Abstract
The convenience of obtaining blood specimens from intravascular catheters for routine laboratory tests makes them a tempting method for the collection of blood culture specimens (Krueger et al., 1981). However, this practice is controversial. A discouraging concern is that the proportion of false-positive results may increase (i.e. decrease of the specificity of the test in diagnosing true bacteraemia), resulting in unnecessary administration of costly and potentially toxic antibiotics to patients, and increased length of hospitalization, health care cost and antimicrobial resistance of micro-organisms (Bates et al., 1991; Bryant & Strand, 1987; Everts et al., 2001; Vaisanen et al., 1985). In addition, frequent manipulations of the intravascular devices may increase the potential for microbial colonization of the device and subsequently development of infection (O'Grady et al., 2002).
However, there is evidence deriving from published studies that blood cultures obtained from central vascular catheters are sufficiently sensitive for detection of bloodstream infection (Felices et al., 1979; Tonnesen et al., 1976; Wormser et al., 1990). Given their convenience, a clinically important question arises whether blood cultures obtained from intravascular catheters have such test characteristics (sensitivity, specificity, and positive and negative predictive value) in diagnosing bacteraemia to be considered equivalent or even better than blood cultures obtained by peripheral venipuncture. Thus we conducted a quantitative systematic review to critically evaluate the published data regarding performance characteristics of blood cultures obtained through intravascular devices compared to peripheral venipuncture.