Clinical calculations

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Transcript Clinical calculations

Clinical
calculations
Number systems:
–Arabic
–Roman
Systems used for Drug
adminstration
Metric system
Apothecary system
Household system
METRIC SYSTEM
DECIMAL SYSTEM
THREE BASIC UNITS
– GRAM
– LITER
– METER
CONVERSIONS WITHIN METRIC
SYSTEM
LARGER to smaller:
multiply
smaller to LARGER:
divide
*Eliminate unnecessary “0”
*PRECEDE decimal with “0”
APOTHECARY SYSTEM
Roman numerals
Fractions
Name precedes number
Conversions within
apothecary system
Larger to smaller unit,
multiply
Smaller to larger unit,
divide
(By constant value)
CONVERSIONS WITHIN THE
HOUSEHOLD SYSTEM
LARGER TO SMALLER
UNIT
SMALLER TO LARGER
UNIT
(By constant value)
CONVERSIONS WITH THE
THREE SYSTEMS
Metric and apothecary equivalents
are approximations
Unequal values should be rounded
to nearest whole number
You must memorize
memorize
1
1
1
1
2
3
gr = 60 mg
g = 15 gr
L = 32 oz
oz = 30 mL
T = 30 mL
t=1T
OTHER DRUG RELATED INFO
ABBREVIATIONS
Drug forms
Drug measurements
Routes of administration
Times of administration
METHODS OF
CALCULATIONS
BASIC FORMULA
D = desired dose
H = on-hand dose
V = vehicle (form and amt that
drug comes)
Ratio and proportion
H and V: left side, known quantities
D and X: right side, desired dose
and unknown
(means & extremes, solve for “X”)
Fractional equation
–Similar to ratio/proportion
–Written as fraction
–Cross multiply, solve for “X”
Dimensional Analysis
1. Drug dose form (V)
2. Equivalency in units (H)
3. Conversion factor (C)
4. Drug order factor (D)
Individualizing doses
Dosing by actual body
weight
Convert pounds to
kilograms
Determine dose per body
weight
remember
I kg = 2.2 pounds
2.2 pounds = 1 kg
BASICS TO REMEMBER
Cc = mL
30 mL = 1 oz
2T=6t
5 mL = 1 t
Gr 1 = 60 mg
Gr xv = 1 g
QD
BID
TID
QID
Qh
NPO
STAT
PRN