Question 8 from the first paper of 2006 and Question 2 from the second paper of 2000 ask for a list of preventative strategies, so as to protect your patients from the evils of CLABSI. On a slightly different note, Question 10 from the first paper of 2017 was a more administrative-oriented question on how one might fashion a departmental policy to investigate and manage and out-of-control CLABSI rate

Below is a summary of recent guidelines and evidence, scraped together from the following sources:

Oh's Manual has a section on "line sepsis" (page 730 of the 7th edition) nested within Rishi and Dhillon's "Nosocomial Infections" chapter. Though brief, the section contains several important definitions worth knowing.

For instance:

Central line colonisation:

The growth of >15 colony-forming units (semiquantitative) or 103 (quantitative) from a proximal or distal catheter segment, in the absence of accompanying clinical symptoms and signs.

Central line associated blood stream infection:

Isolation of the same organism from the catheter segment as from a peripheral blood culture in a patient with signs of infection and in the absence of another source.

Rishi and Dhillon quote this massive 2006 review to produce the following infection risk profile:

Risk of infection per 1000 catheter days:

Peripheral cannula 0.5
Arterial line: 1.7
Normal central line 2.7
Tunneled CVC 1.6
PICC 1.1
PA catheter 3.7

Factors associated with increased risk of central line infection

  • Femoral site (as opposed to subclavian)
  • Non-tunnelled line (tunneling is protective)
  • Plain uncoated catheter
    • Antibacterial coating reduces risk of infection
    • Antiseptic coating reduces the risk of colonisation
  • Multiple lumens
  • Frequent line access
  • Frequent dressing changes (or very infrequent)
  • Insertion by inexperienced operator

Mechanisms of central line infection

  • Contamination during insertion
    • Unclean CVC being inserted with a substandard sterile technique
    • "Re-wiring" of an old line, rather than the insertion of a new line
  • Contamination of insertion site after insertion
    • Use of contaminated site, eg. groin
      • Even subclavian lines can get infected if the patient' head hangs over them, and a stream of drool is constantly washing over the dressing.
    • Poor care for dressings
    • Use of solutions prone to contamination (eg. propofol, lipid or TPN)
  • Contamination of lumen by breaking of sterile line connection
    • Poor line changing and port handling technique (one is supposed to use chlorhexidine-soaked gauze)
  • Haematogenous contamination of intravascular portion
    • Antimicrobial-impregnanted catheters are supposed to prevent this from happening
    • One may wish to be proactive about treating bacteraemia from organisms which are known to colonise plastic.

Prevention of central line associated blood stream infections:

  • Intelligent decisionmaking regarding the indication for CVC insertion
  • Use subclavian lines.
  • Minimum number of lumens.
  • Use of dedicated lumens for lipid infusions.
  • Immunosuppressed patients or those with burns should have antibiotic-coated lines.
  • For insertion, use aseptic technique and maximal barrier precautions.
  • 0.5% chlorhexidine in 70% alcohol is the preferred cleaning agent.
  • Handle ends of administration sets with gauze soaked in chlorhexidine.
  • Review the line site daily.
  • Remove the line as soon as possible.
  • Change lines early - however, there is no evidence for how many days one can safely wait. Oh's Manual recommends that "there is no indication for routine CVC line changing based on catheter days".
  • Sterile, transparent semipermeable dressings
  • Change dressings regularly (every 7 days for standard dressings)

Positive blood cultures from the CVC

So, your CVC culture is positive. The meaning of positive CVC cultures is discussed in full in a separate summary article. In brief:

Positive cultures collected from the CVC could mean one of three things:

  • CVC is colonised by organisms which are benign and doing no harm; in fact 15-25% of CVCs are colonised (usually by coagulase-negative staph) and the patients are fine, without any features of infection.
  • CVC is colonised by organisms which are causing a clinically significant bacteraemia.
  • CVC may still be colonised, but the culture grew organisms representing a systemic bacteraemia which did not originate in the CVC.
Organisms which Usually Represent "True" Bacteraemia:
  • Staphylococcus aureus
  • Streptococcus pneumoniae
  • Streptococcus pyogenes
  • Streptococcus agalactiae
  • Escherichia coli
  • Enterobacteriaceae
  • Pseudomonas aeruginosa
  • Listeria monocytogenes
  • Neisseria meningitidis
  • Neisseria gonorrhoeae
  • Haemophilus influenzae
  • Bacteroides fragilis
  • Cryptococcus neoformans
  • Candida albicans
Organisms which Usually Represent CVC Colonisation:
  • Corynebacterium sp.
  • Bacillus sp. other than Bacillus anthracis
  • Propionibacterium acnes
  • Micrococcus sp.
  • Viridans group streptococci
  • Enterococci
  • Clostridium perfringens
  • Coagulase-negative staphylococci.
Risk factors for clinically significant S.epidermidis bacteraemia:
  • Anyone at risk of native valve endocarditis
  • Artifical valves
  • History of rheumatic heart disease
  • Immunosuppressed
  • Implated pacemaker, or any other surgical implant
  • Low birth infant
  • Elderly person (>65 years of age)

Management of central line associated blood stream infections:

  • Though the advice would have to be tailored to each specific scenario, some broad recommendations can be made:
    • 14 days of antibiotics IV is the standard.
    • Ideally, the infected line should be removed.
    • If the line is a Hickmans and there is a great interest in preserving it, one may atempt to "decontaminate" it by administering the antibiotics though its lumens.