Epinephrine (Adrenaline) in Local Anaesthesia

How it works

By stimulating alpha-1 adrenoceptors it causes local vasoconstriction, slowing clearance of the co-administered anaesthetic from the injection site and improving the surgical field.

Prescribing in practice

• Adrenaline-containing solutions have traditionally been avoided in tissues supplied by end-arteries such as digits, nose, ears and penis owing to ischaemia concerns, and must never be given intravenously.
• It can provoke tachycardia, hypertension and arrhythmia, so use cautiously in cardiovascular disease and significant hyperthyroidism.
• Always confirm the correct preparation and concentration, as accidental use of the wrong adrenaline strength is a recognised error.

Monitoring

Observe for systemic effects such as palpitations or a rise in heart rate and blood pressure, and check distal perfusion when used near extremities.

Counselling the patient

• Adrenaline is added to make the numbing last longer and reduce bleeding.
• You may briefly feel your heart beating faster after the injection.
• Tell the team about heart problems or thyroid disease beforehand.

Evidence & guidelines

Combining adrenaline with local anaesthetic to prolong effect and reduce bleeding is standard practice; the historic absolute ban on use in digits is increasingly recognised as overstated in elective settings.