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': 'In hypovolemic shock all happen EXCEPT: September 2012 \nSelect and explain. \nA. Constriction of capacitance vessels, B. Constriction of aerioles in the skin, C. Decrease in cardiac output, D. Hea rate decreases', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D i.e. Hea rate decreases Hypovolaemic shock It is due to inadequate circulation volume. The most common causes of this type of shock being any cause of fluid loss; haemorrhage, salt and water loss, sepsis, burns, etc. A poor venous return to the hea will decrease the stroke volume and cardiac output. The patient will attempt to compensate by tachycardia and increased systemic vascular resistance (SVR). They become cold peripherally (shut down).', 'role': 'assistant'}]