Central line infections

OVERVIEW

A central line-associated bloodstream infection (CLABSI) is a laboratory-confirmed bloodstream infection (BSI) in a patient who had a central line within the 48 hour period before the development of the BSI, and that is not related to an infection at another site.

  • In Australian and New Zealand intensive care units (ICUs) the rate of CLABSI should be <1/1000 line days
  • the rate of CLABSI can be considered an indirect marker of quality of care
  • ANZICS Guidelines (2012) include recommendations for the prevention of CLABSI

DEFINITIONS

Central line infection

  • Central line infection can be local (e.g. phlebitis) or systemic (e.g. CLABSI)

Central line

  • A central line is  an intravascular access device or catheter that terminates at or close to the heart or in one of the great vessels
  • The line maybe used for infusion, or haemodynamic monitoring and may be inserted centrally or peripherally (i.e. PICC line)

Catheter-related bloodstream infection (CRBSI)

  • bloodstream infection attributed to an intravascular catheter by quantitative culture of the catheter tip or by differences in growth between catheter and peripheral venepuncture blood culture specimens
  • this definition is primarily used in research

Central Line Associated Blood Stream Infection (CLABSI)

  • A central line associated blood stream infection is a laboratory-confirmed bloodstream infection (BSI) in a patient who had a central line within the 48 hour period before the development of the BSI, and that is not related to an infection at another site
  • used in non-research/ clinical settings
  • confirmation of CLABSI requires both a positive blood culture AND a collaborative clinical and microbiological review of the patient
  • There is no minimum period of time that the central line must be in place in order for the BSI to be considered central line-associated, but there must have been one within 48 hours of onset of infection
  • Implanted catheters (including portacaths) have the lowest risk for CLABSI

INCIDENCE

The most precise measure of the incidence is the incidence density, or incidence rate, which is the number of (first) infections that occur over the number of days that the line is in place (ie, line days)

  • The aim of the ANZICS CLABSI Prevention Project was to decrease Australian ICU CLABSI to <1/1000 line days
  • This is calculated asNumber of CLABSI x 1000/ Number of central line days

ASSESSMENT

Suspect CLABSI if evidence of SIRS in a patient with a central line, or one was present within 48h

  • assess exit site of CVC
  • assess for other sources of infection
  • assess for diagnostic criteria (see below)

DIAGNOSIS

CRBSI

  • same organism recovered from percutaneous blood culture and from quantitative (>15 colony-forming units) culture of the catheter tip (paired quantitative culture)
  • same organism recovered from a percutaneous and a catheter lumen blood culture, with growth detected 2 hours sooner (ie, 2 hours less incubation) in the latter (time to positivity)
  • same organism recovered from a quantitative percutaneous and a catheter lumen blood culture, with 3-fold greater colony count in the latter
  • genetic analysis of bacteria (peripheral versus from CVC)
  • endoluminal swab

CLABSI case definition (must meet one of three criteria):

  • Criterion 1:
    • Patient has a recognised pathogen cultured from one or more blood cultures AND
    • Organism cultured from blood is not related to an infection at another site
  • Criterion 2:
    • Patient has at least one of the following signs or symptoms: fever (>38°C), chills, or hypotension AND
    • Signs and symptoms and positive laboratory results are not related to an infection at another site AND
    • Common skin contaminant* is cultured from two or more blood cultures drawn on separate occasions
  • Criterion 3:
    • Patient 1 year of age or under has at least one of the following signs or symptoms: fever (>38°C core) hypothermia (less than 36°C core), apnoea, or bradycardia, AND
    • Signs and symptoms and positive laboratory results are not related to an infection at another site AND
    • Common skin contaminant* is cultured from two or more blood cultures drawn on separate occasions

PATHOGENESIS

Mechanisms

  • contamination during insertion
  • contamination of insertion site (post-insertion)
  • contamination of infused substance
  • subsequent contamination due to breaking of sterile connection (multi-flow, 3 way taps)
  • subsequent contamination from systemic infection

Bacterial migration

  • migration of microbes from catheter-skin interface extralumenally to the catheter-vessel interface (most common situation)
  • migration from hub intra-lumenally

