Intramuscular Injections

Injection of substance directly in muscle, for forms of medicine used delivered in small amounts

Indications: Where IV administration is not available. Drugs with specific actions on muscles. A longer half life is needed eg. Morphine for

anaesthesia

Complications & contraindications

Damage to the sciatic nerve. (Upper outer quadrant) Injection fibrosis - causes inability to flex muscle drug

is administered to. Thrombocytopenia (low platelets) and coagulopathy

(bleeding) can lead to hematomas. Local sepsis Arterial/IV injection Infection

Equipment List

Method Check identity of patient and contents and expiry date of drugs Insert needle into syringe, and fill with the required amount of

drug. Tap syringe to bring any air bubbles to the top and push the air out.

Choose a suitable injection site and inspect for signs of inflammation, swelling, infections or lesions

5 main sites: ▪ Upper arm (deltoid) – vaccines▪ Dorsogluteal (gluteus maximus)▪ Ventrogluteal(gluteus medius)▪ Vastus lateralis (quadriceps femoris) outer side of femur▪ Rectus femoris (anterior quadriceps) – self administration or

infants

Method continued... Swab site with alcohol and let it dry (bactericidal and decreases

pain) Pull skin laterally and insert needle in one swift motion at 90°,

aspirate to avoid an intravenous placement, if blood is drawn in, restart with new medication and slowly inject the drug.

Remove needle and apply a pressure gauze and observe for signs of an adverse reaction.

Moving the skin may distract from the intended needle destination, therefore visualise and aim for the underlying muscle about to receive the injection.

http://www.youtube.com/watch?v=nA8i9eYW0_M

Subcutaneous Injections

Injection of substance into the subcutaneous tissue – layer of skin directly below the dermis and epidermis.

Indications When drug is desired to have a slow, sustained

absorption effect Local anaesthesia Administration of vaccines

and medicines such as insulin and morphine

Complications & Contraindications

Avoid using the same site repetitively which can cause lumps or dents (lypodystrophies – loss or degeneration of fat) from forming.

Accidental IV, ID, IM injections

Equipment List

Method Check identity of patient and contents and expiry date of

drugs Insert needle into syringe, and fill with the required amount

of drug. Tap syringe to bring any air bubbles to the top and push the air out.

Choose a suitable injection site and inspect for signs of inflammation, swelling, infections or lesions

4 main sites: ▪ Upper arm outer area▪ Abdomen – above and below waist, except around navel▪ Anterior thigh – midway of outer side▪ Upper area of butt – behind hip bone

Method continued ... When repeated injections are needed use a hidden site

to cover bruises – but the same area at the same time each day to reduce changes in the action of the insulin

Swab site with alcohol and let it dry (bactericidal and decreases pain)

Gently pinch skin to elevate subcutaneous fat and separate it from underlying muscle.

Insert the needle at a 30° angle and inject the drug – aspiration before injecting the drug is unnecessary as can increase the risk of local hematoma formation for heparin.

http://www.youtube.com/watch?v=bxdYGXKz1iA

Local Anaesthesia Injections

Used when performing invasive medical procedures except in life saving procedures.

Contraindications Patient refusal – but many can be persuaded Allergy – rare DO NOT USE adrenaline containing LA on digits or penis

– vasoconstriction can lead to ischaemia and necrosis. Anticoagulated patients have a tendency to bleed if a

vessel is punctured. Infection at intended site may make it more painful and

spread. Broken needles Acute systemic toxicity – CNS, CVS – when plasma

conc., exceeds toxic limit.

Mechanism of action LA block fast sodium channels in nerve axons

preventing propagation of nerve impulse Pain nerves are usually smaller and non myelinated

fibres so are blocked faster than larger myelinated fibres (motor, proprioception, touch)

Parenteral LA

Injected subcutaneously Onset of effect is 2 minutes, but duration

varies depending on the drug. LA solutions are alkaline pH 10/11

therefore are more painful A less painful approach would be ID

(instant anaesthesia) Avoid intra vascular injection, so aspirate

first.

Have a good rest of your degree!!