Z-Track Method: Overview and Guide

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Lindsay Smith
Last updated at November 30, 2021

Administering medication under the supervision of a physician is one of the critical roles nurses play in healthcare. And one of the methods for ensuring medication is delivered to the proper part of the body is the z-track method.

There are various types of injections, and you're required to learn different techniques of injecting medication before you start working with patients.

The Z-track method is one of these techniques. In this post, we give you an overview of everything that entails administering medication using this technique.

What is the Z-Track Method?

The Z-track method is an intramuscular (IM) injection technique. An IM injection is used to administer medication that needs to be absorbed quickly. 

Since the technique deposits the medicine deep into muscle tissues, the high blood supply in the region allows the body to absorb the medicine quicker than it would by the subcutaneous route.

But the high blood supply in the region also poses some risks. Specifically, it increases the danger of injecting the medication into blood vessels directly. Further, factors that interfere with blood flow in the region influence the extent and speed of absorption.

What are the Requirements?

The Z-track method typically requires a long needle with a large gauge. The large needle makes penetrating deep into the muscle possible. Nurses must determine the appropriate size of the needle based on the patient's age, size, and adipose tissue on the injection site. 

The idea is to use a needle that's long enough to penetrate the muscle but not long enough to hit bones or neurovascular structures in the area.

While vaccines are typically not very viscous and will easily flow through a small-gauge needle, administering immunizations will require you to use a needle with a gauge between 22 and 25.

The CDC specifies healthcare professionals must administer intramuscular shots at a 90-degree angle to the patient's body. Or as close to a 90-degree angle as possible. Further, to reduce the risk of hypertrophy, the sites must be rotated. 

It's also vital for any healthcare professional to avoid giving an IM injection in muscles that are atrophied or emaciated. The medication isn't as effective when administered in such conditions.

Subcutaneous tissue is sensitive to vicious and irritating drugs, making muscle tissue the right site for administrating such recognized drugs. Muscles are less sensitive to irritating medication and don't absorb as much of the medicine. 

It is recommended that no more than 5ml of any medication be administered with an IM injection in adults. On the other hand, older patients may only be administered a maximum of 2ml of medication using this technique.

If you must administer 5ml of a medication to a well-developed adult, it is recommended that you give the shot at the vastus lateralis or rectus femoris. 

No more than 4ml must be administered in the dorsogluteal muscle, and no more than 3ml shot into the ventrogluteal muscle.

In the Z-track technique, before the IM injection is administered, the skin is pulled laterally. Doing this has three outcomes:

  • Medication does not leak into the subcutaneous tissue
  • Medication is sealed into the muscle
  • Irritation is minimized

Drugs can be administered using the Z-track method as long as the overlying tissue can be displaced. It is also important that the appropriate site and needle are selected for the shot.

When is Z-Track Injection Used?

Physicians don't often recommend the Z-track method. That said, the Z-track technique is particularly effective with drugs that only take effect when absorbed by muscles. 

Furthermore, the technique prevents the drugs from seeping into the subcutaneous tissue, ensuring a full dosage. Some medications have a dark color to them. Physicians recommend the use of the Z-track method to prevent the discoloration of the site. The Z-track method also helps prevent lesions.

The Z-track technique is typically recommended for specific medications such as iron dextran. It's certainly not the most common injection technique.

Z-Track Injection Site

To administer intramuscular injections, nurses must pick a site that does not have any pain, infection, bruising, abrasions, or necrosis. Additionally, the nurse must consider the location of the bones, vessels, and nerves, along with the volume of the drug required to be administered.

The dorsogluteal muscle is too close to the sciatic nerve, making it dangerous to administer an intramuscular injection. If the needle accidentally hits the nerve, the patient's legs may be partially or permanently paralyzed.

Manufacturers typically recommend administering the medication in the vastus lateralis or the deltoid muscles because those areas are clear of large blood vessels. That said, an intramuscular injection can be injected into the ventrogluteal site as well.

Vetrogluteal Site

The gluteus medius and minimus muscles are the thickest gluteal muscles, and the area does not have any penetrating nerves and blood vessels. These factors make a safe injection site for developed adults. Further, the narrower layer of fat in this region makes it that much easier to work with.

In contrast, the dorsogluteal site is closer to several neurovascular structures than the ventrogluteal site, making it unsafe for administering a shot. That said, the muscles in the dorsogluteal site are a lot thicker than the muscles in the ventrogluteal site. 

It's not very difficult for a nurse to find the ventrogluteal site for injecting medication. First, place the heel of your hand over the greater trochanter of the patient's hip. Ensure that your wrist is perpendicular to the femur.

If you're administering the shot on the left hip, use your right hand. By the same token, you must use the left hand for the right hip. Your thumb must point towards the patient's groin and the index finger towards the anterior superior iliac spine. 

Further, the index and the middle fingers must form a V-shaped triangle with the iliac crest. When you've found this spot on the patient's hip, you must administer the shot in the center of this triangle.

For the muscles in the region to relax, you must ask the patient to lay down on either their back or side. The hip and knee must be flexed.

Vastus Lateralis Site

In addition to being thick, the vastus lateralis muscles in adults are well developed. You will find this injection site in the anterior lateral region of the thigh. 

