Figure 6-1
1 g = how many mg? 1. Take the 1-gram expression and place the decimal point in the proper place. 1 gram is the same as 1.0 gram (decimal point in place) 2. Move that decimal point three places to the right. Note that as the decimal point is moved, zeros must be added to mark each movement. 1.0 gram = 1.000. = 1,000 milligrams (after converting, you remove the decimal point if no digits follow it.) 1.5 g = how many mg? 1. The 1.5-gram expression has the decimal point already in place. 2. Move that decimal point three places to the right. Remember to add zeros to mark each movement. 1.5 grams = 1.500. = 1,500 milligrams Figure 6-2
1,000 mg = how many g? 1. Place decimal point in proper place. 1,000 mg = 1000. mg 2. Move that decimal point three places to the left. 1000. mg = 1.000. g or 1 g 2,500 mg = how many g? 1. Place decimal point in proper place. 2,500 mg = 2500. mg 2. Then move decimal point three places to the left. 2500. mg = 2.500. g or 2.5 g Figure 6-3
45 kg = how many g? 1. Place decimal point in proper place. 45 kg = 45. kg 2. Move that decimal point three places to the right. Remember to add zeros to mark each movement. 45. kg = 45.000. g or 45,000 g Figure 6-4
25 g = how many kg? 1. Place decimal point in proper place. 25 g = 25. g 2. Move that decimal point three places to the left. Remember to add zeros to mark each movement. 25. g = 0.025. kg or 0.025 kg Figure 6-5
2.525 L = how many ml? 1. 2.525 L: move decimal point three places to right. 2. Then 2.525 L = 2.525 ml = 2525 ml. Figure 6-6
500 ml = how many L? 1. Place decimal point in proper place. 500 ml = 500. ml 2. Then move decimal point three places to the left. Remember to add zeros to mark each movement. 500. ml = 0.500. L or 0.500 L Figure 6-7
Celsius scale Fahrenheit scale Boiling point of pure water 100 212 100 180 37 98.6 Freezing point of pure water 0 32 0 Figure 6-8
Luerlock syringe hub Plunger 1 2 1 1 2 2 2 1 2 3mL Needle Barrel Rubber plunger tip Figure 6-9
Figure 6-10
Figure 6-11
108 ml 892 ml 1000 ml + = READY TO USE (reconstituted) SOLUTE (concentrated) SOLVENT (water) SOLUTION (diluted) Figure 6-12
Figure 6-13
Figure 6-14A
(B) Figure 6-14B
(C) Figure 6-14C
3 ml 3mL 3 ml 3mL 2 ml 2 2 ml 1 ml 1 1 /2 2 2 1 /2 1 1 /2 2 1 /2 1 ml 2 ml 1/2 1 1 1 /2 2 1 ml 1 1 /2 1 1 /2 1 ml 2 ml 1/2 1 1 1 /2 2 Withdraw 1 ml cefazolin solution for the ordered dosage of 225 mg 2 1 /2 2 1 /2 3 ml 3mL 3 ml 3mL + = Inject 2 ml air into sterile water diluent vial Withdraw 2 ml sterile water Add 2 ml sterile water to cefazolin 500 mg powder and shake well. Initial and date vial Make cefazolin 500 mg in 2.2 ml reconstituted solution for cefazolin 225 mg/ml (A) Figure 6-15A
(B) Figure 6-15B
Figure 6-16
Table 6-1 Household System Measures Unit Abbreviation Equivalents cup drop (s) cup gt (gtt) 1 cup = 8 fl oz no standard equivalent ounce (fluid) fl oz 2 T = 1 fl oz ounce (weight) oz 16 oz = 1 lb pint pound quart pt lb qt 1 pt = 2 cups = 16 fl oz 1 lb = 16 oz 1 qt = 2 pt = 4 cups = 32 fl oz tablespoon* T (or tbs) 1 T = 3 t teaspoon t (or tsp) 3 t = 1 T *tablespoon is the larger unit and is expressed with the capital or large T, while teaspoon is the smaller unit and is expressed with the lowercase or small t. Table 6-1
Table 6-2 Apothecary System Weight Measures Unit Abbreviation Equivalents dram (weight) grain dr gr 8 dr = 480 gr = 1 oz 60 gr = 1 dr ounce (weight) oz 12 oz = 1 lb pound minim lb minim 1 lb = 12 oz 60 minim = 1 fl dr d ram (volume) fl dr 8 fl dr = 480 minim = 1 fl oz ounce (volume) fl oz 16 fl oz = 1 pt pint quart Gallon pt qt gal 2 pt = 1 qt 4 qt = 1 gal 1 gal = 4 qt = 8 pt Table 6-2
