Medline ® Abstracts for References 1,2
of 'Epidemiology, pathogenesis, and microbiology of intravascular catheter infections'
Microbiological factors influencing the outcome of nosocomial bloodstream infections: a 6-year validated, population-based model.
Pittet D, Li N, Woolson RF, Wenzel RP
Clin Infect Dis. 1997;24(6):1068.
All patients (n = 1,745) with nosocomial bloodstream infection identified between 1986 and 1991 at a single 900-bed tertiary care hospital were studied to identify microbiological factors independently associated with mortality due to the infection. Patients were identified by prospective, case-based surveillance and positive blood cultures. Mortality rates were examined for secular trends. Prognostic factors were determined with use of univariate and multivariate analyses, and both derivation and validation sets were used. A total of 1,745 patients developed nosocomial bloodstream infection. The 28-day crude mortality was 22%, and crude in-hospital mortality was 35%. Factors independently (all P<.05) associated with increased 28-day mortality rates were older age, longer length of hospital stay before bloodstream infection, and a diagnosis of cancer or disease of the digestive system. After adjustment for major confounders, Candida species were the only organisms independently influencing the outcome of nosocomial bloodstream infection (odds ratio [OR]for mortality = 1.84; 95% confidence interval [CI], 1.22-2.76; P = .0035). The two additional microbiological factors independently associated with increased mortality were pneumonia as a source of secondary infection (OR = 2.74; 95% CI, 1.87-4.00; P<.0001) and polymicrobial infection (OR = 1.68; 95% CI, 1.22-2.32; P = .0014). Our data suggest that microbiological factors independently affect the outcome of nosocomial bloodstream infection.
Division of General Medicine, Clinical Epidemiology and Health Services Research, University of Iowa College of Medicine, Iowa City, USA.
The risk of bloodstream infection in adults with different intravascular devices: a systematic review of 200 published prospective studies.
Maki DG, Kluger DM, Crnich CJ
Mayo Clin Proc. 2006;81(9):1159.
OBJECTIVE: To better understand the absolute and relative risks of bloodstream Infection (BSI) associated with the various types of intravascular devices (IVDs), we analyzed 200 published studies of adults In which every device in the study population was prospectively evaluated for evidence of associated infection and microbiologically based criteria were used to define IVD-related BSI.
METHODS: English-language reports of prospective studies of adults published between January 1, 1966, and July 1, 2005, were identified by MEDLINE search using the following general search strategy: bacteremla [Medical Subject Heading, MeSH]OR septicemia [MeSH]OR bloodstream Infection AND the specific type of intravascular device (e.g., central venous port). Mean rates of IVD-related BSI were calculated from pooled data for each type of device and expressed as BSIs per 100 IVDs (%) and per 1000 IVD days.
RESULTS: Point incidence rates of IVD-related BSI were lowest with peripheral Intravenous catheters (0.1%, 0.5 per 1000 IVD-days) and midline catheters (0.4%, 0.2 per 1000 catheter-days). Far higher rates were seen with short-term noncuffed and nonmedicated central venous catheters (CVCs) (4.4%, 2.7 per 1000 catheter-days). Arterial catheters used for hemodynamic monitoring (0.8%, 1.7 per 1000 catheter-days) and peripherally inserted central catheters used in hospitalized patients (2.4%, 2.1 per 1000 catheter-days) posed risks approaching those seen with short-term conventional CVCs used in the Intensive care unit. Surgically implanted long-term central venous devices--cuffed and tunneled catheters (22.5%, 1.6 per 1000 IVD-days) and central venous ports (3.6%, 0.1 per 1000 IVD-days)--appear to have high rates of Infection when risk Is expressed as BSIs per 100 IVDs but actually pose much lower risk when rates are expressed per 1000 IVD-days. The use of cuffed and tunneled dual lumen CVCs rather than noncuffed, nontunneled catheters for temporary hemodlalysis and novel preventive technologies, such as CVCs with anti-infective surfaces, was associated with considerably lower rates of catheter-related BSI.
CONCLUSIONS: Expressing risk of IVD-related BSI per 1000 IVD-days rather than BSIs per 100 IVDs allows for more meaningful estimates of risk. These data, based on prospective studies In which every IVD in the study cohort was analyzed for evidence of infection by microbiologically based criteria, show that all types of IVDs pose a risk of IVD-related BSI and can be used for benchmarking rates of infection caused by the various types of IVDs In use at the present time. Since almost all the national effort and progress to date to reduce the risk of IVD-related Infection have focused on short-term noncuffed CVCs used in Intensive care units, Infection control programs must now strive to consistently apply essential control measures and preventive technologies with all types of IVDs.
Section of Infectious Diseases, Department of Medicine, University of Wisconsin Medical School, USA. firstname.lastname@example.org