Catheter associated blood stream infections

1. Catheter associated Blood stream Infections
Definition : It is defined as presence of Bacteremia
originating from I.V. Catheter.
Most common cause of Nosocomial Bacteremia.
It is most frequent, lethal and costly complication of
Central Venous Catheterization.

2. • The incidence of CRBSI arising from Central Venous
catheters is approximately 10%
• CRBSI has a mortality rate of up to 25% and significantly
increases hospital length of stay and overall treatment
cost.
• CRBSI can originate from peripheral i.v. and intra-arterial
cannulae, but this is extremely rare.
• Pulmonary artery catheters have similar incidence of
CRBSI to CVCs; dialysis catheters appear to have a much
higher rate.

3. • Example of Intravascular Devices that can cause
CRBSI :
1. Peripheral vascular catheters ( venous/arterial )
2. Central venous catheters
3. Pulmonary Artery catheter
4. Peripherally inserted central catheter.

4. • Common organisms causing CRBSIs:
1. CONS – 31%
2. S. Aureus – 20%
3. Enterococci – 9%
4. Gram Neg. Bacilli ( E.Coli ) – 6%
5. Pseudomonas – 5%
6. Yeasts – 9%
• Recent studies have shown that rates of MRSA,
Ceftazidime resistant P.Aeruginosa, Vancomycin
resistant Enterococci causing CRBSI have increased
significantly.

5. • Pathogenesis of CRBSI : 2 primary causes
1. Contamination of fluids being administered.
2. Bacterial colonization of devices.
a) Extra Luminal : From surrounding skin, Hematogenous
seeding of catheter tip.
b) Intra Luminal : Caused by organism adhering to device
followed by creation of Bio-film, a process responsible
for persistent infection/ Hematogenous spread.
• In short term devices, Extra Luminal route is more
frequent.
• In long term devices ( >10 days ), Intra Luminal route
is more common

6. Diagnosis of CRBSI is based on the following:
1. The presence of a CVC.
2. signs of catheter insertion site infection
3. clinical symptoms and signs of Bacteremia;
4. resolution of the symptoms and signs of
Bacteremia after removal of the suspect CVC;
5. positive blood culture; and
6. growth of the same organism from the catheter.
7. Confirmation that organism is not a contaminant.

7. • In practice, a presumptive diagnosis of CRBSI is
often made on the basis of one or two of above
criteria.
• The ‘gold standard’ is the combination of a positive
blood culture with the same organism isolated from
the catheter.
• However, a major diagnostic problem is that
traditional methods of catheter culture necessitate
removal of the CVC, whereby the line tip is either
rolled on an agar plate or placed in a nutrient broth.

8. • Although catheter removal in suspected CRBSI may
be mandatory when faced with a deteriorating
patient, 80% of catheters removed on the basis of
fever and/or leukocytosis alone will be sterile.
• This places the patient at risk from the discomfort
and mechanical complications of inserting another
CVC and increases costs.
• Thus, there has been an impetus to develop in situ
methods of microbiological diagnosis.

9. • Quantitative blood culture. CRBSI is suggested when
the number of microbes from a CVC sample of blood is
five times that from a simultaneously collected
peripheral sample. This is not widely available. (>100
cfu/ml in case of peripheral line)
• Acridine orange staining of blood taken from the CVC.
This is not widely available.
• Endoluminal brush sampling. A tiny brush is passed
down the catheter lumen and is examined
microbiologically by culture. This test has a high
sensitivity and specificity but is not widely available. In
addition, there are concerns about the generation of a
bacteraemia caused by dislodgement of organisms.
• Differential time to positivity. CRBSI is suggested when
blood from the CVC demonstrates microbial growth at
least 2 h earlier than growth is detected in blood
collected simultaneously from a peripheral vein.

10. • Management : relies on 2 major clinical decisions:
1. Appropriate & Timely administration of Systemic
Antimicrobial Treatment (SAT)
2. Catheter removal or Catheter Salvage Treatment.
• Guidelines from Infectious disease society of America
recommend removal of Catheter in all :
1. All complicated Infections ( thrombophlebitis,
Endocarditis, Osteomylitis )
2. All infections caused by ( S.Aureus, Candida,
Enterococcus, Gram Neg. Bacilli )
• Catheter may be retained in CONS if systemic
antibiotics are given in conjunction with Antibiotic
Lock Therapy.

11. 1. CONS – Remove and give SAT for 5-7 days or Retain
and give SAT+ALT for 10-14 days.
2. S.Aureus – Remove, SAT for minimum of 14 days.
In case of Long term CVC, Remove and SAT for 4-6
weeks
3. Enterococci – Remove, SAT for 10-14 days.
4. Gram Negative Bacilli – Remove, SAT for 10-14
days.
5. Candida species – Remove, SAT for 14 days after
first negative Blood Culture.
6. Complicated Infection ( Endocarditis, Septic
thrombophlebitis, Osteomylitis ) – Remove SAT for
4-6 weeks. For Osteomylitis : 6-8 weeks.

12. • Antibiotic Lock Therapy : Here 2ml of solution is
infused into the lumen of the catheter and remains
there for a certain amount of time per day during
course of treatment.
• In the lock therapy, Antibiotic concentration ranges
100 to 1000 times the usual systemic concentration.
These increased concentration has greater
likelihood for killing organism embedded in biofilm.
• It should be used for 10-14 days.

13. • Prevention :
1. Education and Training all Healthcare personnel
who insert and maintain catheter.
2. Using single lumen catheter unless multiple ports
are essential.
3. Consider use of an antimicrobial impregnated
catheter for patients at high risk of CRBSI.
4. Consider use of peripherally inserted catheters as
an alternative to CVCs.
5. Use of Subclavian route unless contraindicated

14. 6. Use optimum insertion technique including sterile
gown, gloves and drapes
7. Clean the insertion site with alcoholic chlorhexidine
gluconate solution ( or alcoholic povidone iodine )
and allow to dry.
8. Use sterile gauze or transparent dressing over the
insertion site.
9. Catheter flush solutions should contain
anticoagulant.
10. Replacement strategies : Do not routinely replace
CVCs as a strategy to prevent infections.
11. Guidewire exchange is acceptable for
malfunctioning catheters if there is no evidence of
infection.