Obesity

Question 1

what is better at predicting cardio-respiratory comorbidities than BMI

Answer 1

waist or collar circumference

Question 2

BMI limitations

Answer 2

• not a direct measure of adipose tissue or fat distribution

- inaccurate at height extremes of with lean body mass

Question 3

ideal body weight

Answer 3

IBW (kg) = height in cm - x

x=100 for men, 105 for women

Question 4

lean body weight

Answer 4

total body weight - adipose tissue

LBW=IBWx1.3

Question 5

fat distribution patterns

Answer 5

apple/android: male, correlation with metabolic syndrome, increased morbidity and mortality

pear/gynoid: women, not correlated with metabolic syndrome

Question 6

obesity BMI

Answer 6

> 30

Question 7

morbidly obese BMI

Answer 7

> 40 or >35 with obesity-related comorbidity

Question 8

obesity - cardiovascular changes

Answer 8

• increase in CO (SV), blood volume, arrhythmias, workload on heart which leads to hypertrophy, HTN (blood viscosity, catecholamine and estrogen release)
• hyperinsulinemia: increased levels of norepinephrine and angiotensinogen

Question 9

total body water for obese patient

Answer 9

40%

Question 10

obesity - coagulation changes

Answer 10

• hypercoagulability, increased risk of DVT, CVA
• adipose tissues promote chronic inflammatory state
• increased clotting factors

Question 11

obesity - respiratory changes

Answer 11

• diaphragm cephalad
• decreased: chest wall compliance, lung compliance, FRC, ERV, VC, TLC
• increased: elastic resistance, work of breathing, pulmonary blood volume
• unchanged: residual volume and closing capacity, FEV/FVC

*maintain normocapnia by increasing MV with rapid, shallow breathing

Question 12

obstructive sleep apnea diagnosis criteria and 3 types

Answer 12

->10 seconds, >15 episodes per hour, >4% saturation decrease

1. OSA: respiratory efforts without airflow
2. central sleep apnea: no respiratory efforts
3. mixed

Question 13

STOP BANG - OSA criteria

Answer 13

snoring
tiredness
observed stop breathing
blood pressure
BMI>35
age>50
neck circumference>40 cm
gender=male

• high risk = more than 3
• majority of patients are undiagnosed so it is important to screen

Question 14

Pickwickian syndrome

Answer 14

• obesity hypoventilation syndrome (OHS)
• long term result of OSA
• hypoventilation while awake with PaCO2>45 mmHg

Question 15

obesity - gastric changes

Answer 15

• increased: gastric pressure, GERD, volume, acidity, gallstones, pancreatitis
• decreased: LES tone
• delayed gastric emptying

Question 16

obesity - hepatic changes

Answer 16

• non-alcoholic fatty liver disease leads to cirrhosis: due to adipose tissue, impaired insulin activity, and inflammatory cytokines
• elevated ALT

Question 17

obesity - endocrine changes

Answer 17

• decreased insulin secretion, increased resistance

- hypothyroidism: thyroid hormone resistance in peripheral tissues, increased stimulation hormone levels

Question 18

metabolic syndrome

Answer 18

• abdominal obesity: waist >102 cm in men, >88 in women
• triglycerides: >150 mg/dL
• HDL: <40 mg/dL in men, <50 in women
• BP: >130/85
• fasting glucose: >110 mg/dL

*need 3/5

Question 19

obesity - cancer changes

Answer 19

-3.2% of all new cancers are attributable to obesity

Question 20

obesity pharmacology - lipophilic drugs

Answer 20

• increased volume of distribution, prolonged half life

- do not give much

Question 21

obesity pharmacology - hydrophilic drugs

Answer 21

• volume of distribution unchanged

- dose for IBW

Question 22

obesity pharmacology - dose non-depolarizing muscle relaxants on ____

Answer 22

IBW

Question 23

obesity pharmacology - dose succinylcholine on ____

Answer 23

TBW - due to increased pseudocholinesterase activity

Question 24

obesity pharmacology - dose Propofol induction on ____, maintenance on ____

Answer 24

LBW

TBW, and decrease with time to avoid accumulation

Question 25

obesity pharmacology - dose opioids

Answer 25

initial doses are the same, repeat doses are less predictable

Question 26

categories of bariatric surgery

Answer 26

- gastric restrictive | - restrictive and nutrient malabsorptive

Question 27

s/s of anastomotic leak

Answer 27

- unexplained tachycardia - fever - abdominal pain - shoulder pain - SOB - hypotension - hiccups - restlessness

Question 28

Obesity Surgery-Mortality Risk Score

Answer 28

- BMI>50 - male - HTN - high risk DVT - age>45 0-1: low 2-3: intermediate 4-5: high

Question 29

obesity - estimated blood volume

Answer 29

45-55 mL/kg