This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
[{'content': 'General anaesthetic agent causing sympathetic stimulation: September 2011 \nSelect and explain. \nA. Thiopental, B. Ketamine, C. Midazolam, D. Etomidate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Ketamine Ketamine stimulates sympathetic system causing tachycardia and hypeension so it is intravenous anaesthetic of choice for shock Disadvantages of Midazolam: Incidence of apnea, respiratory depression and hypotension are higher and more profound than diazepam Thiopentone causes hypotension which is more because of venodilatation Ketamine: It is phencyclidine Causes dissociative anaesthesia Increases all pressures (BP, intraocular tension, intracranial tension) Causes profound analgesia Causes hallucinations, illusions and delusions Contraindicated in: Intracerebral mass or hemorrhage Causes bronchodilation (used in asthmatics) and increases cardiac output (used in hypovolumic shock)', 'role': 'assistant'}]