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Updated chapter to come.
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Epidemiology and Microbiology
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Definitions2
Catheter colonization: Significant growth of a microorganism in a quantitative or semiquantitative culture of the catheter tip, subcutaneous catheter segment, or catheter hub
Exit-site infection: Erythema, induration, and/or tenderness within 2 cm of the catheter exit site; may be associated with other signs and symptoms of infection, such as fever or pus emerging from the exit site with or without concomitant bloodstream infections
Tunnel infection: Tenderness, erythema, and/or induration within 12 cm from the catheter exit site along the subcutaneous tract of a tunneled catheter (eg, Hickman or Broviac) with or without concomitant bloodstream infections
Pocket infection: Infected fluid in the subcutaneous pocket of a totally implanted intravascular device; often associated with tenderness, erythema, and/or induration over the pocket; spontaneous rupture and drainage, or necrosis of the overlying skin, with or without concomitant bloodstream infection, may also occur
Catheter-related bloodstream infection: Bacteremia or fungemia in a patient who has an intravascular device and 1 positive result from culture of blood samples from the peripheral vein, clinical manifestations of infection (eg, fever, chills, and/or hypotension), and no apparent source for bloodstream infection (except for the catheter). One of the following should be present: a positive result of semiquantitative (>15 CFU per catheter segment) or quantitative (>102 CFU per catheter segment) catheter culture, whereby the same organism (species and antibiogram) is isolated from a catheter segment and a peripheral blood sample; simultaneous quantitative cultures of blood samples with a ratio of >5:1 (central venous catheter [CVC] versus peripheral catheter); differential time to positivity (ie, a positive result of culture from a CVC is obtained at least 2 hours earlier than a positive result from a culture from peripheral blood)
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Diagnosis
Blood cultures
Clinical findings for establishing the diagnosis of catheter-related infection are unreliable because of poor sensitivity and specificity
When catheter infection is suspected, 2 sets of blood cultures should be sent with at least 1 drawn percutaneously2
Paired quantitative or qualitative blood cultures with continuously monitored differential time to ...