applied microbiology

1. Central Line Associated
Blood Streams Infection

2. Introduction
Venous access via catheter insertion is common
practice in the hospital for various purposes,
including hemodynamic monitoring, renal
replacement therapy, nutritional support and
medication administration.
As a consequence of their increasing use,
bloodstream infections resulting from intravascular
catheters have become a costly complication of
health care.

3. Epidemiology
More than 250,000 central line associated blood
stream infections (CLABSI) occur annually in
India with mortality rate of 12-25%.
Each episode significantly increases hospital stay
with additional health care cost.

4. Definition
CRBSI (catheter related blood stream infection)-
refers to blood stream infection attributed to an
intravascular catheter by quantitative culture of the
catheter tip or by differences in growth between
catheter and peripheral venipuncture blood cultures
specimens.
CLABSI ( central line associated blood stream
infection)- refers to blood stream infection that appears
in the presence of a central venous catheter or within
48 hr of removal of a central venous catheter and which
cannot be attributed to an infection unrelated to
catheter.
CLABSI was developed to serve as a surrogate
measure of CRBSI.

5. Risk Factors
It includes Patient, Operator
and Catheter related
factors.
Patient Factors-
 Increasing severity of illness
 Granulocytopenia
(decrease of blood
granulocytes)
 Compromised integrity of
skin
 Presence of distant infection

6. Catheter factors-
 Catheter - Antibiotic or antimicrobial coating of
catheter can reduce risk of CRBSI.
 For non tunneled catheters risk of bsi varies by
anatomical sites- max for groin insertion,
intermediate for neck insertion and lowest for chest
or upper extremity insertion.

7. Pathogenesis
 Migration of skin organism at the insertion site into
catheter tract along the surface of catheter with
colonization of catheter tip.
 Direct contamination of catheter or catheter hub by
contact with hands or contaminated fluid or device.
Colonization of device may be from surrounding
skin or catheter tip
Organism adhering to device followed by creation
of biofilm.

8. Microbiology
Organisms commonly associated with CLABSIs are-
 Coagulase negative staph-31%
 S. aureus- 20%.
 Enterococci- 9%.
 E. coli- 6%.
 Klebsiella species-5%.
 Candida species- 9%.
• A large study found that the rates of MRSA has
increased from 22% in 1995 to 57% in 2001.
• Rates of ceftazidime resistant P
.aeruginosa has
increased from 12% in 1995 to 29% in 2001.

9. Diagnosis
Exit sites of all percutaneous vascular devices should
be assesse to identify obvious inflammation.
Quantitative culture of the distal (5 cm) tip of central
venous and arterial catheters should be performed
when they are removed for suspected infection.
The tip of the introducer should be sent for culture when
a pulmonary artery line is removed.

10. For patients with short-term central venous
catheters without severe sepsis or shock.
catheter may be exchanged over a guide wire
for a new catheter allowing culture of the tip of
the removed catheter without immediately
sacrificing the site of insertion.
At least 2 blood cultures should be obtained
when catheter infection is suspected.

11. When the tip of a catheter is sent for culture, the 2
blood cultures may be obtained by peripheral
venipuncture.
Alternatively or when culture of the tip of the catheter is
not performed, one blood culture should be obtained by
peripheral venipuncture and at least one blood culture
should be obtained from a lumen of the catheter.

12. Management- General
For emperical treatment-
 vancomycin in institutions where the prevalence
of MRSA is increased (otherwise use a 1st gen
cephalosporin).
 daptomycin in place of vancomycin in facilities
where the prevalence of MRSA with reduced
vancomycin susceptibility is increased.
 antibiotics active against Gram-negative bacilli,
based upon local susceptibility patterns, in the
setting of increased severity of illness or femoral
catheterization;

13. Antibiotics active against Pseudomonas
aeruginosa, in the setting of severe illness, or
known colonization.
If blood cultures fail to yield growth, the need
for further empiric antibiotic therapy should be
reassessed.

14. 5 to 7 days for coagulase-negative staphylococci.
7 to 14 days for enterococci and Gram-negative
bacilli.
14 days in the absence of evidence fungal retinitis
for Candida species.
For patients with susceptible pathogens and a
functioning GI tract, oral linezolid or fluconazole
may be considered for treatment of MRSA,
Gram-negative bacilli, and candida,

15. Management: Long-Term Central
Venous CRBSI
Catheter should be removed immediately
especially for S aureus, Bacillus species,
micrococcus, P aeruginosa, candida, or
mycobacterial infection.
4 to 6 weeks of therapy is often required for S
aureus infection.
when S aureus or other bacterial infection resolves
within 72 hours of antibiotic initiation and catheter
removal.

16. For patients with candida infection in whom there is
no suspicion or evidence of infection and for whom
fungemia and evidence of infection resolve
promptly upon catheter removal.
antifungal therapy should be continued for 14 days
after the first negative blood culture.

17. Education, Training and
Staffing
Healthcare personnel should be educated
regarding the indications proper procedures for the
insertion and maintenance of intravascular
catheters.
Periodically assess knowledge of and adherence t o
guidelines for all personnel involved in the insertion
and maintenance of intravascular catheters .

18. Designate only trained personnel who demonstrate
competence for the insertion and maintenance of
peripheral and central intravascular catheters.
Ensure appropriate nursing staff levels in ICUs.

19. Selection of Catheters and
Sites
Peripheral Catheters and Midline Catheters
 In adults, use an upper-extremity site for catheter
insertion.
 Select catheters on the basis of the intended
purpose and duration of use, known infectious and
non-infectious complications and experience of
individual catheter operators.

20.  Evaluate the catheter insertion site daily by palpation
through the dressing to a transparent dressing is in
use.
 Gauze and opaque dressings should not be removed if
the patient has no clinical signs of infection.
 Remove peripheral venous catheters if the patients
develops signs of infection, or a malfunctioning
catheter.

21. Hand Hygiene and Aseptic
Technique

22. Perform hand hygiene procedures, either by washing
hands with conventional soap and water or with alcohol-
based hand rubs.
Maintain aseptic technique for the insertion and care of
intravascular catheters.
Sterile gloves should be worn for the insertion of
arterial, central, and midline catheters.
Use new sterile gloves before handling the new
catheter when guide wire exchanges are performed.
Wear either clean or sterile gloves when changing the
dressing on intravascular catheters.

23. Maximal Sterile Barrier
Precautions
Maximal sterile
barrier precautions
like cap, mask,
sterile gown, sterile
gloves, and a
sterile full body
drape, should be
used for the
insertion.

24. Skin Preparation
 Prepare clean skin with an antiseptic (70% alcohol,
tincture of iodine, or alcoholic chlorhexidine
gluconate solution) before peripheral venous
catheter insertion.
Anticoagulants
 Do not routinely use anticoagulant therapy to
reduce the risk of catheter-related infection in
general patient population.

25. Catheter Site Dressing Regimens
 Use either sterile gauze or sterile, transparent,
semipermeable dressing to cover the catheter site.
 Do not use topical antibiotic ointment or creams on
insertion sites, except for dialysis catheters, because of
their potential to promote fungal infections and
antimicrobial resistance.
 Do not submerge the catheter or catheter site in water.
 Replace dressings used on short-term CVC sites at
least every 7 days for transparent dressings.

26. Surveillance and Reporting:-
 Hospital-based infection control teams
begin surveillance for bloodstream
infections by regularly reviewing results of
blood cultures obtained at their facilities.