Peripheral IV Blood Control Catheter
Design and Biofilm Formation
Center for
Biofilm
Engineering
RYDER SCIENCE, Inc.
…..medical biofilm research
Marcia Ryder1, Elinor deLancey Pulcini2, Albert Parker2, and Garth James2
(1) Ryder Science, Escondido, CA, (2) Center for Biofilm Engineering, Montana State University-Bozeman
a National Science Foundation Engineering Research Center in the MSU College of Engineering
INTRODUCTION
The insertion of peripheral intravenous catheters
(PIVC) is the most common invasive procedure
performed by nurses. This places healthcare
personnel at risk for needlestick injury and infections
related to blood exposure. Manufacturers have
responded with a new generation of advanced
technologies for PIVC insertion. Valved blood control
PIVC (BC-PIVC) technology requires the addition of
internal components within the hub to prevent blood
exposure to clinicians. These components increase
the internal surface area, dead space and volume
within the catheter hub that is thought to increase
biofilm formation and subsequent transfer of bacteria
into the bloodstream. This raises concern for
increased risk of bloodstream infection.
RESULTS
The log sum CFU for biofilm formed on all internal
fluid pathway surfaces within Smiths Medical
ViaValve™ Safety I.V. catheter was 3.84, BD Insyte™
Autoguard™ BC Shielded I.V. Catheter was 4.02,
and B.Braun Introcan Safety® 3 catheter was 4.90.
Biofilm was observed on SEM on internal component
surfaces with higher CFU counts. When pooled
across time points and all experiments, there were
statistically significantly smaller bacterial mean log
densities in Flush 1 and Flush 2 for the C1 catheter
compared to the C2 (p-value = 0.003 and 0.001
respectively) or C3 catheters (p-value=0.014 and
0.010 respectively).
ViaValve™ Safety I.V. Catheter
A
Internal Volume and Surface Area in Contact with Blood
ViaValve™ Autoguard BC™ % difference
0.0082
116%
(2.2 x more volume)
Internal surface area (in2) 0.34
0.73
Internal volume (in3)
Designation Segment Name
A
Catheter Tubing
B
luer fitting inserted .208”Entire
(halfway
catheter
between ISO min & max)length not shown
Log CFU
0.70
Lower Hub assembly + metal eyelet
C
D
E
PURPOSE
Septum
Silicone
Upper Hub assembly
0.70
1.90
3.07
Figure 2. Scanning electron microscopic image of the
inside of a catheter hub. The small groups of spherical
objects are S. aureus cells.
Internal Surface Area (in )
in back of seal
% difference
Table 1. Comparison of the internal volume and surface area of the
Autoguard™ BC and the Introcan Safety®3 catheter hubs to the ViaValve™
4.90
Internal Surface Area (in²)
3.84
4.5
0.34
4.0
Log Sum CFU
4.02
3.84
2
ViaValve
114%
(2.1 x more SA)
0.017
347%
(4.5 x more volume)
0.96
182%
(2.8 x more SA)
Internal surface area (in2) 0.34
5.0
B
0.0038
3.75
Log Sum CFU
in actuator
3.5
BD Insyte™ Autoguard™ BC Shielded I.V. Catheter
E
C
B
3.0
Count
The purpose of the this study is to compare biofilm
formation on the various internal components of the
catheter hub and bacterial transfer rate between three
valved blood control PIVCs in a clinically simulated in
vitro model.
Internal volume (in3) 0.0038
ViaValve™ Introcan®3
ViaValve™ Safety I.V. Catheter
ViaValve
RESULTS
RESULTS
RESULTS
A
2.5
2.0
1.5
0.96
0.73
1.0
METHODS
Three PIVCs were tested: Smiths Medical ViaValve™
Safety I.V. catheter, BD Insyte™ Autoguard™ BC
Shielded I.V. Catheter and the B. Braun Introcan
Safety® 3 catheter.
Six experiments were run with three time points
measured within each run: 0, 72 and 96 hours. A
needleless connector was attached to each catheter,
inoculated by flushing with 0.5 ml of a 104 colony
forming units per ml (CFU/ml) of S. aureus, and
incubated at room temperature for 2 hours. The
connectors were then replaced with new sterile
connectors and unattached bacteria were rinsed from
the fluid path using sterile Phosphate Buffered Saline
(PBS).
