1. Intramuscular route offer a faster rate of absorption than subcutaneous injection, it can hold a volume of fluid in children which is 0.5-2ml depending on the child size.
2. In children age less than 2 years the recommended site of injection is the leg muscle vastus lateralis, middle part and the lateral aspect of the muscle; shown in the figure. Insert the needle at 90 degrees to the long axis of the femur with the skin compressed between the index finger and the thumb.
3. Do the injection with a dart like motion to quickly pierce the skin and administer at a rate of no more than or faster than1ml/10 second in order to minimize the pain
4. For children more than 2 years, upper arm, deltoid muscle site is the recommended site of injection, 2-3 fingers (2.5-5cm) below the lower acromion process and the volume of injection should be limited to 0.5-1ml. This site is not used for injection for large volume of drugs especially for less than 5 year old kids.
5. The ventrogluteal muscle (upper outer part of buttock) is the site of choice for injection in adolescent and adult and not used in children, this site provides greater thickness of gluteal muscle.
6. Needle size Gauge 25 (1 inch, in length, 0.6 mm) is the most appropriate size for intramuscular injection to minimize local irritation and pain in children.
7. Use of longer needle (1inch) significantly reduces the local reaction instead of short needle except in neonate, when 16mm needle is suitable. Longer needle has been associated with reduce redness or swelling compared to shorter needle because the injection is deeper.
8. For cleaning the site of injection I believe using alcohol swab is better than normal saline.
9. Aspiration immediately before administration should be done, it takes only one second and you are sure you’re not hitting a vessel.
10. It is very important to minimize injection induced pain and the child distress. This issue has not been solved yet but there are some technique that can lessen the pain like topical anesthetic (Emla Cream) which takes about half an hour to start of its effect, positioning of the child ,good communication and also distracting the child attention.
Conclusion: The vastus lateralis (tigh muscle) is the site of choice for intramuscular injection in children under the age of 2 years followed by deltoid muscle (arm) for children 2 years and above. Ventrogluteal (buttocks) muscle being the site of choice in I.M. injection in adolescent and adult. Compressing or holding the skin between the index finger and the thumb can help to lessen the injection pain. The needle size of choice is Gauge 25 (1 inch, in length, 0.6 mm) is the choice for I.M. injection. Piercing the skin should be in dart like motion very quick, with quick aspiration prior to administration.