MISC-obesity Flashcards
1
Q
How many calories does each gram of fat provide
A
9 calories of physiologically available energy
2
Q
How many calories do each gram of CHO and protein provide
A
4 calories
3
Q
What 2 medication classes can contribute to obesity
A
- steroid
2. antidepressants
4
Q
What 5 diseases can contribute to obesity
A
- Cushing’s dz
- hypothyroidism
- depression
- eating disorders
- PCOS
5
Q
What 2 genetic conditions can contribute to obesity
A
- Prader-Willi syndrome
2. Bardet-Biedl syndrome
6
Q
When can adipose tissue become pathologic
A
When it releases significant quantities of free fatty acids and cytokines
7
Q
Who is more prone to android obesity
A
men
8
Q
What is the characterization of android obesity
A
Central or abdominal visceral fat accumulation
Men waist size > 40 inches
Women waist size >35 inches
9
Q
With increased waist size comes increased risk for which 5 diseases
A
- ischemic heart disease
- HTN
- dyslipidemia
- insulin resistance
- death
10
Q
Who is more prone to gynoid obesity
A
Women
11
Q
What is the characterization of gynoid obesity
A
Gluteal and femoral fat accumulation
12
Q
What complications are associated with gynecoid fat patterning
A
- joint disease
2. varicose veins
13
Q
What is the CV risk % in pts with metabolic syndrome
A
50-60% greater than the general population
14
Q
How is diagnosis of metabolic syndrome made
A
Must have at least 3 of the following:
- fasting glucose >110 mg/dl
- abdominal obesity (men>40 in, women > 35 in)
- serum triglycerides >150 mg/dl
- serum HDL<40 M, <50 F
- BP > 135/85 mmHg
15
Q
Equation for BMI
A
kg / m^2
16
Q
how does obesity-related morbidity relate to BMI
A
risk of morbidity increases in direct proportion to BMI
17
Q
What is normal BMI
A
18.5-25 kg/m^2
18
Q
What BMI is considered morbid obesity
A
BMI >40
19
Q
What BMI range is considered overweight
A
25 - 30
20
Q
What weight percentile are children considered obese
A
if weight falls in the 95-98th percentile
21
Q
What is the equation for ideal body weight
A
Men kg = height(cm) - 100
Women kg = height(cm) - 105
22
Q
What type of ventilatory defect is associated with obesity
A
restrictive
23
Q
What pulmonary mechanics are altered
A
Lung volume is reduced
Compliance is reduced
24
Q
What CV factor affects pulmonary compliance in the obese pt
A
increased pulmonary BF d/t increased CO, reduces compliance
25
How is the diaphragm affected by obesity
It is shifted cephalad and compresses the lungs
26
How is FRC related to BMI
it is inversely proportional
27
Why is FRC reduced in obesity
because ERV is reduced
28
How does FRC relate to closing capacity in obesity
FRC is reduced below CC
| Causes airway collapse during tidal breathing
29
What is the result of an FRC that is below CC
1. V/Q mismatch (deadspace)
2. shunt
3. hypoxemia
30
What 2 factors cause rapid desaturation in the obese pt during apnea
1. higher O2 consumption
| 2. Smaller FRC
31
Which volumes or capacities are reduced in obesity
1. FRC
2. VC
3. TLC
4. ERV
32
Why is PaCO2 maintained even during apnea
b/c CO2 production is increased d/t the amount of fat that is metabolically active
33
What FiO2 settings can help decrease atelectasis in obese pts
Keeping FiO2 <80% can prevent absorption atelectasis
34
What is a lung protective strategy employed with ventilation of the obese pt
Vt 6-8 mL of IDEAL body weight
35
How should PaCO2 be managed in the obese pt
by adjusting RR not increasing Vt
36
When is postoperative hypoxemia most likely to occur in the obese pt
immediately after extubation and up to 2-5 days following surgery
37
5 strategies to maximize postop oxygenation in the obese pt
1. CPAP or BiPAP after extubation
2. Elevate HOB>30 degrees
3. Early ambulation
4. Control pain w/ non-opioid analgesics and RA
5. Incentive spirometry
38
How does obesity affect the CV system
1. Increased blood volume
2. increased CO
3. increased SV (HR doesn't change)
4. increased VR
5. diastolic dysfunction
39
Why are obese pts less tolerant of excess fluid
D/t increased VR and reduced ventricular compliance and diastolic dysfunction
40
How should fluid administration be dosed for the obese pt
Based on lean body weight
41
What 5 changes in the obese pt can lead to HTN
1. hyperinsulinemia
2. SNS activation
3. RAAS activation
4. atherosclerosis
5. elevated cytokine concentration
42
What are 6 EKG changes that are common in the obese pt
1. low voltage EKG
2. left axis deviation
3. right axis deviation
4. QT prolongation
5. Ischemia
6. Dysrhythmias
43
What causes low voltage EKG changes in the obese pt
D/t increased distance between the heart and the leads
44
What are 2 causes of left axis deviation on EKG in the obese pt
The stomach pushing the heart up and left
| LVH d/t volume overload and HTN
45
What are 2 causes of right axis deviation on EKG in the obese pt
RVH from OSA
| Volume overload
46
What valvular pathology on TEE can confirm pulmonary HTN in the obese pt
Tricuspid regurg
47
Loading dose is based on what pharmacological principle
Volume of distribution
48
Dosing maintenance is based on what pharmacokinetic principle
clearance
49
