Prophylactic antibiotics for preventing early central venous catheter Gram positive infections in oncology patients.

BACKGROUND: Long-term tunnelled central venous catheters (TCVC) are increasingly used in oncology patients. Despite guidelines on insertion, maintenance and use, infections remain an important complication. Most infections are caused by Gram-positive bacteria. Therefore antimicrobial prevention strategies aimed at these micro-organisms could potentially decrease the majority of the TCVC infections.
OBJECTIVES: To determine the efficacy of administering antibiotics prior to insertion of a TCVC with or without vancomycin/heparin flush technique in the first 45 days after insertion of the catheter to prevent Gram-positive catheter-related infections in oncology patients. SEARCH STRATEGY: We searched MEDLINE, EMBASE,and CENTRAL up to July 2001. Reference lists from relevant articles were scanned and conference proceedings were hand searched. The authors of eligible studies were contacted to obtain additional information. SELECTION CRITERIA: We selected randomized controlled trials giving prophylactic antibiotics prior to insertion of the TCVC, and trials using the combination of an antibiotic and heparin to flush the TCVC in oncology patients. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the studies for inclusion, extracted the data and assessed the quality. MAIN
RESULTS: We included eight trials totalling 527 patients. Four reported on vancomycin/teicoplanin prior to insertion of the TCVC, and four reported on antibiotic flushing combined with heparin. The overall effect of an antibiotic prior to catheter insertion decreases the number of Gram-positive TCVC infections (odds ratio [OR] = 0.55, 95% confidence interval [CI] 0.29 to1.04). Given an expected infection rate of TCVC during the first 45 days of up to 30% this OR implies that the number needed to treat (NNT) will be 10 (95% CI 4 to13), this means vancomycin needs to be given to 10 patients to prevent one TCVC infection. Flushing the TCVC with antibiotics and heparin proved to be beneficial (OR = 0.35, 95% CI 0.16 -to 0.77). For intraluminal colonization the baseline infection-rate is 15% which leads to a NNT of 13 (95% CI 5 to 23). REVIEWER'S
CONCLUSIONS: Both interventions lead to a positive overall effect but should be considered with care due to the small number of studies. Depending on the baseline TCVC infection rate it is justified to administer antibiotics prior to the TCVC insertion or to flush the catheter with a combination of an antibiotic and heparin, if the catheter-related infection rate is high.