Parenteral and Enteral Nutrition - Lecture 1

Question 1

Calculating weights

Answer 1

dry weight = admit weight = actual weight

Question 2

IBW formula

Answer 2

male = 50 kg + (2.3 x inches over 60”)
female = 45.5 kg + (2.3 x inches over 60”)

Question 3

Dosing body weight (DBW) formula

Answer 3

DBW = IBW + 0.4(wt - IBW)
use if actual body weight is 130% or more of IBW
applies for dosing certain drugs (antibiotics)

Question 4

Nutrition body weight (NBW) formula

Answer 4

NBW = IBW + 0.25(wt - IBW)
use if actual body weight is 130% or more of IBW
applies for calculating fluid, electrolyte, and nutrition parameters

Question 5

Shift of importance

Answer 5

nutrition support: preserve lean body mass, maintain immune function, avert metabolic complications
now called nutrition therapy

Question 6

Alleviate the stress response

Answer 6

provide macro and micronutrient delivery
careful glycemic control
being enteral nutrition early

Question 7

Benefits of early initiation

Answer 7

decrease in disease severity
decrease in complications
decrease in ICU length of stay
increase in patient outcomes

Question 8

Nutritional assessment

Answer 8

risk factors for malnutrition
history
anthropometrics
classifications of malnutrition
nitrogen balance

Question 9

Nutritional assessment - risk factors for malnutrition

Answer 9

UBW (under body weight) = 20% below IBW
involuntary weight loss > 10% within 6 mo: surrogate marker, consider otehr disease states (cancer, TB)
NPO > 10 days (ICU pt): clinically we use inadequate intake > 7 days
gut malfunction (ICU pt)
mechanical ventilation (ICU pt)
increased metabolic needs (ICU pt): trauma/burn pts, high dose steroids
alcohol/substance abuse: decreased functioncal proteins, empty calories
protracted nutrient losses: chronic disease states (HIV/AIDs, cancer)

Question 10

Determination of nutrition risk

Answer 10

risk factors for malnutrition
intake anticipated to be insufficient
identify who will benefit most from early nutrition therapy
all hospitalized pts within 48 hrs
many screening and assessment tools exist - NUTRIC and nutritional risk score (NRS-2022)

Question 11

NUTRIC

Answer 11

high risk: 6-10 (5-9 w/o IL-6)
low risk: 0-5 (0-4 w/o IL-6)

Question 12

Nutritional assessment - history

Answer 12

dietary: diet PTA, intake, swallowing, ulcers, h/o weight loss, anorexia, vomiting, diarrhea
medical: surgical history, PMH
medications: decrease nutrient absorption, alter taste, increase/decrease appetite, N/V

Question 13

Nutritional assessment - anthropometrics

Answer 13

science of measuring the human body
somatic (muscle) protein status: weight, triceps skin fold, arm muscle circumference, physical appearance
look at trends

Question 14

Visceral protein status

Answer 14

transthyretin (prealbumin): half life (days) - 2-3; normal serum concentration - 15-40 mg/dL

Question 15

Visceral protein status may not

Answer 15

accurately represent nutrition status in the ICU setting

Question 16

C-reactive protein (CRP)

Answer 16

positive acute phase reactant (increased by at least 25% during inflammation)
normal < 1mg/dL (in clinical practice)
use to assess accuracy of prealbumin (if prealbumin low, check CRP)
prealbumin is falsely decreased in the presence of inflammation: prealbumin decreases as CRP increases –> inflammation; prealbumin decreases as CRP normal –> malnutrition

Question 17

Nutritional assessment - classifications of malnutrition: protein-calorie malnutrition

Answer 17

marasmus
decrease total intake and/or utilization of food
wasting of skeletal muscle and SQ fat
immunosuppression in severe cases
cachectic appearance

Question 18

Nutritional assessment - classifications of malnutrition: protein malnutrition

Answer 18

kwashiorkor
adequate caloric intake; relative protein malnutrition
catabolic (breaking down proteins) trauma pts, burn pts

Question 19

Nutritional assessment - classifications of malnutrition: mixed

Answer 19

chronically ill starved pts who are metabolically stressed
decrease in visceral proteins, poor wound healing, immunocompromised

