Clinical Outcomes
Diagnosis of venous access port colonization requires cultures from multiple sites: should guidelines be amended?,☆☆

https://doi.org/10.1016/j.diagmicrobio.2013.11.004Get rights and content

Abstract

Data on microbiological management of withdrawn venous access ports (VAPs) are scarce. The aim of our study was to assess the validity of Gram stain and culture performed on VAPs to detect colonization and VAP-related bloodstream infection (VAP-RBSI). We prospectively performed cultures of the following: catheter tip (roll-plate and sonication), port content aspirate before and after sonication, port sonication fluid (PSF), and port internal surface biofilm (ISB). The gold standard of VAP colonization was positivity of at least 1 of the cultures mentioned above. We collected 223 VAPs in which no single culture had validity values reliable enough to predict colonization and VAP-RBSI. The best validity values were those obtained when cultures of catheter tip (roll-plate), PSF, and port ISB were combined. Cultures from several areas on the VAP are necessary to ensure suitable assessment of colonization and VAP-RBSI.

Introduction

Venous access ports (VAPs) are widely used for long-term access to the vascular system, mainly in patients with prolonged illnesses. Patients with VAPs are at risk of infection, which, although uncommon, is a very serious cause of morbidity and mortality and frequently requires the catheter to be withdrawn (Biffi et al., 1998, Chang et al., 2003, Crisinel et al., 2009, Fernandez-Hidalgo et al., 2008, Groeger et al., 1993, Kuizon et al., 2001, Mauri et al., 2010, Rosenthal et al., 2006, Samaras et al., 2008, Wisplinghoff et al., 2003, Yildizeli et al., 2004). Catheter-related infection is confirmed by demonstration of colonization in parts of the VAP other than the tip, since tip culture alone does not frequently yield microorganisms in cases with demonstrated colonization (Mermel et al., 2009). The issue of which parts of the VAP should be analyzed to detect colonization remains unresolved, although current evidence points to the internal surface of the port reservoir (Douard et al., 1999, Longuet et al., 2001, Whitman and Boatman, 1995).

Our objectives were to evaluate the reliability of Gram stain and culture at different sites on the inside and outside of VAPs and to find the best combination of cultures for predicting VAP colonization and VAP-related bloodstream infection (VAP-RBSI).

Section snippets

Setting

Ours was a prospective study performed between July 2009 and April 2011 at a large institution in Madrid, Spain.

We included all tunneled VAPs (Port-A-Caths) that were routinely removed at the Department of Vascular Interventional Radiology, irrespective of the reason for withdrawal. We also included those devices with suspicion of infection, which were removed in surgery departments or emergency rooms.

Laboratory procedures

When a VAP arrived at the microbiology laboratory, it was cut in 2 parts: the distal segment

Results

During the study period, we included 223 ports from 222 patients. Median indwelling time was 440 days (interquartile range [IQR], 212–907 days). The main underlying disease was colorectal cancer (23.0%). Most catheters were removed because of end of use (60.5%), suspicion of bloodstream infection (19.7%), and a miscellany of other reasons (19.7%). Patient and catheter characteristics are detailed in Table 1.

The overall catheter tip colonization rate was 23.8% (53/223), and the isolated

Discussion

This prospective and comparative study shows that no single site was reliable enough to detect ≥90% of colonized VAPs. We showed that reservoir ports can be colonized on their internal or external surfaces, thus implying the need to obtain cultures to assess both the inside and the outside of the port reservoir.

Indwelling time is long in patients undergoing chemotherapy, thus increasing the likelihood of device infection. However, although VAP-RBSI rates are not very high, the difficulties

Acknowledgments

We thank Thomas O’Boyle for his help in the preparation of the manuscript and Cristina Fernández for the statistical analysis.

We thank the members of the GEIDI study group for their contribution to the work:

José Eugenio Guerrero, Milagros Sancho, Braulio de la Calle, Carlos Sotillo, Guiomar Sánchez, Esther Bermejo López, Lorenzo Fernández Quero, Ana Lajara, Isabel Frías, Carmen Heras, María Jesús Pérez, José Maria Barrio, Alejandro Garrido Sanchez, Patricia Muñoz, Marta Rodríguez-Créixems, Mar

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    Funding sources: This work was supported by Ministerio de Sanidad y Consumo (Instituto de Salud Carlos III) and Fundación para la Investigación Biomédica del Hospital General Gregorio Marañón (FIBHGM) (CM09/00028). This study was partially financed by grants from Fundación Mutua Madrileña de Madrid.

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    Conflict of interest: The authors declare no conflicts of interest.

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