Anesthesia implications for obesity Flashcards

1
Q

Factors that influence obesity

A

Influenced by;
metabolic factors,
hormones,
neural regulation and
pathologic syndromes in addition to behavioral, cultural, and
socioeconomic factors

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2
Q

BMI equation

A

Patient weight (kg)/ height2 in meters = kg/m2

created by insurance companies to calculate risk

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3
Q

What does BMI not differentiate between

A

Overweight and overfat

Waist circumference, waist-hip ration, age

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4
Q

Android fat distribution

A

“central” obesity
Upper body (truncal)
Associated with ↑ oxygen consumption/cardiovascular dz

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5
Q

Gynecoid Fat distribution

A

“peripheral” obesity
Hips, buttocks, thighs
Less metabolically active
Not really associated with CV disease (genetics)

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6
Q

Total blood volume ____ in obesity

A

increases

On a volume-to-weight ratio is lower 50ml/kg

Most distributed to adipose tissue

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7
Q

CO is ____ in obesity because of ______

A

increased
d/t LV dilation and ↑ stroke volume

20-30ml/kg of excess body fat

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8
Q

Increase in cardiac dysrhythmias is due to____

A

d/t fatty infiltrates of conduction system, CAD,

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9
Q

EKG changes with obesity

A

Low QRS voltage; because of increased impedence,

LVH,
left axis

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10
Q

Hematologic changes with obesity

A

↑er levels of fibrinogen, factor VII, VIII, von Willebrand —-> Hypercoagulability

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11
Q

Endothelial dysfunction in obesity is due to_____

A

higher levels of factor VIII and von Willebrand

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12
Q

Gastric considerations for obesity

A

Gastric volume and acidity are increased -> Intragastric pressure increases -> Relaxation of LES and hiatal hernia formation (increased)

Delayed gastric emptying

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13
Q

Gastric levels and ph for risk of pneumonititis

A

Volume > 25 ml and pH < 2.5…levels for aspiration pneumonitis

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14
Q

Hepatic changes with obesity

A

Hepatic function/drug metabolism is altered
decreased albumin in circulation

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15
Q

RBF _____ with obesity

A

increases (Glomerular hyperfiltration)

will then have a drop off as the kidneys dont perfuse as well

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16
Q

Increased renal tubular reabsorption results in what? (2)

A

Impairs natriuresis

Activates renin-angiotensin system

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17
Q

Increased level of SNS activity in obesity results in what? (4)

A

Insulin resistance…impaired glucose metabolism

Enhanced pressor activity of norepi and angiotensin II

Sodium retention

Thyroid hormone resistance

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18
Q

Hypothyroidism prevalence in obesity

A

Hypothyroidism in 25% of morbidly obese patients

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19
Q

Metabolic syndrome (8)

A

*Abdominal obesity; (Uses waist circumference (not BMI))

*Decreases levels of HDL

*Hypertriglyceridemia

Hyperinsulinemia

*Glucose intolerance

*Hypertension

Proinflammatory state

Prothrombotic state

  • at least 3 must be present for diagnosis
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20
Q

Risk factors for metabolic syndrome (3)

A

Increased age

Men > women

Hispanics and South Asians

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21
Q

Metabolic syndrome may result from ____, ____,_____,____

A

May result from chronic corticosteroids, antidepressants, antipsychotics, protease inhibitors

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22
Q

Metabolic syndrome results in increased risk of ________ (5)

A

Cardiovascular disease

Type 2 diabetes mellitus

Polycystic ovary syndrome

Nonalcoholic fatty liver disease

Improper immune responses

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23
Q

OSA dx (4)

A

Complete cessation of breathing

Lasting 10 seconds or >

5x or > each hour of sleep

Decreased sat 4%

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24
Q

Hypopnea dx (4)

