Formulas and Conversions

1 tsp = _______mL

5mL

1 tbsp = __________mL

15mL

1 fl oz = ________mL

30 mL

1 cup = ________oz

8 oz

8 oz = mL

240 mL

1 pint = __________oz

16 oz

16 oz = __________mL

480 mL

1 quart = ___________pints

2 pints

2 pints = __________mL

960 mL

1 gallon = ___________quarts

4 quarts

4 quarts = ____________mL

3,840 mL

1 kg = __________lb

2.2 lb

1 oz = ___________g

28.4 g

1 lb =___________g, ___________oz

454 g, 16 oz

1 grain = _________mg

65 mg

mEq = mmol is a ________ conversion (ratio) for monovalent ions and ________ conversion (ratio) for divalent ions

1:1, 1:0.5

1 in = __________cm

2.54 cm

1 m = __________cm

100 cm

% w/v

x g/100 mL

%v/v =

x mL/100 mL

%w/w

x g/ 100 g

percentage strength =

100 / ratio strength

ratio strength =

100 / percentage strength

specific gravity =

weight of substance (g) / weight of equal volume of water (g)

Dilution and Concentration (changing strength or quantity)

Q1 x C1 = Q2 x C2

osmolarity (mosmol/L) =

[weight (g/L) / MW (g/mol)] x (#particles) x 1,000

isotonicity (E value) =

[(58.5)(i)] / [(MW of drug)(1.8)]

mols =

g / MW

mEq =

[mg x valence] / MW

ENTERAL NUTRITION

carbs = __________kcal/g

4 kcal/g

ENTERAL NUTRITION

protein = __________kcal/g

4 kcal/g

ENTERAL NUTRITION

fat = __________kcal/g

9 kcal/g

PPM --> Percent Strength

move the decimal to the LEFT 4 places

Percent Strength --> PPM

move the decimal to the RIGHT 4 places

PARENTERAL NUTRITION

dextrose monohydrate = ________kcal/g

3.4 kcl/g

PARENTERAL NUTRITION

amino acid solutions = ______kcal/g

4 kcal/g

PARENTERAL NUTRITION

ILE 10% = _________kcal/mL

1.1 kcal/mL

PARENTERAL NUTRITION

ILE 20% = _________kcal/mL

2 kcal/mL

PARENTERAL NUTRITION

ILE 30% = _________kcal/mL

3 kcal/mL

total energy requirement (TEE) Formula

TEE = BEE x stress factor x activity factor

Determining Fluid Needs when weight >20kg

1500 mL + (20mL)(weight in kg -20)

*can estimate using 30-40mL/kg/day

Grams of Nitrogen from Protein

Nitrogen (g) = protein intake (g) / 6.25

Corrected Calcium for Albumin <3.5

Corrected Ca2+ (mg/dL) = Serum Ca2+ Measured + [(4-Albumin Level) x 0.8]

BMI

weight (lbs)/[height (in)]^2 x 703

IBW

Males = 50 + (2.3 x inches >60)

Females = 45.5 + (2.3 x inches >60)

AdjBW

IBW + [0.4(TBW-IBW)]

Which weight to use for drug dosing: underweight patient

TBW

Which weight to use for drug dosing: MOST drugs if normal weight/obese

What are the exceptions to this rule?

TBW for most drugs for normal weight/obese patients

EXCEPTIONS:

IBW: aminophylline, acyclovir, levothyroxine, theophylline (normal weight, obese)

AdjBW: aminoglycosides (obese)

Flow Rates/Drop Factor

#drops/mL x mL/hr x 1hr/60 min = #drops/min

Cockcroft-Gault Equation

(140-age)/(72xScr) x weight (kg) (x 0.85 if female)

Arterial Blood Gases

ABG Fish Bone Values

pH / pCO2 / pO2 / HCO3 / O2 sat

pH value for acidosis

pH < 7.35

pH value for alkalosis

pH > 7.45

Respiratory Acidosis Labs

pH < 7.35 (LOW)

pCO2 > 45 (HIGH)

Respiratory Alkalosis Labs

pH > 7.45 (HIGH)

pCO2 < 35 (LOW)

Metabolic Acidosis Labs

pH < 7.35 (LOW)

HCO3 < 22 (LOW)

Metabolic Alkalosis Labs

pH > 7.45 (HIGH)

HCO3 > 26 (HIGH)

