Chapter 8 Equipment for Dosage Measurement PowerPoint® Presentation to accompany: Math and Dosage Calculations for Healthcare Professionals Fourth Edition Booth, Whaley, Sienkiewicz, and Palmunen

Learning Outcomes 8-1 Recognize medication dosage volumes in different enteral equipment. 8-2 Recognize medication dosage volumes in different parenteral equipment.

Key Terms Ampule Calibrated spoons Calibrations Cartridges Eccentric Enteral Hypodermic syringes Jejunostomy tube Leading ring Ampule – sealed container that usually holds one dose of liquid medication Calibrated spoons – measuring device with a series of calibrations, or marks, numbered at varying intervals; often used for pediatric or elderly patients Calibrations – marks numbered at varying intervals that enable you to measure the amount of liquid in the device Cartridges – prefilled containers shaped like syringe barrels generally holding one dose of medication and designed to fit a reusable syringe Eccentric – off-center Enteral – by way of the gastrointestinal tract Hypodermic syringes – syringes used to administer injections and calibrated with different measurements Jejunostomy tube – tube used to deliver medication and nutrients directly to the small intestine Leading ring – ring at the tip of the plunger of a syringe closest to the needle; liquid in the barrel does not go past this ring

Key Terms Meniscus Nasogastric Parenteral PEG tube Trailing ring Transdermal Vial Meniscus – slight curve in the surface of a liquid Nasogastric – passage from the nose to the stomach Parenteral – bypassing the digestive tract PEG tube – a percutaneous (through the skin) endoscopic gastrostomy (PEG) tube that delivers medication and nutrients directly to the stomach Trailing ring – ring on the plunger that is farthest from the needle Transdermal – through the skin Vial – containers covered with a rubber stopper, or diaphragm, that may hold more than a single dose of medication

Introduction To prepare the correct dosage, it is important to be familiar with and use equipment properly. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Accurately read the dosage markings.

Enteral Administration Measuring devices are calibrated at varying intervals. Calibrations – measure the amount of liquid in the container Should match physician’s order units Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. If container and order do not match, convert order to units of measurement to be used.

Enteral Administration (cont.) Equipment Medicine cups Droppers Calibrated spoons Oral syringes Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment.

Enteral Administration (cont) Medicine cups may show measurements from all three systems. Metric Household Apothecary A meniscus is a curve in the surface of the liquid. Measure quantity at the bottom of the curve. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Although it is marked on medication cups, the dram is an outdated unit of measurement and is rarely, if ever, used in medication administration.

Oral Administration (cont.) Rule 8-1 Do not use medicine cups for doses less than 5 mL. To ensure accuracy use a dropper; calibrated spoon; or oral syringe. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Medicine cups should not be used for doses less than 5 mL, even if the cup has calibrations smaller than 5 mL. Calibrations are not accurate enough for such small doses.

Droppers Droppers measure and administer small amounts of liquid medication. They deliver medication to the eyes, ears, and nose. They are used for oral pediatric doses. Units of measurement vary with dropper. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Droppers have different size openings which affects the size of each drop. Use dropper packaged with product and do not interchange droppers.

Calibrated Spoons Used with pediatric and elderly patients Administer medication directly into the mouth or into a food or beverage Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Calibrated spoons are good for thicker medications that are not easily given through a dropper.

Patient Education Instructions for proper use Medicine cup Locate appropriate calibration. Place cup on flat surface while pouring liquid medicine. Check measurement with cup at eye level. Make measurement at lowest level of meniscus. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Patient instructions should be provided for any patient who takes oral medications at home.

Patient Education (cont.) Instructions for proper use Dropper Measure proper amount before delivery. Hold dropper vertically. Count slowly and allow drops to fully form. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment.

Patient Education (cont.) Instructions for proper use Calibrated spoons are for medications measured by teaspoons, tablespoons, or milliliters; should not be replaced with household spoons. Check medication for expiration date and changes in clarity, color, or consistency. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Household spoons used for eating vary in size and are not reliable measures. Measuring spoons used for baking are acceptable but are not as accurate as calibrated spoons.

