Safe injection techniques

Safe injection technique

Aims and intended learning outcome



ý Identify the safe anatomical sites for ID, SC and IM injections.
ý Locate the specific muscles for IM injections and explain the rationale for their use.
ý Give sound reasons for your method of skin preparation.
ý Discuss ways to reduce patient discomfort during an injection.
ý Describe the nursing care a patient requires to avoid complications associated with injections.

The intradermal route


The intradermal route provides a local, rather than systemic, effect and is used primarily for diagnostic purposes such as allergy or tuberculin testing, or for local anaesthetics. To give an ID injection a 25-gauge needle is inserted at a 10-15° angle, bevel up, just under the epidermis, and up to 0.5ml is injected until a wheal appears on the skin surface
If it is being used for allergen testing, the area should be labelled indicating the antigen so that an allergic response can be monitored after a specified time lapse.
The sites suitable for intradermal testing are similar to those for subcutaneous injections but also include the inner forearm and shoulder blades When testing for allergies, it is essential to ensure that an anaphylactic shock kit is easily accessible in case the patient develops a hypersensitive reaction





The subcutaneous route

medication, up to 1-2ml being injected into the subcutaneous tissue. It is ideal for drugs such as insulin, which require a slow and steady release, and as it is relatively pain free, it is suitable for frequent injections

Traditionally, SC injections have been given at a 45° angle into a raised skin fold However, with the introduction of shorter insulin needles (5, 6 or 8mm), the recommendation for insulin injections is now an angle of 90° The skin should be pinched up to lift the adipose tissue away from the underlying muscle, especially in thin patiens. Some studies using computerized tomography to monitor the destination of the injections, have found that SC injections can be inadvertently administered into muscle, especially in the abdomen and the thigh .

Insulin that is injected into muscle is absorbed more rapidly and can lead to glucose instability and potential hypoglycaemia. Hypoglycaemic episodes may also occur if the anatomical location of the injection is changed, as insulin is absorbed at varying rates from different anatomical sites Therefore insulin injections should be systematically rotated within an anatomical site – for example, using the upper arms or abdomen for several months, before there is a planned move elsewhere in the body. When a diabetic patient is admitted to hospital, the current injection area should be assessed for signs of inflammation, edema, redness or lipohypertrophy, and observations recorded in the nursing notes.

It is no longer necessary to aspirate after needle insertion before injecting subcutaneously. reported studies that found blood was not aspirated prior to SC injection, indicating that piercing a blood vessel in a SC injection was very rare. Additionally, patient education literature from the manufacturers of insulin devices does not advocate aspiration before injection. It has also been noted that aspiration before administration of heparin increases the risk of haematoma formation .














The intramuscular route



Intramuscular injections deliver medication into well perfused muscle, providing rapid systemic action and absorbing relatively large doses; from 1ml in the deltoid site to 5ml elsewhere in adults .
The choice of site should take into consideration the patient’s general physical status and age, and the amount of drug to be given. The proposed site for injection should be inspected for signs of inflammation, swelling, and infection, and any skin lesions should be avoided. Similarly, two to four hours after the injection, the site should be checked to ensure there has been no adverse reaction. If injections are repeated frequently, the sites should be documented to ensure an even rotation. This reduces patient discomfort from overuse of any one area and lessens the likelihood of the development of complications, such as muscle atrophy or sterile abscesses resulting from poor absorption






Older patients are likely to have less muscle than younger, more active patients, and therefore the proposed sites should be assessed for sufficient muscle mass. If the patient has reduced muscle mass it is helpful to ‘bunch up’ the muscle before injecting .


There are five sites that are available for IM injections. Figure 5(a-d) shows details of how to identify
anatomical landmarks for each of these sites. These include:

· The deltoid muscle of the upper arm, which is used for vaccines such as hepatitis B and tetanus toxoid






· The dorsogluteal site using the gluteus maxim us muscle, the traditional site in the UK ). Unfortunately complications are associated with this site as there is a possibility of damaging the sciatic nerve or the superior gluteal artery if the needle is misplaced. cited several studies that have used computerized tomography to confirm that even in mildly obese patients, injections into the dorsogluteal area are more likely to be into adipose tissue rather than muscle, and consequently slow the absorption rate of the drug.






