IM Injection: Site Selection & Needle Size

• Intramuscular (IM) injection site selection depends on age/size of patient, medication to be injected, client’s general condition (skin condition, etc.), and the injection site being used.
• Needle size and gauge depend on these factors.

Maximum Volume for IM Injections

• Ventrogluteal site: 2 - 3 mL (some references state up to 3-5 ml)
• Vastus lateralis site:
  • Adults: 1 - 2 mL (some references state up to 3 ml)
  • Infants and children: 0.5 - 1 mL
  • Trim, average size adults, older children with adequate muscle development, older adults, and thin patients can use this site
• Deltoid muscle: 0.5 - 1 mL in small children up through older adults (not infants)

Needle Size and Gauge for Intramuscular Injections

• Length: 1” to 1.5” or 2”
• Gauge: 20g to 22g, 25g
• Bariatric needles can be up to 3” long
• Gauge refers to the diameter of the needle; the larger the number, the smaller the diameter.

Gauge Usage depends on

• Viscosity of the medication
• Route of medication
• Size of patient and muscle mass

Injection Sites

• Ventrogluteal: Best and safest site for adults; considered least painful
• Deltoid: Common site for injection of small volumes
• Vastus lateralis: Best site for infants, children, elderly, and for self-injection
• Dorsal gluteal: Only if no other site is accessible

Vastus Lateralis Site

• Safe for rapid absorption

Location

• Place one handbreadth above the knee at the lateral femoral condyle.
• Place one handbreadth below the greater trochanter.
• Find the middle third between the greater trochanter and knee.
• Inject on the lateral side in the middle.
• Find the medial lateral portion (the middle third) of the thigh between the knee and greater trochanter.
• Find the middle point between the two.
• Inject on the lateral side of the middle point (above where the pant seam is on the lateral side of the leg).
• Can be used for infants, children and adults.
• Needle length usually: 1 – 1 1/2 inch for adults.

Deltoid Site

• Used for immunizations and nonirritating medications.
• There is a risk of injury to the brachial artery and radial nerve.
• Limit volume of medication based upon size of muscle-0.5-1ml.

Locating the Deltoid Site

• Locate the acromion process, which is the point of the shoulder where the scapula meets the clavicle
• Place the little finger on the acromion process and measure 3 fingerbreadths down.
• Inject at the fullest part of the deltoid, avoiding injecting too high or too low (below the axillary line).
• Avoid injecting too posterior; stay in the middle of the deltoid muscle to prevent damage to the radial nerve or brachial artery.

Dorsogluteal Site

• Locate the muscle by positioning patient prone or lateral.
• Locate the posterior superior iliac spine and the greater trochanter of the femur.
• Draw an imaginary diagonal line between the posterior superior iliac spine and greater trochanter.
• From the midpoint of the imaginary line, go superior 1 inch and lateral 1 inch to inject.
• Current practice is trying to move away from the use of this site, but use is still frequent.

Risks

• Sciatic nerve damage
• Injury to the superior gluteal artery.
• Increased incidence of injecting into fatty tissue due to uneven fat distribution.
• Bigger nerves = more pain.
• Not used in infants or toddlers until walking.

Locating the Ventrogluteal Site

• Palpate greater trochanter, place palm of hand on greater trochanter with thumb facing toward front of body
• Palpate the anterior superior iliac spine with the index finger
• Place index finger on the anterior superior iliac spine
• Place middle finger straight up--on the ridge of the iliac crest this keeps you from injecting too high
• Spread middle finger posteriorly, along the bony ridge of the iliac crest towards the posterior superior iliac crest (towards the back)
• The center of the formed triangle is the ventrogluteal site
• Inject in the center area of the triangle (move fingers out of the way before)
• Thumb pointed towards the front of the body helps indicate you are using the correct hand to palpate

Ventrogluteal Site Advantages

• Free of major blood vessels and nerves; considered safest site.
• Less fatty tissue, with more even fat distribution, making it more likely to inject into the intended muscle.
• Considered least painful site due to fewer nerves.
• Muscles used are the gluteus medius and gluteus minimus in the hip

