Anesthetic not impairing CNS activity is:

Ans-ARef: Miller Textbook of Anaesthesia. 6th edition.Explanation:IsofluraneRaise in intracranial pressure is minimal with isoflurane when compared with other inhalational agents and this rise can be reversed with hyperventilationIt also decreases brain oxygen consumption.These properties make isoflurane the agent of choice for neurosurgical proceduresOther characteristics of IsofluranePungent ethereal odor, so induction is not smoothNot a good analgesicModerate muscle relaxationCardiovascular EffectsHypotension is maximum with isoflurane ( Agent of choice for controlled hypotension)It does not depress myocardiumDoes not cause bradycardia and baroreceptor reflex is preservedIt increases coronary blood flow to nonischemic area which in patients with myocardial ischemia can cause CORONARY STEALRespiratory system effectsRespiratory depression is relatively lessIt blunts ventilatory response to hypercarbia and hypoxiaIsoflurane is an agent of choice for Cardiac patients and Neurosurgery.