· The ventrogluteal site is a safer option which accesses the gluteus medius muscle. An extensive review of the research into IM injections recommends this site as the primary location for IM injections




· as it avoids all major nerves and blood vessels and there have been no reported complications .. Additionally, the ventrogluteal site has a relatively consistent thickness of adipose tissue over it: 3.75cm as compared to 1-9cm in the dorsogluteal site, thus ensuring that a standard size 21-gauge (green) needle will usually penetrate the gluteus medius muscle area.

· The vastus lateralis is a quadriceps muscle situated on the outer side of the femur. This site has been




· The primary site for children, but risks associated with this muscle includes accidental injury to the femoral nerve and muscle atrophy through overuse. suggested that this site is safe for children up to seven months old, but then the ventrogluteal site is the optimum choice.





Steps towards a painless injection:

Prepare patients with appropriate information before the procedure, so that they understand what is happening and can comply with instructions

ý Change the needle after preparation of the drug and before administration to ensure it is clean, sharp and dry, and the right length
ý Make the ventrogluteal site your first choice, to ensure that the medication reaches the muscle layer (in adults and children over seven months)
ý Position the patient so that the designated muscle group is flexed and therefore relaxed
ý If cleaning the skin before needle entry, ensure skin is dry before injecting
ý Consider using ice or freezing spray to numb the skin before injection, particularly in young children or needle-phobic patients
ý Rotate sites so that right and left sites are used in turn, and document rotation
ý Enter the skin firmly with a controlled thrust, positioning the needle at an angle as near to 90°as possible, to prevent shearing and tissue displacement
ý Inject medication steadily and slowly: about 1ml per ten seconds to allow the muscle to accommodate the fluid
ý Allow ten seconds after completion of injection to allow the medication to diffuse and then withdraw needle at the same angle as it entered
ý Do not massage the site afterwards, but be prepared to apply gentle pressure with a gauze swab



Patients are often afraid of receiving injections because they perceive that it will be painful. The pain of IM injections may be registered in the pain receptors in the skin, or the pressure receptors in the muscle. listed a number of factors which cause pain:
v The needle.
v The chemical composition of the drug or its solution.
v The technique.
v The speed of injection.
v The volume of drug.

Patients may have a needle or injection phobia which causes them anxiety, fear and increased pain every time they require an injection . Good technique, appropriate patient information and a calm and confident nurse will help to reduce anxiety. Distraction or behavior modification techniques may be useful, particularly for long courses of treatment, and the use of needle less systems may reduce needle related anxiety. It has been suggested that numbing the skin with ice or freezing sprays before inserting the needle may reduce pain (Springhouse Corporation 1993), although this is a technique currently unsupported by research evidence.

Nurses need to be aware that patients may experience syncope or dizziness after a routine injection, even if otherwise apparently fit and well. Ascertaining the patient’s history and usual response to injections, ensuring that the area is safe and that a couch is readily available for them to lie down, will reduce the risk of injury. Experience suggests that those most prone to fainting, though not exclusively, are teenagers and young men.



Complications


Complications that occur as a result of infection can be largely prevented by strict aseptic precautions and good hand-washing practice. Sterile abscesses may occur as a result of frequent injections to one site or poor local blood flow. Sites that are edematous or paralysed will have limited ability to absorb the drug and should not be used. Careful choice of location will reduce the likelihood of nerve injury, accidental intravenous injection and resultant embolus from the composition of the drug .Systematic rotation of sites will prevent needle sympathy or lipohypertrophy .An appropriate needle size and a preference for the ventrogluteal site, will ensure that the medication is delivered to the muscle, rather than adipose tissue.