Clinical impact of diagnosis methods for catheter-related bloodstream infection in ICU patients

Introduction

The central venous catheter (CVC) is indispensable in the ICU. Catheter-related bloodstream infection (CR-BSI) is the leading cause of healthcare-associated infections and one of the most important complications from the CVC. Nowadays there are two well-known ways to diagnose CR-BSI: the standard method (withdrawal of the catheter) and the conservative method (without withdrawal of the catheter). Our objective was to compare the in-hospital mortality between the two methods in patients with CR-BSI (short-term catheter) in the ICU.

Methods

This study was conducted in a 38-bed mixed ICU in a tertiary hospital. We reviewed all episodes of CR-BSI that occurred in our ICU from January 2000 to December 2008. The standard method was defined in a patient with a CVC with at least one positive blood culture obtained from a peripheral vein and a positive semiquantitative (>15 CFU) catheter segment culture whereby the same organism (species and antibiogram) was isolated from the catheter segment and peripheral blood. The conservative method was defined in a patient with a CVC with at least one positive blood culture obtained from a peripheral vein and one of the following: differential time period of CVC culture versus peripheral culture positivity of more than 2 hours, or simultaneous quantitative blood culture with a ratio ≥5:1 (CVC versus peripheral).

Results

During the study period, 247 episodes of bloodstream infection were identified; of these, 192 were catheter-associated bloodstream infection and 55 were CR-BSI (39 standard method and 17 conservative method). Considering the CR-BSI patients, the mean age ± standard variation (SD) was 64 ± 19.29 (years), 75% were under mechanical ventilation, 55% were under vasopressors, 40% were under total parental nutrition, 40% were under hemodialysis, 72% were double lumen and the mean time ± SD in place was 16.32 ± 8.56 (days). The in-hospital mortality of the standard method versus the conservative method did not show any difference (57% vs 75%, P = 0.208).

Conclusions

This study showed that there is no difference in the in-hospital mortality between the standard method versus the conservative method in patients in the ICU with CR-BSI.