Summary of Text rules Systems Of Measurements Weight Unit Abbreviation Equivalents gram g 1 g = 1,000 mg milligram mg 1 mg = 1,000 mcg = 0.001 g microgram mcg (or µg) 1 mcg = 0.001 mg = 0.000001 g kilogram kg 1 kg = 1,000 g Volume Unit liter milliliter cubic centimeter Abbreviatio n L (or ℓ) mL (or mℓ) Equivalents 1 L = 1,000 mL 1 mL = 0.001 L = 1 cc cc 1 cc = 1 mL = 0.001 L Unit Abbreviation Equivalents drop teaspoon gtt t (or tsp) 5 mL tablespoon ounce (fluid) ounce (weight) cup T (or tbs) oz oz cup pint quart pt qt 1T=3t 2 T = 1 oz 1 lb = 16 oz 1 cup = 8 oz or 240mL 1 pt = 2 cups 1 qt = 4 cups = 2 pt Due to information from our clinical partners and the Board of Nursing the following rule was developed. We will accept documentation in the form of Roman numerals, Arabic numbers, decimals as well as fractions. Chapter 4 MULTIPLY to convert from a larger unit to a smaller unit, or move the decimal point to the right. Example: 3 L = ? mL THINK: Larger to Smaller: (×) Equivalent: 1 L = 1,000 mL 3 L = 3 ×1,000 or 3.000 = 3,000 mL to convert from a smaller unit to a larger unit, or move the decimal point to the left. DIVIDE Example: 400 mg = ? G THINK: Smaller to Larger: () Equivalent: 1 g = 1,000 mg 400 mg = 400 1,000 or 400. = 0.4 g Rule De sire damount Equivale ntthatmatchestheunknown Q uantity Matchingconversion D E Q M Example The physician ordered 125 mcg of digoxin to be given daily. Digoxin was supplied in 0.25 mg scored tablets. How many tablet(s) should be administered? 0.25mg x 1000mcg/mg = 250 mcg 125mcg 1 tablet 0.5 tablets 250 mcg 1 in = 2.5 cm 1 cup = 240 mL 1 oz = 30 mL 1kg = 2.2 lb We will not be using the grain (gr) measurement in our math calculations. 40 kg = ? Lb 40 kg X 2.2lb/kg = 88 lb 66lb = ? kg 66lb 2.2 kg/lb = 30 kg Remember you will round to tenths when needed. Example 5.23 will be rounded to 5.3 40 cm = ? In 40 cm 2.5 cm/in =16 in 32 in = ? cm 32 in x 2.5 cm/in = 80 cm Conversions AM Int’l. Time PM Int’l Time 12:00 midnight 2400 12:00 noon 1200 1:00 0100 1:00 1300 2:00 0200 2:00 1400 3:00 0300 3:00 1500 4:00 0400 4:00 1600 5:00 0500 5:00 1700 6:00 0600 6:00 1800 7:00 0700 7:00 1900 8:00 0800 8:00 2000 9:00 0900 9:00 2100 10:00 1000 10:00 2200 11:00 1100 11:00 2300 Traditional time and international time are the same hours starting with 1:00 AM (0100) through 12:59 PM (1259). Minutes after 12:00 AM (midnight) and before 1:00 AM are 0001 through 0059 in international time. Hours starting with 1:00 PM through 12:00 AM (midnight) are 12 h greater in international time (1300 through 2400) International time is designated by a unique four-digit number (colon’s are not used) Math Tip between the hours of 1:00 PM (1300) and 12:00 AM (2400), add 1200 to traditional time to find the equivalent international time; subtract 1200 from international time to convert to equivalent traditional time. Example 1 3:00 PM = 3:00 + 1200 = 1500 Example 2 2212 = 2212 – 1200 = 10:12 PM Addition review questions p 94 Convert between Fahrenheit and Celsius temperatures: F 32 C 1.8 F 1.8C 32 Convert 95˚ F to Celsius (First subtract 32 then divide the result by 1.8) 95-32 C= 1.8 63 C= 1.8 C = 35° Convert 35˚ C to Fahrenheit F = 1.8 35+12 F = 63+12 F = 95° Equipment Used in Dosage Measurement Medicine cup 1 fluid ounce or 30mL capacity for oral liquids. Calibrated to measure teaspoons and tablespoons Amounts less than 2.5 mL need to be measured in a smaller device, i.e. oral syringe 30 mL = 1 ounce 5 mL = 1 teaspoon 15 mL = 1 tablespoon Used to administer small quantities Useful in medication of children and adults and adding small quantities to liquid Dispense eye and ear medications Calibrations read from top to the black ring of the suction plunger Calibrated in milliliters for each tenth Maximum volume administered in any one site is 3mL Larger volumes of medications can be delivered in divided doses or added to IV infusions or administered IV push, therefore, syringes with 5,6,10, and 12 mL may be used Luerlock syringe hub Plunger Needle Barrel Rubber plunger tip Used only once and is discarded Discard any extra medication