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Fibrin sheath enhances central venous catheter infection
John R Mehall1, Daniel A Saltzman, Richard J Jackson
1Department of Pediatric Surgery, Arkansas Children's Hospital, the University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Objective:
To determine whether fibrin-coated central venous catheters have a higher infection rate, and spawn more septic emboli, than uncoated catheters after exposure to bacteremia.
Design:
Animal study comparing catheter infection and blood cultures of fibrin-coated and uncoated catheters exposed to bacteremia.
Setting:
Animal laboratory.
Subjects:
Adult male Sprague-Dawley rats.
Interventions:
A total of 210 rats had catheters placed with the proximal end buried subcutaneously. Rats were divided into three groups: tail vein bacterial injection on day 0 (no fibrin group) or on day 10 (fibrin group), or no injection/saline injection (control, n = 40). Bacterial injections were 1 x 108 colony forming units of either Staphylococcus epidermidis (n = 100) or Enterobacter cloacae (n = 60). Animals were killed 3 days after injection. Blood cultures were obtained via cardiac puncture, and catheters were removed via the chest. Half of the catheter was rolled onto agar and the other half was placed in trypticase soy broth. Plates and broth were incubated at 37 degrees C for 48 hrs. The presence of >15 colonies on roll plates, or growth in broth, was accepted as a positive sign of infection. Microscopy was performed on day 20-10 catheters. Thirty animals without catheters had bacterial injections and underwent blood culture 3 days after injection.
Measurements And Main Results:
Catheter infection with S. epidermidis occurred in 32% of roll plates and 80% of broth from the fibrin group vs. 4% and 20% from the no fibrin group (p <.01 for each). Catheter infection with E. cloacae occurred in 50% of roll plates and 80% of broth from the fibrin group vs. 0% and 12% from the no fibrin group (p <.01 for each). Positive blood cultures occurred in 47 of 68 animals from the fibrin group vs. 8 of 68 from the no fibrin group (p <.01). Microscopy showed a fibrin sheath on 20 of 20 catheters. Without catheters, 30 of 30 blood cultures were negative.
Conclusion:
The fibrin sheath significantly enhanced catheter-related infection and persistent bacteremia.
Insights
Fibrin-coated central venous catheters significantly increase infection and bacteremia rates compared to uncoated catheters. This animal study highlights the risks associated with fibrin sheaths in catheter materials.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Biomaterials Science
Background:
- Central venous catheters are essential medical devices but are associated with a risk of catheter-related infections.
- The formation of a fibrin sheath on indwelling catheters can potentially influence microbial adhesion and biofilm formation.
Purpose of the Study:
- To investigate the impact of fibrin coating on central venous catheters regarding infection rates and the development of septic emboli following bacteremia exposure.
- To compare the susceptibility of fibrin-coated versus uncoated catheters to bacterial colonization in an animal model.
Main Methods:
- An animal laboratory study was conducted using Sprague-Dawley rats, comparing fibrin-coated and uncoated central venous catheters.
- Rats were exposed to bacteremia induced by Staphylococcus epidermidis or Enterobacter cloacae, with catheter infection assessed via roll plates and broth cultures.
- Blood cultures were performed to detect systemic infection (bacteremia).
Main Results:
- Fibrin-coated catheters showed significantly higher infection rates for both S. epidermidis (32-80% vs. 4-20%) and E. cloacae (50-80% vs. 0-12%) compared to uncoated catheters (p <.01).
- Positive blood cultures were more frequent in the fibrin group (47/68) than the no-fibrin group (8/68) (p <.01).
- Microscopy confirmed the presence of a fibrin sheath on all tested catheters.
Conclusions:
- The presence of a fibrin sheath significantly enhances the risk of catheter-related infections.
- Fibrin coating on central venous catheters is associated with a higher incidence of persistent bacteremia.