What is a possible complication of subclavian venous catheter placement indicated by high airway pressure and decreased mean arterial pressure?

The correct answer, tension pneumothorax, is a serious condition that can occur as a complication of subclavian venous catheter placement. When a catheter is improperly placed or if there is a trauma during the procedure, air can enter the pleural space, creating pressure that collapses the lung on the affected side. This results in increased airway pressure due to the diminished lung capacity to ventilate effectively. The high airway pressure indicates that the lungs are unable to receive adequate air, while the decreased mean arterial pressure suggests compromised cardiovascular function, as the pressure in the thoracic cavity expands and begins to impede venous return to the heart. Together, these signs are indicative of tension pneumothorax, necessitating immediate intervention to relieve the pressure and restore normal respiratory and circulatory function.

Other options like hemothorax, cardiac tamponade, and infection, while they can be complications following the procedure, do not typically present with the specific combination of high airway pressure and decreased mean arterial pressure as seen in tension pneumothorax.