The goal of this clinical trial is to determine if prophylactic antibiotic treatment can reduce the incidence of early catheter-related infections in hemodialysis patients at high risk, including those with femoral catheter placement, atrial fibrillation, or heart failure. The main questions it aims to answer are: 1. Will prophylactic antibiotic administration reduce catheter-related infections by 50% within 45 days of catheter insertion? 2. Will this intervention decrease the rate of secondary complications such as metastatic infections, cardiovascular morbidity, and mortality? Researchers will compare patients receiving prophylactic antibiotics (e.g., cefamezine and gentamicin, or vancomycin for high-risk individuals) to those not receiving antibiotics, to assess the difference in infection rates and associated complications. Participants : * Be randomized into two groups: one receiving prophylactic antibiotics and one without antibiotics before catheter placement or replacement. * Undergo follow-up for 45 days to monitor for catheter-related infections and secondary complications. This study will provide critical data to evaluate whether targeted prophylactic antibiotic treatment should become standard practice for high-risk hemodialysis patients.