Obesity Flashcards
Each gram of fat produces how many calories?
9
Where does obesity stand as a leading cause of preventable death?
Only second to smoking
Which type of fat accumulation is associated with an increased risk of ischemic heart disease?
Android obesity
“Apple shape”
**more common in men
Which type of obesity is associated with a pear?
Gynecoid
Associated with the development of joint disease and varicose veins
**more common in women
What is metabolic syndrome?
Several disease states that coincide with obesity
fasting plasma > 110
Abdominal obesity (> 40 in men and > 35 in women)
Serum triglyceride > 150
HLD < 40 in men and < 50 in women
BP > 135/85
What BMI is considered underweight?
< 18.5
What is considered a normal BMI?
18.5-24.9
What BMI is considered overweight?
25-29
What BMI is considered obesity class 1?
30-35
What BMI is considered obesity class 2?
35-40
What obesity is considered obesity class 3?
> 40
What child body weight class is considered overweight?
85th to the 94th
What child body weight class is considered obese?
95-98th
What child body weight class severely obese?
99th
What body weight describes the BMI associated with the lowest risk of body weight-related comorbidities?
Ideal body weight
What type of resp defect does obesity present?
Restrictive ventilatory defect
What is FRC in relation to BMI?
Inversely proportional
How does obesity affect lung volumes?
Decreased vital capacity
Decreased total lung capacity
Decreased FRC
Normal residual volume
Decrease expiratory reserve volume
How does obesity affect ventilatory defect?
Decreased lung compliance > decreased PaO2 (no real change in PaCO2) > increased O2 consumption and increased CO2 production
How does the extra weight on the obese chest affect breathing?
Increases WOB > rapid shallow breaths provide the most energy efficient way to achieve this goal
What is the optimal position for an obese individual during DL?
Head elevated laryngoscopy position (HELP)
*should be a horizontal line from the sternal notch to the external auditory meatus
How does obesity affect circulation?
Increased adipocytes ^ vasculature demand ~ necessitates an increased blood volume and cardiac output
How much does cardiac output increase per kilogram of fat?
100 mL/min
How does obesity (an an increased blood volume) affect the heart?
Causes diastolic syndication due to increase walk thickness to compensate for increased wall stress
How should you calculate perioperative fluid requirements?
Based on patients lean body weight
Why does obesity stimulate HTN?
Hyperinsulinemia
SNS
RAAS activation
Atherosclerosis
Elevated cytokine concentration
What are some EKG associated with obesity?
> Low voltage EKG (increased distance from leads)
Left axis deviation (LV hypertrophy)
right axis deviation ( RV hypertrophy)
QT prolongation
ischemia (O2 supply/demand mismatch)
dysrhythmias (fatty infiltration if conduction system)
How pharmacodynamic and pharmacokinetic factors change in relation to obesity?
Increased volume of distribution for lipophilic drugs
Increased volume of distribution for hydrophilic drugs
**higher cardiac output hastens IV drug delivery to the site of action (shortens circ time)
How do you determine lean body weight?
IBW x 1.3
What type of volatile agents should be used in the obese?
Agents with the lowest blood:gas coefficients
Sevo and Des are faster emergence than Iso or propofol
How does you dose propofol?
LBW: induction
TBW: maintenance
How does you dose sux?
TBW: ONLY for induction
How does you dose roc/vec?
LBW: for intubation and maintenance
How does you dose cisatracurium/Atracurium?
TBW: loading and maintenance
How does you dose fent?
LBW: maintenance
TBW: loading
How does you dose Remi?
LBW: both loading and maintenance
How does you dose versed?
TBW: both loading and maintenance
How does you dose local anesthetics?
75% of normal dose
Which muscle opens the nasopharynx?
Tensor palatine
Which muscle opens the oropharnx?
Genioglossus
Which muscle opens the hypopharynx?
Hyoid muscles
What is OSA defined as?
Cessation of airflow for at least 10 seconds with 5 or more unsuccessful efforts to breath (obstruction) and a > 4% reduction in SaO2
What is hypopnea defined as?
A 50% reduction in airflow for 10 seconds 15 or more times per hour.
What factors increase the likelihood of OSA?
BMI> 30
Abdominal fat distribution
Large neck girth > 17 inches in men and > 16 inches in women
What is OSA an independent risk factor for?
HTN, Cardiovascular morbidity , and death
What is considered a mild apnea/hypopnea index?
5-15 episodes per hr
What is considered a moderate apnea/hypopnea index score?
15-30 episodes/hr
What is considered a severe apnea/hypopnea index?
> 30 episodes/hr
What is the classic triad of dysfunctional sleep?
Apnea o snoring with hypopnea during sleep
Arousal from sleep
Daytime somnolence
What is the definite test for OSA?
Polysomnography
What STOP-BANG score is considered a high risk for OSA?
> 3
What STOP-BANG score is considered a low risk for OSA?
< 3 questions answered yes
What is the STOP-BANG score?
S: snoring
T: tiredness
O: observes apnea
P: pressure (BP)
B: BMI
A: age (> 50)
N: neck circumference (> 40 cm)
G: gender (male > female)
What is obesity Hypoventilation syndrome?
Long-term consequence of untreated OSA
“Also called pickwickian syndrome)
What is the classic presentation to obesity Hypoventilation syndrome?
Apnea during sleep WITHOUT resp effort ~ resp center in medulla fails to respond to hypercarbia
What is the diagnostic criteria for obesity Hypoventilation syndrome?
BMI> 30
Awake PaCO2 > 45
Dysfunctional breathing during sleep
What are some of the signs of obesity Hypoventilation Syndrome?
Obesity
Hypersomnolence
Hypoxemia
Hypercarbia
Resp acidosis
Polycythemia
Pulmonary HTN
RV failure
What is the MOST sensitive sign of an anastomotic leak following gastric bypass?
Unexplained tachycardia
What is the most effective treatment for reversing obesity?
Bariatric surgery
What is a malabsorption approach to surgical weight loss?
Examples: jejunoileal bypass, biliopancreatic diversion, duodenal switch
> Points: gastric removal and removal of a portion of the small intestine
> limits nutrient absorption
> patient at risk for Vitamin K, B12, iron, and folate depletion.
What is a restriction surgical approach to surgical weight loss?
Examples: gastric band, sleeve gastrectomy
> Points: limits quantity of food
least invasive procedure
nutrient absorption is still good
reduced gastric hormone secretion
What is a combination surgical approach to surgical weight loss?
Examples: Roux-en-Y gastric bypass
> points: combination of malabsorption and restrictive
yields the best weight loss and improvement in comorbidities
risk of nutrient deficiency
What are the most common signs of an anastomotic leak?
Tachycardia (most)
Fever
Abdominal pain
What is the most significant risk factor for the development of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis?
Obesity
What is Ma Huang?
Appetite suppressant
**Natural source of ephedrine
(HTN, CVAs, seizures, adrenergic overstimulation)
What is Orlistat?
Lipase inhibitor ~ hinders absorption in and digestion of fats.
Fat solublevitamins (DAKE) must be supplemented orally
What is sibutramine?
Norepinephrine and serotonin inhibitor
used for appetite suppressant
***risk of serotonin syndrome
