Numerous drugs and vaccines are administered via intramuscular injection. Certain practices can help reduce the risk of adverse effects, which can sometimes be severe: peripheral nerve damage, bruising, abscess, gangrene. Preparation of the injection involves verifying the patient’s identity and checking the drug, its expiry date, aspect, the amount to be injected, etc. Sterile equipment should be used in aseptic conditions, and the patient should be prepared by being given information and helped to relax so as to minimise pain.
The upper outer quadrant of the buttock is no longer considered appropriate as injections on this site are rarely truly intramuscular. There are three recommended sites: the gluteus medius muscle, the lateral outer region of the middle third of the thigh (best in infants under the age of one and for self-injection), and the deltoid muscle (best for vaccinations).
The choice of needle length depends on the injection site, and on the patient’s age and corpulence.
The Z-track technique reduces pain and local reactions. This consists of pulling the skin a few centimetres downwards or to one side of the intended site prior to inserting the needle with the free hand to avoid the alignment of the needle tracks through the cutaneous tissue and muscle. The needle is aimed at the underlying muscle and on removal the retracted skin is released. After the injection, it seems better not to massage the injection site.
©Prescrire July 2010
Source: "Réussir une injection intramusculaire" Rev Prescrire 2010 ; 30 (320) : 433-437.