Obesity Flashcards
(153 cards)
1
Q
what percent of Americans are obese/overweight?
A
75%
over 210 million people
2
Q
are men or women more obese?
A
women
35% men
40.4% women
3
Q
__ leading cause of preventable and premature death, behind tobacco
A
second
4
Q
BMI
A
the measure of body habitus that describes adiposity normalized for height
5
Q
BMI calculation kg
A
weight (kg) / height (Meters)^2
6
Q
BMI calculation lb
A
(weight (lbs) / height (inches)^2 x 703)
7
Q
IBW
A
- measurement of ht and body mass that exhibits the lowest morbidity and mortality
- important for calculating infusion doses for the obese population
8
Q
lean body weight is increased __ d/t increase in muscle mass needed to carry extra weight
A
30%
9
Q
calculate appropriate dosing for lean body weight
A
men IBW = ht (cm) -100
women IBW = ht (cm) -105
LBW = IBW x 1.3
10
Q
underweight BMI
A
less than 18.5
11
Q
normal BMI
A
18.5 - 24.9
12
Q
overweight BMI
A
25 - 29.9
13
Q
Obesity I BMI
A
30 - 34.9
14
Q
Obesity II BMI
A
35 - 39.9
15
Q
Obesity III BMI
A
greater than 40
16
Q
greatest risk for comorbities
A
men, higher age, higher BMI
17
Q
highest comorbidity risk factors
A
- CV disease
- cancers
- diabetes
18
Q
higher risk for psychological conditions like..
A
depression, anxiety, worthlessness
19
Q
hormonal & nonhormonal mechanisms
A
breast, GI, endometrial, and renal cell cancers
20
Q
major integrative physiologic functions of adipose tissue
A
- protein secreting
- considered an endocrine organ
- provides a reservoir of convertible/usable energy
- insulator
- liver fat metabolism
21
Q
liver fat metabolism
A
- degradation of fatty acid into units of energy
- synthesis of triglycerides from carbohydrates & proteins
- synthesis of fatty acids –> cholesterol & phospholipids
22
Q
each gram of fat provides how many calories?
each gram of carb/protein provides how many calories?
A
9 cal
4 cal
23
Q
2 types of distribution
A
- Central/android/abdominal visceral obesity
- peripheral/gynecoid/gluteal obesity
24
Q
characteristics of central obesity
A
- apple: waist/hip ratio > 0.85 in men & 0.92 in women
- correlated with a higher risk of comorbidities
-waist circumference is a newly established marker for abdominal obesity - waist circumference > 102 cm (40in) in men & 88cm (35 in) in women –> increased risk for ischemic heart disease, dm, HTN, dyslipidemia, death
- destroys the liver more than pear-shape
25
central obesity is more common in men or women?
men, metabolically active (free fatty acid)
26
characteristics of peripheral obesity
- pear: waist/hip ratio < 0.76
- associated with varicose veins, joint disease & reduces the incidence of non-insulin-dependent DM
- medical risks decreased
- more common in women, metabolically static, proposed to function as energy deposits for pregnancy and lactation
27
causes of obesity
both genetic and environment
28
genetic being the primary factor
- prader-willi syndrome
- bardet-biedl syndrome
- obesity "hormone" LEPTIN --> not enough, overeating
29
environmental factors
diet, exercise, lifestyle, within family, money
30
diseases causing obesity
PCOS, Cushing's syndrome, hypothyroidism
31
early childhood fat cell formation occurs __
rapidly
32
children: overfeeding accelerates __ __ and triggers ___ of fat cells
fat storage; hyperproliferation
33
adolescence: number of fat cells __ and remain __ throughout adult life
stabilize; consistent
34
adolesence become obese through __ in fat cell __
increase; numbers
35
adult: become obese through __ of existing cells
hypertrophy
35
CV disease primary cause of the
morbidity & mortality
36
what kind of CV dx?
ischemic heart dx, HTN, cardiac failure
increased CO, O2 consumption, & CO2 production
37
extra fat development ...
increase need for extra blood vessels and increased circulatory, pulmonary, central, and peripheral blood volume
38
for every 13.5 kg of gained fat =
25 miles of neovascularization
39
increase CO of 0.1L/ min per
kg of fat acquired
40
chronically elevated CO -->
increases left-sided heart pressures and LV hypertrophy
41
what will lead to HTN and CHHF?
