Question 159
A 32-year-old male presents to an acute care clinic with complaints of chest pain that is worse when he breathes in. The chest pain started about a day ago. A few hours ago he coughed up blood. Physical examination reveals some dullness to percussion in the left upper lobe and crackles are heard at that site. His only past medical history is that he broke his left tibia one week ago while skiing, and has had to wear a cast, which he reports has hindered his ability to get around like normal. Of the following, which laboratory test is most likely to be elevated?
A. D-Dimer
B. PTT
C. AST
D. Hct
E. Glucose
Answer for Question 159
Answer: A (D-dimer)
Explanation: The clinical scenario is consistent with a pulmonary thromboembolus, which can present with pleuritic chest pain and hemoptysis. A peripheral thromboembolus can produce an infarction of the lung, which would lead to the dullness to percussion and crackles. The immobility is a risk factor for deep venous thrombosis and resultant pulmonary thromboembolus. Of the laboratory tests listed, an elevated d-dimer is most associated with deep venous thrombi and a pulmonary thromboembolus. In a patient with anti-phospholipid antibody syndrome, an elevated PTT would be possible, and those patients are at risk for thrombi and embolism; however, the history does not otherwise suggest this condition, and it is only one of many conditions that could possibly predipose to thrombosis and embolism.
Question 160
A 23-year-old tall and thin male presents to the emergency room at 2 am, saying that he awoke due to a sudden pain in his chest that was worse when he breathed, and has had difficulty breathing since that time. Physical examination reveals hyperresonance to percussion on the left side of his chest, which is associated with decreased breath sounds and absence of tactile fremitus. Of the following, what is the most likely diagnosis?
A. Acute myocardial infarct
B. Aortic dissection associated with Marfan syndrome
C. Pneumothorax
D. Lobar pneumonia
E. Pulmonary thromboembolus
Answer for Question 160
Answer: C (Pneumothorax)
Explanation: The clinical presentation is classic for a spontaneous pneumothorax (tall thin young male with sudden onset pleuritic chest pain and dyspnea). Physical examination is likewise consistent with pneumothorax – the hyperresonance occurs because the pleural cavity is filled with air, as do the decreased breath sounds and absence of tactile fremitus, since the lung is displaced away from the chest wall by intervening air. Although tall and thin suggest Marfan syndrome, the physical examination is not consistent with an aortic dissection and hemothorax (especially the hyperresonance); also, the patient would be potentially in shock from blood loss if an aortic dissection were the cause of his symptoms. The physical examination is also not consistent with pulmonary thromboembolus, although the sudden onset of dyspnea and pleuritic chest pain could be consistent.
Question 161
A 16-year-old tall male is playing basketball with friends when he suddenly develops chest pain and shortness of breath. His friends take him to the emergency room where a physical examination reveals hyperresonance to percussion on the left side of his chest, which is associated with decreased breath sounds and absence of tactile fremitus. Of the following, what is the most likely underlying pathologic finding?
A. Ruptured pulmonary bleb
B. Inflammation of blood vessel
C. Tearing of large caliber blood vessel
D. Asymmetric thickening of myocardium
E. Thrombus in blood vessel
Answer for Question 161
Answer: A (Ruptured pulmonary bleb)
Explanation: The clinical presentation is classic for a spontaneous pneumothorax (tall young male with sudden onset chest pain and dyspnea). Physical examination is likewise consistent with pneumothorax – the hyperresonance occurs because the pleural cavity is filled with air, and the decreased breath sounds and absence of tactile fremitus, since the lung is displaced away from the chest wall by intervening air. Although tall and thin suggest Marfan syndrome, the physical examination is not consistent with an aortic dissection and hemothorax (especially the hyperresonance), and thus a tearing of large caliber blood vessel is not the finding; also, the patient would be potentially in shock from blood loss. Although patients with hypertrophic cardiomyopathy can present as sudden death, the history and physical examination findings are not consistent with the diagnosis (i.e., a patient with hypertrophic cardiomyopathy would not normally developed sudden chest pain and shortness of breath). The physical examination findings are not consistent with a vasculitis or pulmonary thromboembolus.