Chapter 37

1. Chapter 37 Administering Intradermal, Subcutaneous, and Intramuscular Injections

2. First-Pass Metabolism • Metabolism of oral medication by the liver, decreasing the effect of the medication • Can be bypassed by using sublingual, buccal, and parenteral routes

3. Advantages of Parenteral Administration • Bypasses gastrointestinal tract; no irritation • Rapid onset time compared to oral route • Ease of administration to uncooperative or unconscious patients • Better absorption of drugs that are otherwise poorly absorbed via oral route

4. Disadvantages of Parenteral Administration • Invasive and uncomfortable for patient • Expensive • Requires additional supplies and equipment • Requires qualified personnel to administer • Carries risk of infection and nerve injury

5. Types of Syringes • Standard syringe • Used for intramuscular or subcutaneous injections • Insulin syringe • Used only for injecting insulin • Tuberculin syringe • Used for small volumes of meds and TB test • Prefilled syringe • Single dose, ready to use syringes

6. True/False Question The nurse giving injections in a hospital setting knows that syringes are available in numerous sizes, ranging from 0.3 to 60 mL, with the most common sizes being 1 and 3 mL. A. True B. False

7. Answer A. True Rationale: Syringes are available in numerous sizes, ranging from 0.3 to 60 mL, with the most common size being 3 to 5 mL. Each syringe has calibrations marked on the barrel in milliliters or units indicating the volume of medication to administer.

8. Parts of a Syringe • Barrel • Plunger with flange on the end • Tip for connecting to the needle • Luer-Loc tip: has threaded grooves that screw onto the needle hub and lock it in place • Slip-tip: has a smooth, slightly tapered tip that inserts into the needle hub

9. Parts of a Needle • Angled bevel on the tip of the needle • Cannula or shaft • Plastic hub • Safety guard

10. Sites for Subcutaneous Injections • Back of the upper arms • Abdomen (staying a minimum of 2” from the umbilicus) • Anterior aspect of thighs • Area of the back just below the scapulae • Upper buttocks

11. Injection Sites • Ventrogluteal: site of choice for those 7 months and older • Deltoid: common site for injection of small volumes • Vastus lateralis: second choice for injections larger than 1 mL • Rectus femoris: last choice of sites, used only in adults • (Dorsal gluteal: ONLY if no other site is accessible)

12. Maximum Volume to Inject Intramuscularly • 3 mL for injecting a large gluteus medius or gluteus minimus of the ventrogluteal site or a very large vastus lateralis muscle of the leg, in an adult • 1 to 2 mL for the vastus lateralis muscle in a trim, average size adult, older children with adequate muscle development, older adults, and thin patients • 0.5 to 1 mL for the deltoid muscle in small children up through older adults (not infants) • 0.5 to 1 mL for the ventrogluteal site and the vastus lateralis muscle in infants older than 7 months and small children

13. Gauge of a Needle • Refers to the diameter of the needle and is indicated by numbers; the larger the number, the smaller the diameter • Gauge used depends on • Viscosity of the medication • Route of medication • Size of patient and muscle mass

14. Length of Needles for Injections • Intradermal: 1/4” to 5/8” in length with a very tiny diameter between 25 and 30 g • Subcutaneous: between 3/8”and 7/8” in length with a diameter between 24 and 29 g • Intramuscular: 1” to 1.5” in length, with a diameter between 20 and 22 g

15. Administering an Intradermal Injection • Position needle with the angled bevel upward • Use a 15-degree angle for insertion of the needle • Do not aspirate • Instill the medication between the layers of the dermis to create a bleb (fluid-filled blister) • Do not apply pressure to or massage injection site

16. Administering a Subcutaneous Injection Administer the injection at a 45-degree angle; angle of needle insertion and length of needle may vary, based on the percentage of body fat and size of the patient

17. Administering an IM Injection • IM: use dominant hand to inject at a 90-degree angle into the body of the target muscle • Needle should swiftly pierce skin and muscle in one smooth motion • Stabilize needle with nondominant hand • Aspirate; if no blood, then instill medication slowly • Remove needle • Cover site with 2” x 2” gauze using nondominant hand, massaging site gently while activating the needle safety guard with dominant hand

18. Administering a Z-Track Injection • Place lateral aspect of nondominant hand against patient’s skin next to intended insertion site • Pull/displace skin and subcut layer 1” to 2” to one side, holding the tissue back • Using dominant hand, insert needle swiftly, piercing the skin, tissue, and muscle with one smooth motion • Aspirate; if no blood, instill drug slowly

19. Z-Track Injection (cont.) • After drug is instilled, wait for 5 to 10 seconds before withdrawing needle • As you are withdrawing needle, release the tissue held back by your nondominant hand, allowing tissue to close over the needle track in the muscle layer • Avoid massaging injection site

20. True/False Question The only part of a needle that can be touched is the barrel. A. True B. False

21. Answer B. False Rationale: The only part of a needle that may be touched is the plastic needle cap. The hub of the needle that attaches to the syringe must be kept sterile while you prepare to attach it.

22. Safety Reminders • Do not recap a needle either new or used (except when you must carry it down the hall to the room) • Do not inject air directly into medication • Do not contaminate any part of the needle or syringe • Avoid using single-dose vials more than once; they do not have preservatives (although multiple-dose vials do)

23. Safety Reminders (cont.) • Never use multiple-dose vials ofbacteriostatic diluent with preservativesto reconstitute drugs intended for newborn injection!

24. Causes of Complications From Intramuscular Injections • Needle puncture • Incorrect technique • Drug solution itself

25. Types of Medication Incompatibilities • Physical: visible reactionssuch ascolor changes, precipitate formation, cloudiness, gas formation, or haze • Chemical: involves the degradation of the drug resulting from a chemical reaction • Therapeutic: occurs within the patient, as the result of two concurrently administered drugs that interact

26. Types of Diluents • Sterile bacteriostatic normal saline 0.9% (multiple-dose vial with preservatives) • Sterile normal saline 0.9% (single-dose vial without preservatives) • Sterile bacteriostatic water for injection (multiple-dose vial with preservatives) • Sterile water (single-dose vial without preservatives)

27. Two Medications Requiring Dosage Verification With Another Nurse • Insulin • Very rapid-acting, rapid-acting, intermediate-acting, long-acting, and very long-acting • Heparin • 1,000 units/mL, 5,000 units/mL, 10,000 units/mL, and 20,000 units/mL • Can be life threatening if incorrect dosage is administered

28. True/False Question When administering insulin or heparin, the nurse should apply gentle pressure to the injection site after removing the needle for better absorption. A. True B. False

29. Answer B. False Rationale: When giving a subcutaneous injection, the nurse should apply gentle pressure to the site after removing the needle and gently massage to distribute the medication into the tissue for better absorption, unless administering insulin or heparin.