Question 20

Marasmus

Answer 20

protein/calorie
sx: peeling and alternatively pigmented skin, hair loss, edema, swelling, skin folds are formed
wasting of muscles: quite evident
treatment: provide a well-balanced substrate, consider addition of vit B

Question 21

Kwashiorkor

Answer 21

protein only
sx: large belly, diarrhea, change in skin pigment, decreased muscle mass, failure to gain weight, fatigue, hair changes
wasting of muscles: not evident
treatment: provide carbs followed by high protein

Question 22

Nutritional assessment - nitrogen balance

Answer 22

measure of urinary excretion of nitrogen as urea nitrogen (urinary urea nitrogen; UUN) - measure of substance in vs measure of substance out (how much extra nitrogen is your body excreting in the form of urine)
nitrogen released from protein catabolism –> converted to urea and excreted in the urine
stress increase, protein catabolism increase and UUN increase
measured from 24-hour urine collection
represents 85-90% of total nitrogen excretion

Question 23

Nitrogen balance - non-urinary sources of nitrogen loss

Answer 23

sweat, feces, respirations, gastrointestinal fistula, wound drainage, skin exfoliation, burns

Question 24

Nitrogen balance study used to assess

Answer 24

the adequacy of protein repletion
ideal goal: +3 to +5 grams (want positive nitrogen balance)

Question 25

Nitrogen balance formula

Answer 25

nitrogen balance = (N in) - (N out)
N in = 24 hr protein intake (g)/6.25
N out = 24 hr UUN (g) + factor (3-5 g)
generally use 4 g as your estimate

Question 26

Nutritional requirements

Answer 26

caloric requirements
protein requirements

Question 27

Estimating caloric needs

Answer 27

harris-benedict equation:
basal energy expenditure (BEE) - bare minimum amount of energy/calories to maintain life
OR
resting energy expenditure (REE)

Question 28

Stress or activity factor to use with harris-benedict equation

Answer 28

maintenance: % of REE = 120-130, activity factor = 1.2-1.3
mild, moderate: % of REE = 150, activity factor = 1.5
severe, thermal burn: % of REE = 200+, activity factor = 2
TEE = REE x stress/activity factor(s)

Question 29

Non-stressed, non-depleted

Answer 29

20-25 kcal/kg/day

Question 30

Trauma/stress/surgery, critically ill, major burns

Answer 30

25-30 kcal/kg/day
basically use for anyone in the hospital

Question 31

Obesity: BMI 30-50

Answer 31

11-14 kcal/kg/day (actual body weight)

Question 32

Obesity: BMI > 50

Answer 32

22-25 kcal/kg/day (ideal body weight)

Question 33

Indirect calorimetry

Answer 33

preferred method for critically ill pts
provides energy expenditure (REE, RQ) at that ONE point in time, then extrapolated to 24 hrs
abbreviated weir equation:
TEE = REE x 1.2 (using activity factor of 1.2)
for all energy production, oxygen is consumed and carbon dioxide is produced: RQ = Vco2/Vo2

Question 34

Respiratory quotient values

Answer 34

overfeeding: lipogenesis - RQ = 1-1.2; carbohydrate oxidation - RQ = 1
normal: mixed substrate - RQ = 0.85-0.95
underfeeding: protein oxidation - RQ = 0.82; fat oxidation - RQ = 0.71; ethanol - RQ = 0.67
goal: 0.85-0.95 (monitor once weekly)

Question 35

Protein requirements

Answer 35

maintenance: 0.8-1 gm/kg/day
mild-moderate stress (floor pts): 1-1.5 gm/kg/day
moderate-severe stress (ICU, trauma, surgery, burn): 1.5-2 gm/kg/day
obesity (BMI > 30): 2 gm/kg/day (ideal body weight)
severe obesity (BMI >/= 40): 2.5 gm/kg/day (ideal body weight)

Question 36

Additional considerations

Answer 36

adequate calories must be present for appropriate protein utilization: ensure adequate NPC, usually include protein in calculation of total calories
protein tolerance may be decreased in some disease states (renal and hepatic failure)

Question 37

Non-protein calorie (NPC) distribution

Answer 37

standard distribution (70/30): 70-85% dextrose, 15-30% fat
adjust based on tolerance: blood sugars, triglycerides, RQ from indirect calorimetry
100/0 may be utilized during sepsis or bloodstream infections (leave out fat)