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
General anaesthetic agent causing sympathetic stimulation: September 2011 
Select and explain. 
A. Thiopental, B. Ketamine, C. Midazolam, D. Etomidate
B: Ketamine
Answer: B: Ketamine 
Explanation: 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)