[Rate of contamination of intravenous indwelling cannulae with sideport access]

136 cannulae with valved side injection port were introduced intravenously into patients from the general surgery, urology and dermato-surgical service under clinical routine conditions. The cannulae were used from 1 up to 4 days for anaesthesia purposes as well as peri- and postoperative infusion therapy and injection of drugs through the sideport. After use the cannulae were removed following an aseptic procedure and examined microbiologically. 37 cannulae (27.2%) were found contaminated, 25 of these (18.3%) with more than 25 colonies. The infusion line (border of the conus, the interior of the conus and the lumen of the cannula) was 21 times (15.4%), the side injection port 6 times (4.4%) and the intravasal capillary surface 17 times (12.5%) contaminated. Contamination of the cannula or of parts of the cannula did not correlate well with observed signs of inflammation at the puncture site (45 patients = 33%). If, however, the contamination of the cannula is considered to be an infection risk, the addition of a side injection port to such a cannula does not increase the risk of infection. This risk is much greater via the infusion line.