This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
Which of the following inhalational agent causes maximum increase in intracranial pressure (ICP). 
Select and explain. 
A. Halothane, B. Isoflurane, C. Sevoflurane, D. Desflurane
A: Halothane
Answer: A: Halothane 
Explanation: All inhalational anaesthetic agents increase cerebral blood flow (CBF) and intracranial pressure (ICP) in dose dependent manner. Halothane increases the ICP most of having maximum vasodilating effect on cerebral blood vessel. Thus for neurosurgery when patient may already have raised intracranial pressure it should be avoided. Sevoflurane , isoflurane and desflurane equally increases intracranial pressure much less than halothane.