respiratory 1 of 3

[yomy]

Question 1 of 3
A 23-year-old, semiconscious man is brought to the emergency room following an automobile accident. He is tachypneic (breathing rapidly) and cyanotic (blue lips and nail beds). The right lower anterolateral thoracic wall reveals a small laceration and flailing (moving inward as the rest of the thoracic cage expands during inspiration). Air does not appear to move into or out of the wound, and it is assumed that the pleura have not been penetrated. After the patient is placed on immediate positive pressure endotracheal respiration, his cyanosis clears and the abnormal movement of the chest wall disappears. Radiographic examination confirms fractures of the fourth through eighth ribs in the right anterior axillary line and of the fourth through sixth ribs at the right costochondral junction. There is no evidence that bony fragments have penetrated the lungs or of pneumothorax (collapsed lung).


The small superficial laceration, once it is ascertained that it has not penetrated the pleura, is sutured and the chest bound in bandages; positive pressure endotracheal respiration is maintained. Several hours later, the cyanosis returns. The right side of the thorax is found to be more expanded than the left, yet moves less during respiration. Chest x-rays are shown above. Which of the following is the most obvious abnormal finding in the inspiratory posteroanterior and lateral chest x-ray of this patient (viewed in the anatomic position)?
see radiography attached


A. Flail chest
B. Right hemothorax
C. Right pneumothorax
D. Paralysis of the right hemidiaphragm

[yomy]

Explanation
The fluid level in the right pleural cavity is indicative of hemothorax caused by bleeding into the pleural space. As blood collects, lung tissue is displaced and cannot expand fully, thereby impairing ventilation. However, perfusion continues so that the ventilation-perfusion ratio is altered.