Epinephrine is added to local anaesthetic in concentrations of 5 mcg/ ml (1:200,000) or less. There are several benefits to this practice: 1. Local receptor-mediated vasoconstriction reduces the uptake into the blood stream and delays the metabolism of local anaesthetic. 2. Improves the quality and reliability of blockade, either by increasing available local anaesthetic through decreased uptake or by an intrinsic anaesthetic mechanism on central alpha 3.
Adrenergic receptors: Reduces peak blood levels and risk of toxicity by slowing vascular absorption. 4. Helps to identify intravascular injection when used as a marker in the latest dose. If the epinephrine containing solutions are injected intravascularly by unintentionally tachycardia suddenly results. Epinephrine may be added to all local anaesthetic solutions for all blocks except those involving end arteries like Digital and…
