Z-track injection is a method of injecting medication into a large muscle using a needle and syringe. This method seals the medication deeply within the muscle and allows no exit path back into the subcutaneous tissue and skin. This is accomplished by displacing the skin and subcutaneous tissue 1–1.5 inches (2.5–3.75 cm), laterally, prior to injection and releasing the tissue immediately after the injection.
The Z-track method of intra-muscular (I.M.) injection is used primarily when giving dark-colored medication solutions, such as iron solutions, that can stain the subcutaneous tissue or skin. It is also the method of choice when giving I.M. medications that are very irritating to the tissue, such as haloperidol or vistaril.
Precautions taken when giving Z-track injections are all aimed at preventing the medication from leaking into the subcutaneous tissue or skin. These precautions include:
•Do not give a Z-track injection into skin that is lumpy, reddened, irritated, bruised, stained, or hardened.
•Add 0.3–0.5 ml of air into the syringe after drawing up the correct dosage of medication.
•Change the needle after drawing the medication into the syringe.
•Select a long needle (2–3 inches; 5–7.5 cm), depending upon the size of the patient, with a 21- or 22-gauge needle to place the medication deeply within the muscle.
•Give Z-track injections into a large muscle in the buttock (the gluteus medius or gluteus minimus).
•Aspirate on the syringe before injecting the medication to be sure not to hit a blood vessel. If blood appears in the syringe, a vein may have been hit. Remove and discard the syringe and medication. Start over with a new syringe, fresh medication, and a new site.
•Caution the patient not to wear restrictive clothing that could put constant pressure on the injection site.
•Rotate the injection sites from one buttock to the other and from site to site.
•Do not place injections into a disabled limb. If there is decreased circulation, the medication absorption will be affected and abscess formation can occur.
•Never inject more than 5ml of medication at a time when using the Z-track method. If a larger dose is ordered, divide it and inject it into two separate sites.
To give a Z-track injection, use the non-dominant hand to move and hold the skin and subcutaneous tissue about 1–1.5 in (2.5–3.75 cm) laterally from the injection site. Alert patients when the medication is about to be injected. Ask them to breathe through their mouth and to try to relax the muscle to avoid muscle resistance. Continue holding the displaced skin and tissue until after the needle is removed. Dart the syringe rapidly into the site at a 90° angle. Aspirate on the syringe to be sure that a blood vessel has not been penetrated. Inject the medication slowly into the muscle. Be sure that the syringe is completely empty, including the air, before withdrawing the syringe. Withdraw the syringe and immediately release the skin and subcutaneous tissue.
Wash both hands and put on gloves. Check the medication label before giving the medicine to avoid medication errors. Be sure it is the right medicine, the right dose (strength), the right time, the right person, and the right
method. Note the expiration date on the label. Do not use outdated medicine. Draw the correct dosage into the syringe including 0.3–0.5 ml of air. Discard the uncapped needle in a needle-box and attach a new sterile needle. Provide privacy and position the patient on the side with the knee slightly bent to relax the buttock muscles. Expose the buttock only, using the patient's clothing or a drape. Use the landmarks defined in the I.M. injection section to identify the desired injection site along the gluteus medius or gluteus minimus muscle. Prepare the site with an alcohol swab by rubbing the swab firmly in a 3-inch (7.5 cm) circle from the center of the site outward to remove bacteria from the skin. Allow the skin to air dry.
Apply gentle pressure to the site, using a dry gauze pad, if necessary. Do not rub the site. Continue pressure if bleeding occurs, and apply a bandage, if necessary. Replace the patient's clothing and allow the patient a 5-minute rest period. Then encourage the patient to walk about to enhance absorption of the medication. Discard the used syringe and uncapped needle in a needle-box. Place gloves and used swabs in a plastic trash bag that can be sealed and discarded. Wash both hands when the procedure is complete.
The complications of a Z-track injection are not common, but include tissue staining, bruising, abscess formation at the injection site, and severe pain at the injection site. Notify the physician if any of these conditions are noted.
Medication administered by Z-track injection is absorbed rapidly from the muscle into the bloodstream. The effects are seen over hours to days, depending upon the medication given