calculation conversions & equations Flashcards
how many mL in 1 oz
29.57 mL
how many g in 1 oz
28.4 g
how many oz in 1 pint
16 oz
how many pints in 1 quart
2 pints
how many quarts in 1 gal
4 quarts
how many mL in 1 gal
3785 mL (128 oz)
how many mg in 1 gr
64.8 mg
phenytoin correction equation
total level / [(0.2 x albumin) + 0.1]
corrected calcium equation
[(0.4 - albumin) x 0.8] + calcium
specific gravity equation
g / mL
osmolarity equation (mOsm/L)
[(g/L) / MW] x dissociation # x 1000
what compounds have a dissociation # of 1
dextrose and mannitol
what compounds have a dissociation # of 2
KCl, NaCl, Na acetate, MgSO4
which compound has a dissociation # of 3
CaCl
which compound has a dissociation # of 4
Na citrate
isotonicity equation
E = (58.5 x isotonicity #) / (MW x 1.8)
how to determine ionization number
if dissociation # is 1, ionization is 1
each dissociation # adds 0.8 (1.8, 2.6, 3.4, 4.2)
mol and mmol equations
mol = g/MW & mmol = mg/MW
mEq equation
mEq = (mg x valence) / MW
which compounds have a valence of 1
ammonium chloride
KCl
potassium gluconate
sodium acetate
sodium bicarb
NaCl
which compounds have a valence of 2
calcium carbonate
calcium chloride
ferrous sulfate
lithium carbonate
magnesium sulfate
equation to determine a patient’s fluid requirements
1500 + [20 x (wt - 20)]
TEE equation
BEE x activity factor x stress factor
calorie conversion for carbs in EN
4 kcal/g
calorie conversion for fats in EN
9 kcal/g
calorie conversion for protein in EN
4 kcal/g
calorie conversion for carbs in PN
3.4 kcal/g for dextrose
4.3 kcal/g for glycerin
calorie conversion for protein in PN
4 kcal/g
calorie conversion for fats in PN
1.1 kcal/mL for 10%
2 kcal/mL for 20%
3 kcal/mL for 3%
nitrogen balance equation
protein intake / 6.25
nitrogen ratio
NPC:N
drug nutrient interactions with EN
warfarin - hold 1 hour before and after
tetracyclines/quinolones/levothyroxine - separate due to chelation
cipro - use IR and crush/mix
phenytoin - separate by 2 hours
BMI equation
kg/m2
IBW equation
50 or 45.5 + (2.3 x in)
AdjBW equation
IBW + 0.4(TBW - IBW)
what drug conversions require IBW
aminophylline/theophylline
acyclovir
what drug conversions require AdjBW
aminoglycosides
what drug conversions require TBW
LMWH, UFH, vancomycin and most drugs
CrCl equation
[(140 - age) / (72 x SCr)] x wt x 0.85 if female
when to use what wt in CrCl
if underweight use TBW
if normal weight or BMI <25 use IBW
if BMI >25 use AdjBW
what levels correlate with metabolic acidosis
low pH
low HCO3
what levels correlate with metabolic alkalosis
high pH
high HCO3
what levels correlate with respiratory acidosis
low pH
high CO2
what levels correlate with respiratory alkalosis
high pH
low CO2
anion gap equation
Na - Cl - HCO3
hendersen hasselbach equation
pH = pKa + log[salt / acid] for acid
pH = pKa + log[base / salt] for base OR
pH = (14 - pKb) + log[base / salt]
drug ionization in a solution equation
% ionization = 100 / [1 + 10^(pKa - pH)] for acid
100 / [1 + 10^(pH - pKa)] for base
ANC equation
[(% segs + % bands) / 100] x WBC
temperature equations
to C: (F - 32) / 1.8
to F: (C x 1.8) + 32
how much elemental calcium is in calcium carbonate
40%
how much elemental calcium is in calcium citrate
21%
how much elemental iron is in the different irons
gluconate 12%
sulfate 20%
sulfate, dried 30%
fumurate 33%
complex 100%
metoprolol IV to PO
1:2.5
furosemide IV to PO
1:2
loop diuretic conversions
furosemide 40 = torsemide 20 = bumetanide 1 = ethacrynic acid 50
insulin conversions
1:1 EXCEPT
BID NPH to glargine = 80% of NPH dose
toujeo to glargine/detemir = 80% of toujeo dose
levothyroxine IV to PO
0.75:1
opioid conversions between drugs
morphine 10:30
hydromorphone 1.5:7.5
oxycodone x:20
how to calculate TDD for insulin
0.5 units/kg/day
divide by 2 then divide rapid acting among meals
insulin to carb ratio for regular insulin
450 / TDD = gC covered by 1 unit
insulin to carb ratio for rapid acting
500 / TDD
correction factor for regular insulin
1500 / TDD = CF for 1 unit (use to find correction dose)
correction factor for rapid acting insulin
1800 / TDD (use to find correction dose)
correction dose for insulin
(BG now - target BG) / CF
friedewald equation
LDL = TC - HDL - (TG/5)
use only if TG <400
MWQ for torsion balance equation
SR / 0.05
BSA calculation
sq rt[(cm x kg) / 3600]
MAP equation
[(2 x DBP) + SBP] / 3