Overview of Intramuscular Injection
An intramuscular injection (IM), often called a “shot,” is a way to put medication into specific muscles in your body. The muscles selected for these injections have plenty of blood supply, which allows the medication to quickly get into your bloodstream and then go to the area of your body where it’s needed most. This method of giving medication bypasses what’s known as “first-pass metabolism,” which means it doesn’t have to go through your liver first before it starts working.
This is a very common medical procedure. But even so, there are still some health professionals who do not follow the recommended guidelines for giving these injections.
Intramuscular injections can be used for both prevention and treatment. About 5% are for prevention, like immunizations (vaccines). The vast majority, about 95%, are for treatment.
Some of the most common medications given through intramuscular injections include antibiotics like penicillin and streptomycin, biological treatments like immunoglobulins (proteins that help your immune system), vaccines, and toxoids (inactive toxins used in vaccines), and hormonal agents like testosterone and medroxyprogesterone.
Drugs that aren’t irritants and can dissolve in water can also be given through an intramuscular injection during a medical emergency.
Anatomy and Physiology of Intramuscular Injection
When giving an injection into a muscle (IM injections), it’s essential to target specific spots on the body to avoid harming any nerves or blood vessels. Here are some guidelines for the most common injection sites:
Back Upper Hip Area (Dorsogluteal Region)
* This site is 5 to 7.5 cm below the top ridge of the hip bone.
* The shot should be given in the upper outside area of the buttocks.
Front Hip Area (Ventrogluteal Region)
* Position your other hand’s heel on the large bony part of the hip. Place your index finger on the forward upper corner of your hip bone and the middle finger below the top ridge of your hip bone.
* The injection should be given within the triangle formed by these three points.
Upper Arm (Deltoid)
* This is 2.5 to 5 cm below the bony tip of the shoulder (acromion process).
Thigh (Vastus Lateralis)
* The injection goes in the middle third of the line that runs from the large bony part of the hip (greater trochanter of the femur) to the outside lower part of the knee (lateral femoral condyle).
Why do People Need Intramuscular Injection
Intramuscular (IM) injections, a way of getting medicine directly into your muscle, might be recommended by your doctor for several reasons. This could be necessary if you:
- Have trouble following your medical instructions (noncompliant)
- Find it hard to cooperate with medical staff (uncooperative)
- Are hesitant about medical procedures (reluctant)
- Cannot take medication in more common ways, like swallowing tablets or liquids
- Experience side effects, such as upset stomach, from oral medications
Your doctor will carefully consider these aspects before recommending this method of giving medication.
When a Person Should Avoid Intramuscular Injection
There are several reasons why a person may not be able to receive a specific type of medication or treatment. These can include:
If there’s an active skin infection, inflammation, or skin disease at the spot where the medicine would be given, it’s not safe to proceed. This is because the skin needs to be healthy to help avoid potential side effects or complications.
A person might also be allergic or have a known sensitivity to the medication. This means they’ve had a bad reaction to it in the past. Giving them the medication could lead to serious side effects or even a life-threatening reaction.
If a person recently had a heart attack, the treatment could interfere with how doctors are managing their condition. In particular, the treatment could complicate the measurement of certain enzymes that are released when heart muscle is damaged.
Thrombocytopenia – a condition characterized by a low platelet count in the blood – can also be a factor. Platelets are crucial for blood clotting, and a low count could result in unnecessary bleeding or complications.
Similarly, defects in the blood’s ability to clot can be a reason to avoid this treatment. Uncontrolled bleeding can lead to severe complications.
If a person is suffering from hypovolemic shock, a severe fluid loss that leads to a drop in blood volume, the treatment may not be effective as their condition could compromise the blood flow to the specific muscle where the drug is injected.
Myopathies, or diseases affecting muscle tissue, can also hamper the treatment. This is because certain drugs may not work as well in damaged muscles and can cause side effects.
If a person has muscular atrophy, that means their muscles are wasting away. This can slow down how the body absorbs the medication and increase the risk of complications affecting the nerves and blood vessels.
Equipment used for Intramuscular Injection
1. A suitable syringe with the right needle size:
- For infants, the needle is generally inserted into the vastus lateralis (a muscle in the thigh area) with a 22-25mm needle when the skin is pinched or ‘bunched,’ and a 16mm needle when the skin is stretched.
