Summary of Parenteral Administration and Injection Techniques

## Introduction Injection administration is a core clinical skill for delivering medications parenterally. This material focuses on preparation, safe technique, site selection, and special considerations for injections that are not covered elsewhere (note: Anticoagulants, Intramuscular injection, Intravenous injection, and Subcutaneous injection are excluded here). It consolidates practical steps, decision points, and patient-centred practice for intradermal and other non-covered injection topics. > **Definition:** Parenteral administration is the delivery of medication by a route other than the gastrointestinal tract, commonly via a needle and syringe into skin, subcutaneous tissue, muscle, or a vein. ## Overview of injection types covered here - **Intradermal (ID)** — into the dermis for local testing and some vaccinations. - **Other preparative and safety concepts** — reconstitution of powdered drugs, preparing ampoules and vials, syringe and needle choices, prevention of needlestick injury, and patient preparation. ## Preparing medications for injection ### Reconstitution of powdered drugs (vials) 1. Verify medication order: patient, drug, dose, route, time, and expiration. 2. Gather supplies: appropriate diluent, syringe, needle, alcohol swabs, and vial adapter if required. 3. Clean vial top with alcohol swab and let dry. 4. Draw air into syringe equal to volume of diluent to be withdrawn (e.g., draw 3 mL air if adding 3 mL diluent). 5. Insert needle into vial and inject the air to avoid negative pressure. 6. Withdraw the required volume of diluent (e.g., 3 mL) and inject into the powdered vial slowly. 7. Gently mix by rolling or inverting — do not shake vigorously unless manufacturer permits. 8. Withdraw reconstituted solution, checking concentration and calculation. > **Tip:** If reconstituted concentration changes (e.g., 10 mg per 2 mL), recalculate dose precisely before drawing. ### Ampoules, vials, and Act-O-vial systems - Ampoules: snap at the neck; use a gauze to protect hands. Use filter needle to withdraw solution, then change to administration needle. - Vials: rubber stopper pierced with needle; maintain sterility. - Act-O-vial: contains diluent and powder separated; follow manufacturer steps to mix. ## Syringes and needles: selection and reading ### Syringe types - Insulin syringes (permanently attached needle) calibrated in units: 100-unit (1 mL), 50-unit (0.5 mL), 30-unit (0.3 mL). Know how many units each increment represents. > **Definition:** Insulin syringe: a syringe with fixed needle calibrated in insulin units; dosage must be read from the top ring near the needle. ### How to read insulin syringes - Read from the top ring (needle side). Example: a 50-unit syringe with 1 unit per tick showing 18 units should align top ring with the 18 mark. - Be aware: some 100-unit syringes are calibrated as 2 units per line or 1 unit per line — confirm before use. ### Needle sizes and considerations - Choose needle gauge and length based on medication viscosity, patient body habitus, and route. - Thicker fluids require lower gauge (larger bore). Shorter needles for superficial injections. ## Preventing needlestick injuries - Use safety-engineered devices when available. - Never recap used needles with two hands; use one-hand scoop if absolutely necessary or a designated sharps container. - Dispose of sharps immediately in puncture-resistant container. - Report and follow institutional protocol for any exposures. ## Intradermal (ID) injection administration > **Definition:** Intradermal injection is placement of a small volume of medication into the dermis, a shallow layer under the epidermis, commonly used for allergy testing, tuberculosis screening, and some local diagnostic tests. ### Purposes (three common uses) - Diagnostic skin tests (e.g., tuberculin skin test) - Allergy testing - Local immunologic or desensitization procedures ### Maximum volume and special considerations - Maximum volume is small,