Intramuscular Injection Techniques

Intramuscular Injection

• Intramuscular (IM) injection is a method of administering medication directly into a muscle
• The purpose of IM injections is to maximize the therapeutic effects of medications while minimizing complications, injury, and discomfort

IM Injection Sites

• Acceptable sites include the thigh (rectus femoris and vastus lateralis), gluteus medius, dorsogluteal site, deltoid site, and ventrogluteal site

Thigh Injection (Vastus Lateralis)

• Drug uptake from the thigh is slower than from the arm but faster than from the buttock, facilitating better drug serum concentrations
• To locate the injection site:
  • Create an imaginary box on the upper leg
  • The upper border of the box is one hand's width below the groin
  • The lower border of the box is one hand's width above the top of the knee
• Stretch the skin, insert the needle at a 90-degree angle, and inject up to 2ml of fluid
• The thigh is useful if other sites are contraindicated or for self-administration in sitting or lying positions
• A disadvantage is from the rectus femoris site, which may cause considerable discomfort
• The site is suitable for infants, children, and adults, with a needle length of 2.5cm or less

Gluteus Medius (Buttock) Injection

• Find the trochanter which is the knobby top of the femur, about the size of a golf ball
• Find the posterior iliac crest
• Draw an imaginary line between the two landmarks
• Find a point one inch toward the head from the center of the imaginary line, which is the insertion point
• Ensure the skin is stretched tight
• Insert the needle at a right angle
• Up to 3ml of fluid can be administered
• The presence of major nerves and blood vessels plus the thick adipose tissue layer makes this site problematic due to slower medication uptake
• The sciatic nerve and superior gluteal artery lie close to the injection site
• Palpating the ileum and trochanter is important since visual estimations alone can result in poorly placed injections

Dorsogluteal Site Risks

• Risk of contacting the sciatic nerve or superior gluteal artery
• Too much fatty tissue can lead to poor absorption rates
• This site is contraindicated in children

Deltoid Site

• The ease of access makes the deltoid site common for IM injections, especially in outpatient settings
• Mostly used for immunizations/non-irritating medications with vaccines which are small in volume administered here
• The small muscle mass and proximity to neurovascular structures mean that more substantial injuries can occur
• Locate the knobby top of the arm (acromion process)
• The top border of an inverted triangle is two finger widths down from the acromion process
• Stretch the skin and then bunch up the muscle
• Insert the needle at a right angle to the skin in the center of the inverted triangle
• Caution should be used here as it is a small site
• One should only give 1-2ml or less of fluid
• Volume of injection should be based on muscle size, such as 0.5-2ml

Ventrogluteal Site

• The ventrogluteal site offers the greatest thickness of gluteal muscle (gluteus medius and minimus)
• It is free of penetrating nerves and blood vessels and has a thinner, more consistent layer of fat compared to the dorsogluteal site
• The site is the preferable site for intramuscular injection since research is supporting its safety

Finding the Ventrogluteal Site

• Find the trochanter and the anterior iliac crest
• Place the palm of your hand over the trochanter and point the index finger toward the anterior iliac crest
• Spread the middle finger back, creating a 'V', and keep thumb pointed towards the front of the leg
• Always have the index finger and middle finger make the “V”
• Inject between the knuckles of your index and middle fingers
• Stretch the skin
• Insert the needle at a right angle
• Up to 3ml of fluid can be given

Equipment needed for IM Injection

• Syringes of appropriate size
• Needles of varying lengths and sizes
• Medication cards
• Ampoule or vial of medication
• Solvent (e.g., normal saline or sterile water), if needed
• Alcohol sponge and dry sponge
• Tray
• Container for disposing of waste (paper bag)

Administering Injection from Ampoule

• Tap top of ampule lightly to dislodge all fluid above the neck
• Place a small dry sponge around the neck of the ampule
• Snap the neck quickly and firmly away from your body
• Draw up medication quickly while holding ampule upside down
• Insert needle into the center of the ampule opening, and ensure that the needle tip or shaft doesn't touch the rim of the ampule
• Aspirate medication by gently pulling back on the plunger
• Keep the needle tip below the surface of the fluid and bring all fluid within reach of the needle
• To expel air bubbles, remove the needle
• Hold the syringe with the needle pointing up
• Tap side of syringe to cause bubbles to rise toward the needle
• Draw back slightly on the plunger, and push the plunger upward to eject air

Administering Injection from Vial

• Remove the metal cap covering the top of the unused vial exposing the rubber seal
• Wipe off surface of rubber seal with alcohol sponge, if vial had been previously opened
• Take syringe and remove needle cap
• Pull back on plunger to draw amount of air into syringe equivalent to volume of medication to be aspirated from vial
• Insert tip of needle, with level pointing up, through center of rubber seal
• Inject air into vial, holding onto plunger
• Invert vial while keeping firm hold on syringe and plunger
• Hold vial between thumb and middle fingers of nondominant hand
• Grasp end of syringe barrel and plunger with thumb and forefinger of dominant hand
• Keep tip of needle below fluid level
• Allow air pressure to fill syringe gradually with medication
• Pull back slightly on plunger if necessary
• Tap side of syringe barrel carefully to dislodge air bubbles and eject air remaining at top of syringe into vial
• After correct dose is obtained, remove needle from vial by pulling back on barrel bubbles of syringe

Preparing a Powdered Drug

• Draw up the recommended amount of solvent
• Inject the solvent into the vial in the same manner as before
• Gently shake the vial between the hands
• Draw up the dissolved medication
• For multi-dose vial, make label that includes date of mixing, concentration of drug per ml and your initials
• Dispose of soiled supplies in proper container
• Check fluid level in syringe and compare with desired dose
• Clean and dry the work area

Reducing Pain from Intramuscular Injections

• Rotate IM injection sites to decrease the risk for tissue hypertrophy
• Avoid use of site on emaciated or atrophied muscles as they absorb medication poorly
• Use the Z-track method, a technique for pulling the skin during an injection, to prevent leakage of medication, seal medication in the muscle, and minimize irritation
• Apply the appropriate-size needle to the syringe
• Select an appropriate IM site preferably in a large, deep muscle such as the ventrogluteal
• Pull the overlying skin and subcutaneous tissues approximately 2.5 to 3.5 cm (1 to 1 ½ inches) laterally to the side with the ulnar side of the nondominant hand
• Hold the skin in this position until you have administered the injection
• After cleaning a site, inject the needle deeply into the muscle
• There is no longer any need to aspirate after the needle is injected when administering vaccines to reduce injection site discomfort
• Keep the needle inserted for 10 seconds to allow the medication to disperse evenly
• Release the skin after withdrawing the needle to encourage a zigzag effect
• This leaves a zigzag path that seals the needle track wherever tissue planes slide across one another, and the medication is sealed in the muscle tissue

Heifer Technique

• The researcher places the patient in side-lying position and flexes the knee to relax the muscles
• The investigator makes a wide V with thumb and the rest of the fingers of the non-dominant hand
• Over the buttocks taping the skin with the middle, ring and little finger of the dominant hand counts 1, 2, 3 simultaneously tap the skin, then inject vitamin with needle gauge 20-22

Complications with Injections

• Potential complications include pain/ minor discomfort for a short time after an injection which is normal
• Nerve damage, tissue necrosis, intramuscular hemorrhage, abscess, allergic reaction, needle phobia
• Muscle fibrosis with repeated use of the same site