Ex 2: Determining Estimating Energy and protein needs Flashcards
Why is there no formula/plan for determining calorie and protein needs that will accurately determine calorie and protein needs for every patient every time?
1) Formulas are based on groups and may not address an individual 2) Energy requirements differ among patients at the same height/weight
TEE
Total Energy expenditure = BEE/BMR + PA + TEF (Basal Energy Expenditure, Basal metabolic rate, Physical activity, Thermic effect of food)
TEE w/medical diagnosis
BEE + PA + TEF + Physiological stress
BMR/BEE vs REE/RMR similarities
1) Estimate calories needed at rest for 24h 2) minimum calories to keep the body going
BEE/BMR vs REE/RMR differences
1) BEE/BMR measured under more restrictive condition (need sleep) 2) REE/RMR - at rest but no sleep requirement
Identify formulas for determining calorie needs most commonly used in the hospital setting.
1) Harris Benedict Equation 2) Mifflin-St. Jeor Equation 3) kcal/kg
What do the Harris Benedict Equation and Mifflin-St. Jeor Equation provide an estimation for? What additional calculations are completed to estimate energy needs?
REE/RMR ; (illness, inactivity factor, increase of temperature,
How does fever impact a patient’s BEE?
Raises BMR; 13% for each degree celsius or 7% for each degrees Fahrenheit
Estimating needs using kcal/kg
Do not make adjustments; mild to moderate illness 25-30 kcal/kg; moderate to severe illness 30-35 kcal/kg; obesity 22 kcal/kg
Stages of weight gain
Stage 1 - rapid/mostly water retention stage 2 - minimal despite adequate protein and calories (diuresis of fluid) Stage 3 - True weight gain where lean tissue and fat are restored.
What is the gold standard for determining energy needs?
Indirect Calorimetry
When is indirect calorimetry an appropriate and desirable mechanism for determining energy needs?
When measuring in the critically ill patient (Hypermetabolic, weaning off a ventilator, and inappropriate response to nutrition support.
The results of indirect calorimetry must be adjusted based on what factor?
must adjust for activity
Refeeding syndrome is a concern in what type of patient?
Patients who have undergone significant weight loss ; classic marasmus, absence of nutrition for 1-2 weeks, prolonged fasting, anorexia nervosa
When does refeeding syndrome typically occur?
4 days
Physiology of refeeding syndrome
Rapid uptake of glucose causes uptake of phosphorous. Results in dangerous hypophosphatemia, lowered amounts of electrolytes, glucose, potassium, magnesium in serum; can leads to cardiac dysfuntion
What steps must be undertaken to prevent refeeding syndrome?
1) Feeding should aim to meet 1.0 x BEE (not total energy needs) and be advanced slowly over 1-3 days 2) monitor for evidence of hypophosphatemia, hypokalemia, hypo magnesemia, fluid overload, congestive heart failure, hyperglycemia 3) electrolytes prn
RDA for protein
0.8 g/kg/day
Protein requirements for adults
Min - 0.54 ; normal - 0.8 -1.0; catabolic states - 1.2 -2.0 ; critically ill/trauma - 1.5 - 2.0
Children protein requirements
3.0 g/kg
The hypermetabolic patient requires what % of calories as protein to achieve positive nitrogen balance?
15-20% of calories as protein to achieve nitrogen balance
Nitrogen needs: normal vs ill
Normal: 1g N/300 kcal ; ill 1g N/ 120-180 kcal
Protein to nitrogen conversion
g protein x 0.16 = g Nitrogen or g protein / 6.25
What is an appropriate Calorie:N ratio?
150:1 17% of calories from protein
