Current approaches to the diagnosis and prevention of catheter-related infections

Despite their potential preventability, catheter-related infections still impose a substantial burden on critically ill patients. Recent advances have mainly concerned refined approaches to diagnosis and new preventive strategies. Only about 15 to 25 percent of the catheters removed because of suspicion of infection prove infected, after specific quantitative catheter cultures are obtained. This situation has prompted the development of methods to diagnose infection while leaving the catheter in place, which can be used in non-severe conditions. Techniques that may rule out infection are especially useful. Targeted skin and hub cultures have high sensitivity and negative predictive value for the diagnosis of catheter-related infection. Quantitative paired blood cultures have high specificity, but are costly. A simple and less costly alternative is to measure the differential time to positivity between central and peripheral blood cultures; this technique is highly sensitive and specific for the diagnosis of catheter-related bacteremia, and could advantageously replace quantitative blood cultures. Recent developments in preventive strategies include strict emphasis on maximal barrier precautions during insertion, and use of tunnelization for central venous catheters at high risk of microbial contamination (ie, internal jugular, and possibly femoral catheters). The development of new catheters impregnated with antiseptics or antibiotics (minocycline-rifampin) is a promising advance. Such catheters appear especially useful when infection rates are persistently high despite adequate compliance with other preventive measures. Curr Opin Crit Care 1999, 5:341-349