prior to injection Also known as Tuberculin or TB syringe Used to administer small doses Calibrated in hundredths of a milliliter Used to give dosages of less than 0.5 mL Measurement and administration of units-100 insulin only Do not use with any other medications Syringe may be a standard units100 or a Lo-dose units-100 for smaller doses The needle is protected by a shield Safety syringes are used to protect from injury Needle’s gauge is it’s interior diameter. Lower the number the larger the diameter; 18-gauge needle is wider than a 22 gauge. The gauge depends on the viscosity (thickness) of the medication as well as the site. The viscous the solution and deeper injections require larger needles (lower gauge number) Injection site (area of tissue to be reached) will determine the length to be used. TYPE AGE NEEDLE SIZE GAUGE(G) NEEDLE LENGTH MAXIMUM INJECTION AMOUNT LOCATION ID All ages Intraderm al 25 to 26 G 1/4 to 5/8 0.1 mL Interior aspect of forearm Subcut 1 to 12 months 23 to 27 G 5/8 0.5 mL Fatty tissue over lateral thigh muscle Subcut 12 months to adult 23 to 27 G ½ to ¾ 0.5 to 1mL Fatty tissue over anterior lateral thigh muscle, triceps, or abdomen IM Infant to child 22 to 25 G 5/8 to 1 inch 0.5 to 1 mL Vastus Lateralis IM Adult 21 to 25 G 1 to 1 ½ inches 2 to 3 mL 0.5 to 1 mL Ventroglueal Deltoid 5/8 most common Understanding Drug Labels Brand, trade, proprietary Manufacturer’s name for a drug. It is usually the most prominent word on the drug label Generic Established, nonproprietary name appears directly under the brand name. Sometimes it can be place inside Brand Name- Carafate Generic Name- Sucralfate Dosage weight or amount of drug provided in a specific unit of measurement 20 mg/ 2mL Structure and composition of drug ◦ Solid forms for oral use ◦ Injectable ◦ Suppositories ◦ Creams ◦ Patches Full quantity contained in bottle or vial Total number of tablets or other solids Total fluid volume for liquids 30 mL multiple dose vial Warnings or special alerts ◦ Examples Refrigerate at all times Keep in a dry place ◦ Manufacturer ◦ Pharmacies Check prior to administration Discard or return to pharmacy if expired Important if drug is recalled Quickly identifies a particular group of medication packages Classifies drugs according to potential for use and abuse ◦ Schedule I – highest potential for abuse ◦ Schedule V – lowest potential for abuse Manufacturer National Bar Code Review Drug Code p 138 & 139 Additional practice on page 142148 Review set 21questions Oral Dosage Calculations Step 1 Convert Be sure that all measurements are in the same system and all units are in the same size, converting when necessary Step 2 Think Carefully consider what is the reasonable amount to administer Step 3 Calculate Dosage Ordered: Flagyl 0.75 g p.o t.i.d You need to convert the 0.75 g to mg prior to calculating amount that you will be administering 0.75 g = 750 mg D desired Q (quanity) X H (have) D 750 mg Q x 1 t ablet 500 mg H Math Tips When solving dosage problems for drugs supplied in tablets or capsules, Q (quantity) is always 1 because the supply dosage is per 1 tablet or capsule. Therefore, Q = 1 tablet or capsule The maximum number of tablets or capsules for a single dose is usually 3. Do not always rely on a formula. Always estimate what is a reasonable amount of the drug to be administered. This helps to identify if the dosages calculated are reasonable and sound. Chapter 11 Routes of administration Intramuscular (IM) Subcutaneous (SC) ◦ Intradermal (ID) ◦ Intravenous (IV) Maximum dosage Average 150 lb adult = 3 mL Maximum for deltoid site is 2 Children age 6-12 years = 2 mL Children birth to age 5 years = 1 mL Parenteral dosages Round amount to be administered to tenths if amount greater than 1 mL . Use a 3 mL syringe Amounts less than 1 mL rounded to hundredths. Use a 1 mL syringe for all amounts less than 0.5 mL Parenteral dosages Amounts of 0.5 mL to 1 mL calculated in tenths can be accurately measured in either a 1 mL or a 3 mL syringe Concentration Type Expiration Date Brand Name Manufacturer Species Generic Name Storage Supply dosage of insulin is 100 units per mL Abbreviated on label as U-100 Syringe must also be U-100 Accuracy is critical Nurses must understand and correctly interpret insulin order and label The correct syringe must be selected 40 units NPH Units-100 insulin 12 units Regular Units -100 insulin Total insulin dosage = 52 units 1. Inject 30 units of air. 2. Inject 10 units of air. 3. Withdraw 10 units regular. 