A

Reduction in airflow 50% or >

Lasting 10 seconds or >

15 x or more/hour of sleep

Decreased sat 4%

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25
Q

name for Sleep study

A

polysomnography

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26
Q

apnea/hypopnea index (AHI)= total # of events/total sleep time

ranking for mild, moderate, severe

A

Mild: 5-15/hr
Moderate: 15-30/hr
Severe: > 30/hr

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27
Q

Treatment (CPAP, weight loss) required for mod/severe disease OSA d/t risk of (4)

A

Systemic/Pulmonary hypertension

LVH

Cardiac dysrhythmias

Cognitive impairment

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28
Q

Obesity hypoventilation syndrome other name

A

Pickwickian syndrome

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29
Q

Obesity hypoventilation syndrome results from _____

A

Results from long-term OSA…5-10% of morbidly obese

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30
Q

Obesity hypoventilation syndrome results in______(2)

A

Pulmonary hypertension
Cor pulmonale

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31
Q

Dx of Obesity hypoventilation syndrome (2)

A

BMI > 30 kg/m2
Awake hypercapnia

32
Q

Phentermine factors (4)

A

Sympathomimetic which ↓ appetite

FDA approved for only 3 months

Tachycardia, palpitations, hypertension, dependence, abuse

No longer in combo with Fenfluramine (caused valvular disorders)

33
Q

Orlistat factors (4)

A

Blocks absorption of dietary fat

Liquid stool, oily spotting, fecal urgency, flatulence, abdominal cramps

Fat soluble vitamin deficiencies with chronic use

Possible Vit K deficiency…prolonged PT

34
Q

when to stop taking Phentermine and what are the side effects if not

A

tachycardia and hypotension

stay off for 2 weeks

35
Q

OTC Herbals on obesity factors (4)

A

Pancreatic lipase inhibitors…caffeine, green tea

Appetite suppressors…ginseng, ephedra, sunflower oil

Energy stimulants…acai berry

Regulate lipid metabolism…soybean, fish oil, oolong tea

36
Q

GLP-1 Agonists

A

Results in delayed gastric emptying

37
Q

Glucagon-like Peptide-1 Receptor Agonists for Adults names

A

Dulaglutide
Exenatide (IR)
Liraglutide(1.2 mg1.8mg)
Semaglutide
Semaglutide

38
Q

Trulicity

A

Dulaglutide

39
Q

Byetta

A

Exenatide (IR)

40
Q

Victoza

A

Liraglutide

41
Q

Ozempic, Wegovy

A

Semaglutide

42
Q

Rybelsus

A

Semaglutide

43
Q

When to hold GLP1-agonists

A

For patients on daily dosing consider holding GLP-1 agonists on the day of the procedure/surgery. For patients on weekly dosing consider holding GLP-1 agonists a week prior to the procedure/surgery

44
Q

If GLP1 - agonists are presceibed for dm management are held ______

A

If GLP-1 agonists prescribed for diabetes management are held for longer than the dosing schedule, consider consulting an endocrinologist for bridging the antidiabetic therapy to avoid hyperglycemia.

45
Q

If pt shows up day of with these symptoms you should delay the case

A

severe nausea/vomiting/retching, abdominal bloating, or abdominal pain are present

46
Q

If the patient has no GI symptoms, but the GLP-1 agonists were not held as advised_____

A

rsi for full stomach

US to eval gastric volume

47
Q

Gastric volume scanning with obese pts

A

depth of 7 instead of 3 cm

CSA of gastric antrum may be bigger but still 1.5 ml/kg (useIBW)

48
Q

Preoperative evaluation focuses on evidence of ______ (4)

A

-Hypertension
-Diabetes
-Heart failure
-Hypoventilation syndrome

49
Q

If they use cpap ________ suggest difficult mask ventilation

A

CPAP usage of > 10cm H2O suggests difficult mask ventilation

consider doing awake intubation

50
Q

Surgical history with obesity to consider

A

-Compare past/current weight
-Ease/difficult intubations
-Intravenous access
-Need for ICU admission
-Surgical outcomes

