ABSITE Review - Nutrition Flashcards
What is the daily caloric need?
25kcal/kg/day
Mention the kcal./g of fat, protein, CHO and dextrose.
Fat 9kcal/g
Protein 4 kcal/g
Oral CHO 4 kcal/g
Dextrose 3.4 kcal/g
What are the nutritional requirements (protein, fat, CHO) for an average healthy adult male?
Protein 1g/kg/day (20% essential AAs)
Fat 30% calories
CHO rest of the calories
Which states of health or disease can increase the kcal requirement?
Trauma, surgery or sepsis - 20-40%
Pregnancy increase 300kcal/day
Lactation increase 500kcal/day
How are the protein and kcal requirements affected by burns?
Calories: 25kcal/kg/day + (30kcal/day x %burn)
Proteins: 1-1.5 g/kg/day + (3g x %burn)
What is the maximum glucose administration in TPN?
3g/kg/hr
What is the fuel for colonocytes?
Short chain fatty acids
What is the fuel for small bowel enterocytes and neoplastic cells?
Glutamine - MC AA in bloodstream and tissue
Releases NH4 in kidney, helping with nitrogen excretion
What are the half-lives of albumin, transferrin and prealbumin?
Albumin - 20 days
Transferrin - 10 days
Prealbumin - 2 days
What are ACUTE indicators of nutritional status?
Retinal binding protein, prealbumin, transferrin, total lymphocyte count
What is the the IBW formula for women and men?
Men = 106lb + 6lb for each inch over 5ft Women = 100lb + 5lb for each inch over 5ft
Mention preoperative signs of poor nutritional status.
Acute weight loss >10% in 6 months
Weight < 3.0 - strong risk factor for morbidity and mortality after surgery
What is the respiratory quotient? What is the number for each metabolism?
Ratio of CO2 produced to O2 consumed = measurement of energy expenditure
RQ > 1 = lipogenesis (overfeeding) - Tx: decrease CHO & caloric intake
RQ < 0.7 = ketosis and fat oxidation (starving) - Tx: increase CHO and caloric intake
RQ = 7 - pure fat metabolism
RQ = 0.8 - pure protein metabolism
RQ = 1.0 - pure CHO metabolism
How long does the the glycogen stores last in starvation? What is used after they are used?
Depleted after 24-36 hours (2/3 skeletal muscle, 1/3 liver) –> body then switches to fats
Where the glucose-6-phosphatase is only found?
Liver
What is the primary substrate of gluconeogenesis?
Alanine
What are the gluconeogenesis precursors?
Amino acids (especially alanine), lactate, pyruvate, glycerol
What is the main source of energy in trauma and starvation?
Fat (ketones)
When bacterial translocation is a risk? What cause it?
Occurs when the gut is not feed. Bacterial overgrowth occurs due to increased permeanility due to starved enterocytes.
What is the fuel of brain usually? What is it in starvation?
Usually glucose
Ketones in starvation.
What are the obligate glucose users?
Peripheral nerves, Adrenal Medulla, RBCs, WBCs
What occurs when feeding after prolonged starvation/malnutrition? What electrolytes abnormalities are common?
Refeeding Syndrome
Results in decrease K, Mg and PO4 –> causes cardiac dysfunction and fluid shifts
What is Kwashiorkor?
Protein deficiency
What is Marasmus?
Starvation
How much nitrogen contains 6.25g of protein?
6.25g of protein contains 1g of nitrogen
What AAs are most of the protein breakdown in the skeletal muscle?
Glutamine and Alanine
What are the fat-soluble vitamins?
ADEK
Medium and short chain fatty acids enter enterocytes by …
Simple diffusion
Long chain fatty acids enter enterocytes by …
Fusing with membrane in micelles
What is the function of the lipoprotein lipase?
Present on liver endothelium
Clears chylomicrons and TAGs from the blood, breaking them to fatty acids and glycerol
What is the most important rout of entry for dietary cholesterol?
VLDL, synthesized in the liver
What is the preferred source of energy for the liver, heart and skeletal muscle?
Fatty acids (ketones - acetoacetate, beta-hydroxybutyrate)
What are the essential fatty acids?
Linolenic, Linoleic
What are the omega-3 fatty acids?
PGI3, TXA3, LTB5 (all odd)
What are the omega-6 fatty acids?
PGE2, TXA2, LTB4 (all even)
Where the CHO digestion starts?
Begins with salivary amylase, then pancreatic amylase and disaccharides
Where the protein digestion starts?
Begins with stomach pepsin, then trypsin, chymotrypsin and carboxypeptidase
Who activates trypsinogen?
Enterokinase released from duodenum
What are the branched-chain amino acids?
Leucine, Isoleucine, Valine
Vitamin Deficiencies
Mention
Hyperglycemia + encephalopathy + Neuropathy =
Chromium deficiency
Cardiomyopathy + weakness + hair loss =
Selenium deficiency
Pancytopenia
Copper deficiency
Hair loss + Poor Healing + rash =
Zinc deficiency
Weakness (failure to wean ventilator) + encephalopathy + decreased phagocytosis =
Phosphate deficiency
Wernicke’s encephalopathy + cardiomyopathy + peripheral neuropathy =
Thiamine (B1) deficiency
Sideroblastic anemia + glossitis + peripheral neuropathy =
Pyridoxine (B6) deficiency
Megaloblastic anemia + peripheral neuropathy + beefy tongue =
Cobalamin (B12) deficiency
Pellagra (diarrhea, dermatitis, dementia)
Niacin deficiency
Dermatitis + hair loss + thrombocytopenia =
Essential fatty acids
What is Cori cycle?
Glucose is converted to lactate in the muscle, then goes to liver and is converted to pyruvate and eventually glucose via gluconeogenesis