Table 6-3 Common Metric Prefixes and Their Value Prefix* Value Decimal Representation Fractional Representation micro- (mc or ) milli- (m) centi- (c) one millionth of a unit one thousandth of a unit one hundredth of a unit 0.000001 base unit 1/1,000,000 base unit 0.001 base unit 1/1,000 base unit 0.01 base unit 1/100 base unit kilo- (k) one thousand units 1000 times base unit * Additional metric prefixes can be found in Appendix G Table 6-3
Table 6-4 Important Metric Relationships Mass and/or Weight Unit Equivalents 1 microgram (mcg, g) 0.000001 g = 0.001 mg = 1 mcg 1 milligram (mg) 0.001 g = 1 mg = 1, 000 mcg 1 gram (g) 1 g = 1,000 mg = 1,000,000 mcg 1 kilogram (kg) 1 kg = 1000 g Volume Unit Equivalents 1 milliliter (ml) 0.001 L = 1 ml 1 liter (L) 1 L = 1,000 ml Length Equivalents 1 micrometer (mcm, μm) 0.000001 m = 0.01 cm = 0.001 mm = 1 mcm 1 millimeter (mm) 0.001 m = 0.1 cm = 1 mm = 1000 mcm 1 centimeter (cm) 0.01 m = 1 cm = 10 mm = 10,000 mcm 1 meter (m) 1 m = 100 cm = 1000 mm = 1,000,000 mcm 1 kilometer (km) 1 km = 1000 m Table 6-4
Table 6-5 Metric System Guidelines 1. Arabic numbers are used to designate whole numbers: 1, 25, 2500, etc. 2. Decimal fractions are used for quantities less than one: 0.1, 0.01, 0.001, etc. 3. To insure accuracy, place a zero before the decimal point: 0.1, 0.01, etc. 4. The Arabic number precedes the metric unit of measurement: 1 g, 30 ml, etc. 5. Abbreviations are generally used. 6. If the term is used, the prefixes are written in lowercase letters: milli, centi, etc. 7. Capitalize the measurement and symbol when it is named after a person: Celsius (C) 8. Periods are not used with most abbreviations or symbols. 9. Abbreviations for units are the same for singular and plural forms. An s is not added to indicate the plural form. 10. Separate the amount from the unit so the number and unit of measure do not run together because the unit can be mistaken as zero or zeros, risking a 10-fold to 100-fold overdose. 11. Place commas for amounts at or above 1000. For example, 10,000 mcg, not 1 12. Decimals are used to designate fractional amounts. For example, 1.5 ml not 1½ ml. Table 6-5
Table 6-6 Equivalents for the Metric, Household, and Apothecary Systems of Measure Length 1 meter = 1.0936 yards 1 centimeter = 0.39370 inch 1 inch = 2.54 centimeters 1 kilometer = 0.62137 mile 1 mile = 5280 feet or 1.6093 kilometers 1 foot = 0.3048 meter Weight 1 kilogram = 2.2 pounds 1 pound = 453.59 grams 1 pound = 16 ounces 1 grain = 65 milligrams or 60 milligrams 1 dram = 3.888 grams 1 ounce = 28.35 grams 1 ton = 2000 pounds 1 gram = 0.035274 ounces 1 gram = 15.4 grains Volume 1 liter = 1.0567 quarts 1 gallon = 4 quarts 1 gallon = 8 pints 1 pint = 2 cups = 16 fluid ounces Volume 1 cup = 8 fluid ounces 1 gallon = 3.7854 liters 1 quart = 32 fluid ounces 1 quart = 0.94633 liter 1 minim = 0.06 milliliter 1 fluid dram = 3.7 milliliter 1 ounce = approximately 30 milliliters 1 milliliter = 1 cubic centimeter 1 teaspoon = 5 milliliters Table 6-6
Table 6-7 Review of Metric-to-Metric Conversions Linear Measure: base unit is meters (m) 1 m = 100 centimeters (cm) 1 m = 1000 millimeters (mm) 1 m = 1,000,000 micrometers or microns (mcm, μm or μ) 1000 m = 1 kilometer (km) or 0.001 m = 1 km Volume Measure: base unit is liter (L) 1 L = 100 centiliters (cl) 1 L = 1000 milliliters (ml) 1000 L = 1 kiloliter (kl) Weight Measure: base unit is gram (g) 1 g = 100 centigrams (cg) 1 g = 1000 milligrams (mg) 1 g = 1,000,000 micrograms or 0.000001 g = 1 microgram (mcg or μg) 0.001 mg = 1 microgram (mcg or μg) 1 mg = 1000 micrograms (mcg or μg) Table 6-7