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: Surgery
[{'content': 'A patient with grossly contaminated wound presents 12 hours after an accident. His wound should be managed by - \nSelect and explain. \nA. Thorough cleaning and primary repair, B. Thorough cleaning with debridement of all dead and devitalised tissue without primary closure, C. Primary closure over a drain, D. Covering the defect with split skin graft after cleaning', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Any wound can be closed by\nprimary suture or\ndelayed primary suture or\nleft open to heal by secondary closure\n\nPrimary suture is suitable for\n\nclean wounds &\nselected contaminated wounds after thorough wound toileting & debridement\n\nDelayed primary closure is done for\n\nheavily contaminated wounds\nwounds in which wound toileting has been delayed for 6-8 hrs.\nBut these were the indications earlier. Now the recent approach is:\nif the blood supply to the wound is adequate and bacterial invasion is absent, wounds can be safely closed anytime following proper debridement & irrigation. \nif there is established infection and tissue of doubtful viability has been left in situ, then the wound is left open and re-explored after 48 hrs. If there is no infection, and the doubtful viable tissue is now healthy, the deep tissues can be repaired & the wound closed. If however there is further necrosis & infection the wound is again debrided & left open.', 'role': 'assistant'}]