Obesity Flashcards
Android vs Gynecoid, which is more common in men?
Android
Android vs Gynecoid, which has more central or abdominal fat accumulation?
Android
Android vs Gynecoid, which has higher risk for heart disease, death, HTN, HLD, and insulin resistance?
Android
Android vs Gynecoid, apple or pear?
Android - APPLE
Android vs Gynecoid, which fat is more metabolically active?
Android
Android vs Gynecoid, which has increased risk for joint disease and varicose veins?
Gynecoid
Android vs Gynecoid, which has reduced risk of non-insulin dependent diabetes?
Gynecoid
Android vs Gynecoid, which is more common in women, has a pear shape, and is localized to the glutes and femoral?
Gynecoid
“Gyn”
What is metabolic syndrome? Why is this important?
Also called X syndrome - a disease that coincides with obesity
Carries a 50-60% greater risk of cardiovascular disease
Diagonostic criteria for metabolic syndrome, fasting glucose?
> 110
Diagonostic criteria for metabolic syndrome, BP?
> 130/85
Diagonostic criteria for metabolic syndrome, HDL for men and women?
<40 for men
< 50 for women
Diagonostic criteria for metabolic syndrome, triglycerides?
> 150
Diagonostic criteria for metabolic syndrome, waist circumference for men and women?
> 40 inches for men
35 inches for women
BMI photo
What is the formula for BMI?
= weight in kg / height in meters squared
How to classify obesity in children?
How to calculate IBW for men and women?
How does obesity create a restrictive ventilatory defect?
Chest fat prevents outward expansion
Abdominal fat pushes diaphragm up and compresses the lungs
Kyphosis and lordosis develop and alters the geometry of the ribcage
Do fat people have slow, deep breathes or fast shallow breaths? Why?
Rapid - shallow breathing due to being more energy efficient
Describe if fat is metabolically active
It is metabolically active - they have increased O2 consumption and CO2 production
Will obese people have a normal PaCO2 or increased? Why?
Normal due to the high diffusing capacity of CO2
What is likely to happen if an obese patient has an elevated PaCO2?
Signals impending respiratory failure
How does obesity affect FRC?
-It is inversely proportional
-The fatter you are, the greater reduction in FRC
How does general anesthesia affect FRC in a normal person and a fat person?
Normal - decrease in FRC by 20%
Obese - decrease in FRC by 50%
Why do obese people desaturate so fast?
High O2 consumption
Decreased FRC
How does premature airway closure affect dead space?
Increases dead space
obese lung volumes
How to reduce atelectasis in an obese patient?
Keep FIO2 < 80% to prevent absorption atelectasis
What 2 ways can you recruit collapsed alveoli?
- 40cm H20 for 10 seconds
- PEEP or CPAP 5-10
Both may reduce venous return
TV for obese patients? Should RR or TV be adjusted?
6-8 mL/kg of IBW
Higher TV can cause sheer stress on the lungs so titrate RR
Should obese patients be an RSI?
Not alone
Take all factors into consideration
How does blood volume and CO change in obesity? What does this lead to?
More blood volume and a higher CO lead to cardiovascular complications
This is from the fat being metabolically active
How does SV and HR change in obesity? CO?
CO is increased due to an increased SV due to increased blood volume
HR is usually not changed
Does obesity lead to systolic or diastolic dysfunction? Which one first?
First diastolic then systolic failure
(biventricular failure)
What is HTN a result from in obesity?
Hyperinsulinemia
SNS activation
RAAS activation
Elevated cytokine in plasma
CV photo
How does EKG voltage change in obesity?
Decreased amplitude from distance between heart and leads
How does QT change in obesity?
Prolongation which increases sudden death
How does axis deviation change in obesity?
Left axis - stomach pushes the heart up to the left. Plus LVH and fluid overload contribute to this
Right axis - RVH from OSA and volume overload
How does cardiac ischemia happen in obesity?
Decreased O2 supply and demand
How do dysrhythmias happen in obesity?
