This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General surgery, Subject name: Surgery
[{'content': 'Maintenance level of Mixed Venous Oxygen Saturation in shock must be \nSelect and explain. \nA. < 40%, B. 40-50%, C. 50-70%, D. >70%.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Mixed Venous Oxygen Saturation: - * This is a measure of oxygen returning to hea from body after delivery and extraction by tissues. * Normal Value- 50-70% * In cardiogenic shock and Hypovolemic shock, the tissues takes up more oxygen and hence value is low < 50% * In Septic and Distributive shock , the tissues takes up less oxygen and hence more oxygenated blood returns to hea and hence value is high > 70% Ref:- Surgery Sixer 3rd Edition; Pg num:- 8', 'role': 'assistant'}]