Obesity Flashcards
what is defined as an increase in body weight above a standard related to height?
Overweight
what is defined as being characterized by an abnormally high percentage of body weight as fat of sufficient magnitude to impair health
obesity
what is a concept defines by life insurance companies- is the weight associated with the lowest mortality rate for a given height and gender?
Ideal body weight (IBW)
IBW:
what is IBW for a female
height (cm) - 105
IBW:
what is IBW for Males
height (cm) - 100
is lean body weight (LBW) synonymous with IBW
no
LBW:
how is it calculated or what is it defined as
the TBW minus the adipose tissue weight
LBW:
formula
IBW + (20 to 40%)
what is the formula for BMI
BMI = kg / m^2
BMI:
Underweight
BMI:
normal
18.5-24.9
BMI:
Overweight
25-29.9
BMI:
Obese (I)
30-34.9
BMI:
Obese (II)
35-39.9
BMI:
Morbid obesity (III)
>/= 40
BMI:
Superobese
>/= 50
BMI:
Super-superobese
>/= 60
Distribution of Body fat:
what are the 2 types of body fat?
Android (apple)
Gynecoid (pear)
Distribution of Body fat:
Apple or Pear

Apple
Distribution of Body fat:
Apple or pear

pear
Distribution of Body fat: Android (apple)
fat is predominetly located where?
upper body
Distribution of Body fat: Android (apple)
associated with increased consumption of what?
O2
Distribution of Body fat: Android (apple)
have an increaced incidence of CV disease particulary what?
LV dysfunction
Distribution of Body fat: Gynecoid (pear)
fat is usually where
hips
butt
thighs
Distribution of Body fat: Gynecoid (pear)
why is there a decreases risk of CV disease in these pt’s
less metabolically active fat
what is the newly est standard used as a marker for abdominal obesity?
waist circumference
A waist circunference greater than what in men denotes an increased risk for certain diseases and conditions including DM, Heart dz, HTN, dyslipidemia, and death?
102 cm (40.2 inches)
A waist circunference greater than what in women denotes an increased risk for certain diseases and conditions including DM, Heart dz, HTN, dyslipidemia, and death?
58cm (34.6 inches)
Respiratory:
what happens to lung voumes
decrease
Respiratory:
what happes to work of breathing
increases
Respiratory:
what are some of the airway changes
decreased pharyngeal area
excessive hypopharyngeal tissue
posterior displaced hyoid bone
Respiratory:
fat accumulation on the thorax and abdomen decress chest wall and lung compliance by about how much
35%
Respiratory:
what happens to TLC, ERV and FRC
decreased
Respiratory:
what happens to TV, residual voume, and closing capacity
nothing, usually no changes
Respiratory:
the reduction in FRC is explained primarily d/t what?
reduced ERV
FRC = RV + ERV
Respiratory:
when CC > FRC what occurs
V/Q mismatch
Respiratory:
Once CC > FRC and the V/Q mismatch arises what occurs?
CO2 retention (acidosis)
right to left shunting
arterial hypoxemia
Respiratory:
In response to the CO2 retention and arteial hypoxia what are their respiration usually like
rapid and shallow
Respiratory:
they develop what type of respiratory disease pattern
restrictive
Respiratory: anesthesia concerns
the obese pt has a decrease in FRC of how much compared to the 20% decrease if the non-obese
50%
Respiratory:
obesity increases ____ and _____ even at rest
oxygen consumption and CO2 production
Respiratory:
bc of the increased O2 consuption and CO2 production combined with the decreased FRC and V/Q mismatch the obese pt usually develops chronic what?
arterial hypoxia
Respiratory:
the chronic arterial hypoxia leads to what CV problems
Pulm HTN and Cor Pulmonale
Aka right heart failure
OSA:
what is a milder precuror to OSA and is defined as partial decreased airflow (>50% reduction), lasting 10 seconds, occuring >15/hr of sleep, and accompied by at least a 4% reduction in arterial oxygenation.
