The intramuscular injection can be applied to the gluteus, the arm or the thigh, and is used to administer vaccines or medications such as Voltaren or Benzetacil, for example.
To apply an intramuscular injection, the following steps must be followed:
- Position the person according to the injection site, for example, if it is in the arm, they should be seated, while if it is in the buttocks, they should be lying on their stomachs or on their sides;
- Aspirate the medicine into the sterile syringe , using a sterile needle;
- Pass an alcohol gauze over the skin of the injection site;
- Make a fold on the skin with your thumb and forefinger , in the case of the arm or thigh. It is not necessary to fold the gluteus;
- Insert the needle at an angle of 90º , keeping the fold. In case of injection into the gluteus, the needle must be inserted first and then the syringe must be added;
- Pull the plunger a little bit to check that there is no blood entering the syringe . If this happens, it means that you are inside a blood vessel and, therefore, it is important to slightly raise the needle and turn its direction slightly to the side, to avoid injecting the medicine directly into the blood;
- Push the plunger of the syringe slowly while holding the pleat on the skin;
- Remove the syringe and needle in a single movement , undo the skin fold and press with clean gauze for 30 seconds;
- Place a band-aid on the injection site.
Intramuscular injections, especially in babies or young children, should only be administered by a nurse or pharmacist trained to avoid serious complications, such as infection, abscess or paralysis.
How to choose the best location
Intramuscular injection can be applied to the gluteus, the arm or the thigh, depending on the type of medication and the amount to be administered:
1. Injection into the gluteus
To find out the exact location of the intramuscular injection in the gluteus, you should divide the gluteus into 4 equal parts and place 3 fingers, diagonally, in the upper right quadrant, next to the intersection of the imaginary lines, as shown in the first image. In this way it is possible to avoid injuring the sciatic nerve which can cause paralysis.
When to administer in the gluteus : it is the most used site for the injection of very thick medications or with more than 3 mL, such as Voltaren, Coltrax or Benzetacil.
2. Injection in the arm
The intramuscular injection site in the arm is the triangle marked in the image:
When to administer in the arm : it is usually used to administer vaccines or drugs with less than 3 mL.
3. Injection in the thigh
For the thigh injection, the application site is located on the external side, one hand above the knee and one hand below the thigh bone, as shown in the image:
When to administer in the thigh : this injection site is the safest, as the risk of reaching a nerve or blood vessel is lower, and therefore it should be preferred for someone who has little practice in giving injections.
What happens if the injection is mishandled
Misapplicated intramuscular injection can cause:
- Severe pain and hardening of the injection site;
- Redness of the skin;
- Decreased sensitivity at the application site;
- Swelling of the skin at the injection site;
- Paralysis or necrosis, which is the death of the muscle.
Therefore, it is very important that the injection is given, preferably, by a trained nurse or pharmacist, in order to avoid these complications that, in severe cases, can endanger the person’s life.