Toxic effects of local anaesthetics commonly occur because of:
- excessive dosage
- direct intravascular injection
- use of agent in inflamed or vascular area
- absorption that is too rapid
- elimination that is too slow
- idiopathic reaction to anaesthetic agent
Clinical feature include:
- neural:
- unease
- anxiety
- perioral tingling
- tinnitus
- euphoria
- irritability
- convulsions
- coma
- respiratory failure: central and peripheral actions
- cardiovascular collapse:
- bradycardia
- vasodilatation
- anaphylactic shock
Treatment targets the presenting complaint:
- oxygenation
- for convulsions, treat as for status epilepticus protocol
- for cardiovascular collapse, full resuscitation is required including intubation, adrenaline and cardiac massage