principles-obesity

Question 1

1. a bmi of what is defined as MORBID obesity?
2. a normal BMI=?
3. a BMI of what is obese?

Answer 1

1. morbid obesity BMI= 40 kg/m2 or greater
2. normal BMI= <25kg/m2
3. obese BMI= 30 kg/m2

Question 2

2 ways to calculate IBW

Answer 2

1. IBW=height in cm-100 (men)
   & height in cm-105 (women)
2. IBW=100 lbs +5 for every inch over 5’ tall (women)
   & 105 lbs +5 for every inch over 5’ tall (men)

Question 3

obesity stats:

1. what % of americans adults >20 y/o are obese?
2. what % of adolescents?

Answer 3

1. 33.4% of adults >20 y/o

2. 25% of adolescents

Question 4

1. when is fat cell formation most rapid?

2. what diseases is fat gain related to on linear scale?

Answer 4

1. fat cell production most rapid in childhood

2. linear relationship with cv disease, cancer, diabetes & obesity

Question 5

1. how is obesity arbitrarily defined?
2. morbid obesity?
3. what % of population fits these catergories?

Answer 5

1. 20% over IBW
2. 2x IBW
3. 10-15% of population is obese or morbidly obese

Question 6

define:

1. grade I obesity:
2. grade II obesity:
3. grade III obesity:

Answer 6

1. 25-29 kg/m2 BMI (Men:25% body fat; women 39% body fat)
2. 30-39.9 kg.m2 BMI; moderate risk of disease
3. 40 or more: highest risk of mortality

Question 7

1. what health issues are common with obese?

2. obesity increases chance of what tumors?

Answer 7

1. obese prone to t2DM, CAD,HTN, IDDM & hypercholesterolemia

2. higher incidence of breast, GI & endometrial tumors in obese

Question 8

define:

1. android obesity: what does it cause?

2. gynecoid obesity: why is it better than android?

Answer 8

1. android obesity: fat centrally/ truncal located. fat is more metabolically active and goes to heart (increased CV disease), and higher o2 consumption
2. gynecoid obesity: more buttocks and thighs, less metabolically active fat, less CV disease risk

Question 9

respiratory issues with obese:

1. ___ vO2 (volume of o2)
2. ___CO2 ________:
3. ____O2________:
4. why does this happen?

Answer 9

1. increased VO2
2. increased CO2 production
3. increased O2 consumption
4. fat is metabolically active, so there is increased o2 demand, increased energy expenditure with a decreased O2 reservior so they need to take in more o2

Question 10

resp effect of obesity:

1. ____chest wall compliance, lung compliance ____ _____:
2. in upright position residual volumes ____ _____:

Answer 10

1. DECREASED ;REMAINS UNCHANGED

2. REMAIN NORMAL.

Question 11

1. ___ and ___ are reduced so that Vt may fall within range of closing volumes.
2. this leads to ensuing____ or _________, which ultimately leads to _____.

Answer 11

1. EXPIRATORY RESERVE VOLUME ;FUNCTIONAL RESIDUAL CAPACITY

2. VQ abnormalities ; Left to right shunt; hypoxemia

Question 12

resp effects of obesity:
1. in supine position ___ falls further within ____ ____
2. this causes ___ _____
3. the normal decrease in FRC in nonobese persons with anesthesia is ____%
in the obese it is a ___% decrease

Answer 12

1. FRC; closing capacity
2. worsening hypoxemia
3. 20%; 50%

Question 13

sleep apnea leads to what conditions?

Answer 13

1. depressed CNS responsiveness to chronic hypoxia leads to
2. hypercarbia and acidsis and polycythemia
3. this leads to CAD and stroke

Question 14

1. sleep apnea is common in approx___ of obese patients.
2. females___males
3. increased icidence of _____, _____,______

Answer 14

1. 1/3
2. less
3. HTN, CAD, chronic hypoxia

Question 15

1. what % of obese have obese hypoventilation syndrome?
2. what is it?
3. s/s:
4. airway issues:
5. changes in alveolar ventilation d/t____:

Answer 15

1. 8%
2. Loss of hyperbaric drive, long term s/e of sleep apnea
3. hypersomnolence
4. potential or overt difficult airway
5. alveolar ventilaton is reduced d/t shallow or inefficient ventilation

Question 16

pickwickian syndrome

1. what is it?
2. how does it develop
3. what are clinical signs and symptoms?
4. what physical attributes are indicators?

Answer 16

1. pulmonary hypertension
2. develops with increased obesity
3. hypercapnia, cyanosis induced polycythemia, right sided or biventricular heart failure, daytime somnolence, blunted respiratory drive, loud snoring, obstructive sleep apnea (5%) for more than 10 seconds.
4. large abdomen girth and large kneck circumference are indicators

Question 17

cardiovascular issues with obesity

1. changes in c.o., workload, blood volume, vascuature?
2. reasons?

