The relationship between catheter indwelling time and catheter-related infections

Introduction

Catheter infection, the most frequent complication of the central venous catheter (CVC), is associated with increased morbidity, mortality and duration of hospital stay. In this study we evaluated the relationship between catheter indwelling time and catheter-related infections. Besides, we searched for the incidence of mechanical complications due to placement of the CVC, the microorganisms responsible for catheter infections and risk factors associated with the catheter infection.

Materials and methods

During the study period (January-October 2002), 140 nontunneled CVCs having been replaced in 100 patients in our 25-bed ICU were collected. They were replaced when there was a suspicion of catheter-related infection or when there was no more need for a CVC. When a CVC was removed, the distal and the subsegmental part were cut off aseptically, and sent to the microbiology laboratory at our hospital where they were cultured by a semiquantitative method and two sets of blood samples were drawn for culture, with at least one set drawn percutaneously. Cultures yielding 15 or more colonies were recorded.

Results

Forty-eight mechanical complications occurred in total, including arterial puncture in 30 procedures (21%), cardiac arrhythmias in 14 procedures (10%), pneumothorax in three procedures (2%) and catheter malposition in one procedure (0.7%). The incidence of catheter-related sepsis (CRS), catheter colonization, secondary bacteremia, catheter-related bacteremia (CRB) and exit site infection were 8% (n = 11), 13% (n = 19), 11% (n = 16), 4% (n = 5) and 2% (n = 2), respectively. In 87 (62%) catheters, no clues for infection were found. The patients were respectively assigned to two groups according to the indwelling time of catheters (group I, less than 12 days; group II, more than 12 days). In groups I and II, CRS was observed in eight (73%) and in three (27%) patients, respectively. The mortality rates in the patients with CRS or bacteremia were 73% and 60%, while the mortality rate was 31% in patients without infection. S. aureus (18%), Klebsiella (18%) and C. albicans (18%) were found as the most frequent microorganism causing CRS. Coagulase-negative staphylococcus was the first bacteria causing colonization (63%) and bacteremia (60%).

Conclusion

Although the group with indwelling time more than 12 days was associated with increased mortality and the incidence of CRS and CRB were higher in group II, these evaluations were not verified according to the statistics. Even though we have completed an extensive study on 140 catheters, we believe the study should be improved with participation of a large series.