated with a decrease in arterial
oxygen saturation (SaO₂) of more than 4%


Obstructive sleep hypopnea (OSH)


Decrease in airflow of more than 50% for more
than 10 seconds,


15 or more times per hour of sleep


Usually associated with snoring and may be
associated with a decrease in SaO₂of greater
than 4%



Table 1.
Definition of OSA and OSH







OSA = obstructive sleep apnea;


OSH = obstructive sleep hypopnea


Obstruction

Decrease in

Airflow

>10seconds

Times/Hour

Decrease in
O₂saturatio
n

Disrupted
Sleep

Daytime
Sleepness


OSA


OSH

100%

>50%

>5

>15

≥4%

≥4%

奥L

奥L

奥L

奥L

Pathopysiology of Obstructive Sleep
Apnea in the Adult Obese Patient


Normal Pharyngeal Muscle Activity


Subatmostheric intraairway pr.


3 pharyngeal segments


Retropalatal pharynx


Retroglossal pharynx


Retroepiglottic pharynx


Collapsible


Ant. And lat. Walls lack bony support

Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient


Fig 1 A


Fig 1 B

Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient


Fig 1 C

Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient


Normal Sleep


NREM sleep ⇒ REM sleep (4~6cycles)


Generalized loss of m. tone


Deep NREM(stage3,4), REM


Compliant lat. Pharyngeal wall (m/c site)


NREM sleep
중의

r. = awake
상의

2



REM sleep
중의

r. > NREM r.


Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient


Obesity and OSA:


Pharyngeal Pathology and Incidence


Inverse relation between obesity and
pahryngeal area


지방축적부위


: uvula, tonsil, tonsillar pillars, tongue,
aryepiglotic folds,
lat. Pharygeal walls


지방축적
↑⇒
근이완때와

비슷한

효과



soft wall


collapse
유발


Transmural pr.& compliance of the wall


Extraluminal pr
.(
목살
,
목둘레가

중요
)



Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient


Arousal


무호흡시에

일어나는

event



PaO₂↓


PaCO₂↑


Ventilatory effort progressively ↑


Intraairway pr. Progressively ↑


Arousal


By reticular activating system


EEG activity↑, vocalization, extremity twitching,


gasping or snorting on airway opening


생존을

위해

필요한

반응

Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient


Systemic Pathophysiology of OSA


Systemic effects of the sleep→arousal→sleep
cycles



SLEEP SNORING, NOCTURNAL
Primary Event


RESTLESSNESS SOCIAL ISOLATION




OBSTRUCTED ↓O₂& ↑CO₂ AROUSAL


BREATHING


DAYTIME SLEEPNESS


ARRTHYMIAS PULM. HTN SYSTEMIC HTN


PERSONALITY


BEHAVIOR CHANGES


COGNITION


MYOCARDIAL


ISCHEMIA RVH LVH ACCIDENT PRONE

Pathopysiology of Obstructive Sleep Apnea in
the Adult Obese Patient

Diagnosis of OSA


관련요소들


Obesity, snoring or apnea during sleep,


periodic snorting and apparent arousal,


daytime sleepness or fatigue,


increased neck circumference

Diagnosis of OSA


Obesity


BMI


= mass/height²=kg/m²or 703
×

lbs/inches²


Underweight(<19), normal(19~24.9),
overweight(25~29.9), obesity(30~34.9),


morbid obesity(>35)


지방과

근육

구분이



안되는

단점


Obstructive
vs

central sleep apnea


숨쉬려는

노력

유무에

따라

나뉨



Fig 3

Diagnosis of OSA


Table 2.
Understanding the Sleep Study Report









SpO₂(oxygen saturation) data are also reported as number of
events per 60
-
69%, 70
-
79%, 80
-
89%, and the lowest SpO₂.


Electrocardiogram and hemodynamics are usually descriptive and
the extremes reported.


