Intravascular catheter-related infections

CDC definition of central line-associated bloodstream infections (CLABSIs)a. IDSA 2009 definition of intravascular catheter-related bloodstream infection (CRBSI)
Patient has a CVC that was in place for > 2 days and CVC was present on the date of the LCBI or the day before. In addition, the LCBI must not be related to an infection at another site and must meet one of the following criteria:

  • A recognized pathogen cultured from one or more blood cultures
  • A common skin contaminant cultured from two or more blood cultures drawn on separate occasions within 2 days of each other and at least one of the following clinical signs or symptoms: fever (>38°C), chills, or hypotension and signs and symptoms
  • For patient 1 year of age, a common skin contaminant is cultured from two or more blood cultures drawn on separate occasions within 2 days of each other and the patient has at least one of the following clinical signs or symptoms: fever (>38°C core), hypothermia (<36°C core), apnea, or bradycardia

  • Diagnostic method sparing the catheter: A definite CRBSI requires one of the following to be present:

    • The same organism is cultured from two simultaneous quantitative blood cultures drawn from the catheter and peripheral site with a CVC/peripheral colony count ratio 3:1
    • The differential time to positivity of at least 2 hours (microbial growth from blood drawn from a catheter is detected at least 2 hours before microbial growth from blood drawn from the peripheral site)

  • Diagnostic method implicating catheter removal:

    A definite CRBSI requires that the same organism is cultured from at least one percutaneous blood culture and from a culture of the catheter tip (in semiquantitative catheter culture 15 CFU per catheter segment, or in quantitative catheter culture 102 CFU per catheter segment)

a CDC definition of CLABSI does not require catheter removal.

Abbreviations: CVC = central venous catheter; LCBI = laboratory-confirmed bloodstream infection.

The CLABSI definition may lack specifity. For example, in some cancer patients, particularly those with compromised mucosal barrier, some laboratory-confirmed bloodstream infections (LCBI) that are labeled CLABSI may have resulted from bacteria translocation from the gastrointestinal tract. To distinguish LCBI related to central lines from those due to inapparent sources, the CDC recently developed a new definition termed mucosal barrier injury LCBI (MBI-LCBI) whereby a recognized intestinal organism is cultured from the blood of patients with clues to mucosal barrier injury such as gastrointestinal graft-versus-host disease, diarrhea, or neutropenia.

CRBSI as defined by the IDSA more specifically identifies the CVC as the source of the bacteremia.

Preventive strategies

Recent guidelines for the prevention of intravascular catheter-related infections emphasize the importance of educating and training healthcare personnel who insert and maintain catheters. CVCs should only be used when medically necessary and should be removed as soon as possible. The subclavian site is preferred for nontunneled CVC. Femoral sites should be avoided in adult patients.

Hand hygiene with soap and water or alcohol-based rubs should be performed before and after inserting, replacing, accessing, or dressing a CVC. The use of maximal sterile barrier precautions that includes the use of a cap, mask, sterile gown, and a sterile full body drape is recommended for CVC insertion.

Skin cleansing using chlorhexidine preparation before CVC insertion reduces the risk of CLABSI. Alternatively, tincture of iodine or 70% alcohol could be used when chlorhexidine is contraindicated.

Chlorhexidine impregnated sponge dressing may decrease CVC colonization.

Currently, the CDC guidelines for the prevention of intravascular catheter-related infections recommend the use of antimicrobial CVC particularly if the CVC is expected to remain in place for more than 5 days, if rates of CLABSI remain elevated despite the implementation of aseptic techniques including maximal sterile barrier precautions. A meta-analysis showed better efficacy of vascular catheters impregnated with the antiseptics chlorhexidine and sulfadiazine in preventing CLABSI when compared with nonimpregnated catheters. Several meta-analyses demonstrated the effectiveness of antimicrobial catheters impregnated with CHSS or M-R. Catheters coated with minocycline and rifampin demonstrated a lower rate of catheter colonization and CLABSI when compared with uncoated catheters. Furthermore, when compared with antiseptic impregnated catheters, antibiotic-coated catheters lowered the rate of infection 12-fold.

Dressing choice may vary: sterile, transparemt dressing allows visual monitoring of the CVC and requires less frequent changes than sterile gauze.

Regular monitoring of CVC by visual inspection or by palpation through the dressing is recommended.

Antimicrobial catheter lock and flush solutions are recommended particularly in patients who have long-term catheters and a history of multiple CLABSIs.

Catheter lock solution technique consists of flushing the catheter lumen and then filling it with 1 to 3 mL of a combination of an anticoagulant plus an antimicrobial agent. The lock dwell time in the lumen of the CVC may vary from 2 to 12 hours depending on the solution. Although heparin has become widely used as an antithrombotic agent to maintain catheter patency, it has been shown to enhance staphylococcal biofilm formation at the concentration of 1000 U/mL used in catheter locks.

Antimicrobial agents used include vancomycin, gentamicin, ciprofloxacin, cefazolin, erythromycin, nafcillin, ceftriaxone, clindamycin, fluconazole, and amphotericin B. Vancomycin in combination with heparin as a daily flushing solution of tunneled CVCs has significantly decreased the frequency of catheter-related bacteremia caused by vancomycin-susceptible microorganisms.

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Jun 18, 2016 | Posted by in INFECTIOUS DISEASE | Comments Off on Intravascular catheter-related infections
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