Intramuscular Injection Intramuscular injections are given to deliver medication/drugs directly into a muscle layer for rapid systemic absorption. Some drugs take longer to absorb into the systemic circulation than others for reasons like pharmacokinetics and viscosity of the solution.
Introduction to Intramuscular Injection
Disclaimer: The below information may differ between health care departments around the world due to differences in medication administration policy, and differences in what is deemed 'best possible practice'. This information is therefore only generalizable to Australia and may still differ between states as per differences in policies.
21-23 gauge needles are used. The size of syringe barrel depends on type and amount of solution. It is not a very smart idea to be injecting large volumes and repeated doses. This increases your chance of acquiring a life threatening infection, ulcer, sepsis...
Tips Related to Infection Prevention
The site for injection should be cleaned with an alcohol wipe and allowed to air dry. The rationale for allowing the injection site to air dry is to allow the alcohol to achieve its full microbial effect re; killing microorganisms on your skin. Never use old or wet cotton filters because bacteria thrive on wet surfaces. Wipe from your intended insertion site and work your way outwards; being careful not to wipe over the same area. Use sterile syringes only and do not share needles with anybody. Don't touch the end of the needles with your fingers or anything else. Ideally they should come straight out of a packet and only be touching your skin on the way in.
Monitor your body for signs of infection: increased heart rate, pain, warmth and redness at injection site, increased body temperature that is outside the normal range, chills, and rigors, then seek medical advice IMMEDIATELY.
Tips Related to Injection
Stretch the skin, hold the syringe like a dart and enter at a ninety degree angle. Aspirate needle to check that you haven't entered a vessel. Assuming you haven't entered the vessel, you push solution in and then remove syringe, replacing with a piece of cotton wall. Hold cotton wool firmly against skin for a minute.
Deltoid
Site for up to 2mL injection volume. To find this injection site, you need to feel 2.5-5cm below the bottom of the acromion process. This site is very small and not recommended for larger volumes or repeated injections.
Vastus lateralis
Site for up to 5mL injection volume. This is the outer side of the thigh. To locate this properly, you need to visualise the very top of femur and the knee. Then you split this area into thirds and use the outer middle third. There are no major nerves or vessels in this space if you locate it the insertion site correctly.
Ventrogluteal
Site for up to 4mL injection volume. This is the 'hip site'. This site is considered the safest administration site as it has no nerves or major vessels in reach, and less chance of hitting the subcutaneous tissue. To find the injection site on a person, you need to place your R) hand on the greater trochanter, pointing index finger to anterior superior iliac spine, spread middle finger to form a V, and the injection site is between the index and middle fingers. If you're going to attempt this injection site, it is suggested that you watch a health-care related youtube before attempting the shot. This is not a location which you will be able to administer yourself easily.
Dorsogluteal
Site for 1-4mL injection volume. This site is not used very much in health care settings due to close proximity to sciatic nerve and major vessels. To locate this site you must make imaginary (or draw it if it's easier) lines to split the butt cheek into four equal areas. The injection site is the upper outer quadrant.
Safety Precautions Involving Intramuscular Injection
Using a .2 Micron Syringe filter with a fresh syringe and saline or distilled water can help reduce contaminants in the injection.
Make sure to inspect the syringe for air bubbles, turning the needle up and flicking the syringe will cause any bubbles to rise to the top. Prior to injection make sure all air is at the top of the syringe before pushing down on the plunger until liquid exits the needle. Done correctly this pushes all air bubbles out of the syringe prior to any liquid.