Answer 17

1. increased cardiac workload, c.o. and blood volume d/t having to perfuse fat (fat needs 2-3ml/100g tissue), also increase in blood vessels to perfuse fat.
2. increased cardiac output is d/t increased stroke volume (C.O. increases 0.1 l/min) d/t increased o2 demands form girth
3. blood volume increases (polycythemia) from hypoxia d/t chronic respiratory insuffeciency

Question 18

1. what does increase stroke volume lead to?
2. what does increased pulmonary blood flow lead to?
3. what does central distribution of fat lead to in heart and in blood?

Answer 18

1. arterial hypertension and left ventricular hypertrophy or cardiomegaly d/t biventricular dilation and hypertrophy
2. increased pulmonary artery vasoconsriction from persistant hypoxia lead to pulm hypertension and cor pulmonale
3. CAD from increased circulating fat and increased fat infiltration into heart (cor-adiposum)which interferes with impulse conduction

Question 19

effects of obesity:

1. blood pressure-how much of a change /increase in weight, how common is it in obese?
2. changes in insulin production, this causes what sympathetic response ?
3. dyslipidemia is a _____ state leading to CAD, HTN, DM
4. CAD occurs how much sooner in men than women?

Answer 19

1. bp increases 6.5 mmhg per every 10% increase in body weight
   HTN has 50-60% occurence in obese.
2. increased circulation of cateholamines which leads to increased Na+, Ca++ reabsorption and hypervolemia
3. chronic inflammatory
   4.10-20 years earlier

Question 20

endocrine changes with obesity:

1. Increased abdomen girth leads to what GI issues?
2. why are obese considered “full stomach” and RSI?
3. what about chances of cholecystitis?
4. what about liver issues?

Answer 20

1. increased hiatal hernia, increased intra abdominal pressure, increased reflux and decreased gastric emptying
2. 90% of obese have >25cc gastric fluid with <2.5 pH
3. 30% increase in gall stones d/t increased bile salts
4. increased fatty liver

Question 21

glucose tolerance changes:

1. what happens?
2. what resolves it?
3. what blocks insulin release?

Answer 21

1. increased adipose leads to increased resistance of periphreal tissues to insulin effect causing insulin resistance & DM)
2. resolved by weight loss in 50% of persons
3. android fat disposition (metabolically active) releases more faty acids which go to liver which leads to gluconeogenesis (this inhibits insulin release).

Question 22

what is APGAR?

Answer 22

acute post gastric reduction surgery neuropathy- causes vomiting, hyporeflexia and muscle weakness

Question 23

how does obesity influence drug pharmokinetics

Answer 23

increased blood volume, increased cardiac output, decreased total body water, altered protein binding and lipid solubility of the drug (gets stuck in all that fat) all alter volume of distribution

Question 24

what delays hepatic clearance

Answer 24

chf (backs up to liver), and decreased hepatic blood flow

Question 25

renal clearance changes?

Answer 25

may increase; GFR may increase (>40%), may cause segmental glumerular sclerosis and proteinuria with decreased renal function

Question 26

dosing medications

Answer 26

dose on ideal body weight initially, titrate next doses to response

Question 27

volitile agents and obese

Answer 27

obesity has no effect on awakening

Question 28

if your patient is over 100 lbs over IBW, what should you be considering as far as labs and airway?

Answer 28

1. patient may be difficult to mask when sedated, ? awake intubation, RSI or fiberoptic (especially with poor malanpati) 2. do they need glucose, ekg, labs

Question 29

1. what pre op actions are more difficult in obese patients 2. what OTC medications might obese persons be on that you should be aware of 3. how should the side effect of this be treated?

Answer 29

1. iv access regional landmarks 2. herbs/ diet pills (can lead to catecholamine depletion (hypotension)-should hold 2 weeks prior) 3. treat hypotension with phenylephrine

Question 30

when assessing an obese patient, what considerations should be taken into account?

