Calculations IV: Clinical

Question 1

BMI equation

Answer 1

BMI = kg/m2

Question 2

IBW equations

Answer 2

male: 50 + (2.3 x “ >5ft)
female: 45.5 + (2.3 x “ >5ft)

Question 3

AdjBW equation

Answer 3

ABW = IBW + 0.4(TBW-IBW)

Question 4

When TBW is >/= ____% of IBW, must consider drug in question for which body weight to use

Answer 4

When TBW >/= 120% of IBW

Question 5

When TBW >/= 120% of IBW, which medications require IBW for calculations

Answer 5

aminophylline
theophylline
acyclovir
levothyroxine

Question 6

When TBW >/= 120% of IBW, use TBW for these drugs

Answer 6

LMWH
UFH
vancomycin

Question 7

When TBW >/= 120% of IBW, use AdjBW for these drugs

Answer 7

aminoglycosides

Question 8

CrCl equation

Answer 8

[140-Age] x IBW (x0.85 if female)
72 x SCr

Question 9

Acid Base normal values

Answer 9

7.35 / 40 / 24
pH /CO2/HCO3

Question 10

Anion Gap
equation
normal value

Answer 10

AG = Na - Cl - HCO3
Normal is <12

Question 11

When pH = pKa, ___% will be ionized and ___% will be in salt form (unionized)

Answer 11

50% and 50%!!

Question 12

What equation is used to determine the pH of a solution with a weak acid

Answer 12

pH = pKa + log [salt/acid]

Question 13

What equation is used to determine the pH of a solution with a weak base

Answer 13

pH = pKa + log[base/salt]

Question 14

How to calculate pKa from pKb

Answer 14

pKa + pKb = 14

Question 15

equation for % ionization of an acid

Answer 15

% ionization = 100
1+ 10^(pKa-pH)

Question 16

equation for % ionization of an base

Answer 16

% ionization = 100
1+ 10^(pH-pKa)

Question 17

Calcium carbonate is ___% elemental Ca and calcium citrate is ___% elemental Ca

A. 40% and 21%
B. 21% and 40%
C. 50% and 21%
D. 21% and 45%
E. 40% and 20%

Answer 17

A. 40% and 21%

Question 18

a patient is taking aminophylline, but the provider wants to change to theophylline. How do we convert?

Answer 18

aminophylline (0.8) = theophylline

Question 19

how are aminophylline and theophylline dosed?

Answer 19

based on IBW

Question 20

How are UFk, LMWH and vanco dosed

Answer 20

based on TBW

Question 21

How are aminoglycosides dosed

Answer 21

based on adjBW
AdjBW = IBW + 0.4(TBW-IBW)

Question 22

How do we calculate ANC?
What are the thresholds for neutropenia, severe neutropenia and profound neutropenia?

Answer 22

ANC = WBC x (% segs + %bands)/100

<1000 = neutropenia
<500 = severe neutropenia
<100 = profound neutropenia