How to Inject Intramuscular

Identify the parts of the syringe. Injections are easier if you understand the mechanism behind what you’re doing.

• The syringe consists of three main parts: the needle, the reservoir, and the piston. Needle used to puncture the muscle; container graduated in cc (cubic centimeter) or ml (milliliter) with numerals on the side, used for drug storage; The plunger is used to draw the medication in and push it out of the tube. ^[11]
• Intramuscular drugs are measured in cm3 or ml. The amount of drug in one cc is equal to one ml.

Know where to inject. The human body has several points of receptivity to drugs.

• Outer thigh muscle : First you divide the thigh into three equal parts. The middle part is where the medicine can be injected. The thigh is a suitable place for injection because it is easy to see. It is also a suitable injection site for children under three years of age. ^[12]
• Abs-buttocks (hips): To determine the correct position, place your palms on the outer cheeks of the upper thighs, where the buttocks are reached. The thumb points to the groin and the remaining fingers point towards the patient’s head. Separate the first finger from the other three to form a V. You should feel the edge of the bone running along the tips of your little and ring fingers. The injection site is located in the middle of the letter V. The hip is a suitable place to inject drugs for adults and children over seven months of age. ^[13]
• Biceps : Open up the shirt to reveal the biceps completely. Feel for the bone that runs across the top of the biceps. That’s called the scapula. The base of this bone is where the triangular base forms. The top of the triangle is located just below the midpoint of the base and about level with the armpit. The injection site is at the center of the triangle, 2.5 to 5.1cm below the acrosis of the shoulder. The injection should not be given to this site if the patient is very thin or has very little muscle. ^[14]
• Buttock : Exposing one side of the buttocks. Using a cotton ball soaked in alcohol, draw a line from the top of the buttock to one side of the body. Find the midpoint of that line and draw 7.6cm above it. From that point, draw another line down and across the first line, ending around the middle of the buttock. You now have a cross. You should feel an arc bone in the upper outer quadrant. The injection site is located in this quadrant and below that arc bone. Do not inject into this site for infants and children under three years of age because their muscles are not developed enough. ^[15]

Know who needs the injection. Each person has a unique site for injection, so you should consider several factors before proceeding:

• Age. For infants and children 2 years of age and younger, thigh muscles are best. For children three years and older, you can choose the hamstrings or the glottis. You should use a needle size between 22 and 30 (mostly depends on the consistency of the medication – your doctor will tell you which needle size to use). ^[16]
  • Note: For very young children, a smaller needle is recommended. Compared to biceps, thigh muscles can accept larger needles. ^[17]
• Consider the previous injection site. If the patient has just been injected at this site, you should inject at another site, thus avoiding scarring and skin damage. ^[18]

Know how to inject medication into a syringe. Some syringes come prefilled with medication, sometimes the medication is supplied in a vial and you need to withdraw it. Before withdrawing medicine from the vial, you must make sure that you have taken the correct medicine, that the medicine is not expired, has not changed color or has foreign objects floating inside. ^[19] If it is a new potion, check that the seal is not broken.

• Sterilize the mouth of the vial with a cotton swab soaked in alcohol.
• Hold the syringe with the needle pointed up, the vial cap still closed. Draw the plunger to the graduation line corresponding to the amount of drug to be injected to draw air in. ^[20]
• Insert the needle through the rubber cap of the vial and push the plunger in, which will push air into the vial. ^[21]
• With the vial upside down and the needle in the medicine, you pull the plunger back up to the dose you want to inject (or a little over if there are air bubbles). Snap your fingers on the syringe to push the air bubbles to the top, then push them into the vial. Check that there is the correct amount of medicine in the tube. ^[22]
• Remove the needle from the vial. If not using immediately, you must cover the needle grip. ^[23]

Understand the benefits of the zigzag technique. When injected intramuscularly, the needle action creates a narrow passage between the tissues, and the drug can leak out of the body through this passage. The zigzag injection helps to reduce skin irritation and allows for better absorption because the muscle tissue locks tightly to prevent the drug from leaking out. ^[24]

Repeat the steps of washing hands, withdrawing medication, and selecting and cleaning the injection site.

Stretch the skin 2.5cm towards the non-dominant hand. Hold your hand firmly to keep the skin and underlying tissue in place.

Use your dominant hand to insert the needle into the muscle layer at a 90-degree angle. Pull the plunger back slightly to check for blood draw in, then push slowly to inject the medication.

Hold the needle for 10 seconds to give the medicine time to disperse evenly into the muscle tissue.