An intramuscular injection can be applied to the gluteus, arm or thigh, and it is used to administer vaccines or medicines like Voltaren or Benzetacil, for example.
To apply an intramuscular injection the following steps must be taken:
- Position the person according to where you are going to administer the injection, for example, if it is on the arm, the person should be seated, while if it is on the gluteus they should be lying with their belly down or on their side;
- Aspirate the medication into a sterilized syringe with the aid of a sterile needle;
- Pass a gauze with alcohol on the skin where you are going to give the injection;
- Do a skin fold with the thumb and forefinger, in the case of the arm or thigh. It is not necessary to fold the gluteus;
- Insert the needle at a 90 ° angle, maintaining the fold. If the injection is applied in the gluteus, you should first insert the needle and only after the syringe;
- Pull the plunger a little to check for blood entering the syringe. If this happens, it means you are inside a blood vessel, so it is important to slightly lift the needle and turn it a little to the side to avoid injecting the medication directly into the blood;
- Push the syringe plunger slowly while holding the crease in the skin;
- Remove the injection, undo the skin fold and apply press with a clean gauze for 30 seconds;
- Place a band aid where the injection was given.
Intramuscular injections, especially in infants or young children, should only be performed by a trained nurse or pharmacist to avoid serious complications such as infection, abscess, or paralysis.
How to choose the best location for an intramuscular injection
Intramuscular injections may be applied to the gluteus, arm or thigh, depending on the type of medication and the amount to be administered:
1. Injection in the gluteus
To know the exact location of where to administer an intramuscular injection in the gluteus, 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 the injection in the gluteus: it is the most used place when the medication to be injected is very thick or has more than 3 mL, like Voltaren, Coltrax or Benzetacil.
2. Injection in the arm
The best location for an intramuscular injection in the arm is signalized by the triangle in the image below:
When to administer the injection in the arm: it is generally used to administer vaccines or medications under 3 ml.
3. Injection in the thigh
To apply a thigh injection, it should be administered on the outer side, one foot above the knee and one foot below the thigh bone, as shown in the image:
When to administer the injection to the thigh: This injection region is the safest because the risk of reaching a nerve or blood vessel is lower, so it should be the chosen region for someone who has little practice in injecting.
What happens when an intramuscular injection isn't administered properly
Poorly applied intramuscular injection can cause:
- Intense pain and hardening of the region where the injection was applied;
- Redness of the skin;
- Decreased sensitivity at region where the injection was administered;
- Swelling of the skin where the injection was administered;
- Paralysis or necrosis, which is the death of the muscle.
Therefore, it is very important that the injection is applied by a trained nurse or pharmacist, in order to avoid these complications that, in serious cases, could endanger the life of the person.