Needle Gauge Use

• Needle gauge used is determined by the medication’s solution
  • Aqueous solution: Administer with 20- to 25-gauge needle.
  • Viscous or oil-based solutions: Administer with 18- to 21-gauge needles.
• Needle length is based on patient weight and body mass index.
  • Thin adult: 5/8-inch to 1-inch (16 mm to 25 mm) needle.
  • Average adult: 1-inch (25 mm) needle.
  • Larger adult (over 70 kg): 1-inch to 1½-inch (25 mm to 38 mm) needle.
  • Children and infants require shorter needles; refer to agency policies regarding needle length for infants, children, and adolescents.
• Up to 3 mL of medication may be administered in the ventrogluteal muscle of an average adult and up to 1 mL in children.
• Position patient sitting or lateral

Administering an IM Injection

• Hold syringe in dominant hand and 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 non-dominant hand.
• Aspirate-per facility policies
• Aspirate-pull back on the syringe to see if the needle is in the vessel; if no blood, then instill all medication slowly and hold plunger for 10 seconds.
• Remove needle at the same angle it was inserted.
• Cover site with 2” x 2” gauze using non-dominant hand, massage if indicated for the medication.
• Activate the needle safety with one-hand technique.
• If drawing up out of a vial, best practice per facility would be to change out your needle.

Key things to remember

• Check facility policy about aspiration
• See Intramuscular Injection Checklist in D2L for complete steps
• Tips to Decrease Injection Discomfort review page 774 in textbook
• Label the site Right or Left if necessary
• Chart on the PRN MAR
• RVG or LVG- ventrogluteal site
• RD or LD- deltoid site

Z-Track Injections

• Used for irritating solutions to reduce discomfort and inflammation.
• Common medications include Vistaril, Haldol, and Iron.
• Use a 1-3 ml syringe with 22-gauge needle, 1 ½ -2 inches long.
• Inject at a 90-degree angle.
• Sites used are dorsal gluteal and ventral gluteal.
• Displace the tissue laterally (away) from the injection site to create a track, preventing medication from seeping back into the subcutaneous tissue.

Air Seal Technique

• Draw up the needed dose from the vial as usual.
• Add the Air Seal: add 0.2-0.3 mls of air into the syringe.
• Prior to injecting the needle into the muscle make sure the medication is at the needle end of the syringe and the air is at the plunger end of the syringe.
• The air will be injected into the muscle last.

Aspiration

• If required by the facility, aspirate at this point in the injection.
• Aspiration means checking that the needle is not in a vessel by pulling back on the plunger to check for blood return.
• Stabilize the needle and syringe and pull back on the plunger.
• If blood is seen when you aspirate, immediately withdraw the needle and dispose of it safely and properly; get a new needle and syringe and redraw the medication dose.
• If no blood is aspirated, continue injection as usual.

Displacing the Skin

• Skin is pulled upward, downward, or laterally away from the injection site.
• Keep the skin displaced with non-dominant hand.
• Insert the needle with dominant hand into the muscle with a smooth, steady, quick continuous motion at a 90 degree angle.
• Stabilize the syringe by placing the thumb and forefinger on nondominant hand on the end of the syringe WHILE continuing to displace skin 1-2 inches away from injection site.

Administering a Z-Track Injection

• Complete 3 checks and 6 Rights
• Draw up the medication amount that equals the dose ordered in the syringe from the vial per checklist
• Make sure there are no bubbles in the syringe
• Recap using One Handed Scoop Technique
• Add 0.2 ml of air to the syringe
• Lock Med cart and go to patient's room KWIIIPES
• Find site using landmarks, clean site with alcohol inner to outer, let dry.
• Remove needle cap, make sure air bubble is at the bottom of the syringe (air will be injected last)
• Using dominant hand, insert needle swiftly, piercing the skin, tissue, and muscle with one smooth motion
• Aspirate per facility; student can verbalize how aspiration is performed and what is being checked
• After drug is instilled, hold plunger in for 5 to 10 seconds before withdrawing needle
• As you are withdrawing needle, release the tissue held back by your non-dominant hand, allowing tissue to close over the needle track in the muscle layer
• Avoid massaging injection site
• See Z-track Checklist in D2L for complete steps