Entries Tagged as 'J Med Microbiol'
Comparison of utility of blood cultures from intravascular catheters and peripheral veins: a systematic review and decision analysis.
J Med Microbiol. 2008 Jan;57(Pt 1):1-8
Authors: Falagas ME, Kazantzi MS, Bliziotis IA
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.
PMID: 18065660 [PubMed - indexed for MEDLINE]
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Tags: J Med Microbiol
A hospital-wide study of the impact of introducing a personal data assistant-augmented blood culture round.
J Med Microbiol. 2008 Jan;57(Pt 1):43-9
Authors: Inglis TJ, Hodge M, Ketharanathan S
Blood culture is the cornerstone of an established aetiological diagnosis of septicaemia. The automated blood culture systems used for this purpose have changed little in the last decade, and the clinical value of results depends on a variety of factors, including pre- and post-analytical variables. Growing scepticism over the value of blood culture results and pressure for the introduction of molecular detection systems have prompted a critical path analysis of pre-, peri- and post-analytical stages in the generation of positive blood culture results. The impact of a positive blood culture was studied in a teaching hospital for 12 months before and 12 months after the introduction of a microbiologist’s blood culture round. Active culture reporting via a blood culture ward round was supported by a personal data assistant database of contemporaneous laboratory and clinical data. Hospital occupancy and death register records were subsequently obtained through the State Government data linkage project. There was no evidence that faster laboratory generation of positive blood culture results, faster reporting of results or direct clinical interaction with the patient’s primary medical team reduced the risk of death in hospital. However, there was a threefold increase in the rate of death in hospital following a 1 day delay in collection of blood cultures after hospital admission (P=0.0010). The overall duration of hospital stay for patients with a positive blood culture fell by 2.5 days compared with the previous 12 month period (P=0.0003). The interval between the initial positive culture result and patient discharge fell by 2 days (P=0.0010). This difference was attributed to shorter overall admissions and shorter intervals between positive cultures containing Gram-positive cocci and subsequent patient discharge (P=0.0018). An increased mortality rate from community-acquired bacteraemic infections was associated with delayed culture collection, but not with a prolonged laboratory processing interval. Thus, the speed of conventional blood culture analysis and the form of clinical reporting have little direct effect on the clinical outcome of bacteraemia, but may contribute to a reduction in the length of hospital admission. Introduction of molecular identification tests, such as multiplex PCR methods, at the Gram-stain stage of blood culture is unlikely to affect the rate of death in hospital, but may reduce the length of hospital admission.
PMID: 18065666 [PubMed - indexed for MEDLINE]
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