TV = tidal volume; AHI = apnea
-
hypopnea index


ODI = oxygen desaturation; AI = arousal index

Diagnosis of OSA

Events

Indexes

Apnea = no airflow > 10 sc

Hypopnea = TV <50% for 10 sc

Desaturation = SpO₂dec >4%

Arousal = clinical or EEG

Events/hour; AHI, ODI, AI

Severity of sleep apnea is

f(AHI) 6
-
20 = mild


21
-
50= moderate


> 51 = severe

Effect of Anesthetic Drugs on Airway
Patency in the Adult Obese Patient with
OSA


All central depressant drugs


⇒ pharyngeal dilator m. action ↓


Propofol, thiopental, narcotics, benzodiazepines,


small doses of neuraomuscular blockers, nitrous oxide


Opioids


Cause airway obx., poor ventilatory response


Post op pain↑⇒ opioids
사용량
↑ ⇒
위험도



수술뒤

1
주까지는

위험한

기간

(by REM sleep)




Preoperative Evaluation: OSA and Airway
Status


미리

진단된

사람

적다


마취과

의사는

gatekeeper


Nocturnal snoring
-
snorting
-
apnea, arousals,
diurnal sleepness
등을

확인


HTN history,
목둘레

40
-
42cm
이상이면

위험증가


Nocturnal diaphoresis and enuresis, frequent
nocturia, morning headaches, and abnormal
cardiovascular and neuropsychiatric function


Regional anesthesia


Implications for Airway Management

Implications for Airway Management


Tracheal Intubation




어려운

경우

많다


Obesity, short thick neck, excess pharyngeal tissue


같은

나이의

환자보다

difficult
비율

100



Awake? Or under general anesthesia?


Premedication
신중을



다른

기구들을

활용


Ex) flexible fiberscope


Fully preoxygenation


Small FRC(small oxygen reservoir)


High oxygen consumption


Laryngoscopy : optimal manner


Two hand mask


다른

유사시를

대비
. 2


이상


Fig 4

Implications for Airway Management


Extubation : Awake vs Leaving the Tube In


Risk of airway obx. After extubation↑


Nasal packing




증가


Life
-
threatening postextubating obx.: 5%


Negative
-
pr. Pulm. Edema


Narcotics
과다

사용은

피하라


Regional anesthesia


도움되기도


Reverse Trendelenburg or semiupright positon


체위이용도

도움


Two
-
hand manuver, reintu


상황에

대비하여

2


이상

대기


N
-
CPAP : SpO₂
떨어질때만

O₂
분율

높여라

Implications for Airway Management


Table 3.
Major Determinants of Awake versus Asleep(DEEP) Extubation
in Patients with OSA undergoing UPPP or Nasal surgery

Implications for Airway Management

Individual Factors

Status of Factors

Extubation
Decision

Ease of mask

ventilation Experience at the

Ease of tracheal beginning of the case

Intubation


BMI Severity


AHI

Associated cardiopulmonary disease

All factors good




One factor severe


In between the
above extremes

Can be asleep if

Really indicated



Awake


Requires
judgement

→ awake



Opioid Pain Management


: Location of Patient


Opioid
-
induced upper airway obx.


Moitored
-
care environment


필요한

이유


고려할

factor



Table 4.
Determinants of Whether Extubated Obese Patients with Sleep
Apnea → Ward vs ICU







BMI = body mass index; AHI = apnea
-
hypopnea index

BP = blood pressure

Implications for Airway Management

1. BMI (severity of obesity)

2. AHI (severity of sleep apnea)

3. Associated cardiopulmonary dis. (dual circulation ↑BP, biventricular
hypertrophy), (compromise of airway patency)

4. Postop narcotic/sedative requirement



Table 5. Extubated Obese Sleep Apnea Patients


: Ward vs ICU


Implications for Airway Management

Condition

Location

All factors mild

One factor severe

In between the above extremes

Ward

ICU

Judgement → observation unit