cardiomegaly, atrial and biventricular dilation, and biventricular hypertrophy ensue
42
HNT is
SBP > 140 & DBP > 90
2x as high in this population
43
BP shown to increase __ for every __% increase in body weight
6.5; 10
44
renal mechanisms are associated with
the development of obesity-related HTN
45
hypercholesterolemia (> __ mg/dL) often coexists with __ --> __ & __
240; HTN; atherosclerosis; CVA's
46
what is frequently associated with obesity but is an independent risk factor appearing with or without HTN, DM, HLD
CAD
more common in those with central fat distribution
47
decrease in respiratory function results from
- compression of fat on abdominal, diaphragmatic, and thoracic structures
- thoracic kyphosis and lumbar lordosis develop --> impaired rib movement and fixation of thorax in inspiratory position --> chest wall, lung, parenchyma and pulmonary compliance decrease by 35%
- metabolic needs & increased work of brething --> increased myocardial O2 consumption
48
increased CO2 porduction & retention & decreased ventilation -->
reduced respiratory muscle effort
49
lung inflation inhibited -->
decline in FRC to less than closing capacity
premature airway closure increases dead space causing CO2 retention , V/Q mismatch, shunting & hypoxemia
50
extreme obesity: __ in FRC, ERV, TLC
decrease
51
FRC __ proportional to BMI
inversley
52
ventilation pattern exhibited those of __ lung disease
restrictive
53
eventual hypoventilation, hpercarbia, and acidosis result from
the depression of central nervous responsiveness to chronic hypoxia
polycythemia --> increased risk of CAD and CVA
54
simply, OSA is __ airway
blocked
55
OSA overview
Increasing in direct proportion to the level of obesity
- tend to have BMI > 30
- abdominal fat distribution
- large neck girth: Men > 17 in^2, women > 16 in^2
characterized by excessive episodes of apnea (10 seconds) and hypopnea during sleep caused by complete or partial obstruction
- apnea is the cessation of airflow at nose & mouth for more than 10 seconds
- hypopnea is 50% reduction in airflow for 10 seconds that occurs 15 or more times per hour of sleep
snoring and 4% decrease in O2 saturation
56
OSA diagnosis
diagnosis done via polysomnography (PSG) using apnea-hypopnea index (AHI)
57
AHI =
number of abnormal respiratory events per hour of sleep
58
american academy defines OSA as:
mild: 5 - 15 AHI
moderate: 15 -30 AHI
severe: > 30 AHI
59
OSA pathogenesis
multifactorial dependent on anatomy, muscle, and ventilatory stability
- upper airway obstruction typically in the pharynx
- the pharyngeal luminal area during respiration reflects a balance between collapsing intrapharyngeal negative suction pressure and dilating forces provided by pharyngeal muscles
60
when awake, patency is maintained by continual mediation of __ of the __ __ in __
contraction; tensor muscles; CNS
61
these dilator muscles __ the negative collapsing force developed during __
oppose; inspiration
62
cardivascular possibilites with OSA
- bradycardia during apneic episodes
- long sinus pause
- second degree heart block
- ventricular ectopy
63
muscle tone activation is __ during sleep (also anesthesia)
reduced
64
whats the percentage of OSA undiagnosed & untreated
80 - 95%
65
OSA patients have a higher incidence of
comorbidities
66
with OSA consider:
1. sleep apnea status
2. anatomical & physiological abnormalities
3. status of coexisting dx
4. nature of surgery
5. type of anesthesia
6. need for postoperative opioids
7. age
8. adequacy of postoperative observation
9. capabilities of OP facility (emergency airway equipment)
67
STOP-BANG
1. Snoring: snore loudly?
2. Tired: often fatigued?
3. Observed: Did you stop breathing during sleep?
4. blood Pressure: high BP
BMI higher than > 35
Age: more than 50 years old?
Neck circumference: greater than 40cm
Gender: male?
high risk of OSA: answering yes to 3 or more items
low risk: answering yes to fewer than 3 items
68
anesthetic concern with patients with OSA:
preoperative concern
- cardiac arrhythmias and unstable hemodynamic profile
- multisystem comorbidites
- sedative premedication
- OSA risk stratification, evaluation, and optimization
69
anesthetic concern with patients with OSA:
intraoperative concern
- regional anesthesia
- difficult intubation
- opioid-related respiratory depression
- carry-over sedation effects from longer-acting intravenous sedatives and inhaled anesthetic agents
- excessive sedation in monitored anesthetic care
70
anesthetic concern with patients with OSA:
reversal of anesthesia
post-extubation airway obstruction and desaturations
71
anesthetic concern with patients with OSA:
immediate postoperative period
- respiratory
- suitability for outpatient surgery
- postoperative respiratory event in known and suspected high-risk patients with OSA
72
Pickwickian syndrome
- AKA obesity hypoventilation syndrome (OHS)
- characterized by OSA, hypercapnia, daytime hypersomnolence, arterial hypoxemia, cyanosis-induced polycythemia, respiratory acidosis, pulmonary HTN, and right-sided HF
- OHS = obesity (BMI > 30), daytime hypoventilation with awake PCO2 > 45 and sleep disordered breathing
- 8% of obese population
- cardiac enlargement, cyanosis, polycythemia, twitching
73
what gastrointestinal disease's increase with obesity?
