Flashcards in Dosing and Calculations Deck (15):

1

## Ratio

### the relative magnitude of two like quantities (Ie: 20g:4g terms must be in the same units)

2

## Proportion

###
An expression of the equality of two ratios

A/B=C/D

Ex: If 3 tablets contain 975 milligrams of aspirin, how many milligrams should be obtained in the 12 tablets? 3900

3

## Inverse Proportion

###
If 10 pints of a 5% solution are diluted to 40 pints what is the percentage strength?

(10)(0.5)=(40)(x) is 1.25%

4

## Dimensional analysis

###
Canceling out units

A medication order calls for 1L dextrose 10% infusion to be administered over an 8hr period. Using an IV pump set that delivers 10drops/milliliter how many drops a minute should be delivered to the patient?

1000ml/8hr X 10 drops/mL X 1hr/60 minutes = 21 drops/min

5

## Metric system

###
1000mcg=1mg

1000mg=1g

1000g=1kg

1inch=2.54cm

1tsp=5mL

2.2lb=1kg

6

## Median effective dose

### Amount that produces desired intensity of effect in 50% of individuals tested

7

## Median toxic dose

### amount that produces toxic effects in 50% of individuals tested

8

## Minimun effective concentration

### Minimum dose we see working in the blood

9

## Minimum toxic concentration

### minimum toxic level in the blood

10

## Pediatrics

###
Neonate- birth to 1 month

Infant- 1 month to 1 year

Early childhood- 1 year to 5 years

Late childhood- 5 years to 12 years

Adolescence- 13 years to 17 years

11

## Pediatric Rx restrictions

###
Consider age and weight

Based on weight often expressed as mg/kg

Based on body surface area

12

## Expressions of Concentrations

###
%w/v=grams/100mL

%v/v=mL/100mL

%w/w=grams/100grams

13

## IBW

###
Males- IBW= 50kg + 2.3kg for each inch over 5 ft

Females- IBW= 45.5kg + 2.3kg for each inch over 5ft

14

## Adjusted Body Weight

### AjBW=IBW + 0.4(ABW-IBW)

15