What are 4 factors that alter the volume of distribution in the obese pt
1. increased blood volume
2. increased CO
3. altered plasma protein binding
4. lipid solubility of the drug
50
How is medication Vd altered by blood volume in the obese pt
The required dose to achieve a given plasma concentration is higher
51
How is medication Vd altered by CO in the obese pt
Drugs are delivered faster to vessel rich groups
52
How is medication Vd altered by altered plasma protein binding in the obese pt
Free fraction of available drug is altered
53
How is medication Vd altered by drug lipid solubility
A larger fat mass increases the Vd for lipophilic drugs
54
How does increased body fat alter Vd of lipophilic vs hydrophilic drugs
They are both increased, but Vd for lipophilic drugs increases more than hydrophilic
55
How is lean body weight estimated
LBW = IBW x 1.3
56
What type of volatile agents should be used in the obese population
Agents with the lowest blood:gas coefficients
57
Which volatile agents provide faster emergence
Sevoflurane and desflurane
58
How is MAC affected by obesity
it is unchanged
59
Why is succinylcholine dose based on total body weight
The combination of increased blood volume (Vd) and increased pseudocholinesterase activity (clearance) requires increased dosing
60
How is epidural LA volume administration affected by obesity
The dose should be reduced to 75% b/c epidural vein engorgement and increased epidural fat content cause greater spread of LA
61
The opposing forces of which 2 upper airway factors maintain airway patency
pharyngeal dilator muscles oppose negative pressure of inspiration that promotes airway collapse
62
How is the upper airway anatomy altered in the obese pt and what are 3 results of this change
Fat accumulation in the lateral walls of the pharynx
1. narrows internal diameter
2. decreases airflow
3. increases tendency for collapse
63
What are 3 factors that increase the likelihood of OSA
1. BMI >30 kg/m^2
2. abdominal fat distribution
3. large neck girth (>17 in M, >16 in F)
64
OSA increases the risk for which 3 comorbidities
1. HTN
2. CV morbidity
3. Death
65
What are 5 results of hypoxemia and hypercarbia with OSA
ANS stimulation causing
1. HTN
2. dysrhythmias
3. MI
4. pulm htn
5. heart failure
66
What are the 3 pharyngeal dilator muscles
1. tensor palatine
2. genioglossus
3. hyoid
67
What do each of the following pharyngeal dilator muscles open
Tensor palatine=
genioglossus=
hyoid=
Tensor palatine= nasopharynx
genioglossus= oropharynx
hyoid= hypopharynx
68
What are the pharyngeal dilator muscles associated with the following pharynx anatomy
Hypopharynx=
nasopharynx=
genioglossus=
```
Hypopharynx= hyoid
nasopharynx= tensor palatine
genioglossus= genioglossus
```
69
What measure is used to quantify the severity of OSA
The apnea-hypopnea index
| (# times of apnea or hypopnea)/hours of sleep
70
What is the corresponding score for the following apnea-hypopnea index grading:
mild=
moderate=
severe=
```
mild= 5-15 episodes/hr
moderate= 15-30 episodes/hr
severe= >30 episodes/hr
```
71
What 2 airway management difficulties are pts w/ OSA at increased risk for
1. difficult mask ventilation
| 2. difficult intubation
72
What is the classic triad for dysfunctional sleep
1. apnea or snoring
2. arousal from sleep
3. daytime somnolence
73
What is Pickwickian syndrome
obesity hypoventilation syndrome
74
What is obesity hypoventilation syndrome
Long-term consequence of OSA
| Respiratory center in medulla fails to respond to hypercarbia
75
What are 3 diagnostic criteria for obesity hypoventilation syndrome
1. BMI >30 kg/m^2
2. awake PaCO2 >45 mmHg
3. Dysfunctional breathing during sleep
76
What hematologic consequence is the result of obesity hypoventilation syndrome
Polycythemia
77
What are 2 restrictive types of bariatric surgeries
1. gastric band
| 2. sleeve gastrectomy
78
How do restrictive bariatric procedures lead to weight loss
limits quantity of food consumed
79
What are the benefits of restrictive bariatric procedures
1. least invasive
2. small intestines remain intact allowing for nutrient absorption
3. reduces gastric hormone secretion
80
Name 3 bariatric procedures that cause malabsorption
1. jejunoileal bypass
2. biliopancreatic diversion
3. duodenal switch
81
What are 2 key draw backs of the malabsorption bariatric procedure
1. gastric reduction and removal of portion of small intestines
2. limits nutrient absorption
82
What 4 nutrients are typically depleted in the pt that has undergone a malabsorptive bariatric procedure
1. vit K
2. Vit B12
3. iron
4. folate
83
What type of bariatric procedure is the Roux-en-Y gastric bypass
Combination of malabsorption and restrictive procedure type
84
What are the 3 most common signs of anastomotic leak following gastric bypass are (greatest to least)
1. tachycardia
2. fever
3. abdominal pain
85
What is the most sensitive sign of anastomotic leak
unexplained tachycardia
86
What are 9 less common s/sx of anastomotic leak
1. shoulder pain (left)
2. pelvic pain
3. substernal pressure
4. dyspnea
5. HoTN
6. oliguria
7. increased thirst
8. restlessness
9. hiccups