increased incidence of GERD, gallstones, pancreatitis, nonalcoholic fatty liver dx (NAFLD)
74
NAFLD =
steatosis, steatohepatitis, fibrosis, cirrhosis, hepatomegaly, abnormal liver chemistry. confirmed with liver biopsy
- most common liver condition worldwide
- related to insulin resistance with higher incidence in those with central obesity or diabetes
- clinically asymptomatic
- higher mortality rate, higher incidence of CV disease and diabetes
| steatosis = fat build up in an organ
steatohepatitis = fatty liver
75
what endocrine/metabolic disorders should be monitored for?
thyroid, adrenocortcoid, & pituitary functions
76
gallstone increase __ %
30%
higher concentration of cholesterol in bile, laparoscopic approach
77
menstrual functions may signify the presence of __-__ abnormalities
hypothalamic-pituitary
77
what percent of people who are obese have diabetes type II?
80%
78
ankles, hips, knees, and lumbar spine often develop..
OA from increased mechanical stress
78
metabolic syndrome
consists of glucose intolerance +/- DM II, HTN, dyslipidemia, and CV dx
- create a proinflammatory and prothrombotic state
- increases the risk of CAD, stroke, PVD, and DM II,
- CV risk increase alone is 50-60% higher than healthy population
79
decreased bone resorption from __ physical activity can lead to __ bone density and lead to __ fractures
decreased; decreased; stress
79
what is the percentage of the obese pediatric population? 2-19 yrs of age
31.8%
80
whats the percentage of obese children that have a chance of being obese as an adult?
70 - 80 %
81
pediatric obesity is associated with higher chance of
premature death in adulthood
82
pediatric obesity
- linked to cardiac and endocrine problems
- 3x more likely to suffer stroke or heart attack by 65
- joint replacement is more likely
- pediatric obesity is more common than diabetes, HIV, cystic fibrosis and all childhood cancers combined
- HTN, OSA, those with type 2 diabetes are usually obese, psychosocial
83
maternal obesity
- pregravid obesity --> complications
- maternal obesity seems to be the most significant link to the increase in birth weight
- longer 1st & 2nd stages
- GHTN, GDM, hydraminos
- metabolic syndrome during pregnancy will show as preeclampsia, preterm labor, C/S, PP hemorrhage, infection, PIH and macrosomic infants
84
fetal macrosomia =
wt > 4000g
increased risk of adolescent metabolic syndrome and DMII
| macrosomia = growth beyond a specific threshold, regardless of gest age
85
peripartum risks
- C/S, difficult epidural/spinal placement, difficult intubation, decreased ability of US to detect craniospinal or cardiac defects, increased postop complications (longer surgery, wound infections, endometriosis, VTE, excessive blood loss)
- C/S rates increased in those with a hx of bariatric surgery
86
maternal obesity -->
significant risk factor in adverse outcomes in pregnancy
87
higher birth weights have a definite connection in
children and obesity as adults
88
some FDA approved drugs for the long-term treatment of obesity
- sympathomimetic amine/antiepileptic combination: phentermine/topiramate ER (qsymia)
- lipase inhibitor: orlistat (Xenical) (Alli)
- serotonin receptor agonist: lorcaserin (Belviq)
- opioid antagonist/antidepressant combination: naltrexone/bupropion (contrave)
- GLP 1- receptor agonist: liraglutide (saxenda)
88
mechanism of action of select bariatric operations: restrictive
- vertical banded gastroplasty (VBG; historic purposes only)
- laparoscopic adjustable gastric banding (LAGB)
- laparoscopic sleeve gastrectomy (LSG)
89
mechanism of action of select bariatric operations: largely restrictive, mildly malabsorptive
roux-en-Y gastric bypass (RYGB)
90
mechanism of action of select bariatric operations: largely malabsorptive, mildly restrictive
- biliopancreatic diversion (BPD)
- duodenal switch (DS)
91
indications for bariatric surgery
- BMI greater than 40 or BMI less than 35 with an associated medical comorbidity worsened by obesity
- failed dietary therapy
- psychiatrically stable without alcohol dependence or illegal drug use
- knowledgeable about the operation and its sequelae
motivated individual
- medical problems not precluding probable survival from surgery
92
postoperative complications
leak
93
most common S/S of leak
- tachycardia, fever, abdominal pain
- tachycardia most sensitive sign. BPM > 120 should be investigated
- tachypnea or desaturating can also be an early sign of sepsis from a leak
94
BOX 48.8 S/S anastomotic leak
- unexplained tachycardia (> 120bpm)
- shoulder pain (usually left)
- abd pain
- pelvic pain
- substernal pressure
- shortness of breath
- fever
- increased thirst
- hypotension
- unexplained oliguria
- hiccups
- restlessness
95
obesity causes physiological changes tht can affect __ & __ of anesthetic agents
pharmacokinetics; pharmacodynamics
96
give water-soluble drugs according to
IBW
97
give lipid-soluble drugs according to
TBW
98
lean body mass increases 〜20-40% in obesity, so adding __% to the IBW is a convenint dose adjustment
30%
99
postoperative respiraotry __ is problematic, consider __ acting opioids
depression; short
100
consider what IVA becasue they have a faster off?