Oral Syringes Used for quantities less than 5 mL Safety features Eccentric tips Tips of different shape or size Tinted Not sterile Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Oral syringes provide accurate readings for small quantities of liquid. Safety features prevent confusion with hypodermic syringes. Eccentric tips are off center.

Oral Syringes Rule 8–2 Never attach a needle to an oral syringe. Never inject an oral dose. In emergencies, you may use a hypodermic syringe without a needle to measure and administer liquid oral doses. Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment.

Other Equipment for Enteral Medications When a patient cannot take medication orally, medications can be administered through a tube. Types of tubes Nasogastric tube Nasal-small bowel tube PEG tube Jejunostomy tube Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. It is preferable to use liquid medications; however, some solid medications can be crushed and added to water to put through the tube. Nasogastric tube – delivers medications into stomach Nasal-small bowel tube – just as the name suggests, delivers medications from nose to the small bowel PEG tube [percutaneous (through the skin) endoscopic gastrostomy tube] – placed directly into stomach through the abdominal wall Jejunostomy tube – delivers medication directly into small intestine Regardless of equipment used, accurate dosage measurement using the equipment’s calibrations is essential.

Error Alert! Utensil used must provide the calibration needed to accurately measure the dose. Example Which would you select to administer ½ tsp of a liquid medication? Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Remember to use the piece of equipment that has the correct calibrations. No! Yes!

Practice True or False False False True A hypodermic syringe with a needle can be used to measure liquid for oral administration. Oral and hypodermic syringes are identical in appearance. Measuring spoons used for baking are acceptable for measuring liquid medications. False False Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Hypodermic syringes can be used in an emergency but only if the needle is removed. Oral syringes differ in appearance from hypodermic syringes. They may have: eccentric tips; tips of different shape or size; tinted rather than clear color. Measuring spoons used for baking are acceptable but not quite as accurate as calibrated spoons. True

Practice Oral medication comes in a bottle labeled 200 mg/5 mL. The dose to be administered is 600 mg. Which of the following is the correct dose? 1 tsp 2 tsp 1 tbsp 2 tbsp = 15 mL Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. 200 mg : 5 mL = 600 mg : x Cancel units 5 mL x 600 = 200 X x 3000 mL = 200 x; divide both sides by 200 15 mL = x

Parenteral Medication Administration Devices Parenteral administration Topical and transdermal medications Inhalers Sublingual medications Injections Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Parenteral – bypasses the GI tract Although parenteral dosage forms include topical, transdermal, inhalant, and sublingual medications, the term is most often applied to injections.

Parenteral Medication Administration Devices (cont.) Administer medications by injection Intravenous (IV) Intramuscular (IM) Intradermal (ID) Subcutaneous (Subcut) Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Hypodermic syringes are calibrated with different amounts – selection will depend on type and amount of medication to be administered.

Standard Syringes Calibrated in milliliters (mL) Allow for measurement of small doses Are usually 3-mL Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Metric system is used most often for calibration; however, some syringes may also be marked in minims. On the 3-mL syringe, half and whole milliliters are numbered Although cc (cubic centimeters ) is an error prone abbreviation, it may still be on some syringes. 1 cc = 1 mL

Standard Syringes (cont.) Zero calibration – edge of barrel near needle Leading ring - tip of plunger closest to needle Trailing ring – ring farthest from needle Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Liquid in the barrel of the syringe is filled to the leading ring and does not go past it. Do not measure from the trailing ring. Click to view syringe

Hypodermic Syringe Plunger Needle Barrel Trailing Ring Leading Ring Syringe hub Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Needlestick prevention safety device

Safety Syringes Have same components as standard syringes Include a safety mechanism Reduce the chance of needlestick injury Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. The safety mechanism may be a shield or a retractable needle. Safety syringes do not totally prevent needle sticks. They come in all sizes with various calibrations.

