Nutritional Issues in the Hospital

Question 1

When does nutritional depletion occur?

Answer 1

• This is when you ought to be moving towards feeding
• Normal, not sick = 10-14 days
• Normal and pretty sick or nutritionally depleted and not sick = 5-7 days (oxidizing more)
• Nutritionally depleted and sick = 3-5 days
• Need to assess pre-morbid nutritional state

Question 2

Nutritional Assessment

Answer 2

• Hx of alcoholism, homelessness, unusual diet, elderly, disabled
• Chronic medical problems: GI, pulm, renal, cancer
• Prior weight loss before or in hospital
• Weight for height BMI

Question 3

How much to feed?

Answer 3

• Energy intake = expenditure
• Harris benedict equation
• Indirect calorimetry
• Swan Ganz AV O2 balance using the fick principle
• Sick-o-meter: 25-35 kcal/kg/day, the sicker the person, the greater the energy requirement. The bigger the person the greater the energy requirement

Question 4

What route to feed?

Answer 4

• Enteral: feed the GI tract and body; may improve gut barrier function
• Parenteral: requires central IV catheter (risk of placement, bleeding, infection) give AA, glucose and lipid emulsion IV.

Question 5

What to feed?

Answer 5

• Ask nurse or dietician for a copy of the hospital’s enteral feeding formulary.
• 1 kcalml
• 44g protein /l
• 152 g/l carb
• 37 g/l fat
• vitamins, micronutrients
• 1.321 l to get “RDA” for a 70 kg person

Question 6

Initiating tube feedings

Answer 6

• place N/G tube
• start tube feeding slowly (10-20 ml/hr) and check residuals after 5-10 hrs
• Gradually increase flow rate and continue to check residuals. If the residual >100 ml reduce the flow rate
• If residauls persist, have patient repositioned, elevate head of bed, right lateral decubitus position

Question 7

How do we determine the adequacy of what we are feeding?

Answer 7

• check and record total calories per day
• overfeeding causes hyperglycemia; may take 1-2 days to show up because glycogen pool buffers; may take 1-2 days to resolve because glycogen pool needs to deplete
• nitrogen balance = 1 wk after you get your target infusion

Question 8

UUN (urine urea nitrogen)

Answer 8

If BUN is stable, then most of the UUN represents the oxidation of the protein

• usual protein requirement is 0.5-0.8 g/day
• higher requirements in burns and post-op patients

g protein out = (2g skin + 2g stool + 24 hr UUN) x 6.25 (corrects grams of nitrogen to grams of protein)

Question 9

Water soluble vitamins vs. Fat soluble vitamins

Answer 9

Water soluble pool

Question 10

Micronutrients

Answer 10

• Zn deficiency - diarrhea
• Fe deficiency - anemia, immune dysfunction
• Chromium deficiency - insulin resistance
• Selenium deficiency - CHF (Keshan’s Disease)

Question 11

Nutrients: Arginine

Answer 11

• not very stable in enteral formulations “conditionally essential”
• precursor for NO
• direct immunomodulatory measured by response to mitogens
• Supplementation improves nitrogen balance
• Stimulates GH and insulin secretion

Question 12

Nutrients; Glutamine

Answer 12

• Preferred nutrient for gut epithelium
• “conditionally essential” as requirements increase with serious illness
• Supplementation increases immune function, gut histology, and barrier function
• Important gluconeogenic precursor so supplementation improves nitrogen balance

Question 13

Special lipids

Answer 13

• very little omega 3 FA in standard “house formulas”

- LC polyunsaturated fats are precursors for leukotrienes and PGs

Question 14

Special conditions

Answer 14

• Resp failure: high carb diet and overfeeding increase respiratory quotient/repsiratory exchange ratio, and therefore increased work of breathing and vent pressures (higher fat and less calories may be beneficial)
• Liver failure: diets lower in aromatic AA and higher in branched chain AA may be helpful because aromatic AA can turn into “false neurotransmitters”
• Renal failure: volume overload is a problem; protein oxidation leads to increased BUN. Increased protein catabolism, urinary protein loss with nephrotic syndrome
• Burns, trauma, post-op: increased energy requirement may be as high as 30-35 kcal/kg/day; may have increased protein requirement (1-1.5 g/kg/day)
• Re-feeding: complications of hypophosphatemia, hypokalemia, diarrhea, Wernicke’s; begin with thiamin, folate and multivatimin solution intravenously.