<prompt> During surgery for aortic arch aneurysm under deep hypothermic circulatory arrest, which of the following anesthetic agent administered prior to circulatory arrest that also provides cerebral protection ?EtomidateThiopental sodiumPropofolKetamine  <response>: Thiopental, etomidate and propofol, all three are cerebroprotective. However, thiopental has maximum cerebroprotective action.Propofol and etomidate appear to lack the same protective effects as thiopental in focal cerebral ischemia Morgan 