Subcutaneous medication administration is the method of delivering small volumes of medication-less than 2 milliliters-into the tissue layer just under the skin. It is a route commonly used for administering anticoagulant medications, epinephrine, insulin, and some immunizations. The absorption and onset of action are slower than with intravenous administration, with some absorption rates lasting 24 hours or longer.

Here, we will demonstrate how to prepare and administer a subcutaneous injection using insulin as an example.

The first step, upon entering the patient’s room, is to wash your hands with soap and warm water using vigorous friction for 20 seconds, or use hand sanitizer with vigorous friction if your hands are not visibly soiled.

Next, log into the patient’s Electronic Health Record at the bedside computer to review the medical history and previous medication administration. Also, review and discuss any medication allergies with the patient. In the Medication Administration Record, review the medications that are to be administered and discuss any preference for injection site and technique with the patient. In addition, when administering immediate- or short-acting insulin it is important to discuss when the patient will be eating their next meal. They should eat within 20 to 30 minutes of the injection in order to avoid hypoglycemia.

Now you are ready to obtain the medication. Leave the patient’s room and perform hand hygiene as described previously. In the medication preparation area, complete the first safety check according to the “5 Rights” of medication administration. If there is an opened multi-dose vial in the patient’s medication bin, check the expiration date and the date that the medication vial was opened. Insulin vials expire 30 days after opening. If there is no unexpired opened vial, retrieve a new box from the medication dispensing device. Next, to warm and mix the insulin, gently roll the vial back and forth between your hands. Avoid shaking the vials, as this can cause the proteins to precipitate and cluster. If using a previously unopened vial, remove the plastic cap. Then scrub the top of the vial with an alcohol wipe using friction and intent for 20 seconds.

Now, obtain the smallest syringe that will accommodate the total amount of fluid to be injected. The insulin syringes are packaged with an attached needle. The needles used for subcutaneous administration are 26 gauge or smaller in diameter. For accurate dosing, the syringes are calibrated and graduated in units, instead of milliliters.

Choose a syringe with a needle length appropriate for the patient. For patients with small amounts of adipose tissue, a 4-5 mm long needle will be adequate, whereas an 8 mm long needle may be needed for patients with large amounts of adipose tissue. Open the syringe package, remove the needle cap and place it on the counter, maintaining sterility of the needle tip.

The next step is to inject air into the insulin vial. Start by holding the needle upright in your dominant hand with the needle pointing toward the ceiling. Now draw back on the plunger with your non-dominant hand to pull air into the syringe equal to the insulin dose. Then, insert the needle through the soft rubber portion of the cap without contaminating the syringe tip or the needle, and inject the air into the vial. This is to avoid creating a vacuum when aspirating from the vial.

Now, hold the vial and syringe inverted at eye level, and ensure that the needle tip is within the liquid in the vial. Slowly pull back on the plunger to aspirate the correct number of units of insulin into the syringe. Then remove the needle from the vial and place the vial on the counter. Now, without touching the needle cap, place the needle tip within the cap, scoop the cap onto the needle, and then secure it with your non-dominant hand. This method of re-capping will help avoid accidental needle sticks. Label the syringe with the medication name and dosage, complying with the requirements of the institution, and dispose of all packaging material. Also, complete the second safety check using the “5 Rights” of medication administration.

Finally, gather supplies, including an alcohol prep pad, non-sterile gloves, and an adhesive bandage, and return to the patient’s room.

Upon re-entering the patient’s room, set the medication and supplies on the counter and perform hand hygiene as previously described. Then perform the third and final medication safety check using the “5 Rights” of medication administration.

Next, select the injection site based on the type of medication, patient preference, and injection site rotation. Subcutaneous injection sites include: the back of the arms, abdomen, thighs, and adipose portion of the hips. Access the injection site by removing bed linens or clothing as needed. Then don clean gloves. If the injection site is visibly soiled, clean the area with an alcohol prep pad and allow the alcohol to dry. According to the CDC, this is not necessary if the site is not visibly soiled.

Now, hold the syringe in your dominant hand, remove the needle cap with your non-dominant hand, and place the cap on the counter. Hold the syringe like a pencil or dart between the thumb and index finger of your dominant hand. For non-obese patients, use your non-dominant hand to pinch the skin at the injection site. For obese patients, pull the skin taut using the thumb and index fingers of the non-dominant hand. If the skin fold exceeds 1 inch, insert the needle at a 90° angle; if the skin fold is less than 1 inch, insert the needle at a 45° angle.

With a quick, purposeful motion, insert the needle into the skin and, using your dominant thumb or index finger, press the plunger of the syringe to slowly inject the medication, while stabilizing the syringe with your non-dominant hand if desired. Next, remove the needle smoothly along the line of insertion, engage the needle safety device, if present, and dispose of the needle and syringe in the sharps container. Then, place an adhesive bandage over the injection site if there is blood present or if the patient desires.

Remove and dispose of your gloves and perform hand hygiene. Then document the medication administration in the MAR, including the date, time, and location of the injection. Finally, remind the patient of possible side effects or adverse reactions prior to leaving the room and performing hand hygiene again.

“Subcutaneous injections are a common route of medication administration used in hospital settings. It is used to deliver commonly administered medications like insulin and epinephrine. During the administration process, one should remember to consider the patient’s adipose tissue and previous injections when choosing an appropriate injection site.”

“Common errors in subcutaneous injection administration include contaminating the injection site by blowing on it or wiping it after cleaning with an alcohol wipe, using a needle with an inappropriate length or gauge, and removing the needle too quickly after the injection, which might result in medication loss. Also, as with any injection, inadvertent needle stick is a risk which should be avoided.”

You have just watched a JoVE educational video on subcutaneous medication administration. You should now understand how to measure and prepare the medication, how to choose an injection site, and how to safely and accurately administer the injection. As always, thanks for watching!