Risk factors related to bacterial contamination of indwelling vascular catheters in non-infected hosts.

Aerobic, anaerobic and fungal cultures were performed on 70 vascular catheters from 57 non-infected patients. Despite the exclusion of any patient who developed non-catheter-related foci of infection, 46% of all cannulae became contaminated, usually with relatively non-pathogenic organisms. Multiple organisms were observed in one-third of all infected catheters, and six patients developed probable catheter related bacteraemia. Of the risk factors studied, only duration of placement exceeding 3 days was significant. Obsessive aseptic measures did not reduce the rate of contamination.