Final answer:
Immediate action is required if a patient exhibits difficulty breathing and decreased oxygen saturation following the insertion of a left subclavian central venous catheter, as they may signal serious complications (option c).
Step-by-step explanation:
The nurse is caring for a patient following insertion of a left subclavian central venous catheter (CVC). Considering the possible complications and clinical focus case presented, the assessment finding that warrants immediate action is c) Difficulty breathing and decreased oxygen saturation. This could indicate a serious complication such as a pneumothorax, hemothorax, or air embolism, which are potential immediate risks after CVC insertion. It is critical for the nurse to promptly respond to these symptoms by evaluating the patient's respiratory status, checking oxygen levels, and alerting the medical team for urgent assessment and intervention to prevent further deterioration of the patient’s condition.
While slight redness and swelling (a), a small amount of blood (b), and mild discomfort at the insertion site (d) are common and often expected findings post-procedure, difficulty breathing and changes in oxygen saturation could indicate a life-threatening situation requiring swift medical attention.
Hence, the answer is option c.