Diagnosis Of Catheter-related Sepsis Research Articles

Segmental percutaneous central venous line cultures for diagnosis of catheter-related sepsis

ObjectiveCulture of percutaneous central venous line (PCVL) segments may assist the diagnosis of line colonisation and catheter-related sepsis (CRS). The authors aimed to determine if the diagnosis of CRS and...

New tools in diagnosing catheter-related infections.

Clinical criteria alone are insufficient to allow a diagnosis of intravascular catheter-related sepsis (CRS). A definite diagnosis of CRS usually requires removal of the catheter for quantitative catheter tip culture. However, only about 15-25% of central venous catheters (CVC) removed because infection is suspected actually prove to be infected, and the diagnosis is always retrospective. Other diagnostic tests, such as differential quantitative blood cultures from samples taken simultaneously from the catheter and a peripheral vein, have been proposed to avoid unjustified removal of the catheter and the potential risks associated with the placement of a new catheter at a new site: a central-to-peripheral blood culture colony count ratio of 5:1 to 10:1 is considered indicative of CRS. Despite its high specificity, the latter diagnostic technique is not routinely used in clinical practice because of its complexity and cost. The measurement of the differential time to positivity between hub blood (taken from the catheter port) and peripheral blood cultures might be a reliable tool facilitating the diagnosis of CRS in situ. In an in vitro study, we found a strong relationship between the inoculum size of various microorganisms and the time to positivity of cultures. When the times to positivity of cultures of blood taken simultaneously from central and peripheral veins in patients with and without CRS were examined, we found that earlier positivity of central vs peripheral vein blood cultures was highly correlated with CRS. Using a cut-off value of +120 min, the "differential time to positivity" of the paired blood samples, defined as time to positivity of the peripheral blood minus that of the hub blood culture, had 91% specificity and 94% sensitivity for the diagnosis of CRS. This method may be coupled with other techniques that have high negative predictive value, such as skin cultures at the catheter exit site. This diagnostic test can be proposed for routine clinical practice in most hospitals using automatic devices for blood cultures positivity detection. Endoluminal brushing of the catheter is considered sensitive and specific for the diagnosis of CRS, but the risk of embolisation or subsequent bacteraemia should be considered. Gram staining and the acridine-orange leucocyte cytospin test on through-catheter blood culture have been proposed for rapid diagnosis of CRS without catheter removal. The technique, which requires 100 microl catheter blood and the use of light and ultraviolet microscopy, is considered simple, rapid (30 min) and inexpensive. In conclusion, diagnostic tools such as paired blood cultures or Gram staining and the acridine-orange leucocyte cytospin test should allow a diagnosis of CRS without catheter removal in cancer patients.

Endoluminal brush technique in the diagnosis of catheter related sepsis (CRS)

European Society of Anaesthesiologists; 8th Annual Meeting with the Austrian International Congress; Vienna, Austria, 1-4 April 2000

The use of continuous monitoring blood culture systems in the diagnosis of catheter related sepsis.

AIM: To assess whether the information provided by automated continuous monitoring blood culture systems could aid in the diagnosis of catheter related sepsis. METHODS: Serial dilutions of a strain of...

P.77 Economic evaluation of the use of endoluminal brushes in the diagnosis of catheter related sepsis (CRS) in a surgical unit

P.77 Economic evaluation of the use of endoluminal brushes in the diagnosis of catheter related sepsis (CRS) in a surgical unit

Evaluation of a novel endoluminal brush method for in situ diagnosis of catheter related sepsis.

AIMS: To determine the accuracy of a novel endoluminal brush method for the diagnosis of catheter related sepsis (CRS), which is performed in situ and hence does not require line...

Central venous catheter-related sepsis in a cohort of 366 hospitalised patients.