Prefilled Syringes Prefilled syringes contain a single, standard dose of medication. When using a prefilled syringe, measure the dose carefully. Discard any excess medication in a prefilled syringe prior to injection. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. A prefilled syringe has the same parts as a standard syringe. A prefilled syringe should be used once and discarded. Dose markings are marked on the syringe – no need to convert.

Prefilled Syringes Rule 8-3 When using a prefilled syringe, examine the markings to determine whether the syringe is calibrated in milliliters or milligrams; calculate the dose accordingly. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment.

Insulin Syringes Insulin syringes are used only to measure and administer insulin. U-100 insulin most common form They are calibrated in units. U-100 insulin syringes are available in 50 and 100 unit capacities. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Insulin syringes are unique – they are calibrated in units not volume. U-100 insulin contains 100 units per 1 mL.

Insulin Syringes (cont.) 100 Unit Insulin Syringe Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Top syringe can hold up to 100 units of insulin. Bottom syringe holds up to 50 units and is used to administer smaller doses of insulin. 50 Unit Insulin Syringe

Insulin Syringes (cont.) Comparison of insulin syringes: Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. On the 50 unit syringe, the large markings indicate 5 units, and each small mark is 1 unit. On the 100 unit syringe, the large mark indicates 10 units, and smaller marks indicate 2 units. 50 unit syringe 100 unit syringe

Insulin Syringes (cont.) Rule 8-4 Never use any type of syringe other than an insulin syringe to measure and administer insulin. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment.

Tuberculin Syringes Uses Examples: PPD skin test Subcutaneous injections Intradermal injections Doses less than 1 mL Examples: PPD skin test Vaccines Heparin Pediatric medicines Allergen extracts Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Intradermal injections are generally purified protein derivative (PPD) skin test for determination of exposure to tuberculosis.

Tuberculin Syringes (cont.) Calibrated in hundredths of a mL Require careful measurement Calibrations are close together. Carefully align leading ring with correct calibration. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Marked numbers represent tenths of a milliliter. Smaller lines represent one hundredth of a milliliter. Also available as a half-milliliter tuberculin syringe.

Tuberculin Syringes (cont.) 1 mL Tuberculin Syringe Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. 0.5 mL Tuberculin Syringe

Tuberculin Syringes (cont.) Comparison of tuberculin syringes: Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Each syringe is calibrated to 0.01 mL (small lines). Large lines = 0.1 mL 1 mL syringe 0.5 mL syringe

Syringes for Established IV Lines Used to administer medication and fluids directly into a patient’s vein Use the injection port of an IV line Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment.

Syringes for Established IV Lines Advantages eliminate repeated punctures decrease risk of needlestick injuries allow compatible drugs to be administered together enable periodic drug delivery enable dilution of the medication Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment.

Large-Capacity Syringes Syringes with 5 mL, 6 mL, 12 mL Volume is measured in milliliters but calibrations may vary. Look carefully at the marks to measure an accurate amount of medication. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Not all medication can be delivered in doses of 3 mL or less. Syringes larger than 12 mL are also available.

Large-Capacity Syringes (cont.) Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. 10 mL syringe

Error Alert! Pay close attention to the calibration of any syringe you use. Check the marks carefully. Always align the leading ring with the calibration. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Remember: the leading ring must be aligned with the correct calibration.

Ampules, Vials, and Cartridges Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. These are different packaging for parenteral medications Ampule

Cartridges Prefilled container shaped like a syringe barrel One dose of medication Fits a reusable syringe Examples Tubex® Carpuject® Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment.

Ampule An ampule is a sealed container holding one dose of medication. It snaps open. Use a standard syringe to withdraw the medication. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. After opening check for glass that may have gotten into the liquid.

Vials Container covered with a rubber stopper Contains one or more doses of medication May contain either liquid or powder medication Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. If in powder form of medication, a diluent is injected into the vial to reconstitute the medication. Check for stopper material that may have gotten into the liquid when it is punctured by the needle.

Preparing the Syringe Rule 8-5 In most circumstances, the person who prepares a syringe for injection should deliver the injection. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. When filling a syringe, you must label it with contents.

