Catheter Related Bloodstream Infections

Question 1

Which patients generally have central catheters inserted?

Answer 1

1. ICU patients
2. Haemodialysis
3. Chemotherapy

Question 2

What are some of the catheter related blood stream infections?

Answer 2

• catheter colonization
• phlebitis
• exit site infection (microbiological / clinical)
• tunnel infection
• pocket infections
• bloodstream infection (infusate / catheter related)

Question 3

How many patients in ICU have catheters inserted?

Answer 3

Catheters are an important “feature” of patients in ICU settings - 48% of patients in ICU have central catheters

Question 4

What are the effects of catheter related bloodstream infections?

Answer 4

• Increase morbidity
• High mortality (mortality associated with CRBSI = approx. 20%)
• Increase hospital stay by approx. 7 days
• Costly

Question 5

What is the most common organism associated with catheter related bloodstream infections?

Answer 5

Coagulase Negative Staphylococci (CNS)

Question 6

What are the three groups of organisms commonly implicated in catheter related bloodstream infections?

Answer 6

1. Gram positive organisms
2. Gram negative organisms
3. Fungi

Question 7

What are the gram positive organisms commonly implicated in catheter related bloodstream infections?

Answer 7

1. CNS
2. Staphylococcus aureus
3. Enterococcus faecalis / enterococcus faecium

Question 8

What are the gram negative organisms commonly implicated in catheter related bloodstream infections?

Answer 8

1. Enterobactericae (E. coli, K. pneumoniae, E. cloacae
2. Acinetobacter baumannii
3. Pseudomonas Aeruginosa
4. Burkholderia cepacia complex

Question 9

What are the fungal organisms commonly implicated in catheter related bloodstream infections?

Answer 9

Candida species (including C. albicans, C. parapsilosis, C. krusei, C. glabrata)

Question 10

What is the most common portal of entry in catheter related bloodstream infections?

Answer 10

Skin, during catheter insertion

Question 11

What is the second most common portal of entry in catheter related bloodstream infections?

Answer 11

Contamination of the catheter during manipulation by medical staff

Question 12

What are other portals of entry in catheter related bloodstream infections?

Answer 12

1. Haematogenous dissemination from a distal infected focus
2. Administration of infected infusates
3. Contaminated transducer kits, disinfectants and infusion lines

Question 13

Explain the pathogenesis of biofilm formation in catheter related bloodstream infections.

Answer 13

Catheter insertion - fibrin sheath develops around the catheter which promotes adherence of pathogens = biofilm

Question 14

Explain the pathogenesis of bloodstream infection in catheter related bloodstream infections.

Answer 14

Skin organisms migrate along the external surface of the catheter - colonize the distal intravascular tip - bloodstream infection.

Question 15

What is the most common cause of contamination of the device / catheter prior to insertion?

Answer 15

Extrinsic&raquo_space; Manufacturer

Question 16

What is considered a catheter related bloodstream infection in a patient?

Answer 16

• Bacteraemia / fungaemia
• In a patient who has an intravascular device
• > 1 positive blood culture result obtained from the peripheral vein
• Clinical manifestations of infection (e.g. fever, chills and / or hypotension)
• NO apparent source for bloodstream infection (with the exception of the catheter)

Question 17

One of the following three criteria must be met for the diagnosis of catheter related bloodstream infection to be made:

Answer 17

1. A positive result of semiquantitative or quantitative catheter culture + same organism (species) is isolated from from a catheter segment and a peripheral blood culture
2. Simultaneous quantitative cultures of blood with ratio of >3:1 cfu/ml blood (catheter vs. peripheral blood)
3. Differential time to positivity (growth in a culture of blood obtained through a catheter hub is detected by an automated system at least 2 hours earlier than a culture of simultaneously drawn blood of equal volume)

Question 18

What does a semiquantitative catheter culture mean?

Answer 18

Pathogens only taken from outside not inside of catheter. (roll-plate)

Question 19

What does a quantitative catheter culture mean?

Answer 19

Pathogens taken from outside and inside of catheter (broth)

Question 20

How are bloodstream infections differentiated from catheter colonization?

