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': 'True about Epidural anesthesia – a) Effects start immediatelyb) C/I in coagulopathiesc) Given in subarachnoid spaced) Venous return decreases \nSelect and explain. \nA. bd, B. d, C. ab, D. ac', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Epidural anesthesia is given outside the dura in epidural (extradural) space (not in subarachnoid space).\nOnset of effect takes place in 15-30 minutes (not immediately). In contrast, spinal anesthesia has immediate effect (approximately 5 minutes).\nNeuraxial block (spinal & epidural) anesthesia is contraindicated in coagulopathy or bleeding diasthesis.\nNeuraxial block (spinal & epidural) can cause venous pooling and decreased venous return.', 'role': 'assistant'}]