Final answer:
The nurse's primary concern would be preventing peritonitis, a severe and life-threatening inflammation of the peritoneum, which can follow signs of infection at a catheter site in a patient on peritoneal dialysis.
Step-by-step explanation:
The primary concern for a client with chronic kidney disease on peritoneal dialysis who exhibits redness, tenderness, and drainage around the catheter site would be the risk of peritonitis. This is supported by the clinical presentation in the scenario which indicates possible infection and the fact that peritonitis is a known serious complication associated with peritoneal dialysis. Peritonitis, which is an inflammation of the peritoneum, can become life-threatening if not promptly and effectively treated. It often requires intensive antibiotic therapy and sometimes emergency surgery to correct the underlying issue.
While exit site infection is a concern as well, it often precedes peritonitis and is less severe by itself. Atelectasis and outflow obstruction, while valid considerations in general, are not the most immediate concerns given the presented signs of infection at the catheter site that could easily lead to peritonitis. Peritonitis is usually associated with bacterial infection, and it is a life-threatening condition that requires emergency surgery and intensive antibiotic therapy. The mortality rate from peritonitis can be high, ranging from 30 to 40 percent.