In our recent LinkedIn Post, we asked our followers that which injection technique is used to inject Covid-19 vaccine? And this inspired us to write and share knowledge on what are the different types of injection techniques and what are their functions. Let us first understand-
What is an injection?
An injection is a way of administering a sterile liquid form of medication into tissues of the body beneath the skin, usually using a sharp, hollow needle or tube. Most people with access to healthcare services experience injections at some point in their lives, such as childhood immunizations or medical treatment. Injections are usually used for drugs which need to act quickly or do not absorb well in the digestive system.
Some medications can be given as long-acting injections, known as depot injections. An amount of slow-release medication is injected and steadily absorbed into the body over a number of weeks or even months. Depot injections are only available for specific medications but can be helpful for people who find it difficult to remember to take their medication, or for situations where a missed dose could cause serious problems. Hormonal contraceptives or some psychiatric medications may be given as depot injections.
Different Techniques of Injection:
1. Intramuscular Injection (IM)
An intramuscular injection delivers medication into a muscle. Doctors frequently use intramuscular injections to administer vaccines and certain other drugs.
Intramuscular injections offer some benefits over other types of delivery methods, such as oral, intravenous injections into a vein, and subcutaneous injections into fatty tissue under the skin.
A doctor may use an intramuscular shot if:
- they cannot locate an appropriate vein
- the particular drug would irritate the veins
- the digestive system would render pills ineffective
Intramuscular injections have other advantages too. The muscles have a plentiful supply of blood, which helps ensure that the body absorbs the medication quickly. The tissue in the muscles can also hold more medication than fatty tissue.
2. Subcutaneous Injection (SC)
A subcutaneous injection is a method of administering medication. Subcutaneous means under the skin.
In this type of injection, a short needle is used to inject a drug into the tissue layer between the skin and the muscle. Medication given this way is usually absorbed more slowly than if injected into a vein, sometimes over a period of 24 hours.
This type of injection is used when other methods of administration might be less effective. For example, some medications can’t be given by mouth because acid and enzymes in the stomach would destroy them.
Medications administered by subcutaneous injection include drugs that can be given in small volumes (usually less than 1 mL but up to 2 mL is safe). Insulin and some hormones are commonly administered as subcutaneous injections.
Other drugs that need to be given very quickly can also be administered via subcutaneous injection.
3. Intravenous Injection (IV)
Some medications must be given by an intravenous (IV) injection or infusion. This means they’re sent directly into your vein using a needle or tube. In fact, the term “intravenous” means “into the vein.”
With IV administration, a thin plastic tube called an IV catheter is inserted into your vein. The catheter allows your healthcare provider to give you multiple safe doses of medication without needing to poke you with a needle each time.
IV medication is often used because of the control it provides over dosage. For instance, in some situations, people must receive medication very quickly. This includes emergencies, such as a heart attack, stroke, or poisoning. In these instances, taking pills or liquids by mouth may not be fast enough to get these drugs into the bloodstream. IV administration, on the other hand, quickly sends a medication directly into the bloodstream.
3. Intradermal Injection (ID)
These are injections given in between the layers of the skin. This route is usually used when a localised reaction is required, for example with some vaccinations, allergy testing, or tests to determine previous exposure to some infections. In general, people who are up-to-date with common childhood vaccinations have experienced an intradermal injection.
Intradermal injections are more immunogenic than equivalent single intramuscular ones due to the presence of dendritic cells in skin.
The ID injection route has the longest absorption time of all parenteral routes. These types of injections are used for sensitivity tests, such as TB, allergy, and local anesthesia tests. The advantage of these tests is that the body reaction is easy to visualize, and the degree of reaction can be assessed.
Some people have to get themselves injected on a regular basis. It is essential of them to have a basic understanding of injection techniques and which injection technique could be right for administration of drugs into the body.