This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anaesthesia
[{'content': 'In epidural anaesthesia drug is injected \nSelect and explain. \nA. Outside the dura, B. Inside the duramater, C. Inside arachnoidamater, D. inside piamater', 'role': 'user'}, {'content': "Answer: A \nExplanation: Epidural (extradural anaesthesia)Local anaesthetic is injected in epidural space, i.e., outside the dura mater with Tuohy&;s needleIn extradural space, LA acts on the nerve rootsIt is used in thoracic, lumbar and sacral (caudal) regions (in contrast to spinal anaesthesia which is given in lumbar region)Continuous analgesia is achieved by mixing the LA with an opioid, eg fentanylIt is mainly used to control postoperative pain (by continuous epidural anaesthesia)It can also b used for all surgeries which can be performed under spinal anaesthesia.(Refer: stoelting's pharmacology and physiology in anaesthetic practice, 5th edition, pg no.189)", 'role': 'assistant'}]