Answer 20

Higher from peripherally collected blood = bloodstream infection
Higher from catheter collected blood = colonization of the catheter

Question 21

How is catheter colonization defined?

Answer 21

1. Growth of >15 cfu from a 5-cm segment of the catheter tip by semiquantitative culture
2. Growth of 10^2 cfu from catheter by quantitative (sonication) broth culture

Question 22

What should be taken into consideration when deciding on the management of catheter related bloodstream infections?

Answer 22

1. Type of catheter
2. Severity of the illness
3. Complications present?
4. Likely pathogens associated with the infection

Question 23

What is generally done for initial management of catheter related bloodstream infections?

Answer 23

Antibiotics may be started empirically in severely ill patients - changed once catheter culture results are available

Question 24

What are special considerations in the management of CNS catheter related bloodstream infections: for uncomplicated infections?

Answer 24

Removal of catheter with close observation

Question 25

What are special considerations in the management of CNS catheter related bloodstream infections: for complicated infections / if there is presence of prosthetic material ?

Answer 25

Remove and treat for 5-7 days

Question 26

How long should a patient with A. Aureus catheter related bloodstream infection be treated for?

Answer 26

14 days of therapy if: 
- no evidence of endocarditis 
- non-diabetic 
- not immunocompromised 
- infected catheter removed 
- no prosthetic material 
- resolution of bacteremia and fever after 72 hours on antimicrobial therapy 
- no evidence of metastatic infection 
If any of the above apply, then 4-6 weeks of treatment

Question 27

What are special considerations in the management of gram negative bacteria catheter related bloodstream infections?

Answer 27

Remove catheter

Treat empirically

Question 28

What are special considerations in the management of candida catheter related bloodstream infections?

Answer 28

Prompt removal of catheter
Appropriate antifungal therapy
Dilated eye examination (retinitis)

Question 29

What are some of the potential complications of catheter related bloodstream infections?

Answer 29

1. Sepsis
2. Suppurative thrombophlebitis
3. Endocarditis
4. Persistent bloodstream infection
5. Osteomyelitis
6. Local catheter site infection
7. Metastatic infections

Question 30

What are some of the strategies that can be used to prevent catheter related bloodstream infections?

Answer 30

1. Hand hygiene
2. Aseptic technique
3. Barrier precautions (cap, mask, sterile gown, full body drape for insertion CVC - subclavian and jugular > femoral)
4. Skin preparations with antiseptic prior to catheter insertion
5. Catheter care ‘bundles’
6. Removal or replacement of catheters

Question 31

What is the definition of catheter colonization?

Answer 31

Significant growth of >1 microorganism in a quantitative or semiquantitative culture of the catheter tip, subcutaneous catheter segment, or catheter hub

Question 32

What is the definition of phlebitis?

Answer 32

Induration or erythema, warmth, and pain or tenderness along the tract of a catheterized or recently catheterized vein.

Question 33

What is the definition of microbiological exit site infection?

Answer 33

Exudate at catheter exit site yields a microorganism with or without concomitant bloodstream infection.

Question 34

What is the definition of clinical exit site infection?

Answer 34

Erythema, induration, and / or tenderness within 2 cm of the catheter exit site; may be associated with other signs and symptoms of infection e.g. fever, purulent drainage emerging from the exit site, with or without concomitant bloodstream infection.

Question 35

What is the definition of tunnel infection?

Answer 35

Tenderness, erythema and / or induration >2 cm from the catheter exit site, along the subcutaneous tract of a tunnel catheter (e.g. Hickman or Broviac catheter), with or without concomitant bloodstream infection.

Question 36

What is the definition of pocket infection?

Answer 36

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 bloodstream infection

Question 37

What is the definition of infusate related bloodstream infection?

Answer 37

Concordant growth of a microorganism from infusate and cultures of percutaneously obtained blood cultures with no other identifiable source of infection.

Question 38

What is the definition of catheter related bloodstream infection?

Answer 38

Bacteraemia or fungemia in a patient who has an intravascular device and >1 positive blood culture result obtained from the peripheral vein, clinical manifestations of infection and no apparent source for bloodstream infection (apart from the catheter). 1 of the 3 criteria described previously should be met.