Comparison of utility of blood cultures from intravascular catheters and peripheral veins: a systematic review and decision analysis

Abstract

Blood cultures are sometimes obtained from intravascular catheters for convenience. However, there is controversy regarding this practice. The authors compared the diagnostic test characteristics of blood cultures obtained from intravascular catheters and peripheral veins. Relevant studies for inclusion in this review were identified through PubMed (January 1970-October 2005 and the Cochrane Central Register of Controlled Trials. Studies that reported clear definitions of true bacteraemia were included in the analysis. Two reviewers independently extracted the data. Six studies were included in the analysis, providing data for 2677 pairs of blood cultures obtained from an intravascular catheter and a peripheral venipuncture. A culture obtained from an intravascular catheter was found to be a diagnostic test for bacteraemia with better sensitivity (OR 1.85, 95 % CI 1.14-2.99, fixed effects model) and better negative predictive value (almost with statistical significance) (OR 1.55, 95 % CI 0.999"2.39, fixed effects model) but with less specificity (OR 0.33, 95 % CI 0.18-0.59, random effects model) and lower positive predictive value (OR 0.41, 95 % CI 0.23-0.76, random effects model) compared to a culture taken by peripheral venipuncture. In a group of 1000 patients, eight additional patients with true bacteraemia would be identified and 59 falsely diagnosed as having bacteraemia by a blood culture obtained from an intravascular catheter compared to results of the peripheral blood culture. Given the consequences of undertreating patients with bacteraemia, the authors believe that, based on the available evidence, at least one blood culture should be obtained from the intravascular catheter.

Blood Cultures at Central Line Insertion in the Intensive Care Unit: Comparison with Peripheral Venipuncture

“…Such cultures are unable to reflect reliably the presence or absence of true bacteremia (12,15,25,37) and often represent line colonization rather than patient infection (15). Furthermore, the disinfection of these devices may be more difficult than the disinfection of skin before blood cultures are drawn (37).…”

Blood Cultures and Central Catheters: Is the "Easiest Way" Best Practice?

“…First, if peripheral access is not possible, 2 blood samples may be collected through different lumens (when available) of the same central catheter, although this technique may be associated with higher false-positive rates. [2][3][4] Another exception to collecting blood samples for culture via venipuncture is patients with central catheters who have no obvious source of infection and thus may have a catheter-related bloodstream infection. In these cases, 1 set of samples should be obtained peripherally and the second set should be obtained through the distal lumen of the catheter suspected to be infected (as determined by catheter duration, especially >48 hours, or the presence of purulence or cellulitis at the insertion site) 8,10 by using the steps outlined in Table 3.…”

Utility of peripheral blood cultures in bacteremic pediatric cancer patients with a central line

“…Studies that describe the proportion of episodes of true bloodstream infection that are only positive on peripheral culture [modified from[5]]NA not available, ICU intensive care unit, Hem/Onc hematology/oncology, CVC central venous catheter uation of the practice of routine peripheral cultures in addition to CVC cultures at the onset of fever for children with cancer who are not already receiving broad-spectrum antibiotics.…”