Bariatric Anesthesia

Question 1

American Heart Association defines obesity as body weight what percent greater than the ideal body wt?

Answer 1

30%

Question 2

Is obesity a disease?

Answer 2

Yes

Question 3

BMI equation?

Answer 3

Wt (kg)/ht(m)^2

Question 4

Overweight classification:

Answer 4

> 25

Question 5

Obesity classification:

Answer 5

> 30

Question 6

Extreme obesity classification:

Answer 6

> 40

Question 7

Which BMI has coexisting comorbidities?

Answer 7

35

Question 8

Super obese pt classification:

Answer 8

> 50

Question 9

Obesity class 3 BMI

Answer 9

> 40

Question 10

Obesity class 2 BMI:

Answer 10

35-39.9

Question 11

Obesity class 1 BMI:

Answer 11

30-34.9

Question 12

Overweight BMI:

Answer 12

25-29.9

Question 13

Normal BMI:

Answer 13

18.5-24.9

Question 14

For every 13.6 kg fat wt gain how many miles is that?

Answer 14

25 miles of neovascularization

Question 15

0.1 L/min CO increase for how much of fat?

Answer 15

Every 1 kg of fat

Question 16

Sympathetic activation contributes to obesity induced Na retention and HTN bc why?

Answer 16

Adrenergic blockade or renal denervation

Question 17

What plays a key role in mediating obesity HTN?

Answer 17

Excess renal Na reabsorption

Question 18

Recent observations suggest that what may be a partial link between excess wt gain and increased sympathetic activity?

Answer 18

Leptin and its multi interactions with other neuro chemical pathways in hypothalamus

Question 19

What is the key role in the elevation of SNS?

Answer 19

Leptin

Question 20

Does insulin stimulate SNS?

Answer 20

Yes

Question 21

The ‘satiation hormone’ is made by adipose cells that helps to regulate energy balance by inhibiting hunger

Answer 21

Leptin

Question 22

Leptin is opposed by the actions of the what other hormone?

Answer 22

Ghrelin (hunger hormone)

Question 23

What do leptin levels in hypothalamus do in response to fasting and evoke profound changes in energy balance and hormone levels?

Answer 23

Fall rapidly

Question 24

Adipose tissue source of pro-inflammatory molecules (4)

Answer 24

1. Leptin
2. Tumor necrosis factor alpha
3. Ang II
4. Interleukin-6

Question 25

What is an important predictor of DM?

Answer 25

Decreased secretion of adiponectin

Question 26

What is a signal-averaged ECG?

Answer 26

More detailed type of ECG

Question 27

Restrictive lung disease is accentuated by what 2 positions?

Answer 27

Supine and trendelenburg

Question 28

Normal neck circumference equation:

Answer 28

Ideal wt (kg)/ 2

Question 29

If normal neck circumference is increased by how much then will be difficult intubation?

Answer 29

13%

Question 30

Severely obese TBW is how much?

Answer 30

40%

Question 31

Estimated blood volume in obese pt is?

Answer 31

45-55 actually body wt

Question 32

4 facts of volume replacement:

Answer 32

1. Avoid rapid rehydration 2. Administer colloids at recommendations of IBW (20ml/kg) 3. Albumin 5% and 25% 4. Replace blood loss with crystalloid (3:1 ratio)

Question 33

Obese pts have a lower incidence of what stomach contents compared with lean pts?

Answer 33

High volume, low pH

Question 34

After how long of a fast does obese pts have larger volumes of gastric content?

Answer 34

9 hrs

Question 35

Your obese pts should be drinking clear liquids until what time before surgery?

Answer 35

2 hrs

Question 36

What should be used with risk for aspiration pneumonitis?

Answer 36

Consider H2 antagonists (cimetidine, ranitidine)

Question 37

What limited mobility do obese pts have? (2)

Answer 37

1. TM joint | 2. Atlanto-occipital

Question 38

FRC in obese pts?

Answer 38

Greatly decreased and direct inverse relationship between BMI and FRC

Question 39

Tidal volume should be accorded to what wt?

Answer 39

IBW (5-7 ml/kg) bc lungs aren’t bigger

Question 40

What should the rate be put at on machine for obese pt?

Answer 40

Increased rate

Question 41

An increase in Vd dose what to half life?

Answer 41

Prolongs the elimination half-life, despite increased clearance

Question 42

There is a significant increase in volume of distribution for a number of what type of drugs?

Answer 42

Highly fat soluble (benzodiazepines and barbiturates)

Question 43

Highly fat soluble drugs should be dosed in what wt?

Answer 43

TBW

Question 44

In obese pts there is a little or no change in volume of distribution to which drugs?

Answer 44

Less fat soluble (NMB agents)

Question 45

What should less fat soluble drugs be dosed in wt wise?

Answer 45

LBW (or IBW+20%)

Question 46

What the the one exception to less fat soluble drugs being dosed in LBW?

Answer 46

Sux should be dosed to TBW

Question 47

Local anesthetic doses should be reduced by how much for subarachnoid and epidural blocks?

Answer 47

25%

Question 48

Some drugs are cleared more rapidly in obese pts and why is this?

Answer 48

Higher CO and splanchnic BF

Question 49

Males IBW equation:

Answer 49

50kg + 2.3kg for each inch over 60

Question 50

Females IBW equation:

Answer 50

45.5 (kg) +2.3kg for each inch over 60

Question 51

Propofol dosing should be in what for induction and infusion?

Answer 51

Induction: IBW Infusion: TBW

Question 52

What should sux be dosed at?

Answer 52

TBW

Question 53

What should vec and roc be dosed at?

Answer 53

IBW

Question 54

What should cisatracurium be dosed at for loading and maintenance?

Answer 54

TBW loading, IBW maintenance

Question 55

Fentanyl, sufentanil, remi should be dosed at what?

Answer 55

IBW

Question 56

What position is poorly tolerated in obese pts?

Answer 56

Prone

Question 57

Watch position keeps abdominal wt off chest?

Answer 57

Lateral decubitus

Question 58

What is semi-Fowler’s semi-recumbent position?

Answer 58

Upper body elevated 30-40 degrees that is best position during post op period

Question 59

How should morbidly obese pts NEVER lie?

Answer 59

Flat

Question 60

What is the best intraop position?

Answer 60

Reverse trendelenburg

Question 61

Reverse trendelenburg may be better solution than what other 2 options?

Answer 61

Large TV and PEEP

Question 62

Postop analgesic techniques?

Answer 62

NSAIDS instead of narcotics

Question 63

Pulmonary emboli occur in what percent of obese pts who undergo surgery?

Answer 63

5-12%

Question 64

Alpha 2 agonist, clonidine, tizanidine, and dexmedetomidine cause what in obese pts?

Answer 64

Hypotension and bradycardia

Question 65

What form is best when taking acetaminophen?

Answer 65

Orally