Caused by fatty infiltrates of the conduction system
What valvular defect is highly suggestive of pulmonary HTN in obesity?
Tricuspid regurg on TEE
How is the volume of distribution affected by obesity?
- Increased blood volume - need more drug
- Increased CO - faster delivery to vessel rich group
- Altered plasma protein bunding - free fractions available
- Lipid solubility - more fat (lipids) higher Vd
How does obesity affect Vd of lipophilic and hydrophilic drugs?
Both are increased
Is MAC changed by obesity?
No
Which anesthetic gas has the faster emergence ?
- Sevo
- Des
- Iso
- Propofol
Should nitrous be avoided? Why or why not?
Generally avoided because it restricts the maximum FiO2 that can be delivered
Should agents with the lowest or highest blood: gas coefficients be used?
Agents with the lowest
How should propofol be dosed on obese? Induction of Maintenace?
Induction - LBW
Maintenace - TBW
What is one water soluble drug that should be dosed on TBW? Why?
Succ - due to increased blood volume and increased pseudocholinesterase activity
How is roc and vec dosed?
LBW
How is cis and atracurium dosed?
TBW
How are opioids dosed? Why? Which is the exception?
Induction based on TBW
Maintenace is based on LBW
Remi is different because of the plasma esterases - use LBW
How does obesity affect epidural dosing?
Engorgement of epidural veins and increased epidural fat cause a GREATER spread.
Reduce dose by 75%
Which muscles open the airway?
Define hypopnea
50% reduction in airflow for 10 seconds, 15 or more times per hour
This is linked to snoring and decreased O2 saturation
How is OSA defined?
Cessation of airflow for at least 10 seconds with 5 or more unsuccessful efforts to breathe and a greater than 4% reduction in SaO2
OSA photo
What is the definitive test for OSA?
Polysomnography
Number of episodes / hours of sleep
How is mild, moderate, and severe OSA calculated?
What is stop bang?
What is obesity hypoventilation syndrome? How is it identified?
Long term consequence of untreated OSA
-The respiratory center fails to respond to hypercarbia
**apnea during sleep WITHOUT any respiratory effort
BMI > 30
Awake PaCO2 > 45
Dysfunctional breathing during sleep
Which bariatric surgeries are likely to cause malnutrition?
Roux-en-Y
Biliopancreatic diversion
OSA is defined as a cessation of airflow for how many seconds? What is the drop in SaO2?
10 seconds
At least 4% deduction in SaO2
Which conditions contribute to HTN in the obese population?
Hyperinsulinemia
Cytokines
Angiotensinogen
What is the most effective weight loss surgery?
Roux - en - Y
One gram of fat is equal to how many calories? What about carbs and protein?
Fat - 9 calories
Protein - 4 calories
Carb - 4 calories
How to convert inches to m2?
Is RV reduced in obesity?
No
Are lung volumes and VC increased or decreased in obesity?
Decreased
Is lung compliance increased or decreased in obesity?
Decreased
Is there a change in airflow obstruction in obesity?
No change
What should the goal be for preoxygenation for obesity?
100% FiO2 + CPAP of 10cm until end tidal exceeds 90%
This will prolong the time to desaturation by 50%
How long can postoperative hypoxemia occur after surgery?
Immediately and up to 5 days after
5 strategies to maximize postop oxygenation?
- CPAP or BIPAP
- HOB 30 degrees
- Early ambulation
- Pain control without narcs
- IS
Why does CO change in obesity?
Due to increased Stroke volume from increased blood volume
HR stays the same
How is versed dosed for loading and maintenance?
BOTH TBW
Is the absorption of drugs orally changed in obesity?
No
How is remifent dosed for loading and maintenance?
BOTH LBW
Most common signs of gastric leak? How often?
2% chanc
Tachycardia
Fever
Abdominal pain
Which appetite suppressant is associated with serotonin syndrome?
Sibutramine
Is there an increased incidence of pulmonary aspiration based on BMI alone?
No
Does a hiatal hernia increase the risk of aspiration?
Yes
What should fluid requirements be based on in the obese population?
LBW