Answer 30

mask ventilation/ intubation difficulties gerd prophylaxis bed size (can it hold the patient) and positioning (will you need more ramps) bp cuff size and placement

Question 31

assessment of obese person: | cardiac

Answer 31

``` assess for: LVH or RVH on ekg, prolonged QT, ischemic heart disease, consult cardiology if need be ```

Question 32

obese person: | respiratory assessment

Answer 32

``` look for orthopnea, tripod position, hypoventilation syndrome (with questionaire), sleep apnea may need : cxr, pulmonary consult, ABGs ```

Question 33

obese person assessment: | GI:

Answer 33

``` risk of regurg d/t increased gastric volume from slower motility and increased gastric pressure, also increased ph give reglan 10 mg pepcid 20mg or zantac 50 mg bicitra 30 cc (all 1 hour prior to surgery) possible glucose check hgb A1c <7% increases surgical risk cbc, lipids, LFTs, coags, lytes ```

Question 34

airway assessment in obese

Answer 34

``` airway assessment -"any difficulties" with past intubations, neck girth, malmampati score, limited mouth opening, fat pad on back of neck limits neck extension, redundant tissue in mouth, short mandible distance, limited TMJ and allanto-occipital joint ```

Question 35

surgical treatment of obesity:

Answer 35

gastric banding gastroplasty with roux-en-Y gastroenterostomy gastric sleeve

Question 36

1. what is a gastroplasty with roux-en-y? | 2. what are side effects? how much weight can be lost?

Answer 36

1. gastric antrum (distal stomach)and proximal small intestine are almost completely bypassed, the proximal jejunum is connected to a small part of gastric fundus (proximal stomach) 2. - decreased digestive time leads to dumping syndrome - decreased intake leads to nutrient malnutrition - 55-65% weight loss

Question 37

criteria for gastric bypass et:

Answer 37

- less than 65 y/o - 100 lbs over IBW - previous attempt - r/o psych issues - physiological eval - agree to long term follow up morbidity rte 10-15%

Question 38

anesthetic management:

Answer 38

- GETA (especially if really obese) if short GYN case and patient is "chubby, LMA is ok). - regional may be difficult - ramp the bed - large BP cuff - large body surface cools quick (bair hugger) - OR table extenders - ramping with blankets

Question 39

how to dose medications: 1. fat slouble drugs based on what body weight? why? 2. what fat soluble drug should you base on lean body weight intitially, then bolus by total body weight?

Answer 39

1. fat soluble=total body weight (TBW) due to increased volume of distribution into fat cells 2. propofol =LBW initially, then TBW for maintainance

Question 40

water soluble drugs: 1. what body weight to base dose on? 2. why? 3. what water soluble drug goes against the rule of thumb?

Answer 40

1. water soluble=IBW (ideal body weight) since they have a small volume of distribution (cannot pass thru lipid membranes). 2. succinylcholine is highly water soluble but must be dosed on TBW for intubation

Question 41

spinal anesthesia in the obese: 1. how to dose : 2. why?

Answer 41

1. reduce spinal and epidural amount by 20-25% 2. due to epidural fat, abdominal pressure and distended epidural veins, there will be a higher spinal if the amount is not adjusted.

Question 42

best 2 choices for intubation of obese:

Answer 42

1. awake with fiberoptic (best option) | 2. RSI (only after careful consideration)

Question 43

1. best VA for obese? | 2. why?

Answer 43

1. desflurane is best metabolized (,.02% is excreted in kidneys); sevo has fluoride compound metabolites-bad for kidneys (no delay in emergence in obese though)

Question 44

narcotic management of obese: | what are 3 best approaches to pain control

Answer 44

1. front load narcotics to decrease post op pain without side effects (no narcs at the end of the case) 2. epidural for inpatient with anticipated pain issues 3. encourage surgeon to give local keep to minimum to delay post op narcotization

Question 45

muscle relaxats in the obese: | keys to use

Answer 45

fully reverse, avoid if necessary- remember airway issues from re-curization (especially negative pressure pulmonary edema)

Question 46

what is good to prevent atalectasis in obese patiets

Answer 46

1. recruitment manuvers 2. "sigh" program in vent 3. peep on vent 4. pre-oxigenate with peep 5. ventilate with large Vt (15 ml/kg)at rate of 8-10 6. PC vent with 1:1 ratio (longer I time) 7. keep O2 at less than 80% to decrease atalectasis

Question 47

positioning in obese: - pressure points (which are most affected), - for oxigenation and intubation - OR table weight (what is standard limit)?

Answer 47

- pad bony prominences (risk for sciatic and ulnar nerve palsies - ramp patient into sniffing position, sometimes can leave that way throughout case - standard OR bed limit is 300 lbs.

Question 48

1. best emergence for obese? | 2. what can be used in pacu for obese

Answer 48

1. awake (especially if RSI) 2. head up 45 degree to decrease diaphragm pressure, cpap/ bipap (home or hospital) in pacu 3. supplemental O2 (even if sat ok)

Question 49

1. obese have high incidence of respiratory issues with what surgeries (keeping in mind they may already have pickwickian or obesity hypovenilation syndrome) 2. name two DONT'S to obese/obstetrics post op/ respiratory care

Answer 49

1. abdominal and thoracic surgery (including obstetrics) 2. ... - do NOT extubate early - do NOT give late narcotics