This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Poal Hypeension, Subject name: Surgery
[{'content': 'The Sengstaken tube must maintain a pressure of ...... to stop bleeding from varices: \nSelect and explain. \nA. 20 mm Hg, B. 25 mm Hg, C. 35 mm Hg, D. 45 mm Hg', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Sengstaken tube - have 2 balloon 1)Gastric balloon 2)Esophageal balloon It is triple lumen; double ballooned tube. It is used mainly during transpoation of patient. Total amount of air inseed in gastric balloon = 50 + 250 ml (min air) =300 ml Maximum pressure exeed by esophageal balloon = 35-40 mm of Hg Every 12 hrs the esophageal balloon has to be deflated to prevent Ischemia & necrosis of the esophagus.', 'role': 'assistant'}]