Preparing the Syringe Rule 8-5 Exceptions include: pharmacy technicians who pre-fill syringes; nurses or medical assistants preparing a syringe for a physician; healthcare workers teaching a patient to administer his or her own medication. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Pharmacy technicians pre-fill syringes that are delivered to a patient unit for administration by a nurse or medication aid.

Needle Gauge and Length Choose appropriate needle for injection. Gauge The gauge is the interior diameter. Smaller gauges correspond to larger diameters. Length is determined by the injection site. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Use larger gauge needles for more viscous drugs and deeper injections. The needle should be long enough to reach the desired area of tissue but not be so long that it penetrates beyond the desired area.

Needle Gauge and Length (cont.) Type of Injection Needle Gauge Available Lengths (inches) Intradermal 25 – 26 Subcutaneous 23 – 27 Intramuscular 18 – 23 Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. Refer to Table 8-1 for a more detailed description of needle choice based on type of injection, site, and age of patient.

Practice Plunger Needle Barrel Trailing Ring Leading Ring A. B. C. D. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. F. E. G.

Practice Syringe hub Plunger Needle Barrel Trailing Ring Leading Ring Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. F. E. G. Needlestick prevention safety device

Practice You have an order to administer 1.5 mL of a medication. It comes in a 3 mL prefilled syringe. What should you do? 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. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment.

In Summary In this chapter you learned about enteral medication administration devices. Enteral devices are for medications absorbed through the GI Tract. Medicine cup: for liquids (measure at the bottom of the meniscus); allow easy administration; calibrations include mL, tsp, tbs, oz Dropper: for administering small amounts of liquids; calibrations vary; droppers may have different size openings – do not interchange droppers Calibrated spoons: used for small amounts of oral medication for pediatric and geriatric patients; calibrations include mL and tsp Oral syringes: for administering small amounts of oral medications; calibrations include mL and tsp; clean, not sterile – DO NOT USE for parenteral medication administration Enteral tubes (NGT, GT, PEG, JT): can become clogged by medications; liquid medication is preferable; some solid medications can be crushed/opened and mixed with water (some medications such as gel caps, enteric coated medications, and some capsules should not be crushed)

In Summary (cont.) parenteral medication administration devices. Parenteral devices are for medications given via the injection route. 3-mL syringe: most commonly used for injections; calibrated to the tenths 1-mL/tuberculin syringe: used to administer small doses; calibrated to the hundredths Large capacity syringe: delivers 5, 6, 10, 12 or more mL; calibration varies Insulin syringe: used to administer insulin only; 1-mL standard insulin syringe is calibrated by 1 or 2 unit markings; deliver up to 100 units; 0.5-mL/low-dose syringe is calibrated by 1 unit markings; delivers up to 50 units Safety syringe: has shield that covers the needle; comes in various sizes and various calibrations Prefilled syringe: filled with single dose of medication Syringe parts: needle, hub, barrel, plunger, trailing ring, leading ring Zero calibration: edge of the barrel closest to needle Cartridge: prefilled contained shaped like syringe barrel Ampule: sealed, single-dose container Vial: single- or multiple-dose container with rubber stopper or diaphragm through which medication is withdrawn Needle Gauge: interior diameter of a needle; 18 – 23 gauge for IM injections; 23 – 27 gauge for subcut injections; 25 – 26 for intradermal injections Needle Length: 1 – 2 inches for IM injections; ½ - 5/8 inches for subcut injections; 3/8-5/8 for intradermal injections

Apply Your Knowledge Which type of delivery device is used to administer medication to the eyes and ears? ANSWER: Dropper What kind of syringe is used to deliver vaccinations? Learning Outcome 8.1 Recognize medication dosage volumes in different enteral equipment. Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. ANSWER: Tuberculin

Apply your Knowledge How many mL are indicated on this syringe? Learning Outcome 8.2 Recognize medication dosage volumes in different parenteral equipment. ANSWER: 1.6 mL

End of Chapter 8 Nothing will work unless you do. ~Maya Angelou