What is the most common cause of side effects related to local anaesthetic?

Intravascular injection is recognized as the most common cause of side effects associated with local anaesthetic use. When local anaesthetics are inadvertently injected directly into a blood vessel, they can cause rapid systemic effects due to their immediate entry into the circulatory system. This can lead to symptoms such as tinnitus, lightheadedness, seizures, or even cardiovascular complications, as the anesthetic quickly affects the central nervous system and cardiovascular function.

While hypersensitivity can occur, it is relatively rare and typically manifests as an allergic reaction, which is not as frequent as complications arising from intravascular injections. Overdose of medication is another potential cause of side effects, but it usually results from administration without proper dosing guidelines; however, the frequency of this happening is less than that of intravascular injection. Inexperienced administration may contribute to improper techniques that increase the risk of side effects, but again, the direct result of injecting into a blood vessel remains the more prevalent issue in clinical settings.