Math and Dosage Calculations for Health Care Third Edition Booth & Whaley McGraw-Hill 4- Chapter 4: Equipment for Dosage Measurement Edited by B. Holmes MSN/Ed, RN
Learning Outcomes Identify equipment used to administer medication. Indicate the appropriate equipment for delivering various types of medicine. Measure medications using the calibrations on the equipment. 4-
Describe the method of administration appropriate for each piece of measuring equipment.
Introduction To prepare the correct dosage, it is important to be familiar with and use equipment properly. Accurately read the dosage markings 4-
Parenteral – bypassing the digestive tract
Oral Administration Measuring devices are calibrated or marked at varying intervals. Measure the amount of liquid in the container Match physician’s order units 4-
If container and order do not match, convert order to units of measurement to be used.
Oral Administration (cont.) 4-
Oral Administration (cont.) Measurements from all three systems Curve in the surface of the liquid 4-
Measure quantity at the bottom of the curve
Oral Administration (cont.) 4-
Do not use medicine cups for doses less than 5 mL, even if the cup has calibrations smaller than 5 mL.
Droppers Measure and administer small amounts of oral liquid medication Deliver medication to the eyes, ears, and nose Units of measurement vary with dropper Do not interchange droppers 4-
Do not put the dropper in the patient’s mouth
Calibrated Spoons Used with pediatric and elderly patients 4-
Administer medication directly into the mouth or into food or beverage
Oral Syringes 4-
Used for quantities less than 5 mL
Oral Syringes (cont.) 1. Never attach a hypodermic needle to an oral syringe. 2. Never inject an oral dose. 4-
3. In emergencies, you may use a hypodermic syringe without a needle to measure and administer liquid oral doses, but never while its needle is attached.
Oral Administration (cont.) 4-
When a patient cannot take medication orally, medications can be administered through a tube to the stomach.
Error Alert! 4- Example Which would you select to administer ½ tsp. of a liquid medication? Yes! No!
Utensil used must provide the calibration needed to accurately measure the dose.
Practice Determine if the statements below are true. 1. You may use a hypodermic syringe with a needle to measure liquid for oral administration. 2. Oral and hypodermic syringes are identical in appearance. 4- False False True
3. Measuring spoons used for baking are acceptable for measuring liquid medications.
4. Oral medication comes in a bottle labeled 200 mg/5 cc. The dose to be administered is 600 mg. Which of the following is the correct dose?
Hypodermic Syringes Parenteral administration 4-
Administer medications by injection
Standard Syringes Calibrated in milliliters (mL) Metric system is used most often 4-
Allow for measurement of small doses
Standard Syringes (cont.) Zero calibration – edge of barrel near needle Leading ring - tip of plunger closest to needle 4- Click to view syringe
Trailing ring – ring farthest from needle
Hypodermic Syringes (cont.) 4- Trailing Ring Leading Ring Plunger Leading Ring Trailing Ring Leading Ring Barrel Syringe hub Needle Trailing Ring Leading Ring Plunger
Safety Syringes Same components as standard syringe Safety shields protect needle 4- 3 mL syringe with retractable needle
Reduce the chance of needlestick injury
Prefilled Syringes A single, standard dose of medication Usually marked in tenths of a mL Measure the dose carefully 4-
Discard any excess medication prior to injection
Prefilled Syringes 4-
Rule 4 - 3 When using a prefilled syringe, always examine the markings to determine whether the syringe is calibrated in milliliters or milligrams and calculate the dose accordingly.
Insulin Syringes (cont.) Used only to measure and administer insulin Insulin doses order in units U-100 insulin most common form 100 units of insulin per 1 mL 4-
Syringes available in 30, 50, and 100 Unit capacities
Insulin Syringes (cont.) 4- 100 Unit Insulin Syringe 50 Unit Insulin Syringe
Insulin Syringes (cont.) 4- Comparison of insulin syringes: 50 unit syringe 100 unit syringe
Insulin Syringes (cont.) 4-
Rule 4 - 4 Never use any type of syringe other than an insulin syringe to measure and administer insulin.
