Local Anaesthetic Systemic Toxicity- Management and Prevention. A Narrative Review and Recent Updates

Local anaesthetic systemic toxicity (LAST) is a life-threatening complication caused by either inadvertent intravascular injection (IV) or systemic absorption of injected local anaestheitc (LA) to a toxic level. The diagnosis of LAST may be difficult and often unrecognized or misdiagnosed. LAST is a serious adverse effect that can occur with all local anaesthetics irrespective of routes of administration. Primary affected organs are central nervous system and cardiovascular system and can be often fatal. Clinical presentation of toxicity is highly variable and unpredictable, a high degree of suspicion of LAST should be done whenever any unexplained physiological changes are noticed after administration of LA. Risk factors for LAST include the dose and type of LA, site of injection, the plasma level of LA and patient’s physiological status and co-morbidities. The standard treatment guideline for LAST emerged after 2010 when America society of regional anesthesia and pain medicine (ASRA) first published the evidence-based treatment guideline for LAST using modified Advanced cardiac Life support (ACLS) and intravenous lipid emulsion therapy. The sequence of management as per the priority include- addressing the airway and breathing to prevent hypoxia and acidosis, control of seizure activity and cardiopulmonary resuscitation and timely administration of intravenous lipid emulsion infusion. The article highlighted the importance of preventive measures to avert LAST and continuous vigilance and timely management of LAST. The article is also intended to provide the recent changes and recent updated guidelines in the prevention and management of LAST.