Chapter 10 - Nutrition Flashcards
What is the approximate daily caloric need?
25 kcal/kg/day
How many kcal/gram of fat?
9
How many kcal/gram of protein?
4
How many kcal/gram of oral carbohydrates?
4
How many kcal/gram of Dextrose?
3.4
How many kcal/cc is there in a 10% lipid solution?
1.1
How many kcal/cc are there in a 20% lipid solution?
2
What are the protein requirements of a healthy adult male?
1g/kg/day protein (20% essential AA)
How much does trauma, surgery, or sepsis stress increase the k/cal requirements?
20-30%
How much does pregnancy increase the kcal requirements?
300 kcal/day
How much does lactation increase kcal requirements?
500kcal/day
How do you calculate the calories required in a burn?
25kcal/kg/day + (30 kcal/day x % of burn)
How do you calculate protein required in a burn?
1-1.5 g/kg/day + (3g x % of burn)
How much does the basal metabolic rate rise in fever?
10% for each degree above 38.0
Central line TPN is based on what?
Glucose. Max glucose administration is 3g/kg/hr
Peripheral line parenteral nutrition is based on what?
fat
What is the fuel for colonocytes?
short chain fatty acids
What is the fuel for small bowel enterocytes?
Glutamine
What is the most common AA in bloodstream and tissue?
Glutamine
What does Glutamine do in kidney?
Releases NH4, helping with nitrogen excretion (can also be used for gluconeogenesis)
What is the primary fuel for neoplastic cells?
Glutamine
What is the half life of albumin?
20 days
What is the half life of Transferrin?
10 days
What is the half life of Pre-albumin?
2 days
What is the normal protein level?
6.0-8.5
What is the normal albumin level?
3.5-5.5
What are acute indicators of nutritional status?
retinal binding protein, pre-albumin, transferrin, total lymphocyte count
What is the Ideal Body Weight calculation?
Men: 106 + 6 for every inch over 5ft
Women: 100 + 5 for every inch over 5ft
What are preoperative signs of poor nutrition?
- Weight loss >10% in 6 months
- Hx of poor intake
- Loss of muscle mass and subq fat
- Worsening weakness
- Edema (sign of hypoalbuminemia)
- Labs only in addition to physical - transferrin, albumin, prealbumin
What is the respiratory quotient?
What is it used for?
ratio of CO2 produced to O2 consumed
used to measure the sufficiency of nutritional intake by determining the type of metabolism the body is using
ketones, protein, carbs give different RQs
An RQ of >1 means what?
lipogenesis - overfeeding; decrease carbs and caloric intake
can lead to ventilator problems for CO2 buildup
An RQ of <0.7 means what?
ketosis and fat oxidation (starving). Increase carbs and caloric intake
Pure fat metabolism has an RQ of?
0.7
Pure protein metabolism has an RQ of?
0.8
Pure carbohydrate metabolism has an RQ of?
1.0
Postoperative diuresis phase occurs when?
days 2-5
Postoperative catabolic phase occurs when?
days 0-3 (negative nitrogen balance)
Postoperative Anabolic phase occurs when?
days 3-6 (positive nitrogen balance)
How long before glycogen stores are depleted?
24-36 hours of starvation (2/3 in skeletal muscle, 1/3 in liver)
What do skeletal muscles lack that is found in the liver in regards to glycogen metabolism?
Glucose-6-phosphatase
What are the gluconeogenesis precursors?
AA (especially alanine), lactate, pyruvate, glycerol. Alanine is simpleist AA precursor for gluconeogenesis and is primary substrate.
What AA increase during times of stress?
Alanine and Phenylalanine
In late starvation, gluconeogenesis also occurs in what organ?
Kidney
Why do protein conserving mechanisms not take place after trauma?
catecholamines and cortisol
What is the main source of energy during trauma and starvation?
Fat (ketones)
What percentage of weight loss can most patients tolerate without major complications?
15%
How many days can patients tolerate without eating?
7 days. After that place dobbhoff or start TPN
Why do you want to feed gut?
avoid bacterial translocation (enterocytes starved and allow bacterial leak)
What is an elemental formula?
When would it be used?
all protein given in the form of amino acids
used for people having trouble absorbing/breaking down proteins - short bowel syndrome, infants w/ protein allergies
When to consider PEG?
when regular feeding not possible (CVA), or when feeding not to occur for >4 weeks
What does the brain utilize with progressive starvation?
ketones
What are the obligate glucose users?
