Summary of Text rules

Systems Of Measurements

UnitAbbreviationEquivalents gramg1 g = 1,000 mg milligrammg1 mg = 1,000 mcg = g microgrammcg (or µg)1 mcg = mg = g kilogramkg1 kg = 1,000 g Weight

UnitAbbreviatio n Equivalents literL (or ℓ)1 L = 1,000 mL millilitermL (or mℓ)1 mL = L = 1 cc cubic centimeter cc1 cc = 1 mL = L Volume

UnitAbbreviationEquivalents dropgtt teaspoont (or tsp)5 mL tablespoonT (or tbs)1 T = 3 t ounce (fluid)oz2 T = 1 oz ounce (weight)oz1 lb = 16 oz cup 1 cup = 8 oz or 240mL pintpt1 pt = 2 cups quartqt1 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 mL

 DIVIDE to convert from a smaller unit to a larger unit, or move the decimal point to the left.

 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

 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

 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

AMInt’l. TimePMInt’l Time 12:00 midnight240012:00 noon1200 1: : : : : : : : : : : : : : : : : : : : : :002300

 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: = 1500  Example = 2212 – 1200 = 10:12 PM Addition review questions p 94

 Convert between Fahrenheit and Celsius temperatures:

 Convert 95˚ F to Celsius (First subtract 32 then divide the result by 1.8)

 Convert 35˚ C to Fahrenheit

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 Needle Barrel Rubber plunger tip Plunger

 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 units- 100 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.

TYPEAGENEEDLE SIZE GAUGE(G) NEEDLE LENGTH MAXIMUM INJECTION AMOUNT LOCATION ID Intraderm al All ages25 to 26 G 1/4 to 5/8 0.1 mLInterior aspect of forearm Subcut1 to 12 months 23 to 27 G 5/8 0.5 mLFatty tissue over lateral thigh muscle Subcut12 months to adult 23 to 27 G½ to ¾ 5/8 most common 0.5 to 1mL Fatty tissue over anterior lateral thigh muscle, triceps, or abdomen IMInfant to child 22 to 25 G5/8 to 1 inch 0.5 to 1 mL Vastus Lateralis IMAdult21 to 25 G1 to 1 ½ inches 2 to 3 mL 0.5 to 1 mL Ventroglueal Deltoid

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

Oral Forms

 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 Drug Code  Bar Code  Review p 138 & 139

 Additional practice on page 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

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

Brand Name Storage Expiration Date Type Generic Name Species Manufacturer Concentration

 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 selecte d

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= 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 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 (rounded to a whole number)

 Order reads: D 5 W 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: – Set pump at 125 mL per hour – Set total volume to infuse at 250 mL

(rounded to a whole number)

 Order: ◦ Ampicillin 500 mg IV in 50 mL D 5 NS 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: ◦ D 5 W 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

6 1 Use your watch to count drops and adjust roller clamp to deliver 21 drops per min

 Order: D 5 W NS IV at 50 mL per h  Drop 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