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
[{'content': 'Intra arterial injection of thiopentone causes – \nSelect and explain. \nA. Vasospasm, B. Vasodialation, C. Necrosis of vessel wall, D. Hypotension', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Inadverent intra-arterial injection causes local vasoconstriction (vasospasm) and thrombosis which can cause ischemia and gangrene of the limb.\nNote-IV injection cause generalized venodilatation due to which there is pooling of blood & hypotension. On the other hand intra-arterial injection results in localized vasospasm of the involved artery.', 'role': 'assistant'}]