OSH
obstructie sleep hypopnea
OSA:
risk factors obese
male
middle aged
BMI > 30
evening ETOH consumption
OSA:
risk factor for non-obese
crainofacial dytoses
cartilaginous abnormalities
Chronic nasal obstruction
tonsilar hypertrophy
trisomy 21
OSA:
what are the hallmark signs of OSA
Snoring
daytime sleepiness
impaired concentration
memory problems
morning headaches
OSA:
apnea is defined as what?
cessation of airflow > 10 sec
=/> 5 times per hour of sleep
dispite continued ventilatory effort against clossed glottis
in combination with at least 4% decrease in arterial oxygenation
OSA:
what follows period of apnea and why?
hyperventilation
to compensate for hypercarbia
OSA: Physical Alteration
what happens to arterial O2
Arterial Hypoxemia
OSA: Physical Alteration
what happens to CO2
Hypercarbia
OSA: Physical Alteration
what happens to pulmonary and systemic vasculature
Vasoconstriction
OSA: Physical Alteration
what happens to blood components
polycythemia
OSA:
the definative diagnosis for of OSA is made how?
polysomnography in sleep lab
OSA:
what is an assessment questionmaire you may use in the preop period
STOP BANG
OSA:
explain the STOP BANG questionnaire
- do you SNORE loudly
- do you feel TIRED during the daytime most everyday
- has anyone see you STOP breathing during sleep
- so you have a high blood PRESSURE
- is BMI > 35
- is AGE greater then 50
- is NECK circumference greater then 40cm
- in GENDER male
OSA:
with the STOP BANG your at high risk for OSA if you score what?
> 3 are yes
OSA:
you are at low risk for OSA if your score is what on the STOP BANG?
OSA:
definative treatment of OSA is what?
Positive airway pressure in the forms of IPAP. EPAP, and CPAP
OSA: Anesthestic concerns
they are exquisitely sensitive to all CNS depressants, so what should we use sparingly in the preop phase
Benzo
Opioids
what is a disorder like OSA but more severe?
Obesity Hypoventilation Syndrome (OHS)
Obesity Hypoventilation Syndrome (OHS)
is also called what?
Pickwickian Syndrome
Obesity Hypoventilation Syndrome (OHS)
is a complication of extreme obesity, characterized by what
OSA
Hypercapnia
Daytime Hypersolmnolence
arterial hypoxemia
Cyanosis-induced polycythemia
respiratory acidosis
Pulm HTN
right sided heart failure
Obesity Hypoventilation Syndrome (OHS)
can lead to central apnea, what is that?
Apnea without resp effort
what is the main difference b/t Obesity Hypoventilation Syndrome (OHS) and OSA?
Obesity Hypoventilation Syndrome (OHS)- can lead to central apnea which is apnea without respiratory effort
Obesity Hypoventilation Syndrome (OHS)
what are the 3 main diagnostic critera to define it
BMI > 30
Awake PCO2 > 45mmHg
sleep disordered breathing
the prevalence of Obesity Hypoventilation Syndrome (OHS) in pts with OSA is what?
small 4-20%
the prevelance of OSA with Obesity Hypoventilation Syndrome (OHS) is what?
high- 90%
basically pts with Obesity Hypoventilation Syndrome (OHS) almost always have OSA
but pt’s with OSA usually don’t have Obesity Hypoventilation Syndrome (OHS)
CV and Hematologic:
CO increases how much for each kg of excess body fat?
20-30 mL/kg
(about 100mL/min per kg)
CV and Hematologic:
total blood volume is increased in the obese BUT on a volume to weight basis it is ______ than in the non-obese
less
CV and Hematologic:
EBV calculation for Obese
50mL/kg
(vs 60mL/kg female non-obese and 70mL/kg male)
CV and Hematologic:
the expanded blood volume places a greater demand on what?
the myocardium
CV and Hematologic:
the expanded blood volume places a greater demand on the myocardium, specifically increased what?
LV wall stress
CV and Hematologic:
the expanded blood volume places a greater demand on the myocardium, specifically increased LV wall stress. According to the LAw of Laplace the LV will do what in attempt to reduce wall stress
Hypertrophy
CV and Hematologic:
LV hyertrophy leads to what complications
Hypertrophy
reduced LV wall stress
impaired diastolic filling
elevated LV pressures
Pulmonary edema
Systolic dysfunction
Biventricular failure
CV and Hematologic:
adipose tissues releases a number of bioactive mediators (cytokines, chemokines, hormones) that promote a chronic, sub-clinical inflammatory state. This can contribute to what complications?
