Chapter 10: Nutrition Flashcards
(110 cards)
1
Q
Caloric need
A
Approximately 20-25 cal/kg/d
2
Q
Calories/gram: fat
A
9 Calories/gram
3
Q
Calories/gram: protein
A
4 calories / gram
4
Q
Calories/gram: oral carbohydrates
A
4 calories / gram
5
Q
Calories/gram: dextrose
A
3.4 calories / gram
6
Q
Nutritional requirements for average healthy male
A
- 20% protein calories (1g protein/kg/d; 20% should be essential amino acids)
- 30% fat calories - important for essential fatty acids
- 50% carbohydrate calories
7
Q
% kcal requirement increase: trauma, surgery, or sepsis
A
20% - 40%
8
Q
kcal/day requirement: pregnancy
A
300 kcal / day
9
Q
kcal/day requirement: lactation
A
500 kcal / day
10
Q
Calculation: calorie requirement in burns
A
25 kcal/kg/d + (30 kcal/d x % burn)
11
Q
Calculation: protein requirement in burns
A
1-1.5 g/kg/d + (3g x %burn)
12
Q
How does fever affect basal metabolic rate?
A
Fever increased BMR 10% for each degree above 38.0 degrees Celsius
13
Q
Calculation: caloric need in obesity
A
Weight = [(actual weight - ideal body weight) x 0.25] + IBW
14
Q
Calculates basal energy expenditure based on weight, height, age, and gender
A
Harris-Benedict Equation
15
Q
Glucose goals central line TPN
A
Glucose based
- Maximum glucose administration -> 3 g/kg/h
16
Q
Fuel for colonocytes
A
Short-chain fatty acids (e.g., butyric acid)
17
Q
Fuel for small bowel enterocytes
A
Glutamine
18
Q
- MC amino acid in bloodstream and tissue
- Releases NH4 in kidney, thus helping with nitrogen excretion
- Can be used for gluconeogenesis
A
Glutamine
19
Q
Primary fuel for most neoplastic cells
A
Glutamine
20
Q
Half-life: albumin
A
18 days
21
Q
Half-life transferrin
A
10 days
22
Q
Half-life prealbumin
A
2 days
23
Q
Normal protein level
A
6.0 - 8.5
24
Q
Normal albumin level
A
3.5 - 5.5
25
Acute indicators of nutritional status
Retinal binding protein.
Prealbumin.
Transferrin.
26
Ideal body weight:
- Men
- Women
- Men = 106lb + 6lb for each inch over 5ft
| - Women = 100lb + 5lb for each inch over 5 ft
27
Preoperative signs of poor nutritional status
- Acute weight loss > 10% in 6 months
| - Weight
28
Strong risk factor for morbidity and mortality after surgery
Low albumin
29
Respiratory quotient
Ratio of CO2 produced to O2 consumed
| Measurement of energy expenditure
30
Def: RQ > 1
Lipogenesis (overfeeding)
Tx: decreased carbohydrates and caloric intake.
- High carbohydrate intake can lead to CO2 buildup and ventilator problems
31
Def: RQ
Ketosis and fat oxidation (starving)
| - Tx: increased carbohydrates and caloric intake
32
RQ: pure fat utilization
RQ = 0.7
33
RQ: pure protein utilization
RQ = 0.8
34
RQ: pure carbohydrate utilization
RQ = 1.0
35
Post op: diuresis phase
Post op days 2-5
36
Post op: catabolic phase
Post op days 0-3
37
RQ: pure carbohydrate utilization
RQ = 1.0
38
When does glycogen deplete?
Depleted after 24-36 hours of starvation on (2/3 in skeletal muscle, 1/3 in liver) -> body then switches to fat.
39
Where is glucose-6-phosphatase found?
Only in the liver.
| None in skeletal muscle: G6P stays in muscle after breakdown from glycogen and is utilized.
40
Gluconeogenesis precursors (x4)
Amino acids (esp alanine).
Lactate.
Pyruvate.
Glycerol.
41
Simplest amino acid precursor for gluconeogenesis.
| - Primary substrate for gluconeogenesis
Alanine
42
Only amino acids to increase during times of stress
Alanine and phenylalanine
43
Where does gluconeogenesis occur in late starvation?
Kidney
44
Why do protein-conserving mechanisms not happen after trauma?
Secondary to catecholamines and cortisol.
45
Main source of energy in starvation and in trauma
Fat (ketones)
| - In trauma, energy is more mixed (fat and protein)
46
% weight loss: pt can tolerate without complications
15%
47
When do you consider Dobhoff tube or TPN?
After about 7 days without eating.
48
Why do you want to feed gut?
To avoid bacterial translocation (bacterial overgrowth, increased permeability due to starved enterocytes, bacteremia) and TPN complications
49
Consider when regular feeding not possible (e.g., CVA) or predicted to not occur for > 4 weeks
PEG tube
50
Utilizes ketones with progressive starvation (normally uses glucose)
Brain
51
Obligate glucose users
Peripheral nerves.
Adrenal medulla.
Red blood cells.
White blood cells.
52
Refeeding syndrome
- Occurs when feeding after prolonged starvation / maturation.
- Results in decreased K, Mg, PO4-.
- Causes cardiac dysfunction, profound weakness, encephalopathy.
53
How do you prevent refeeding syndrome?
