187. A previously healthy 59-year-old man comes to the emergency department because of a 1-day history of fever, shortness of breath, and productive cough. He appears to be inmoderate distress. His temperature is 38.4°C (101.1°F), and respirations are 26/min. Pulse oximetry on room air shows an oxygen saturation of 88%. Bronchial breath sounds areheard over the right lung base posteriorly with egophony and increased tactile fremitus. A chest x-ray shows right lower lobe pneumonia. Which of the following mechanisms is themost likely cause of the hypoxia in this patient?A) Alveolar fibrosisB) HypoventilationC) Right-to-left cardiac shuntD) Right ventricular failureE) Ventilation-perfusion mismatch27

The key points to be noted from the scenario are as follows:The patient is a 59 year old manHe…

derate distress. His temperature is 38.4°C (101.1°F), and respirations are 26/min. Pulse oximetry on room air shows an oxygen saturation of 88%. Bronchial breath sounds are ard over the right lung base posteriorly with egophony and increased tactile fremitus. A chest x-ray shows right lower lobe pneumonia. Which of the following mechanisms is the st likely cause of the hypoxia in this patient? Alveolar fibrosis Hypoventilation Right-to-left cardiac shunt Right ventricular failure Ventilation-perfusion mismatch 4 D

derate distress. His temperature is 38.4°C (101.1°F), and respirations are 26/min. Pulse oximetry on room air shows an oxygen saturation of 88%. Bronchial breath sounds are ard over the right lung base posteriorly with egophony and increased tactile fremitus. A chest x-ray shows right lower lobe pneumonia. Which of the following mechanisms is the st likely cause of the hypoxia in this patient? Alveolar fibrosis Hypoventilation Right-to-left cardiac shunt Right ventricular failure Ventilation-perfusion mismatch 4 D