[Central venous catheter - related infections]

Central venous catheters are essential in complex medical and surgical interventions. It is estimated that 200,000 nosocomial bloodstream infections occur each year; 90% of these infections are related to the use of central venous catheters with increased morbidity and mortality, prolonged hospitalization and intensive unit stay, and greater hospital cost. The cause of the increased incidence of bacteremia and intravascular catheter infections is multifactorial and a source of ongoing debate. The skin, parenteral nutritional mixtures or hematogenous seeding accounted for 70% of the catheter-related bloodstream infections (CBI); the remaining 30% were traced to the hub. The three most common types of organisms causing CBI are coagulase negative staphylococci (usually S. epidermidis), S. aureus, and Candida spp. More rarely, gram-negative bacilli (Pseudomonas spp, Acinetobacter spp), enteric organisms and enterococci are implicated. Treatment includes catheter withdrawal and appropriate antibiotic coverage. For patients requiring only short-term access, the most effective approach is catheter removal, administration of parenteral antibiotics and replacement of the catheter at a different site. However, critically ill patients in hemodynamic monitoring or in TPN or chemotherapy require continuous central venous access, and the approach is to change the potentially infected line over guidewire, intravenous antibiotics and "catheter antibiotic lock" for 24 hours. If a patient's clinical course fails to improve after 28-48 hours of antimicrobial therapy, the catheter should be removed and replaced at a new site.