How to calculate the Anion Gap

Na - Cl - HCO3

pH for a weak acid

pH = pKa + log (salt/acid)

pH for a weak base

pH = pka + log (base/sakt)

percent ionization for a weak acid

100/(1+10^(pKa-pH))

same as base except pka - pH; start with pkA for weak Acids

percent ionization for a weak base

100 / (1 + 10^(pH - pKa))

same as acid except pH - pka

ANC

WBC x [(% segs + % bands)/100]

Calvert Equation (for carboplatin dosing)

Dose Carboplatin (mg) = Target AUC x (eGFR + 25)

*can substitute eGFR with CrCl if eGFR is not available

*target AUC is usually 2-8mg/mL x min

neutropenia

ANC < 1,000 cell/mm3

severe neutropenia

ANC < 500 cells/mm3

profound neutropenia

ANC < 100 cells/mm3

Celsius to Fahrenheit

F = (1.8 x C) +32

Fahrenheit to Celsius

C = (F-32)/1.8

Time to Burn (TTB)

TTB (with sunscreen in min.) = SPF x TTB without sunscreen (usually about 10 min.)

Mean, Median, Mode Definitions

Mean = average value

Median = middle value of an ordered list

Mode = most frequently occurring value

Risk Formula

Risk = # of subjects in the group that experienced the adverse outcome/total # of subjects

Relative Risk (RR) Formula

RR = risk in the treatment group/ risk in the control group

Relative Risk Reduction (RRR) Formula

RRR = 1-RR OR (% Risk in the Control Group - % Risk in the Treatment group)/Risk in the Control Group

Absolute Risk Reduction (ARR) Formula

(% risk in control group) - (% risk in treatment group)

Number Needed to Harm (NNH) Formula

1/ARR

*ARR expressed as a decimal

**round the number DOWN

Number Needed to Treat (NNT) Formula

1/ARR

*ARR expressed as a decimal

**round the number UP; think T looks like an up arrow

Odds Ratio Formula

Exposure: Outcome Present / Outcome Absent

Present: A / B

Absent: C / D

OR = AD/BC

Hazard Ratio (HR)

HR = (Hazard rate in treatment group) / (Hazard rate in control group)

Pack-Year Smoking History

Pack Years = cigarette packs per day x years smoked

*20 cigarettes in one pack

Steps for Initiating Basal-Bolus Insulin Regimen in a T1D Patient

1. Calculate TDD: 0.5u/kg/day using TBW

2. Split TDD in half (50% = basal; 50% = bolus)

3. Split bolus equally between meals

Insulin to Carb Ratio (ICR) for REGULAR insulin

Rule of 450 for Regular Insulin

450/TDD = ICR

ICR expresses how many grams of carbs are covered by 1 unit of regular insulin

Insulin to Carb Ratio (ICR) for RAPID-ACTING Insulin

Rule of 500 for RAPID-ACTING Insulin

500/TDD = ICR

ICR expresses how many grams of carbs are covered by 1 unit of rapid-acting insulin

Correction Factor for REGULAR Insulin

Rule of 1500

1500/TDD = Correction Factor for 1 unit of Regular Insulin

Correction Factor for RAPID-ACTING Insulin

Rule of 1800:

1800/TDD = Correction factor for 1 unit of rapid-acting insulin

Correction Dose

(Current BG - Target BG)/ Correction Factor = Correction Dose

Friedwald Equation

LDL = TC - HDL - (TG/5)

***don't use if TG > 400***

MWQ (minimum weighable quantity)

sensitivity requirement / acceptable error rate (usually 0.05)

Body Surface Area (BSA)

BSA (m2) = Square root of {(Height cm x Weight kg)/3600}

Bioavailability Formula

F(%) = 100 x AUCoral/AUCiv x Doseiv/Doseoral

Volume of Distribution (Vd)

Vd= amount of drug in the body / plasma drug concentration

Clearance (Cl)

Cl = (F x Dose)/AUC

*F=1 for IV drugs!

or

Cl = ke x Vd

Elimination Rate Constant (ke)

ke = Cl/Vd

Predicting Drug Concentrations

C2 = C1 x e^-kt

Ke = ln(C1/C2)/t

Half-Life (first order)

t1/2 = 0.693/ke

loading dose (LD)

LD = (desired concentration x Vd) / F

Mean Arterial Pressure (MAP)

MAP = [(2 x diastolic) + systolic pressure]/3

Phenytoin Corrected fro Albumin <3.5

Corrected Phenytoin = Phenytoin Measured/ [(0.2 x albumin) + 0.1]

KCl Solution (oral) to tablets

KCl 10% = 20 mEq/15mL

Calcium Salts: % elemental calcium

-calcium citrate

-calcium carbonate

calcium citrate = 21% elemental calcium

calcium carbonate = 40% elemental calcium