This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia, Subject name: Pharmacology
[{'content': 'Which anaesthetic modality is to be avoided in sickle cell disease? \nSelect and explain. \nA. General Anaesthesia, B. Brachial Plexus Block, C. Intravenous Regional Anaesthesia, D. Spinal Anaesthesia', 'role': 'user'}, {'content': 'Answer: C \nExplanation: IV regional anaesthesia is useful for rapid anesthetization of an extremity (upper or lower). A rubber bandage is used to force the blood out of the limb and a tourniquet is applied to prevent the re-entry of blood.This causes risk of massive hemolysis due to low oxygen tension or hemolytic crisis due to low blood flow.All the other given methods above don&;t carry that risk.', 'role': 'assistant'}]