sevoflurane & desflurane
101
what inhaled anesthetic is safer for those who do not require high O2
Nitrous oxide
- can be used as volatile-sparring adjunct
- second gas effect
- can reduce chronic postoeprtive pain
102
succ should be given according too
TBW
103
remifentanil should be given according to
IBW
popular d/t rapid offset
104
what is a good adjunct to opioid/sedation/amnesia/analgesia
dexmedetomidine
105
sugammadex is given in the usual doses
check twitches & don't be afraid to give more
106
pharmacokinetic changes associated with obesity
- increased fat mass
- increased cardiac output
- increased blood volume
- increased lean body weight
- changes in plasma protein binding
- reduced TBW
- increased renal clearance
- increased volume of distribution of lipid-soluble drugs
- abnormal liver function
- decreased pulmonary function
107
preanestetic evaluation: medication
- take note of weight-reducing substances, herbal supplements, anorexiant drugs, ozempic
- most meds can be taken up until surgery except insulin and oral hypoglycemics
- VTE prophylaxis d/t increase incidence
- abx administration important d/t increase in would infections in this population
108
pre anesthetic evaluation: lab testing
- d/t high risk of CV dx, consider ECHO, ECG
- d/t high risk of DM, consider glucose and A1C testing
- BUN creatinine levels may be higher d/t dehydration or renal dysfunction
- LFTs typically elevated in obese patients d/t infiltration of the hepatocytes and triglycerides --> may require a lesser dose of anesthetic if severe fatty liver
- patients on anticoagulants for DVT or Affib treatment may show elevated PT/PTT times
109
pre anesthetic evaluation: cardiac
- investigate for prior MI, HTN, angina, PVD
- LV dysfunction comes from exercise intolerance, hx of orthopnea, & paroxysmal nocturnal dyspnea
- cardiac meds
- exercise testing is typically helpful, but patients typically can't complete
- CXR
110
ECG is essential d/t increased incidences of
CAD & MI
- cardiac clearance or office visit to compare to the day of surgery
- ECG may show low voltage based on excess overlying tissue and therefore might result in underestimating of severity of ventricular hypertrophy
axis deviation & tachyarrhythmias are common
111
QT prolongation is a marker for sudden
cardiac arrest
- more common in the obese population with LVH
- if this is suspected, obtain ECHO
- tricuspid regurg on ECHO is most confirmatory test of PHTN
111
pre anesthetic evaluation: respiratory
- a pt who becomes dyspneic & desaturates when recumbent will experience the same during induction in the supine position
- evaluate for OSA/OHS/orthopnea, wheezing, sputum production, smoking hx
- recent URI, snoring, sleep disturbances may signal obstructive processes
- difficult mask ventilation
112
airway evaluation
- refer to your airway evaluation
- high mallampati + large neck circumference and hx of sleep apnea is a good predictor of difficult intubation
113
"big boy" hydraulic beds should be used
- heavy-duty stirrups
- extra-large retractors
- elongated instruments
- arm sleds, double arm boards, gel pads
113
OR table -->
weight restriction
verify with OR staff on equipment needed for table
114
T/F BP can not be used on forearms
false
115
T/F more hypothermic d/t large body surface area exposed
true
116
consider difficult __ cart and assorted intubation equipment & __
airway; sizes
117
T/F not the same NPO guidelines as non-obese people
false
118
what ECG leads should be monitored for myocardial ischemia detection?
