PHRM 534 Milliequivalent, Osmolarity, and TPN

Define milliequivalent (mEq)

Amount of chemical activity of an electrolyte

What is the formula for mEq?

mEq = (mg x valence) / MW

What equation describes the relationship between mEq and osmolarity?

mmol x valence = mEq

What is the formula for milliosmoles (mOsm)?

mOsm = (mg x i-value) / MW

What is the formula for osmolarity (mOsm/L)?

mOsm/L = (mOsm/volume) x 1000

Define isotonic

275-310 mOsm/L

Solute concentration is equal inside and outside the cell

No net movement of water

Define hypertonic

> 310 mOsm/L

Higher solute concentration outside the cell causing water to flow out of the cell

Crenation occurs

Define crenation

Blood cells shrink

Define hypotonic

< 275 mOsm/L

Lower solute concentration outside the cell causing water to flow into the cell

Hemolysis occurs

Define hemolysis

Blood cells swell and eventually burst

What is the osmolarity of D5W?

250 mOsm/L

What is the osmolarity of NS?

308 mOsm/L

What is the osmolarity of SWFI?

0 mOsm/L

What is the osmolarity range for peripheral IV administration?

154-600 mOsm/L

What is the osmolarity range for peripheral IV administration with monitoring?

600-900 mOsm/L

What is the osmolarity range for central IV administration?

< 154 mOsm/L

> 900 mOsm/L

What is the formula for total energy expenditure (TEE)?

TEE = BEE x activity factor x stress factor

What are the components of TPN?

Macronutrients

Micronutrients

Water

Potential other additives

Which TPN components are macronutrients?

Protein (amino acids)

Carbohydrates (dextrose)

Fat (lipids)

Which TPN components are micronutrients?

Electrolytes

Vitamins

Trace elements

What are other potential additives for TPN?

Folic acid

Regular insulin

Heparin

What is the rounding rule for macronutrients?

Round to a whole number

What is the rounding rule for micronutrients?

Round to one decimal place

What is the rounding rule for water?

Round to a whole number

Define 2-in-1 TPN formulations

Two macronutrients in one bag

Amino acids and dextrose

Define 3-in-1 TPN formulations

Three macronutrients in one bag

Amino acids, dextrose, lipids

How many kcal do amino acids have?

4 kcal/g

How many kcal does dextrose have?

3.4 kcal/g

How many kcal do lipids have?

10% = 1.1 kcal/mL

20% = 2 kcal/mL

30% = 3 kcal/mL