Catheters were then either sampled or subjected to
simulated clinical use by flushing 17 times daily with
0.5 ml sterile nutrient and 1 flush at the end of the day
with normal saline for 72 and 96 hours.
Catheters were sampled with a two-step procedure.
First, each catheter was flushed to recover planktonic
bacteria and plated to determine CFU/ml (Flush 1).
The connector surface was disinfected, sonicated in
PBS to remove firmly attached bacteria, and flushed a
second time and plated (Flush 2).
At Time 96 hours, one of each catheter type was
destructively sampled (including all internal
components; the hub, spike, septum, etc.). Each part
was vortexed , sonicated, and vortexed again to
detach and disaggregate the biofilm and form a
bacterial suspension for viable plate counts (CFU/ml).
One of each assembly type was formalin fixed for
scanning electron microscopy (SEM), disassembled
and imaged.
D
0.34
0.5
BD Insyte™ Autoguard™ BC Shielded I.V. Catheter
A
B
0.0
ViaValve™
entire tube lengths
not shown
BD BC
in & around
plunger
BD BC
in seal
Designation
A
B
C
D
E
in tube (entire
length not shown)
Segment Name
Log CFU
Catheter Tubing
1.30
Lower Hub assembly + metal eyelet
1.78
Septum
1.30
Spike
3.58
Hub assembly
3.82
Log Sum CFU
4.02
Internal Surface Area (in2)
0.73
Figure 3. Scanning electron microscope image of the white
arm within the flow path. The large aggregates of spherical
objects Indicate biofilm formation by Staph aureus.
H
G
F E
DC
B
A
B.Braun Introcan Safety® 3 catheter
in hub
Figure 4. Scanning electron microscopic image of the
intraluminal surface of a catheter tubing. The small
groups of spherical objects are S. aureus cells.
In and around
plunger
DISCUSSION
CONCLUSIONS
Introcan 3
Introcan 3
Figure 6. Comparison for surface area (in2) and biofilm
count (CFU)
As shown in the illustrations and Table 1, the, BD
Insyte™ Autoguard™ BC Shielded I.V. Catheter and
the B.Braun Introcan Safety® 3 catheters have more
complex flow paths than the ViaValve™ Safety I.V.
catheter, as well as higher internal surface areas.
Flow path irregularities, in particular areas that
receive minimal fluid flow, are areas that promote
bacterial attachment and biofilm formation. This is
analogous to dead-legs and surface irregularities in
high purity water systems, which serve as reservoirs
for biofilm accumulation and contamination of the
system.
in eyelet
in hub
B
Introcan® Safety 3
Product
B.Braun Introcan Safety® 3 catheter
A
Autoguard™ BC
in tube (entire
length not shown)
in eyelet
Figure 1. A. Cross-sectional schematic of the catheter hub
accessed with syringe. B. Internal volume and surface area in
contact with blood (in red). Blood locations used to calculate
surface area and volume in Table 1.
Designation
A
B
C
D
E
F
G
H
Segment Name
Catheter Tubing
Outer hub + metal eyelet
Septum
Lower outer hub
Cone
White arms
Inner hub
Upper outer Hub
Log CFU
0.70
1.90
3.83
3.53
4.03
3.97
3.53
4.66
Log Sum CFU
4.90
Internal Surface Area (in2)
0.96
There are differences in biofilm formation among the
devices with higher internal surface areas, volume
and dead space. These differences increase the
potential risk for transfer of bacteria into the
bloodstream among the different blood control valved
PIVC designs.
ViaValve™ Safety I.V. catheters had statistically
significantly fewer bacteria in flush counts compared
to both Autoguard™ BC and Introcan® Safety 3. It
also had fewer bacteria on internal surfaces as well
as a smaller internal surface area and less complex
fluid path. These differences may reduce the potential
risk for bacterial transfer and bloodstream infection.
Figure 5. This three-dimensional reconstruction of confocal
scanning laser microscope images shows biofilm growth on
a catheter septum. The biofilm was stained with the
LIVE/DEAD® BacLight™ Bacterial Viability Kit (Life
Technologies Corporation, Carlsbad, CA). Live bacteria appear
This project was funded by Smiths Medical Inc.
This information was provided under a Montana State University Testing
Services Agreement and is not intended to endorse or recommend any
product or service
May 2013