This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
The most common cause of preventable hospital death is 
Select and explain. 
A. Acute pulmonary embolism, B. Hea failure, C. Myocardial infraction, D. Cancer
A: Acute pulmonary embolism
Answer: A: Acute pulmonary embolism 
Explanation: PE is the most common preventable cause of death among hospitalized patients. Clinical features The diagnosis of pulmonary embolism (PE) may be aided by asking three questions: * Is the clinical presentation consistent with PE? * Does the patient have risk factors for PE? * Are there any alternative diagnoses that can explain the patient's presentation? Clinical presentation varies, depending on number, size and distribution of emboli and on underlying cardiorespiratory reserve (Box 17.83). A recognised risk factor is present in 80-90% (see Box 23.65, p. 975). The presence of one or more risk factors increases the risk fuher still. Ref Davidson edition23rd pg 619