Local & General Anesthetics

Local and general anesthetics are the drugs that remove sensation for procedures: a local anesthetic such as lidocaine or bupivacaine blocks sodium channels so one area goes numb while the client stays awake, and general anesthesia combines IV and inhaled drugs to produce unconsciousness, amnesia, analgesia and muscle relaxation. The danger to know first is local anesthetic systemic toxicity, which starts with numb lips or tongue, a metallic taste, tinnitus, dizziness and agitation before progressing to seizures, dysrhythmias and cardiac arrest; the nurse stops the injection, calls for help, gives 100% oxygen and expects 20% lipid emulsion. After throat-numbing spray, the client stays NPO until the gag reflex returns. Propofol works fast but gives no pain relief and can cause hypotension and apnea, while ketamine keeps airway reflexes and blood pressure but can cause emergence reactions. Neuromuscular blockers such as succinylcholine paralyze without sedation or pain relief, so they are never given to an awake client, and succinylcholine raises potassium and can trigger malignant hyperthermia.