During insertion of a subclavian central venous catheter (SCV line), the physician notes decreased breath sounds on the right side post-procedure. What complication should be suspected?

Correct option is B

Decreased unilateral breath sounds immediately after SCV line placement strongly suggest pneumothorax, a common complication due to pleural puncture.
Explanation of options: (a) ✘ Hemothorax causes dullness on percussion, but pneumothorax is more likely after line insertion. (b) ✔ Correct; pneumothorax is classic after subclavian/ IJ cannulation. (c) ✘ Air embolism → sudden dyspnea, chest pain, circulatory collapse, not localized decreased sounds. (d) ✘ Catheter-related infection is a late complication, not immediate.