Ans. is 'a' i.e., Emergence delirium Ketamine The primary site of action is in the coex and subcoical areas; not in the reticular activating system (site of action of barbiturates). It acts on NMDA receptors. Sho duration of action (10-15 minutes) is due to redistribution from brain and blood to other tissues of the body. Ketamine is different from most other anaesthetic induction agents in that it has significant analgesic action. Ketamine increases IOT and cerebral metabolism --> contraindicated in head injury. It causes sympathetic stimulation with elevation of HR, CO & BP --) contraindicated in hypeension and ischemic hea disease. It also raises IOT --> contraindicated in glaucoma. It relieves bronchospasm --> intravenous anaesthetic of choice in asthmatics (inhalation anaesthetic of choice in asthmatic is halothane). Injection is not painful (All other inducing agents cause pain on injection). It is i.v. anaesthetic of choice in children (Sevoflurane is inhalation agent of choice). Because it causes sympathetic stimulation it is intravenous anaesthetic of choice in patients with shock and hypovolumia. It has no muscle relaxant propey rather muscle tone is increased. Airway reflexes (pharyngeal and laryngeal) are not depressed --> intravenous anaesthetic of choice for emergency anaesthesia (no starvation is required). Ketamine produces emergence reaction during awakening from anaesthesia --> vivid dreaming, illusions, extracorporeal experiences, excitment, confusion, fear and euphoria --> contraindicated in psychiatric illness like schizophrenia.