51
Q

Medications to dc with obese pts

A

antihypertensives,
insulin,
oral hypoglycemics

52
Q

Respiratory volumes changes with obesity

A

⬇️ vital capacity
⬇️ inspiratory capacity
⬇️ expiratory reserve volume
⬇️ functional residual capacity
Low compliance
Closing capacity is close to or within tidal breathing (especially when supine/recumbent)

53
Q

Supine considerations for obesity

A

Ventilatory impairment
Compression of IVC and Ao

Reports of rhabdomyolysis on gluteal muscles
(Leads to renal failure/death)

54
Q

Prone considerations for obesity

A

Cushioning pads may have excessive pressure

Skin breakdown, tissue necrosis/infections

55
Q

Lateral decubitus considerations with obesity

A

Dependent hip pressure ulcers

Impossible or unnecessary to place axillary rolls

Favored over prone

56
Q

Lithotomy considerations with obesity

A

Regular stirrups may not support weight

Tissue compression/compartment syndrome

57
Q

Airway assessment in obesity can have increased adipose depositing into ______ (6)

A

Uvula
Tonsils
Tonsillar pillars
Tongue
Aryepiglottic folds
Lateral pharyngeal walls

58
Q

The oropharynx can change into an _____ in obestiy

A

Changes oropharynx into an ellipse

Short transverse/long AP axis

59
Q

Inverse relationship between degree of obesity and_______ area

A

pharyngeal

60
Q

Predictors of difficult intubation (4)

A

Small mouth opening
Large/protuberant teeth
Limited neck mobility
Retrognathia

BMI not necessarily an independent predictor

61
Q

Desaturation to 90% with Normal vs obese

A

Normal BMI: 6 minutes
Morbidly obese BMI: less than 3 minutes

62
Q

In an effort to prevent atelectasis and desaturation you should _______

A

CPAP during preoxygenation… 10cm (close apl)

Positioning 25-30 degrees head up for obese patients.30 degrees reverse Trendelenburg even better

Recruitment maneuvers then PEEP 10cm

Mechanical ventilation after induction

63
Q

Aspiration Prophylaxis with identifiable risk factors in Obesity (4)

A

Histamine receptor agonists

Proton pump inhibitors

RSI

Awake fiberoptic intubation

64
Q

Advantages of regional anesthesia in obesity

A

Less airway manipulation

Fewer cardiopulmonary depressants

↓ chance of PONV

Better postop pain control (at least initially)

65
Q

Technical difficulties with regional anesthesia in obesity

A

Longer needles
Different ultrasound probes

Smaller doses (epidurals) d/t smaller space…cephalad spread

Higher rates of block failure

Higher rates of hypotension after block d/t IVC/Ao compression

66
Q

BP falsely ____ if cuff is too small

A

elevated

67
Q

Bp cuff bladder should circle at least ____ of circumference

A

75%

68
Q

Opioids, Propofol, Benzodiazepines on obese pts

A

Exaggerated responses (especially in pts with OSA)

Decrease pharyngeal musculature

Decreased airway patency

69
Q

Meds favored for OSA

A

Short acting…remi/fentanyl most favored

α2 agonists…dexmedetomidine

70
Q

Volatiles on obesity

A

Diminish ventilatory response to CO2

Nitrous not favored d/t high oxygen demand in pts

71
Q

Drugs based on IBW

A

Propofol
Vecuronium
Rocuronium
Remifentanil

72
Q

Drugs based on TBW (hydrohilic)

A

Midazolam
Succinylcholine
Cisatracurium
Fentanyl
Sufentail

73
Q

Drug dosing is based on _____ of the drug

A

lipid solubility

74
Q

Favored volatile for Obesity

A

Based on tissue solubility
Desflurane probably favored

75
Q

Obese are more likely to becomes what temperature?

A

hypothermic (larger body habitus exposed)

76
Q

Postoperative management for obese pts

A

-sit up
-fully reverse nmB
-Pressure support mode during emergence
-Continue home levels of CPAP
-Non-opioid or opioid sparing
-Consider when/where cases are done

77
Q

non opioid analgesia for obese pts

A

Tramadol, dexmedetomidine, ketamine, clonidine