What are the signs of local anesthetic systemic toxicity (LAST)?

Local anesthetic systemic toxicity (LAST) occurs when local anesthetics enter the systemic circulation, leading to a potentially life-threatening situation. The correct choice highlights a collection of classical signs and symptoms associated with LAST.

Tinnitus and a metallic taste are early neurological symptoms that may indicate the onset of systemic absorption of the local anesthetic. These signs arise due to the drug's effect on the central nervous system, leading to excitatory symptoms like seizures. Seizures are a significant sign of LAST as increased central nervous system stimulation occurs before more severe depression sets in. Additionally, cardiovascular collapse may occur as local anesthetics can negatively affect cardiac conduction and myocardial contractility, leading to arrhythmias and, in severe cases, cardiac arrest.

Understanding these signs is crucial for recognizing LAST promptly and initiating appropriate interventions to manage the condition. By being aware of these distinctive symptoms, healthcare providers, including CRNAs, can take swift action to mitigate its effects, ensuring patient safety during procedures involving local anesthetics.