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

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

3. 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

4. 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

5. 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.

6. 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.

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

8. 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.

9. 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.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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.

17. 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.

18. 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!

19. 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

20. 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

21. 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.

22. 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.

23. 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

24. 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

25. 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

26. 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.

27. 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.

28. 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.

29. 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.

30. 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

31. 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

32. 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.

33. 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.

34. 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.

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

36. 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

37. 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.

38. 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.

39. 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.

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

41. 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.

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

43. 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.

44. 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.

45. 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.

46. 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.

47. 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.

48. 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.

49. 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.

50. 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.

51. 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

52. 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.

53. 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)

54. 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

55. 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

56. 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

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