Although half of intensivists routinely replace their central venous catheters (CVCs), this practice is not supported by data from randomized control studies or by pathophysiology of CVC infection. The daily risk of CVC infection is considered to be a constant; the risk of catheter infection is directly related to the duration of catheter insertion. Consequently, the routine change of the catheter is able to decrease the number of infections per catheter but not to modify the number of infections per day of catheter insertion. This assertion is supported by evidence-based medicine: scheduled replacement every 3 or 7 days has not been shown to alter the infectious risks of CVCs in randomized studies or a meta-analysis.
Moreover, routine replacement at a new site exposes the patient to an increased risk of mechanical complications. The overall rate of mechanical complications per catheter inserted is approximately 3%. Guidewire exchange of the catheters may reduce the risk of mechanical complications, but unfortunately is associated with a higher rate of catheter colonization and catheter-related bacteremia. Routine replacement of CVCs is not necessary.