- For toddlers and older children, the needle is commonly inserted into the deltoid (upper arm muscle) or the vastus lateralis, and the needle size is usually from 25mm to 38mm.
2. A filter needle: It’s a type of needle that has a built-in filter. It’s used to remove any small particles that might be present in the fluid being drawn into the syringe.
3. An alcohol-based antiseptic solution: This is used to clean the skin area where the needle will be inserted to reduce the risk of infection.
4. The right medication in the correct dosage: This means using the specific drug that has been prescribed and ensuring that the amount given is the exact dose that has been ordered.
5. A dry cotton swab: This is typically used to apply antiseptic solution to the skin and can also help stop any minor bleeding after the needle has been removed.
6. A self-sticking bandage: This is a type of bandage that sticks to itself and is used to cover the injection site after the needle has been removed to keep the area clean and help prevent infection.
7. A safe needle and waste disposal unit: After the injection, the used needle and syringe should be immediately disposed of in a safe and secure manner into a designated container that’s meant for this purpose.
Who is needed to perform Intramuscular Injection?
You might encounter a few different healthcare professionals during your appointment or hospital stay. For example, you might interact with a trained nurse, who has extensive healthcare education and practical experience. Or, you could meet a pharmacist, who is an expert in medications and their effects. Sometimes, a paramedic might be involved too, and they are the trained professionals who give first aid and emergency treatment.
Most importantly, you’ll be with your clinician, the healthcare professional who’s in charge of your treatment. This could be your doctor, nurse, or another kind of healthcare provider. They use all the medical information available and apply their expert knowledge to find the best treatment options for your specific situation.
Preparing for Intramuscular Injection
Each year, around 12 billion injections are given worldwide. Unfortunately, it’s been found that half of these are given by staff who aren’t properly trained. Not only that, but about three-quarters of these injections might not even be needed. This emphasizes the importance of making sure injections are administered correctly and only when necessary.
Medical staff should always double-check the “Medication Administration Record”. This means making sure they are giving the medication to the right patient, ensuring it’s the right drug, checking the dose is correct, giving the injection in the right place, and doing so at the right time. This thorough process is designed to keep the patient safe and guarantee they’re getting the appropriate medication and treatment.
It’s also crucial that the patient is fully informed and consents to the procedure. They need to be aware that they’re receiving the correct treatment and understand why it’s necessary.
Depending on the patient’s age group, there are different ideal sites for injections. For babies, the best place to administer an injection is in the vastus lateralis muscle, which is in the thigh area. For children, the vastus lateralis and the deltoid muscle (upper arm area) are both suitable. For adults, it’s most appropriate to use the ventrogluteal or deltoid muscles. Doctors and nurses choose these specific sites to ensure the medicine is effectively absorbed and to try to minimize any discomfort during the procedure.
How is Intramuscular Injection performed
If you’re receiving an injection into your muscle (an intramuscular injection), your healthcare professional will go through a series of essential steps to give you the shot safely and effectively. Here’s what they generally do:
- First, they’ll clean their hands meticulously and put on gloves.
- They’ll then prepare your skin by applying a 70% isopropyl swab for 30 seconds. They’ll let it dry naturally.
- They’ll use a sharp, clean needle to avoid contamination. They’ll insert it upward, parallel to the angle of the rubber stopper, so as not to dull the needle.
- They’ll carefully draw up the medication from the container, avoiding any last drops to prevent injecting air.
- If any medication splashes onto the needle, they’ll clean it off with a sterile piece of gauze.
- Contrary to popular belief, they won’t draw up an air bubble into the syringe.
Now, the actual injection:
- They’ll use the ‘z-track’ technique, which involves pushing the skin slightly to one side before the injection – this helps seal the medication in.
- The needle will be quickly “darted” into your muscle at a 90-degree angle.
- They’ll confirm the needle is in the right position by checking if its sideways movement is limited – a sign it’s in the muscle layer (not the fatty tissue under the skin).
- During the injection, they’ll draw back on the syringe slightly to ensure the needle’s not in a blood vessel – usually done for 5-10 seconds in specific areas like the upper buttock.