Insertion site

  • subclavian generally preferred
  • higher rates of CLABSI with internal jugular access in tracheostomy patients
  • some studies suggest greater colonisation and infection of central lines at the femoral site followed by the jugular
  • femoral access may have higher rates of CLABSI in patients with a high BMI
  • A 2012 meta-analysis found that femoral access did not have higher rates of CLABSI (MArik et al, 2012)

RISK FACTORS

Patient-related factors

  • increasing severity of illness
  • granulocytopenia
  • compromised integrity of the skin
  • presence of distant infection

Catheter-related factors

  • catheter type
  • number of lumens
  • duration in situ
  •  antimicrobial coating

Operator factors

  • breaks in aseptic technique during placement and maintenance
  • frequent catheter access

CAUSATIVE ORGANISMS

Recognised pathogens include:

  • Staphylococci (S. aureus, coagulase negatives)
  • Gram negative bacteria (e.g. E. coli, Pseudomonas spp, Klebsiella spp)
  •  Enterococcus spp
  • Candida spp

Examples of common skin contaminants:

  • diphtheroids [Corynebacterium spp]
  • Bacillus [not B. anthracis] spp
  • Propionibacterium spp
  • Coagulase-negative staphylococci [including S. epidermidis]
  • Viridans group streptococci
  • Aerococcus spp
  • Micrococcus spp

PREVENTION

Pronovost et al (2006) published a prospective cohort study in NEJM that showed a significant decrease in CRBSI if the following were carried out as a bundle of care:

  • hand washing
  • full barrier precautions during insertion of CVL’s (mask, hair cap, sterile gloves, gown and full-sized sterile drape)
  • clean skin with chlorhexidine (2%) and allow to dry
  • avoid femoral site if possible
  • removing unnecessary catheters early
  • education
  • CVC cart
  • checklist for infection control
  • providers stopped if practices were not adhered to (not in emergencies)
  • removal of catheters discussed daily at rounds
  • catheter-related bloodstream infection rates/month communicated to teams

ANZICS Central Line Insertion & Maintenance Guideline (2012) recommendations:

  • Insertion site
    • SCV preferred, then IJ then femoral
  • Central line selection
    • minimise the number of lumens, lipid-containing fluids require dedicated lumens, select patients should have antibiotic-coated CVLs (chlorhexidine and silver sulphadiazine coated lines (not silver-only or rifampicin and minocycline lines): high CLABSI rate despite prevention protocol compliance,  >7 day duration, immunocompromise or burns)
  • Preparation
    • dedicated trolley and packs
  • Aseptic technique and maximal barrier precautions
    • no hand scrubbing with a brush, clip hair do not shave, ≥0.5% chlorhexidine in 70% alcohol preferred but if contraindicated use 5% povidone iodine in alcohol, cover whole patient with drapes, stop if sterility is compromised, handle ends of administration sets with gauze soaked in chlorhexidine
  • Central line review
    • performed daily, look for: signs of local infection at the insertion site (tenderness, pain, redness, swelling), signs of systemic infection, suture and dressing integrity, catheter position, patency of lumens and ongoing need – remove as soon as possible
  • Central line replacement
    • replace in  <24 hours if suspicion of suboptimal sterility (e.g. emergency insertion), avoid rewiring (consider if: risks outweighed e.g. burns, coagulopathy, <72h since CVL inserted, and no evidence of CLABSI, remove within 24 if lumen blocked)
  • Securement devices
    • fix adequately to prevent movement, suture-less securement devices (unclear benefit in CVLs, reduce CLABSI in PICC lines)
  • Dressings
    • Sterile, transparent semipermeable dressings allow visualisation of the insertion site, and an additional anchor if properly maintained. Use sterile gauze if bloody or wet, changes dressings regularly (7 days for standard dressings, 2 days for gauze)
  • Central line maintenance
    • hand hygiene and swab hub, use chlorhex swabs
  • Other considerations
    • chlorhexidine baths (no difference in a study where the underlying CLABSI rate was <5/1000)
    • avoid prolonged connections of solutions prone to contamination (e.g TPN, propofol)
    • decrease breaks in system (change administration sets every 96 hrs)
    • clean injection ports before accessing (chlorhexidine better ethanol)
    • use alternate routes for blood transfusion

