Diagnosis, management, and prevention of catheter-related infections

Antibiotic and other lock treatments for tunnelled central venous catheter-related infections in children with cancer

BACKGROUND

The risk of developing a tunnelled central venous catheter (CVC)-related infection ranges between 0.1 and 2.3 per 1000 catheter days for children with cancer. These infections are difficult to treat with systemic antibiotics (salvage rate 24% - 66%) due to biofilm formation in the CVC. Lock treatments can achieve 100 - 1000 times higher concentrations locally without exposure to high systemic concentrations.

OBJECTIVES

Our objective was to investigate the efficacy of antibiotic and other lock treatments in the treatment of CVC-related infections in children with cancer compared to a control intervention. We also assessed adverse events of lock treatments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, issue 3, 2011), MEDLINE/PubMed (1945 to August 2011) and EMBASE/Ovid (1980 to August 2011). In addition we searched reference lists from relevant articles and the conference proceedings of the International Society for Paediatric Oncology (SIOP) (from 2006 to 2010), American Society of Clinical Oncology (ASCO) (from 2006 to 2010), the Multinational Association of Supportive Care in Cancer (MASCC) (from 2006 to 2011), the American Society of Hematology (ASH) (from 2006 to 2010) and the International Society of Thrombosis and Haematology (ISTH) (from 2006 to 2011). We scanned the ISRCTN Register and the National Institute of Health Register for ongoing trials (www.controlled-trials.com) (August 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing an antibiotic lock or other lock treatment (with or without concomitant systemic antibiotics) with a control intervention (other lock treatment with or without concomitant systemic antibiotics or systemic antibiotics alone) for the treatment of CVC-related infections in children with cancer. For the description of adverse events, cohort studies were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, extracted data and performed 'Risk of bias' assessments of included studies. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Two RCTs evaluated urokinase lock treatment with concomitant systemic antibiotics (n = 56) versus systemic antibiotics alone (n = 48), and one CCT evaluated ethanol lock treatment with concomitant systemic antibiotics (n = 15) versus systemic antibiotics alone (n = 13). No RCTs or CCTs evaluating antibiotic lock treatments were identified. All studies had methodological limitations and clinical heterogeneity between studies was present. We found no evidence of significant difference between ethanol or urokinase lock treatments with concomitant systemic antibiotics and systemic antibiotics alone regarding the number of participants cured, the number of recurrent CVC-related infections, the number of days until the first negative blood culture, the number of CVCs prematurely removed, ICU admission and sepsis. Not all studies were included in all analyses. No adverse events occurred in the five publications of cohort studies (one cohort was included in two publications) assessing this outcome; CVC malfunctioning occurred in three out of five publications of cohort studies assessing this outcome.

AUTHORS' CONCLUSIONS

No significant effect of urokinase or ethanol lock in addition to systemic antibiotics was found. However, this could be due to low power or a too-short follow-up. The cohort studies identified no adverse events; some cohort studies reported CVC malfunctioning. No RCTs or CCTs were published on antibiotic lock treatment alone. More well-designed RCTs are needed to further explore the effect of antibiotic or other lock treatments in the treatment of CVC-related infections in children with cancer.

Central venous catheter-related blood stream infections in children undergoing hematopoietic stem cell transplant for primary immunodeficiency and other nonmalignant disorders

A single-center experience of catheter-related blood stream infections in children undergoing hematopoietic stem cell transplant for primary immunodeficiency is described. The rate of definite central venous catheter infections was 5.31/1000 line days. Staphylococcus epidermidis was the most commonly identified organism. Teicoplanin resistance occurred in 17% of S. epidermidis infections. The central catheter was removed in 21% of infections.

Prophylactic antibiotics for preventing early Gram-positive central venous catheter infections in oncology patients, a Cochrane systematic review

OBJECTIVE

Long-term tunnelled central venous catheters (TCVC) are increasingly used in oncology patients. Infections are a frequent complication of TCVC, mostly caused by Gram-positive bacteria. The objective of this review is to evaluate the efficacy of antibiotics in the prevention of early Gram-positive TCVC infections, in oncology patients.

DATA SOURCES

We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Register up to July 2003.

REVIEW METHODS

We selected randomised controlled trials (RCT) evaluating prophylactic antibiotics prior to insertion of the TCVC, and the combination of an antibiotic and heparin to flush the TCVC, in paediatric and adult oncology patients. The primary outcome was documented Gram-positive bacteraemia in patients with a TCVC. All trials identified were assessed and the data extracted independently by two reviewers.

RESULTS

There were nine trials included. Four trials reported on vancomycin/teicoplanin prior to insertion of the TCVC compared to no antibiotics. There was no reduction in the number of Gram-positive TCVC infections with an Odds ratio of 0.42 (95% confidence interval 0.13-1.31). Five trials studied flushing of the TCVC with a vancomycin/heparin solution compared to heparin flushing only. This method decreased the number of TCVC infections significantly with an Odds ratio of 0.43 (95% CI 0.21-0.87).

CONCLUSION

Flushing the TCVC with a vancomycin/heparin solution reduced the incidence of Gram-positive infections.

In situ diagnosis of central venous catheter-related bloodstream infection without peripheral blood culture

BACKGROUND

Catheter-related bloodstream infections (CRBIs) are frequent complications of the use of long term central venous catheters (CVCs). Comparative quantitative culture of blood obtained via the CVC and a peripheral vein (PV) is a well-accepted method of diagnosing CRBI; however, an alternative definition for use when a PV culture is not available is desirable.

METHODS

A computerized search of patient records identified all positive blood culture results from the St. Jude Children's Research Hospital Microbiology Laboratory between January 1996 and May 2001. Demographic data, catheter information and culture results were abstracted. Sensitivity, specificity, positive predictive value (PPV), and likelihood ratio were calculated for 2 alternative definitions of CRBI.

RESULTS

Review of the medical records revealed 136 episodes of bacteremia that were evaluable for alternative definition 1 and 241 episodes that were evaluable for alternative definition 2. In patients with a double lumen CVC, CRBI can be diagnosed by a > or = 5-fold difference in colony-forming units/mL between the 2 lumens (alternative definition 1) with sensitivity, specificity, PPV and likelihood ratio of 61.8, 93.3, 92.2 and 9.22, respectively. In patients with a single or double lumen CVC, CRBI can be diagnosed when the CVC culture yields > or = 100 colony-forming units/mL (alternative definition 2) with sensitivity, specificity, PPV and likelihood ratio of 75.5, 69.1, 79.3, and 2.44, respectively.

CONCLUSIONS

Our study suggests that comparison of colony counts from 2 lumens of a double lumen catheter is acceptable for diagnosis of CRBI when a PV culture is not available. Further validation is needed before discontinuing the recommendation to obtain a PV culture.