Central Venous Catheters: Do we need to Review Practice on Positioning?

It is generally agreed that the tip of an inserted central venous catheter (CVC) should not lie within the right atrium. However, the tip of a CVC not inserted to an adequate depth could lie outside the superior vena cava, predisposing to thrombus formation and infection. A retrospective audit of the position of CVCs on chest radiographs in intensive care patients and the associated incidence of catheter-related infections was therefore undertaken. Chest radiographs of 100 patients who had central venous catheterisation were assessed using the electronic record system, measuring the distance of the CVC tip from the tracheal carina and the site of insertion. Comparisons were then made of the incidence of infection in the groups where the CVC tip was above or below the carina. In a significant proportion of patients (31%) the CVC tip lay too far below the carina. There was no significant difference in the incidence of catheter-related infections between the groups where the catheter was too far below the carina and too far above the carina. CVCs should not be placed too far below the carina as seen on the chest radiograph. Leaving a portion of CVC outside the skin does not appear to increase the incidence of infection in this small group of patients.