A 59 year old man has progressive exertional dyspnea and dry cough for 1 year. He worked in construction and now has bibasilar end inspiratory crackles. Pulmonary function testing shows reduced total lung capacity and reduced diffusion capacity for carbon monoxide. During exercise, his oxygen saturation drops significantly. Which of the following is the most likely cause of his exercise induced hypoxemia?
- A)Increased airway resistance due to bronchial smooth muscle contraction
- B)Loss of central respiratory drive due to medullary depression
- C)Right to left intracardiac shunting through a patent foramen ovale
- D)Destruction of alveolar walls causing increased compliance
- E)Thickening of the alveolar membrane that limits diffusionGABARITO
Explicação
Thickening of the alveolar membrane that limits diffusion is correct. Interstitial lung disease causes fibrosis of the alveolar interstitium, lowering diffusion capacity and making oxygen transfer especially difficult during exercise because transit time throu... Ver explicação completa e trilha adaptativa →