4. Withdraw 30 units NPH for a total of 40 units. 1) Inject 30 U air 2) Inject 10 U air 3) Withdraw 10 U Regular 4) Withdraw 30 U NPH For a total of 40 U Chapter 12 When a fraction expresses the strength of a solution, made from a liquid concentration 1. The numerator of the fraction is the number of parts of the solute. 2. The denominator of the fraction is the total number of parts of the solution. 3. The difference between the denominator(final solution) and the numerator (parts of solute) is the number of parts of solvent. Solute- a concentrated or solid substance to be dissolved or diluted. Solvent- is the diluent used to dissolve the solute Solution- the resulting mixture of a solute plus a solvent Example ¼ strength reconstituted OJ made from canned frozen concentrate ¼ strength =1 part frozen juice concentrate 4 parts total reconstituted OJ 1 part -OJ concentrate (solute, numerator) 4 parts- total reconstituted OJ ( solution, denominator) 4-1 = 3 parts water (solvent) Example 1 ⁄ 3 strength formula 1 part concentrate formula (solute) 3 parts total solution 3-1= 2 parts solvent (water) Remember to convert all fluids to the same equivalent when necessary. Example: Order Ensure ¼ strength 120mL for 3 feedings (Stock 4 fl oz can) Step 1 convert fluid to same equivalent 4 fl oz x 30mL/fl oz = 120mL ensure concentrate Step 2 calculate solute, solvent, and total solution 1 part solute(ensure) of 360 = 90 mL 4 parts solution ( solute and solvent) (3 feeding of 120 mL ¼ feeding = 120 x 3= 360 mL) 4-1= 3 parts solvent 270mL Chapter 14 Convert child’s weight from lb.'s to kg’s and round answer to tenths Example 45lb ÷ 2.2 lb/kg= 20.45 rounded to 20.5 Example Convert 10 lb 12 oz to kg First convert ounces to lb 12 oz ÷16 oz/lb= 12/16 = ¾ lb= 0.75 lb 10.75 lb ÷ 2.2 lb/kg = 4.88 rounded to 4.9 Second step: multiply mg/kg by child’s weight in kg. Example Order Morphine Sulfate 0.05 mg/kg per dose Childs weight 35.9 kg 0.05 mg/kg/dose x 35.9 kg = 1.79 mg/dose Rounded to 1.8 mg/dose Chapter 15 Peripheral ◦ Rate of infusion should not exceed 200 mL in one hour Central line ◦ Accommodates larger concentrations and volumes of fluid Regulate an IV volume by electronic infusion pump or controller calibrated in mL per hour TotalmL ordered mL/h Totalh ordered (rounded to a whole number) Order reads: D5W 250 mL IV over the next two hours by infusion pump Step 1: Think •Pump is set by the rate of mL per hour •So, if 250 mL is to be infused in two hours, how much will be infused in one hour? • Step 2: Use the formula: T otalm L ordered m L/h T otalh ordered 250 m L 125 m L 2h 1h – Set pump at 125 mL per hour – Set total volume to infuse at 250 mL TotalmL ordered 60 min/h mL/h Totalminordered (rounded to a whole number) Order: ◦ Ampicillin 500 mg IV in 50 mL D5NS to infuse over 30 min via infusion pump 50mL X 60 min/h = 100 mL/h 30 min Set infusion pump to infuse at 100 mL/h with an infusion volume of 50 mL Step 1: Calculate infusion volume for 1h (Volume ordered ÷by number of hours to infuse) round this answer to a whole number Step 2: V x Drop factor= qtt/min T Physician orders: ◦ D5W IV at 125 mL per hour Infusion set is calibrated for a drop factor of 10 drops per mL Calculate IV flow rate in drops per min Notice that the mL cancel out, leaving drops per min 1 125mL 125 mL 10 gtt 10 gtt/mL 60 min 60 min 1mL 6 20.8 gtt/min • Use your watch to count drops and adjust roller clamp to deliver 21 drops per min Order: Drop D5W NS IV at 50 mL per h factor is 60 drops per mL Notice order, 50 mL per hour, is the same as the flow rate of 50 drops per min when drop factor is 60 drops per mL 50 mL 60 gtt per mL 60 min 50 drops per min