II & V5
119
patients with hx of recent gastric banding are at increased risk of
pulmonary aspiration of esophageal contents
119
forearm measurments with standard cuffs overestimate __ & __ in obese patients
SBP & DBP
120
nausea following bariatric surgery is very
common
- highest after gastric sleeve, lowest with gastric band
- standard antiemetic therapy & consider opioid-free anesthetic
121
sniffing or ramping
- placement of towels/blankets under shoulders & head
- easier view with a little reverse Trendelenburg: better for pt FRC, greatly improves view, helps with recue ventilation if needed
- want pt positioned with head neck and shoulders significantly elevated above chest, imaginary line to connect sternal notch with the external auditory meatus
122
intubation considerations
- reverse trendlenburg
- on OR table if able
- preoxygenation 3 to 5 mins
- careful with sedatives
- "awake" look
- modified RSI
123
RSI
To use cricoid pressure or to not
- when pressure is applied to the cricoid cartilage, causes occlusion to the esophagus between cricoid cartilage & vertebral body
- cricoid pressure --> reduction of LES pressure in anesthetized patients: gastric pressure < esophageal pressure & barrier remains intact
- may cause lateral displacement of the esophagus
- conflicting studies
124
GA causes __% decrease in FRC in obese population, __% in nonobese population
50%; 20%
125
adding PEEP improves
FRC & arterial O2 tension, only at the expense of CO and O2 delivery
126
TV __ to __ mL/kg of IBW (avoid barotrauma)
6 to 10
127
RR __ - __ for laparscopic procedures
12 - 14
128
prolonged procedures (2-3 hrs) and hose involving abd/spine/thorax --> negative influence on respiratory function
- Trendelenburg/recumbent positioning decreases FRC, and causes elevated filling pressures --> increase in RV preload
- myocardial O2 consumption, CO, pulmonary arterial occluding pressures, PIP, and venous admixtures are increased above sitting values
129
optimizing oxygenation by using at least __% O2
50
use recruitment breaths
130
anesthetic choice
- patient dependent
- short-acting anesthetics recommended
- avoid residual muscle relaxants
- consider multimodal (regional for less narcotics)
- epidurals are great for postoperative pain
131
estimated blood volume is __ in obese population
diminished
132
fat contains __ - __% water, contributes less fluid to TBW than equivalent amounts of muscle
8-10%
normal adult TBW to 60-65%
severely obese patients 40%
133
calculated EBV for obese ppl is what instead of 70mL
45-55 mL/kg
134
renal failure in __% of bariatric surgery
2%
predisposing factors: hypovolemia, BMI > 50, prolonged surgery time, intraop hypotension, preexisting dx
135
adequate intraop fluid replacement helps
PONV
136
Regional anesthesia
- may be used as primary anesthetic, for post-op pain & mobility management
- more difficult to obtain d/t body habitus & inability to view landmarks
- subarachnoid/epidural anesthesia: consider longer tuohy or spinal needle, generous lidocaine for reinsertion, lack of predictability of spread
137
Hetastarch volume expander should NOT be administered more than
20 mL/kg of IBW
dilution coagulopathy, factor VIII inhibition & decreased platelet aggregation results from excessive administration
138
extubation
- increased risk of airway obstrtuction
- emergence based on mask ventilation, intubation, preexisting medical conditions..
- have patient sitting up, OPA, exchange catheter
139
postoperative managment
obese patients are more sensitive to the respiratory depressant effects of opioids
- supplemental O2 & pulse ox
- if patient on CPAP prior to anesthesia, should be on in PACU
140
postoperative complications: rhabdomyolysis
- CPK pre and postoperatively to aid in early diagnosis & treatment: cpk is the most sensitive diagnostic
141
risk factors for rhabdo
male, elevated BMI & prolonged procedure time
142
treatment rhabdo:
- preserve renal function
- avoid dehydration, hypovolemia, tubular obstruction, aciduria, & free radical release: administer fluids, bicarb & mannitol
142
postoperative complications: thromboembolism
- amplified with higher BMI
- facilitated by immobility, increased blood viscosity, increased abdominal pressure & abnormalities in serum procoagulant & anticoagulants
- 50% of deaths
143
VTE risk factors:
- venous stasis
- BMI > 60
- truncal obesity
- OHS/OSA
144
treatment of VTE:
- heparin 5000 u SQ BID
- anti embolic stockings
- compression booties lessen the occurrence
- early ambulation
