Injection Techniques Overview

Aug 17, 2025

Overview

This lecture demonstrates the correct procedures and techniques for intradermal, subcutaneous, and intramuscular injections, emphasizing safety, site selection, and proper angle of insertion.

Intradermal Injections

  • Commonly performed on the forearm for tests like TB.
  • Clean the selected site with an antiseptic, center to outward.
  • Use a small gauge needle with the bevel facing up.
  • Hold syringe high; inject at a 5°–15° angle to form a bleb/wheal.
  • Do not massage the injection site afterward.

Subcutaneous Injections

  • Performed in areas with fatty tissue: abdomen, back of arms, or lateral thigh.
  • Clean site in a circular motion and let dry.
  • Use a 90° insertion angle if ≥1 inch of fat; use 45° if less fat.
  • Pinch the skin, insert needle, let go to inject, and remove at same angle.
  • Immediately dispose of needle in a sharps container.
  • Do not massage the site post-injection.

Intramuscular Injections

  • Vastus lateralis site located using anatomical landmarks (greater trochanter, iliac crest, groin).
  • Clean site in concentric circles, let dry.
  • Pull skin taut, hold syringe like a dart, and inject at a 90° angle.
  • Anchor the syringe if necessary and inject medication slowly.
  • Withdraw needle at the same angle and dispose of it immediately.

Z-Track Intramuscular Injection Method

  • Displace upper tissue layers laterally by about 1 inch using the side of the nondominant hand.
  • Follow standard cleaning and 90° injection procedure.
  • After withdrawal, allow tissue to return and seal track, reducing leakage.
  • Use needle safety feature if available, then dispose in sharps container.

Key Terms & Definitions

  • Intradermal injection — injection placed between upper skin layers, often for allergy or TB tests.
  • Bleb/Wheal — small bubble under the skin indicating correct intradermal placement.
  • Subcutaneous injection — injection into fatty tissue below the skin for slow absorption.
  • Intramuscular injection (IM) — injection directly into muscle for faster absorption.
  • Z-track method — technique for IM injections to prevent medication from leaking into other tissues.

Action Items / Next Steps

  • Practice injection techniques following the outlined steps.
  • Review anatomical landmarks for injection site selection.
  • Follow sharps disposal protocols after each injection.