Most people know the feeling of getting a shot and having your arm feel sore for several days afterward. Some might even expect it as a side effect. The soreness happens when vaccines or medications are injected into muscle tissue.
To help reduce pain and discomfort, many medical professionals prefer to use a technique called the Z-track method. This method leaves behind a zigzag track from the needle, helping to seal in medication and reduce irritation.
What Is the Z-Track Method?
The Z-track method is a technique in which the provider slightly pulls and holds pressure on the skin when giving an injection, which leaves a zigzag path behind when they remove the needle and release the skin. The Z-track method is used when giving an intramuscular injection. Intramuscular injections are when you inject medication or vaccines directly into a muscle.
There are several different injection methods. Some of the other more common ones include intravenous (IV) injections and subcutaneous (SC) injections. Intravenous injections are when medication is injected directly into the vein. This is the fastest method of getting medication or infusions into the body.
Subcutaneous injections happen when the needle delivers medication to the layer of fat just under the skin. It’s used for many common medications, like insulin, and many types of vaccines. These are usually less uncomfortable than intramuscular injections.
Muscles have a good supply of blood vessels, so the body absorbs medications from intravenous injections faster than it absorbs medications from subcutaneous injections. A majority of vaccines are given this way, including:
- COVID-19
- Diphtheria, tetanus, and pertussis (DTaP)
- Haemophilus influenzae type B vaccine (Hib)
- Hepatitis A and B vaccines (hepA and hepB)
- Meningococcal (MCV)
- Pneumococcal (PCV)
- Rabies
- Seasonal flu
- Tetanus, diphtheria, and pertussis (TDaP)
Many important medications, like antibiotics, are intramuscular injections. Some medications, like epinephrine, which is used as an emergency countermeasure to an allergy attack, can be delivered in multiple ways.
What Is the Z-Track Method Used For?
In general, medical providers prefer to use the Z-track injection technique for all intramuscular injections in adults. As a result, most medications given through intramuscular injection are also Z-track method medications.
Providers use the Z-track method because it has several benefits over a standard intramuscular injection. These benefits include:
- Working with patients with reduced muscle mass, like elderly patients
- Causing less pain at the injection site
- Minimizing skin irritation and lesions
- Preventing the medication from leaking into the patient’s subcutaneous tissue
- Sealing the drug into the muscle
While all of these are important reasons to use the Z-track method over other intramuscular injection techniques, perhaps the most important is that it prevents the medication from leaking. The Z-track method seals the drug into the muscle, ensuring that the patient gets the full dose of medication. Preventing leaks is also important because some medications can cause irritation or discoloration if they leak into the subcutaneous tissue.
How to Give a Z-Track Injection
You can use the Z-track injection method for most intramuscular injections in adults, including on yourself.
Before you begin. Whether you’re a medical provider or administering an injection at home, there are steps to take before the injection.
If you’re a medical provider, you first must:
- Properly prepare the ordered medication
- Confirm the patient’s identity
- Explain the procedure, if they are unaware
If you are giving yourself or a loved one an injection at home, you may have to draw up the syringe yourself. To do this:
- Wash your hands with soap and water.
- Gather your supplies and place them on a clean, dry surface.
- If your syringe does not already have a needle attached, screw a needle onto the syringe hub.
- Flip the plastic top off of the vial.
- Use an alcohol swab to wipe the top surface of the vial well for about 10 seconds.
- Remove the needle cover.
- To draw air into the syringe, pull the syringe plunger back until you reach the correct volume marker.
- Insert the needle straight into the vial through the vial’s rubber top.
- Inject air into the bottle by pushing down on the plunger.
- Use one hand to turn the vial with the syringe upside down. Check to be sure that the needle is in the bottle and below the level of fluid.
- Draw back the plunger to the correct mark.
- Check the syringe for air bubbles. If you find air bubbles, flick the syringe with your finger to remove them.
- If there is an air bubble at the top of the syringe, gently push down on the plunger so the air can go back into the bottle.
- Before removing the needle, be sure you have the right amount of medication in the syringe.
- Don’t place a syringe with an uncovered needle down on a surface you’re working on. If you need to set the syringe down, place the cover back on the needle for a short time.
Choose the injection location. Intramuscular injections must be injected into muscle tissue, and some muscles are better for this than others. The muscle should be as large a muscle as possible so there is less risk of damaging a large blood vessel or nerve.
For infants and children, the best place to administer an intramuscular injection is the anterolateral thigh, or the outside of the thigh near the front. For children who have developed enough muscle mass in the deltoid muscle, you can give the injection in this area as well. The deltoid muscle is the muscle that covers your shoulders and the top of your arm.
For adults, the preferred injection site is the deltoid muscle. If you’re administering an injection to yourself, the best place to do so is the middle outer part of the thigh.
Check to make sure whatever area you’re working with is free from infections or bruising. Don’t inject more than 3 milliliters (mL) at one site. If the amount needed is more than 3 mL, divide the dose and inject at separate sites.
Perform the Z-track injection. Now that you are prepared and have chosen the injection site, you can administer the Z-track medication.
- Clean the site with an alcohol pad and allow the area to dry.
- Use your non-dominant hand to pull the skin downward or to the side. The tissue should be displaced about an inch. This is what will give the Z-track injection the zigzag shape.
- Hold the needle at a 90-degree angle to the site and pierce the skin.
- Continue to hold the skin taut while you carefully pull back on the syringe to check for blood. This is called aspiration, and you should do it for 5 to 10 seconds to make sure you didn’t hit a blood vessel.
- Inject the medication slowly, at about 10 seconds per milliliter of medication.
- Once you’ve injected all the medication, wait about 10 seconds before smoothly pulling out the needle and releasing the skin.
- Use gauze or a dry sponge to apply pressure over the site for about 30 seconds to a minute. Don’t massage the site, as this can cause irritation.
- Properly dispose of the needle and wash your hands.