Chapter 9 - 13: Calculations Flashcards
Ratio strength
one unit of solute contained in the total amount of the soln or mixture
specific gravity
the ratio of the density of the substance to the density of water (in g/mL)
water’s specific gravity is 1 (1g = 1 ml), if specific gravity < 1 it is lighter than water
dissociation vs valence
- dissociation: how many ions it breaks up into
- valence: amount of positive charge (Ca2+ counts as 2 for valence, but 1 for dissociation)
calories source in TPN
- carbs
- fat
- protein
forr pharmacy calculations, calories refers to kcals
types of parenteral admixtures
- 2in1: contains the macronutirents dextrose and amino acids (lipids infused separately)
- 3 in 1: contains the macronutrients dextrose, amino acids, and lipids
does paretneral nutrition require a filter
yes, dt risk of precipitate
daily fluid needs calculation
1500 mL + [(2mL)(kg - 20)]
total energy expenditure equaton
baseline energy expenditure x activity factor x stress factor
Stress factors
- minor surgery: 1.2
- infection: 1.4
- major trauma, sepsis, burns < 30% BSA: 1.5
- burns > 30% BSA: 1.5-2
baseline energy expenditure equation
- male: 66.47 + (13.75 x kg) + (5 x cm) - (6.76 x age)
- female: 6551 + (9.6 x kg) + (1.85 x cm) - (4.68 x age)
calories per gram of carbs
4 kcal/gm
calories per gram of fat
9 kcal/gm
calories per gm of protein
4 kcal/gm
calories per gram of dextrose monohydrate
3.4 kcal/gm
calories per gm of glycerol/glycerin
4.3 kcal/gm
calories per mL of injectable lipid emulsion 10%
1.1 kcal/mL
calories per mL of injectable lipid emulsion 20%
2 kcal/mL
intralipid; smoflipid
calories per mL of injectable lipid emulsion 30%
3 kcal/mL
calories per gm of amino acid solutions
4 kcal/gm
-
protein requirements
- if ambulatory: 0.8 - 1.0 g/kg/day
- if hospitalized or malnourished: 1.2 - 2.0 g/kg/day
non-protein calories to nitorgen ratio
- 1g of N = 6.25 g of protein
- divide non-protein calories (NPC; dextrose and lipids) by g of nitrogen
desired NPC:N ratio
- 80:1 in the most severely stressed patients
- 100:1 in severely stressed pts
- 150:1 in unstressed pt
examples of amino acid solutions
- Aminosyn
- FreAmine
- Travasol
- TrophAmine
- Clinisol
examples of drugs forumalted in a lipid emulsion
- propofol
- clevidipine
sodium in PN
- sodium chloride
- sodium acetate (preferred if acidosis because it is converted into bicarb)
- sodium phosphate
how to reduce occurence of calcium-phosphate precipitates
- use calcium gluconate
- add phosphate first (after dextrose and amino acids), followed by other PN components. agitate the soln, then add Ca
- If Ca and phosphate must be added together, do NOT excceed 45 mEq/L
MVI-13 vs MVI-12 in parenteral nutrition
12 does NOT have vitK
can insulin be added to parenteral nutrition
yes, half of the previous day’s sliding scale requirement can be added as regualr insulin
warfarin feeding interactiosns
hold tube feeds one hr before and one after warfarin
example of drugs that will chelate to polyvalent cations (Ca, Mg, Fe) and neeed to be administered separate from tube feeds
- tetracyclines
- quinolones
- levothyroxine
ciprofloxacin feeding considerations
PO susspension not compaitible with tube feeds because its oil suspension can adhere to tube, instead, crush tabs and mix with water
phenytoin feeding considerations
- levvels reduced when drug binds to feeding soln
- separate tube feeds by 2 hrs
what BMI is considered underweigh
< 18.5
normal BMI
18.5 - 24.9
overweight BMi
25 - 29.9
obses Bmi
> 30
