Chapter 24: Surgical Nutrition Flashcards
What are the normal daily dietary requirements for adults of thefollowing:
Protein?
Calories?
Protein: 1 g/kg/day
Calories: 30 kcal/kg/day
What is the calorie content of the following substances:
Fat?
Protein?
Carbohydrate?
Fat:9 kcal/g
Protein:4 kcal/g
Carbohydrate:4 kcal/g
What is the formula for converting nitrogen requirement/loss to protein requirement/loss?
Nitrogen × 6.25 = protein
What is RQ?
Respiratory Quotient; ratio of CO2 produced to O2 consumed
What is the normal RQ?
0.8
What can be done to decrease the RQ?
More fat, less carbohydrates
What dietary change can be made to decrease CO2 production in a patient in whom CO2 retention is a concern?
Decrease carbohydrate calories and increase calories from fat
What lab tests are used to monitor nutritional status?
Blood levels of:
Prealbumin (t½≈2 to 3 days)—acute change determination
Transferrin (t½≈8 to 9 days)
Albumin (t½≈14 to 20 days)—more chronic determination
Total lymphocyte count
Anergy
Retinol-binding protein (t½≈12 hours)
Where is iron absorbed?
Duodenum (some in proximal jejunum)
Where is vitamin B12 absorbed?
Terminal ileum
What are the surgical causes of vitamin B12 deficiency?
- Gastrectomy
- excision of terminal ileum
- blind loop syndrome
Where are bile salts absorbed?
Terminal ileum
Where are fat-soluble vitamins absorbed?
Terminal ileum
Which vitamins are fat soluble?
K,A,D,E (“KADE”)
What are the signs of the following disorder:
Vitamin A deficiency
Poor wound healing
What are the signs of the following disorder:
Vitamin B12/folate deficiency
Megaloblastic anemia
Vitamin C deficiency signs
Poor wound healing, bleeding gums
Vitamin K deficiency
Decrease in vitamin K–dependent clotting factors (II, VII, IX, and X);bleeding; elevated PT
Chromium deficiency
Diabetic state
Zinc deficiency
Poor wound healing, alopecia, dermatitis, taste disorder
Fatty acid deficiency
Dry, flaky skin; alopecia
What vitamin increases the PO absorption of iron?
PO vitamin C (ascorbic acid)
What vitamin lessens the deleterious effects of steroids on wound healing?
Vit A
What are the common indications for total parenteral nutrition(TPN)?
- NPO >7 days
- Enterocutaneous fistulas
- Short bowel syndrome
- Prolonged ileus
What is the major nutrient of the gut (small bowel)?
Glutamine
What is “refeeding syndrome”?
Decreased serum potassium, magnesium, and phosphate after refeeding (viaTPN or enterally) a starving patient
What is an elemental tube feed?
Very low residue tube feed in which almost all the tube feed is absorbed
Where is calcium absorbed?
Duodenum (actively)
Jejunum (passively)
What is the major nutrient of the colon?
Butyrate (and other short-chain fatty acids)
What must bind B12 for absorption?
Intrinsic factor from the gastric parietal cells
What sedative medication has caloric value?
Propofol delivers 1 kcal/cc in the form of lipid!
Why may all the insulin placed in a TPN bag not get to the patient?
Insulin will bind to the IV tubing
How can serum bicarbonate be increased in patients on TPN?
Increase acetate (which is metabolized into bicarbonate)
What are “trophic” tube feeds?
Very low rate of tube feeds (usually 10 to 25 cc/hr), which are thought to keep mucosa alive and healthy
What is the best lab to check adequacy of nutritional status?
Prealbumin