- peripheral nerves
- adrenal medulla
- red blood cells
- white blood cells
What happens during refeeding syndrome?
drop in K+, Mg+, and PO4. causes cardiac dysfunction and fluid shifts. Start refeeding at low rate (10-15kcal/kg/day)
What cell signaling protein is thought to mediate cachexia?
TNF alpha
What is kwashiorkor?
protein deficiency
What is Marasmus?
starvation
How many grams of protein contains 1 gram of Nitrogen?
6.25
How do you calculate Nitrogen balance?
- (protein in/6.25) - (24 hour Urine N + 4 grams)
- positive # = anabolism
- negative # = catabolism
What is the total protein synthesis for a healthy, normal, 70kg male?
250 g/day
What is the function of Urea production?
get rid of ammonia from amino acid breakdown
What is AA is produced in the majority of skeletal muscle breakdown?
glutamine and alanine
In digestion, what breaks down triacylglycerides, cholesterol, and lipids?
What are they broken down into?
Pancreatic lipase, cholesterol esterase, phospholipase
broken down into micelles and free fatty acids
What are Micelles?
Aggregates of bile salts, long chain fatty acids, and monoacylglycerides
How do micelles enter enterocytes?
they fuse with the membrane
What are the fat soluble vitamins?
A, D, E, K
How do medium and short chain fatty acids enter enterocytes?
simple diffusion
After micelles and other fatty acids enter enterocytes, how are they transported out?
- chylomicrons are formed - 90% TAG’s, 10% phospholipids/proteins/cholesterol
- chylomicrons enter lymphatics - thoracic duct
- MC & SC FA’s - portal system - liver
- LC FA’s enter lymphatics like chylomicrons
Where is lipoprotein lipase found and what does it do?
liver endothelium; clears chylomicrons and TAG’s from blood breaking them down to FA’s and glycerol. Then taken up by hepatocytes
Where is free fatty acid binding protein found and what does it do?
Liver endothelium; binds short and medium chain FA’s
MCFAs/SCFAs - simple diffusion into enterocytes - portal system - liver
What is the most important route of entry for dietary cholesterol?
VLDL; synthesized in liver
What are saturated fatty acids used for?
Fuel for cardiac and skeletal muscles
What are unsaturated fatty acids used for by the body?
structural components of cells
Where is Hormone sensitive lipase found, what does it do, and what stimulates it?
- found in fat cells
- breaks down TAG’s to fatty acids and glycerol
- stimulated by GH, catecholamines, glucocorticoids
What are essential fatty acids?
linolenic, linoleic
Omega-3 fatty acids are needed for what?
PGI3, TXA3, LTB5 (all even)
Omega-6 fatty acids are needed for what?
PGE2, TXA2, LTB4 (all even)
Glucose and Galactose use what process for absorption?
secondary active transport
Fructose uses what process for absorption?
Facilitated diffusion
Sucrose is made up of what?
fructose + glucose
Lactose is made up of what?
galactose + glucose
Maltose is made up of what?
glucose + glucose
Trypsinogen is released from where and activated by what?
pancreas; activated by enterokinase from duodenum (can also be autoactivated by trypsin)
What are the branched chain amino acids?
isoleucine, leucine, valine
The BRANCH IS LOOSE, VAL!
Chromium deficiency?
hyperglycemia, encephalopathy, neuropathy
Selenium deficiency?
Cardiomyopathy, Weakness, Hair loss
Copper deficiency?
Pancytopenia
Zinc deficiency?
Hair loss, poor healing, rash
Trace element deficiency?
poor wound healing
Phosphate deficiency?
Weakness, failure to wean off Vent (hyporesponsive diaphragm) encephalopathy, decreased phagocytosis
Thamine B1 deficiency?
Wernicke’s, cardiomyopathy, peripheral neuropathy
Pyridoxine deficiency?
Sideroblastic anemia, glossitis, peripheral neuropathy
Cobalamin B12 deficiency?
Megaloblasic anemia, peripheral neuropathy (as opposed to folate deficiency), beefy tongue
Folate deficiency?
megaloblastic anemia, glossitis
Niacin deficiency?
Pellagra (diarrhea, dermatitis, dementia)
essential fatty acid deficiency?
dermatitis, hair loss, thrombocytopenia
Vitamin A deficiency?
Night blindness
Vitamin K deficiency?
coagulopathy
Vitamin D deficiency?
Rickets, osteomalacia
Vitamin E deficiency?
Neuropathy
Briefly describe steps of Cori cycle
Glucose used in muscle, broken down to lactate, lactate to liver, lactate converted to pyruvate, pyruvate to glucose via gluconeogenesis, glucose back to muscle
