All midwives must be proficient in the administration of medication by injection. An injection is the process by which medication is given using a needle and syringe and is most commonly given intramuscularly (IM) or subcutaneously (SC). Intradermal injections are given into the dermis and are not commonly given by midwives; however, some may administer the BCG vaccination to susceptible neonates using this method in accordance with local policy. The location of the injection depends on the amount of medication, the required speed of administration, accessibility to the site, how the drug has been manufactured and the manufacturers guidance. Consideration should also be given to the anatomical structures such as blood vessels, bones and nerves in the location.

Practitioners need to know how to prepare and administer the medication, and be aware of any side effects and contraindications to minimise the risk to the woman and themselves.

Nerve damage, pain and abscesses may be experienced by the woman if poor techniques are used. To reduce this risk it is important to consider the choice of equipment, choice of needle length and gauge (diameter).

The correct procedure should be followed to reduce the risk of a needlestick injury. Needles must never be resheathed and must be disposed of straight away in a sharps bin. Some needles and syringes now come with safety devices fitted to further reduce the risk of needlestick injuries and should be used as the first choice if they are available.

Best practice is to draw up the medication to be given with a filter needle that prevents any debris such as glass shards from entering into the syringe.

Intramuscular injections can be given in four different sites: the deltoid muscle, the quadriceps muscle (vastus lateralis), the dorsogluteal muscle and the ventrogluteal muscle. There is a rich blood supply to muscles and less pain receptors, which enables medications to be absorbed more quickly than with oral or subcutaneous administration but slower than intravenous administration. Most commonly, analgesics, antiemetics, antibiotics and vitamin K (for babies) are given via intramuscular injections. Skin cleansing is not routinely recommended; however, if alcohol swabs are used in accordance with local policy, the site must be completely dry before giving the injection.

Subcutaneous injections are made into the subcutaneous tissue beneath the skin. Medications are absorbed more slowly than intramuscular or intravenous injections due to the reduced blood supply of subcutaneous tissues. There are three sites for subcutaneous injections: the deltoid area of both arms, the umbilical area of the abdomen and the central region on thighs. Alcohol wipes are not recommended when carrying out this method of administration as they can harden the skin over time and interfere with the absorption of some medications. Common drugs such as insulin and low molecular weight heparin are given this way.

Procedure

Sometimes more than one injection is given at the same time. If this occurs, the syringes must be clearly labelled. Take the medication in the receiver and prescription chart to the woman and confirm their identity verbally and by checking their wrist band. The injection site will determine where and how the woman is positioned. With intramuscular injections, the midwife should stretch the skin 2 or 3 cm and maintain this traction until the needle has been removed as this helps to reduce pain and leakage from the injection site. This is known as z-tracking (Figure 73.1). Insert the needle to its full length using a darting motion at 90° to the surface of the skin and depress the plunger slowly to inject the medication so the muscle fibres can gently stretch to accommodate the medication. There is no need to check for flashback of blood in the syringe unless injecting into the dorsogluteal muscle. If any blood appears when the plunger has been pulled back, then the procedure should be stopped as the injection is not in the correct site and is inadvertently being given directly into the blood stream.

After the injection it is best practice to wait 10 seconds before removing the needle and then the gentle traction on the skin can be released. Apply pressure to the site with dry gauze. Wash hands following the procedure and dispose of the needle and syringe into a sharps bin and clear away any other equipment. Any medication that is given must be documented on the prescription chart and the woman must be assessed for any adverse reactions.

The procedure for a subcutaneous injection is the same but the skin should be pinched between the thumb and forefinger of the non-dominant hand to raise the subcutaneous tissue away from the muscle layer and the needle can be removed quickly once the medication has been injected.