This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intravenous Anesthetic Agents, Subject name: Anaesthesia
Cardio protective effect of Thiopentone is effective in all of the following clinical scenario except:- 
Select and explain. 
A. Neurosurgery, B. Cardiac surgery, C. Comatose survival of cardiac arrest, D. None of the above
C: Comatose survival of cardiac arrest
Answer: C: Comatose survival of cardiac arrest 
Explanation: The ability of barbiturates therapy to improve brain survival after global cerebral ischemia due to cardiac arrest is unlikely, because there drugs are effective only when the EEG remains active and metabolic suppression is possible. During cardiac arrest the EEG becomes flat in 20 to 30 seconds and barbiturate would not be expected to improve outcome.