Locating the site is easier if you remember that the muscles lie between a handbreadth above the knee and a handbreadth below the greater trochanter of the femur. You must split up the muscle into three parts mentally and administer the medication in the middle part of the region. 

You must ask the patient to lie facing upwards and flex their knee and foot as if they were sitting. 

Deltoid Muscle

The advantage of choosing the deltoid muscle to administer a shot is that it is easy to access. However, in most adults, the muscle isn't developed well enough. 

Injecting in a poorly-developed deltoid muscle poses an increased risk of injury to the axillary, radial, brachial, and ulnar nerves. In addition to these nerves, the brachial artery is also present in the upper arm along the humerus. 

That said, it is the recommended site for administering routine immunizations, but nurses must remember not to inject more than 2ml of any medication at the site in one injection.

To find the muscle to inject in, you must fully expose the shoulder and upper arm and ask the patient to flex their elbow. When the patient is ready for their shot, you must picture that the acromion process forms the base of a triangle.

Measure two or three finger widths from the base of the triangle, and imagine the apex of the triangle pointing toward the elbow. Administer the shot in the center of the triangle.

Ensure that the patient is seated when administering any injection on the shoulder since it helps prevent injury in the region by ensuring the angle of the needle is proper. If a patient is wearing a shirt, ask them to roll up their sleeve, so you can visualize the landmarks and inject the medication in the appropriate spot.

Preparing to Administer a Z-Track Injection

Intramuscular injections administered via the Z-track method must be given with a needle of the appropriate length and gauge. Consider the weight, age, and build of the patient. In adults, you will be instructed to use a needle that's between 22 and 25 gauge. The needle length will typically be between one and one and a half inches long.

If you're working with a young patient, you will need to use a smaller needle to administer the same medication. 

Administering Medication with Z-Track Technique

Administering a shot with the Z-track method involves nine steps:

Step #1: Clean Up 

Before you gather supplies or start the process, nurses must wash their hands. Use soap and water, and scrub between the fingers, under the fingernails, and on the backs of your hands. The CDC recommends that you lather the soap for 20 seconds to ensure all the dirt and germs come off your hands. 

An easy way to remember this rule is to sing “Happy Birthday” twice when you wash your hands. By the time you finish singing it for the second time, your hands will be sufficiently clean, and you can wash the soap off with water.

Step #2: Gather Supplies

Besides the syringe and the medicine, you will need:

  • Alcohol pads
  • Gauze
  • Bandages
  • A container to discard the used needle

Step #3: Clean the Site

Take the alcohol pad and wipe the surface of the injection site with it. This will kill off germs on the site, thereby reducing the chances of infection. After wiping, let the surface dry for a few seconds to a minute.

Step #4: Prepare the Muscle

You will need the patient to relax the muscle you're going to inject the medicine into. Get them into a comfortable position — sitting on a chair, bending over a counter, or lying on the stomach helps. 

Step #5: Ready the Syringe 

There are many steps you must take the prepare the injection to be administered:

First, remove the cap from the vial. If it is a multi-dose vial, check it to see when it was first opened. Clean the rubber stopper with an alcohol swab.

Draw the plunger backward and fill the syringe up with air. Pull the plunger until the dose you want to inject. The idea behind this is that the vial is a vacuum, and to regulate the pressure in it, you must release an equal amount of air into it. 

Take the needle's cap off, and push it through the stopper. Press the plunger to inject the air into the vial. Ensure that you do not touch the needle and keep it clean. 

Carefully turn the vial and the syringe that you've inserted into it upside down. The needle should point upwards. Now, you can pull the plunger backward to withdraw as much of the medication you want to administer.

Tap on the syringe to displace bubbles that many have come into the syringe. The bubbles will rise to the top, and you can then push the plunger gently to release them from the syringe.

Step #6: Inject

Depending on the injection site, use the instructions as mentioned above to find the right spot to inject into. Pull the skin about an inch away from its position, and use the other hand to hold the syringe perpendicular to the site. Insert it swiftly into the site, and go deep enough to penetrate the muscle.

When the needle is where you need it to be, quickly check to see if there's any blood in the syringe. If no, then push the plunger slowly to inject the medication into the patient.

Step #7: Create the Z-Track

Nurses must hold the needle in place for about ten seconds before removing it. After the needle is out, let go of the skin you pulled. This will close off the hole created by the needle, and since the skin was displaced, there's no opportunity for the medication to seep into subcutaneous tissue. Administering intramuscular injections using this method creates a “Z” pattern under the skin, hence the name “Z-track.”

Step #8: Apply Pressure

Grab the gauze and gently put pressure on the site of the injection for a few seconds. If there is any bleeding, apply a bandage.

Never massage the site of a Z-track shot since this causes irritation and increases the chances of the medication leaking.

Potential Side Effects of Z-Track Injections

While the technique is considered safe, the patient may experience swelling, pain in the site, and sometimes bruising. However, the technique also poses some serious risks, such as infection, formation of an abscess, damage to nerves, bones, blood vessels or tissues, and hemorrhage.

These must be reported to a physician immediately.

Check out some of our other nursing tips including how to use mnemonics like HELLPBUBBLE HEVEAL CHOP, and LARA CROFT. I also have an EKG interpretation cheat sheet you might find useful.