CV disease
Insulin resistance
coagulopathies
CV and Hematologic:
obese people have a 2xs higher risk of developing what coag disorder
DVT
CV and Hematologic:
high Factor ____ levels are associated w/ increased CV mortality
VIII
Gastrointestinal:
what happens to gastric volume and acidity
increased
Gastrointestinal:
why do they develop delayed gastric emptying?
increased abd mas
Gastrointestinal:
what liver abnormalities are associated with obesity
NAFLD
inflammation
focal necrosis
Cirrhosis (1.5-2.5 x greater)
Gastrointestinal:
both males and females who are obese have an increased risk for what cancer
esophageal and colorectal
Endocrine and Metabolic:
the risk of what is linear with BMI
DMII
Endocrine and Metabolic:
obese people have a higher incidence of what metobolic d/o (not DM)
Metabolic syndome
Endocrine and Metabolic:
what is metabolic syndrome
constellation of metabolic abnormalities including
Abdominal obesity
glucose intolerance
HTN
dyslipidemia
Endocrine and Metabolic:
diagnosis of metabolic syndrome requires what?
Android obesity
with at least 2 of the following
- high triglycerides
- reduced HDL
- HTN
- elevated fasting serum glucose
Genitourinary:
what happens to Renal blood flow and GFR
increased
Genitourinary:
why does GFR and Renal blood flow increase in the obese
d/t the increased CO and Increased MAP
Bariatric Surgery:
what are the 2 categories of sx
gastric restrictive
combo gastric restrictive and malabsortion
Bariatric Surgery: Restrictive
what is the goal of this category
reduce and limt the pts capacity for food intake
Bariatric Surgery: Restrictive
what are 3 procedures
Vertical band Gastroplasty (VBG)
Laparoscopic gastric band (LGB)
laparoscopic sleeve gastrectomy (LSG)
Bariatric Surgery: Combined Restrictive & Malabsorption:
what is an example
Roux-en-Y gastric bypass (RYGB)
Bariatric Surgery: Combined Restrictive & Malabsorption:
what is the biggest risk with the surgery
Anastomosis leak and peritonitis
Pharmacology:
2 pharmacokinetics principles should be kept in mind when determining drug doses for obese pt’s what are they?
volume of distribution
clearance
Pharmacology:
what is general rule to give drugs
IBW (induction) then titrate to effect
Pharmacology:
most drugs we give should be given based off what weight (except for NDMR)
TBW
Pharmacology:
how should NDMR be dosed
LBW (IBW)
Anesthestic Management: Preop
what should we look for to evaluate for LEft and right ventricular failure
Elevated Jugular venous pressures
added heart sounds
Pulmonary crackles
Hepatomegaly
peripheral edema
Anesthestic Management: Preop
what on the echo will inticate to us the pt has pulm htn
tricuspid regurg
Anesthestic Management: Preop
what should we ask about r/t respiratory
Smoke
Exercise tolerance
somnolence
OSA
Anesthestic Management: Preop
what do we wanna look for during airway evaluation
limited movement of Alantoaxial joint (fat pads)
Limited movent of cervical (fat pads)
Short thick neck
excessive tissue (neck folds)
very thick submental fat
Anesthestic Management: Preop
Airway- is difficult airway closely correlated with BMI?
No
Anesthestic Management: Preop
since difficult airway is not corralated with BMI what is it correlated with
Increased age
Male
TMJ
MALAMPATTI II or IV
abnormal upper teeth
OSA
Neck circumference
Anesthestic Management:
what position provides the longest safe apnea period during induction of general anesthesia
Head up
Reverse trend
fowlers
what are the the 3 axis to line up prior to intibation
oral axis
Pharyngal axis
laryngeal axis

what is the only ventilatory parameter to show improved respiratory fxn in the obese
PEEP
what happens to LA needs in the obese
may decrease by 20%
at the end of sx goin from supine to sitting increases FRC by how much in the obese
30%