Tuberculin Syringes Used for doses less than 1 mL Calibrated in hundredths of a mL 4-
Requires careful measurement
Tuberculin Syringes (cont.) 4- 1 mL Tuberculin Syringe 0.5 mL Tuberculin Syringe
Tuberculin Syringes (cont.) 4- Comparison of tuberculin syringes: 0.5 mL syringe 1 mL syringe
Syringes for Established IV Lines Used to administer medication and fluids directly into a patient’s vein Uses the injection port of an IV line Eliminates repeated punctures for the patient Decreased risk of needlestick injuries Compatible drugs can be administered together Enables drug delivery on a periodic basis 4-
Enables dilution of the medication
Syringes for Established IV Lines (cont.) 4- Plastic injection tip Injection port on IV line
Large-Capacity Syringes Not all medication can be delivered in doses of 3 mL or less. Syringes with 5 mL, 10mL, 20 mL are available Volume is measured in milliliters but calibrations between may vary. 4-
Look carefully at the marks to measure an accurate amount of medication.
Large-Capacity Syringes (cont.) 4- 10 mL syringe
Error Alert! Pay close attention to the calibration of any syringe you use. Check the marks carefully. 4-
Always align the leading ring with calibration.
Ampules, Vials, and Cartridges 4- Cartridge Vial Ampule
Prefilled container shaped like a syringe barrel
Ampule Sealed container holding one dose of medication Use a standard syringe to withdraw the medication Use a paper towel to snap the top of the ampule 4-
Change needle after withdrawing the medication
Vials Container covered with a rubber stopper Contain one or more doses of medication 4-
Either liquid or powder form of medication that must be reconstituted
Preparing the Syringe Rule 4 - 5 In most circumstances, the person who prepares a syringe for injection should deliver the injection. 1. Pharmacy technicians who prefill syringes for nurses, medical assistants, or patients 2. Nurses or medical assistants preparing a syringe for a physician 4-
3. Health-care workers teaching a patient to administer his or her own medication
Needle Gauge and Length Choose appropriate needle for injection Smaller gauges correspond to larger diameters 4-
Use larger needles for more viscous drugs and deeper injections
Needle Gauge and Length (cont.) The injection site determines length. Such as the size of your patient Length must be long enough to reach the desired area of tissue. 4-
Length must not be so long that it penetrates beyond the desired area.
Needle Gauge and Length (cont.) 4- Type of Injection Needle Gauge Length (inches) for Adults Intradermal 25-26 3/8 – 5/6 Subcutaneous 23 - 27 ½ - 5/8 Intramuscular 18 - 23 1 - 2
Practice 4- A. B. C. D. E. F. Barrel Syringe hub Needle Trailing Ring Leading Ring Plunger
Identify the parts of this syringe:
Practice 4- ANSWER Carefully check the calibration and discard the excess medication prior to giving the injection. In this case, you would discard 1.5 mL medication. You should NEVER attempt to inject the correct dose without removing the excess medication first.
You have an order to administer 1.5 mL of a medication. It comes in a 3 mL prefilled syringe. What should you do?
Topical Medications Gels, creams, ointments, and pastes Apply directly to the skin Use a glove, tongue blade, or cotton-tipped applicator Avoid contact your own skin 4-
Wear non-sterile gloves to apply or remove
Transdermal Medications Form of topical medication absorbed through the skin. Use a self-adhesive patch. Place patch on clean, dry, hairless skin with no rash or irritation and with good circulation. Remove older patches and dispose of them properly. 4-
Mark each new patch with your initials, the date, and the time.
Transdermal Medications (cont.) 4-
Maintain a consistent level of medication in the blood.
Drops, Sprays, and Mists Use the equipment that comes with the drug to administer the medication. Vaporizers – water used to create mist 4-
Nebulizers and metered dose inhalers (MDIs)
Vaginal and Rectal Medications Douches for liquid forms of medication 4-
Enemas for liquid forms of medication
Apply Your Knowledge 4- What instructions should you provide a patient who is starting a new medication delivered by a transdermal patch? Which type of delivery device is used to administer medication to the eyes and ears?
ANSWER The patch should be put on clean, dry, hairless skin with no rash or irritation. Placement sites should be rotated. Older patches should be removed and disposes of properly.
Apply your Knowledge 4-
What kind of syringe is used to deliver vaccinations?
Apply your Knowledge 4-
How many mL are indicated on this syringe?
End of Chapter 4 4- Nothing will work unless you do. ~Maya Angelou