A 68-year-old man comes to the emergency department due to cough, breathlessness, and chest pain. The patient has a medical history of hypertension and type 2 diabetes mellitus. He is a former smoker with a 20-pack-year history. Temperature is 38 C (100.4 F), blood pressure is 130/80 mm Hg, respirations are 22/min, and oxygen saturation is 95% while breathing ambient air. The trachea is central in position. There is dullness to percussion over the lower right lung area compared to the resonancy on the left. Auscultation of the right lower lobe reveals breath sounds that are loud, hollow, and high-pitched. When the patient recites the word "ninety-nine" in a normal voice, the sound has higher clarity and intensity over the right base compared to other lung areas. Which of the following is the most likely cause of these findings?

Question

A 68-year-old man comes to the emergency department due to cough, breathlessness, and chest pain.  The patient has a medical history of hypertension and type 2 diabetes mellitus.  He is a former smoker with a 20-pack-year history.  Temperature is 38 C (100.4 F), blood pressure is 130/80 mm Hg, respirations are 22/min, and oxygen saturation is 95% while breathing ambient air.  The trachea is central in position.  There is dullness to percussion over the lower right lung area compared to the resonancy on the left.  Auscultation of the right lower lobe reveals breath sounds that are loud, hollow, and high-pitched.  When the patient recites the word "ninety-nine" in a normal voice, the sound has higher clarity and intensity over the right base compared to other lung areas.  Which of the following is the most likely cause of these findings?

Quizplus · Accepted Answer

11ec160b_3b30_d58a_9249_e16342069399_MD0001_00 This patient's presentation is consistent with bacterial pneumonia. The infection causes the alveoli to fill with inflammatory, neutrophil-rich exudate (pus); alveolar filling with any kind of fluid (eg, pus, edema, blood) creates alveolar consolidation. Alveolar consolidation leads to a number of characteristic physical examination findings. Sound travels faster and more efficiently through liquids than gases; therefore, fluid-filled alveoli transmit higher intensity sound than those filled with air. As a result, breath sounds and tactile fremitus (vibration) are more prominent over areas of alveolar consolidation. Bronchophony, a phenomenon in which a patient's spoken words (eg, "ninety-nine," "toy boat") are heard more loudly and clearly when auscultated over an area of consolidation compared to normal lung, is also present. The higher density of fluid-filled alveoli also creates relative dullness to percussion compared to the resonant sound created on percussion of air-filled alveoli. (Choice A) Accumulation of interstitial fluid within the pleural space (pleural effusion) insulates breath sounds and vibrations that originate in the airways of the lungs. Consequently, tactile fremitus and breath sound intensity are decreased. The fluid in the chest cavity creates dullness to percussion over the affected area. (Choice B) Pulmonary embolism typically has minimal effect on physical examination findings for the lungs. (Choice D) As in pleural effusion, accumulation of air in the pleural space (pneumothorax) insulates sounds and vibrations that originate in the lungs, and breath sound intensity and tactile fremitus are decreased. In contrast to pleural effusion, the relatively low density of the air in the pleural space creates hyperresonance to percussion. (Choice E) A mass in a proximal bronchial airway (eg, malignancy, mucus plug) can cause airway obstruction and consequent collapse (atelectasis) of distal alveoli. Breath sounds and tactile fremitus are decreased, and dullness to percussion is created due to the absence of air. (Choice F) Transudation of interstitial fluid into the alveoli occurs in heart failure and can create alveolar consolidation with physical examination findings similar to bacterial pneumonia. However, in heart failure the findings are typically similar bilaterally. Pneumonia, with accumulation of inflammatory exudate, is more likely in this patient with low-grade fever and evidence of unilateral alveolar consolidation. Educational objective: Alveolar consolidation occurs when the alveoli become filled with fluid (eg, inflammatory exudate in bacterial pneumonia). The increased compactness of the alveolar fluid (compared to air) causes sound to travel faster and more efficiently, resulting in bronchophony, increased tactile fremitus (vibration), and increased intensity of breath sounds over the affected area. Dullness to percussion is also present.

A 68-Year-Old Man Comes to the Emergency Department Due to Cough