Five hundred two central venous catheters inserted in 366 patients were evaluated prospectively over a one-year period to determine the frequency and risk factors associated with catheter-related sepsis. For study purposes, in cases in which catheter infection was suspected but the initial blood cultures were negative, the catheters were replaced by guidewire technique; otherwise, the catheters were routinely changed after 21 days by guidewire technique. A catheter-related infection was suspected in 190 cases (190/502, 38%). A diagnosis of catheter-related sepsis was established in 50 patients, which represents 10% of the total number of lines (502). Over a total of 6428 days of catheter use, the infection rate was 0.8 cases of sepsis per 100 catheter-days. Staphylococcus epidermidis, Staphylococcus aureus, and Candida spp. were the most frequently isolated aetiological agents of sepsis. On univariate analysis, six variables affecting the rate of catheter-related sepsis were identified: neutropenia for more than eight days (p < 0.001); AIDS (p < 0.001); haematological malignancy (p < 0.001); administration of total parenteral nutrition (p = 0.001); duration of site use (p = 0.04); and high APACHE II score (p = 0.04). The logistic regression analysis revealed that AIDS and haematological malignancies were independent risk factors of catheter-related sepsis. Catheter replacement over a guidewire was no more likely to be associated with sepsis than was percutaneous catheter insertion. In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases of suspected infection it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than to remove the catheter immediately. Such a policy may help reduce the number of unnecessary catheter removals.

Value of differential quantitative blood cultures in the diagnosis of catheter-related sepsis.

A prospective study was performed to assess the value of differential quantitative blood cultures in the diagnosis of catheter-related sepsis when this condition is suspected on clinical grounds and to establish a reliable discriminative value for application without removal of the inserted catheter. A total of 107 central venous catheters from 64 patients were used for the study. Blood was obtained simultaneously through the suspected infected device and from a peripheral venipuncture. The catheter was removed and its tip cultured semiquantitatively. Catheter-related sepsis occurred in 17 patients. Using as cut-off value a colony count fourfold higher in blood drawn through the catheter than in simultaneously drawn peripheral blood, a sensitivity of 94%, specificity of 100% and positive predictive value of 100% were obtained. A single bacterial count greater than 100 cfu/ml in the quantitative culture of the catheter blood specimen in the presence of a positive qualitative peripheral blood culture of the same organism was also highly suggestive of catheter-related sepsis. Differential quantitative blood culture is a reliable method for the diagnosis of catheter-associated sepsis without catheter removal.

Diagnosis of Central Vein Catheter-Related Sepsis-Reply

We thannk Dr Collignon for his interest to our work,1and for the opportunity he gives us to clarify some points. The major aim of our study was to determine the critical level of a simplified quantitative culture technique of catheter tips that would accurately identify clinically significant catheter-related sepsis (CRS), whether bacteremic or not. We found that a cutoff of ≥103colony-forming units (CFUs) was adequate for this purpose, yielding a sensitivity and specificity for the diagnosis of CRS, both over 85%. Dr Collignon questions the use of the positivity of the catheter tip culture as one of the criteria for the diagnosis of CRS in our study. Clinical criteria alone cannot be used in such a study population with central vein catheterization. Besides, the knowledge of a bacterial growth from the catheter is obviously necessary for the interpretation of bacteremic episodes. If one is to ascribe

Diagnosis of Central Venous Catheter-Related Sepsis

The results of a simplified quantitative broth dilution quantitative tip culture (QTC) of 331 central venous catheters were compared with clinical data prospectively recorded in critically III patients to diagnose bacteremic or nonbacteremic catheter-related sepsis (CRS) (36 catheters), as opposed to contamination (42 catheters) or simple colonization from a distant septic focus (seven catheters). Thirty-five of 36 catheters associated with CRS yielded 10(3) colony-forming units per milliliter (CFU/mL) or more, and 3.8 X 10(2) Candida organisms grew from one. In contrast, 5 X 10(2) CFU/mL or less grew from 37 of 42 contaminated catheters. A QTC of 10(3) CFU/mL or more was 97.5% sensitive and 88% specific for the diagnosis of CRS. The QTC appeared especially useful for the diagnosis of CRS secondary to blood-borne seeding of catheters, or associated with coagulase-negative staphylococci.