About lignocaine, all are true except ?

Ans. is 'a' i.e., It is ester group of local anaesthetic Lidocaine It is the most commonly used local anaesthetic. It also has antiarrhythmic propey. Systemic toxicity is less than bupivacaine. CNS involvement occurs at much lesser dose than CVS involvement. It can precipitate malignant hypehermia --> should not be used in these patients. For regional anaesthesia, it is used in different concentraions for different type of anaesthesia Surface (topical) analgesia : 4%, nerve block : 1 - 2%, Spinal anaesthesia : 5%, Epidural : 1 - 2 %, Beir's block (intravenous regional anaesthesia) : 0.5% and infiltration block : 1 - 2%. Maximum safe dose of lidocaine wihout adrenaline is 300 mg (4.5 mg/kg) and with adrenaline is 500 mg (7 mg/kg). Besides local anaesthesia lidocaine is used : - To treat ventricular arrhythmias. To blunt the cardiovascular response to laryngoscopy and intubation, (i.v. or intrathecal administered lidocaine).