Vastus Lateralis Injection Site
When giving any type of injection the first thing you want to do is explain to the person or parent/guardian, exactly what you are about to do. If you are giving the injection to yourself then pay close attention. When giving a vastus lateralis injection also known as a thigh injection, find the greater trochanter of the thigh you are going to be using. Look at the picture if you need a visual aid. Keep in mind that you will not see the greater trochanter without an x-ray, unless the person has lost a severe amount of weight. In this case the vastus lateralis injection site would not be an ideal choice because it would be so small and hard to locate. Try to find the general location of where the greater trochanter would be by feeling for it. Locate the knee joint. Imagine a road from the greater trochanter to the knee joint (kneecap), divide the road in half and slide to the outer part of the thigh you are using and you will have found the location for the vastus lateralis injection site. If you go too far to the outer thigh you will feel your fingers fall into a crevasse. If you feel that crevasse or dividing line, slide your fingers back up about a half inch and that will be the site for injection. It should be noted that most injections should be given by a healthcare professional. The only time you should inject yourself or somebody else is if you have been properly instructed on how to do so, finding the landmarks for every injection is one of the most important steps to avoid long term damage or death.
Vastus Lateralis Injection Landmarks
Vastus Lateralis Injection Site
NEEDLE INSERTION AND SIZE FOR THE VASTUS LATERALIS INJECTION SITE
The insertion of the needle should be at a 90 degree angle in relation to the knee in infants and young children. In adults you can inject at a 90 degree angle in relation to the inner thigh because the vastus lateralis is larger in adults. This injection site is the standard for infants and young children because it is the safest and largest muscle they possess. The size of the needle can be 22 to 25 gauge and the length of the needle can be 5/8 to 1 inch. When choosing needle size consider the person, if they are tiny like an infant would be go with a 5/8 inch needle. The reason is because even if you find the correct site by locating all of the landmarks associated with the vastus lateralis injection site you could still inject to deeply and hit bone or a nerve. It is not always necessary to inject the whole needle into the leg, just make sure the needle is in the muscle. Once you have inserted the needle into the muscle don't forget to aspirate (pull the plunger back) to make sure the needle did not enter the blood stream. Depending on the medication, if you were to inject into the blood stream, there is a greater chance of exhibiting the adverse affects associated with those medicines.
ADVANTAGES OF THE VASTUS LATERALIS INJECTION SITE
Main advantage of this site is that the muscle is normally well developed even in infants and children. The amount of fluid should not exceed 2.0ml for children older than 1 year. Fluid should not exceed 1.0ml in infants. It is best to give this injection lying flat or on the side with the site pointing at the ceiling. It can also can be given while sitting down, especially handy if you are giving the injection to yourself.
DISADVANTAGES OF THE VASTUS LATERALIS INJECTION SITE
Some disadvantages include the possible formation of a thrombosis in the femoral artery. This is only possible by not properly locating the landmarks associated with the vastus lateralis injection. The femoral artery is located on the opposite side of the injection site. Another possible injury that can be caused by not properly finding landmarks is damage to the sciatic nerve. Also possible to hit the sciatic nerve by using to long of a needle and injecting to far back. The vastus lateralis injection is more painful than the deltoid or ventrogluteal injection sites.
dr piyush on March 07, 2012:
very useful information for me ...thanks a lot