O’Grady et al (2011) published the HICPAC Guidelines for the prevention of intravascular catheter-related infections, which included the following recommendations:

  • Limit insertion to trained personnel
  • Avoid use of the femoral vein
  • Use subclavian vein in lieu of the internal jugular or femoral vein depending upon risk of injury during insertion
  • Use a central venous catheter with the minimum number of lumens required for patient care
  • Complete hand hygiene prior to insertion and assessment or dressing change of catheter exit site
  • Prepare clean skin of insertion site with >0.5% chlorhexidine plus alcohol
  • Do not administer systemic antimicrobial prophylaxis
  • Use a chlorhexidene/silver sulfadiazine or a minocycline-/rifampin-impregnated central venous catheters when the local rate of central line-associated bloodstream infection is not declining despite
    • Education of optimal insertion and maintenance practices
    • Use of maximum sterile barrier precautions during insertion
    • Use of >0.5% chlorhexidene plus alcohol for preparation of skin before insertion
  • Use maximum sterile barrier precautions, including cap, mask, sterile gown, sterile gloves, and a sterile full-body drape for insertion and during guide wire exchange
    • Don new sterile gloves before inserting new catheter during exchange over guide wire
  • Place semipermeable transparent or gauze dressing over insertion site
    • Gauze favored when exit site is bloody or moist
    • Restrict application of antimicrobial ointment to exit sites of hemodialysis catheters and only then when approved for use by catheter manufacturer
    • Assess exit site daily
      • Visually for transparent dressings
      • By palpation for gauze dressings (remove for visual inspection if tender)
    • Exchange exit site dressing whenever damp, loosened, or soiled
      • Replace gauze dressings every 2 days
      • Replace semipermeable transparent dressings every 7 days
  • When adherence to aseptic technique was compromised during insertion, replace the catheter as soon as possible
  • Do not routinely replace central venous catheters to prevent infection
  • Remove any intravascular catheter as soon as it is no longer required for patient care

References and Links

Journal articles

  • Frasca D, Dahyot-Fizelier C, Mimoz O. Prevention of central venouscatheter-related infection in the intensive care unit. Crit Care. 2010;14(2):212.PMC2887105.
  • Han Z, Liang SY, Marschall J. Current strategies for the prevention andmanagement of central line-associated bloodstream infections. Infect Drug Resist.2010;3:147-63. PMC3108742.
  • Marik PE, Flemmer M, Harrison W. The risk of catheter-related bloodstreaminfection with femoral venous catheters as compared to subclavian and internaljugular venous catheters: a systematic review of the literature andmeta-analysis. Crit Care Med. 2012 Aug;40(8):2479-85. PMID: 22809915.
  • O’Grady NP, et al; Healthcare Infection Control Practices Advisory Committee (HICPAC). Guidelines for the prevention of intravascular catheter-related infections. Clin Infect Dis. 2011 May;52(9):e162-93. PMC3106269.
  • Pronovost P, Needham D, Berenholtz S, Sinopoli D, Chu H, Cosgrove S, Sexton B,Hyzy R, Welsh R, Roth G, Bander J, Kepros J, Goeschel C. An intervention todecrease catheter-related bloodstream infections in the ICU. N Engl J Med. 2006Dec 28;355(26):2725-32. Erratum in: N Engl J Med. 2007 Jun 21;356(25):2660. PMID: 17192537
  • Shah H, Bosch W, Thompson KM, Hellinger WC. Intravascular catheter-related bloodstream infection. Neurohospitalist. 2013 Jul;3(3):144-51. PMC3805442.
  • Timsit JF, Dubois Y, Minet C, Bonadona A, Lugosi M, Ara-Somohano C,Hamidfar-Roy R, Schwebel C. New materials and devices for preventingcatheter-related infections. Ann Intensive Care. 2011 Aug 18;1:34. PMC3170570.

FOAM and web resources


CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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