How Should Long-Term Tunneled Central Venous Catheters Be Managed in Microbiology Laboratories in Order To Provide an Accurate Diagnosis of Colonization?

Abstract

Guidelines recommend the roll-plate technique for short-term central venous catheter (CVC) tip cultures. However, the issue of whether the roll-plate technique is better than the sonication method for long-term CVCs remains unresolved. In addition, no data are available for predicting the value of direct Gram staining in anticipating catheter colonization or catheter-related bloodstream infection (CRBSI) in these long-term CVCs. Our objectives were to compare the roll-plate technique and the sonication method and to define the validity values of Gram staining for the prediction of colonization and CRBSI in patients with longterm tunneled CVCs. During the study period, all tunneled CVCs removed at our institution were prospectively and routinely sent to the microbiology laboratory for Gram staining (first) and tip culture (the Maki technique and sonication, in a random order). We received 149 tunneled CVCs, 39 (26.2%) of which were colonized and 11 (7.4%) of which were associated with CRBSI. Overall, the roll-plate method detected 94.9% of the colonized catheters, whereas sonication detected only 43.6% (P < 0.001).The validity values of Gram staining for the detection of colonization and CRBSI were as follows: a sensitivity of 35.9% to 60.0%, a specificity of 100% to 94.2%, a positive predictive value of 100% to 42.9%, and a negative predictive value of 81.5% to 97.0%. The roll-plate technique proved to be better than sonication for the detection of bacteria in long-term tunneled CVCs. Gram staining of the tips of tunneled CVCs can anticipate a positive culture and rule out CRBSI. In our opinion, direct Gram staining should be incorporated into routine microbiological assessments of long-term catheter tips. The recently reported Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Diagnosis and Management of Intravascular Catheter-Related Infection recommend the roll-plate technique for the routine clinical microbiological analysis of short-term catheter tips (9). However, for the analysis of long-term catheter tips, in which the endoluminal progression of microorganisms is more frequent, the best methodology for culture remains an unresolved issue (7,12,15).Although the sonication of catheter tips can better detect the microbiological colonization of the inner surface, both the inner and outer surfaces can be colonized simultaneously (6). The results of the few studies comparing the roll-plate and sonication methods are not homogenous for catheter type or the sequence order of the procedure (2,6,11,16). In the present study, it was demonstrated that the roll-plate technique was at least as efficient as sonication for the overall group of catheters received in the microbiology laboratory, although the number of long-term catheters was limited. Moreover, both techniques were compared in selected subpopulations with tunneled central venous catheters (CVCs).Acridine orange and Gram staining have been used to provide a rapid diagnosis of catheter-related bloodstream infection (CRBSI) wit...

Utility of routine surveillance blood cultures in asymptomatic allogeneic hematopoietic stem cell transplant recipients with indwelling central venous catheters at a comprehensive cancer center

“…We believe that even among these patients not all interventions were necessary or beneficial because most patients with CVC colonization do not develop subsequent BSI. 7,30 Nevertheless, many treating physicians felt the need to act on the information provided by these SBCs, particularly because no accurate prediction rules for the development of BSI in patients with colonized CVCs exist. Some treating physicians felt strongly that early intervention when the catheter was just colonized would prevent subsequent infection; however, there are no data to support this.…”

Comparison of methods for the microbiological diagnosis of totally implantable venous access port-related infections

“…In other studies, the two techniques were considered equivalent [9,12,22] or complementary [23]. Finally, in one report the roll-plate technique proved to be better than sonication for the detection of bacteria in long-term tunnelled CVCs [24].…”

Innovative Strategies for Preventing Central-Line Associated Infections

“…When there is suspicion of CRBSI and the catheter has been removed, it is recommended to perform a catheter tip culture by the roll plate technique (≥15 cfu/plate) for short-term catheters (introducer tip for pulmonary artery catheters) [19,20]. Also, qualitative cultures of the port reservoir contents, in addition to the catheter tip should be done if a venous access subcutaneous port is present [21].…”