- The medication is injected slowly (10 seconds for every milliliter) to let your muscle stretch gradually around it. This reduces leakage along the track the needle makes.
- After the injection, they’ll wait 10 seconds for the medication to spread out in the muscle before pulling out the needle.
- The needle’s smoothly and steadily removed, and then disposed of safely in a sharps container, using the ‘scoop method’ to replace the needle cap and avoid accidental injuries.
Lastly, they’ll check the injection area for any complications or side effects that might have arisen immediately after the injection or might occur later on.
Possible Complications of Intramuscular Injection
After receiving an injection into a muscle, there might be some side effects. These can range from long-lasting pain at the spot where the injection was given, hardening and shrinkage of muscle tissue, an abscess or collection of pus, gangrene, damage to nerves, skin sloughing off, inflammation of the bone or bone marrow, transmission of serious diseases like HIV or Hepatitis, accidentally injecting small glass particles when using glass containers, or damage to a blood vessel.
One of the most common side effects of getting an injection is pain. Luckily, there are several ways to ease the discomfort:
– A device called Buzzy and a substance called Cold Spray have both been shown to be effective.
– The Palm Stimulator, a device applied to the skin, can also ease pain.
– Rubbing a special type of anesthetic cream (EMLA) onto the skin can numb the area.
– Something called Kangaroo care, which is a method of holding a baby that involves skin-to-skin contact, can ease babies’ pain.
– The same goes for manual pressure, rhythmic tapping, acupressure.
– Distractions like virtual reality glasses, special cards, or optical illusion pictures can help distract from the pain.
Different injection techniques can also help, such as injecting slowly (over the course of 10 seconds), or injecting into a different part of the body. Interestingly, asking the patient to cough right before the injection can also help — the sensation of coughing travels to the brain faster than pain does.
Some methods don’t work so well, like cooling the skin with a spray or ice pack, using a cold needle, or warming up the substance being injected.
Sometimes, nerve damage can occur after an injection — this happened to a few people during a vaccination campaign in Pakistan. Different factors can affect the risk, like where the injection is given, how long the needle is, at what angle it’s given, how the patient is positioned, and how skilled the healthcare worker is.
All these factors become even more important when the injection is given in the buttock, where there’s a risk of injuring a large nerve that runs down the leg called the sciatic nerve. If this nerve gets damaged, a patient might not be able to lift their foot properly. Other nerves can be injured as well.
Depending on how bad the nerve damage is, different treatments might be used. For minor injuries, the nerve can heal itself. For more serious injuries, a treatment called neurolysis may be necessary, which involves freeing up the nerve. If the injury is very severe, surgery might be needed.
There are safer spots where an injection can be given, like specific points on the arm or thigh. These spots are less likely to cause nerve damage or other side effects.
What Else Should I Know About Intramuscular Injection?
Injecting medicine directly into a muscle, known as an intramuscular (IM) injection, has several advantages. First, it allows the medicine to be absorbed quickly and evenly, especially if the medicine is in liquid form (aqueous solutions). This can make the medicine work faster than if it were swallowed or injected under the skin, avoiding certain processes in the body that can change or limit the amount of medicine that gets to the disease site. It can be really effective during emergency situations like severe seizures and can provide long-lasting medicine action. Also, it allows for giving larger amounts of the medicine than an under-skin injection would allow.
However, there are also some downsides to IM injections. They need to be given by someone who’s trained to do it. The amount of medicine that gets absorbed can depend on factors like muscle size and blood supply. Once the medicine is injected, you can’t control how quickly it works or how long it lasts. And, in case something goes wrong, like an allergic reaction or hurting a nerve, you may need to also have another method of giving medicine in case of emergency (like injecting directly into a vein through an IV). Sometimes, giving an IM injection in the correct spot can be hard such as in children or people who need to be physically restrained. This method can also cause pain and anxiety, especially in children, and is difficult to do on yourself. Some medicines, like those mixed in oil or in suspension, can’t be used for IM injections.
Sometimes, if the medicine solvent gets absorbed too quickly, the medicine can end up working longer or later than intended. Lastly, patients, especially children, may need to be temporarily held still for the injection.