10 - 15 kcal/kg/d
54
Cachexia
- Anorexia, weight loss, wasting
- Thought to be mediated by TNF-alpha
- Glycogen breakdown, lipolysis, protein catabolism
55
Kawshiorkor
Protein deficiency
56
Marasmus
Starvation
57
___ gram protein = ___ gram nitrogen
6.25g protein = 1g nitrogen
58
Calculate nitrogen balacne
Nin-Nout =
| [protein/6.25] - [24hr urine N + 4g]
59
g/d: total protein synthesis for a healthy, normal 70kg male
250 g/d
60
- Responsible for amino acid production and breakdown
| - Urea production is used to get rid of ammonia from amino acid breakdown
Liver
61
Amino acids: majority of protein breakdown from skeletal muscle
Glutamine and alanine
62
Broken down by pancreatic lipase, cholesterol esterase, and phospholipase to micelles and free fatty acids
Triacylglycerides (TAGs), cholesterol, and lipids
63
Aggregates of bile salts, long-chain free fatty acids, and monoacylglycerides
- Enter enterocyte by fusing with membrane
Micelles
64
Increase absorption area for fats, helping form micelles
Bile salts
65
Used to synthesize bile salts
Cholesterol
66
Fat soluble vitamins, absorbed in micelles
A, D, E, K
67
Enter enterocyte by simple diffuse
Medium and short chain fatty acids
68
Composition of chylomicrons
90% TAGS
| 10% phospholipids / proteins / cholesterol
69
Where do chylomicrons go after they are formed (form micelles and other fatty acids when they enter the enterocytes)?
Lymphatics by way of the thoracic duct
70
Fatty acids: enter lymphatics along with chylomicrons
Long-chain fatty acids
71
Fatty acids: enter the portal system (same as amino acids and carbohydrates)
Medium- and short-chain fatty acids
72
Lipoprotein lipase
On endothelium in liver and adipose tissue; clears chylomicrons and TAGs from the blood, breaking them down to fatty acids and glycerol
73
Free fatty acid-binding protein
On endothelium in the liver and adipose tissue; binds short and medium-chain fatty acids
74
Used for fuel by cardiac and skeletal muscles
Saturated fatty acids
75
Preferred source of energy for colonocytes, liver, heart, and skeletal muscle
Fatty acids (ketones - acetoacetate, beta-hyroxybutyrate)
76
Used as structural components for cells
Unsaturated fatty acids
77
In fat cells; breaks down TAGS (storage form of fat) to fatty acids and glycol, which are released into the bloodstream; sensitive to growth hormone, catecholamines, glucocorticoids
Hormone-sensitive lipase (HSL)
78
Essential fatty acids
Linolenic, linoleic
- Needed for prostaglandin synthesis (long-chain fatty acids)
- Important for immune cells
79
What does carbohydrate digestion start with?
Begins with salivary amylase, then pancreatic amylase and disaccharidases
80
Carbs: absorbed by secondary active transport; released into portal vein
Glucose and galactose
81
Carbs: facilitated diffusion, released into portal vein
Fructose
82
Fructose + glucose
Sucrose
83
Galactose + Glucose
Lactose
84
Glucose + Glucose
Maltose
85
What does protein digestion begin with?
Stomach pepsin, then trypsin, chymotrypsin, and carboxypeptidase
86
Trypsinogen
Released from pancreas and activated by enterokinase, which is release from the duodenum
87
What releases enterokinase?
Duodenum
88
Activates trypsinogen
Enterokinase
89
- Activates pancreatic protein enzymes
| - Can auto activate other trypsinogen molecules
Trypsin
90
How is protein absorbed?
Secondary active transport
91
Why limit protein intake in liver and renal failure?
To avoid ammonia buildup and possible worsening encephalopathy
92
Branched chain amino acids
Leucine, isoleucine, valine ("LIV")
- Metabolized in muscle
- Possibly important in patients with liver failure
- Are essential amino acids
93
Essential amino acids
Leucine, isoleucine, valine, arginine, histidine, lysine, methionin, phenylalanine, threonine, and tryptophan
94
General composition TPN
- 10% amino acid
- 50% dextrose
- Electrolyes (Na, Cl, K, Ca, -Mg, PO4, Acetate)
- Mineral and vitamine
- Lipids (given separately from TPN)
95
Deficiency: Chromium
Hyperglycemia, encephalopathy, neuropathy
96
Deficiency: Selenium
Cardiomyopathy, weakness
97
Deficiency: Copper
Pancytopenia
98
Deficiency: Zinc
Poor wound healing
99
Deficiency: Phosphate
Weakness (failure to wean off ventilator), encephalopathy, decreased phagocytosis
100
Deficiency: Thiamine (B1)
Wernicke's encephalaopthy, cardiomyopathy
101
Deficiency: Pyridoxine (B6)
Sideroblastic anemia, glossitis, peripheral neuropathy
102
Deficiency: Cobalamin (B12)
Megaloblastic anemia, peripheral neuropathy, beefy tongue
103
Deficiency: Folate
Megaloblastic anemia, glossitis
104
Deficiency: Niacin
Pellagra (diarrhea, dermatitis, dementia)
105
Deficiency: Essential fatty acids
Dermatitis, hair loss, thrombocytopenia
106
Deficiency: Vitamin A
Night blindness
107
Deficiency: Vitamin K
Coagulopathy
108
Deficiency: Vitamin D
Rickets, osteomalacia, osteoporosis
109
Deficiency: Vitamin E
Neuropathy
110
Cori Cycle
Lactate moved to liver where it is converted back to pyruvate and eventually glucose
