Infection Control Today: Renowned Expert Dennis Maki

February 1, 2005


Renowned Expert Dennis Maki, MD, Continues Discussion of IVs
and Central Venous Catheters

Second part of a two-part interview


This second part of ICTs interview with Dr. Dennis Maki
centers on his views regarding central venous catheter care and maintenance. As
before, Maki amplifies upon current CDC guidelines with his own knowledge of
scientific facts established since the Guidelines were adopted in 2002. The
interview ends with Maki summarizing his position on key elements of care and
maintenance of both peripheral IVs and central venous catheters.

ICT:
Are there any specific recommendations you would
make with regard to central venous catheter-related bloodstream infections?


DM: Most certainly. With long-term
central devices, theres overwhelming evidence that an anti-infective lock
solution will significantly reduce the risk of infection. The Centers for
Disease Control and Prevention (CDC) guideline committee was cautious about
forming a consensus to recommend these be used routinely. But anti-infective
locks can be used selectively in individual patients and in certain settings. I
think the evidence is very compelling that these anti-infective lock solutions
could become standard care in many settings and would reduce risk to patients. Im
confident that in the next draft of the guidelines, that will be the case.

A second area is a novel technology called BioPatch, which is
a chlorhexidine-impregnated synthetic disk that is affixed around central
catheters, peripheral inserted catheters, and arterial catheters. This appears
to reduce risk of bacteremia significantly. Again, the guidelines committee took
a very cautious view here, because the published evidenced was still incomplete.
I think that the evidence will be more than adequate next time, and in the next
draft of the guidelines, there will be a strong recommendation for use of the
BioPatch.


ICT: Lets discuss site
selection. Is there any evidence to suggest a preferred insertion site between
the internal jugular vs. the subclavian?


DM: The subclavian has a lower risk
of infection than the internal jugular. I think the evidence is pretty convincing of that.


ICT: I understand from our
preceding discussion that you strongly recommend chlorhexidine as a skin
preparation prior to CVC placement. How often should a skin antiseptic like chlorhexidine be used
after CVC placement and why?


DM: I think every time that you
re-dress the device you should use chlorhexidine antiseptic. However, there are
no good studies that tell us how often we need to re-dress these devices. I
think if we use some of the technology we have already talked about, such as
transparent dressings or the BioPatch (the chlorhexidine-impregnated disc),
theres probably not a need to change most of these dressings more often than
about every five to seven days.


ICT: Regarding the catheter, is
there a preferred kind of CVC antimicrobial vs. non-antimicrobial?


DM: I think
antimicrobial-impregnated or coated catheters do reduce risk of infection. Whats
not clear is whether we get any significant added reduction in risk if we use
chlorhexidine for the skin prep, or if we use something like a
chlorhexadine-impregnated dressing. If we use those two technologies, its not
clear that we get much added reduction in risk with a coated catheter. If
chlorhexidine for prep of the skin is not used, then I think an anti-infected
coated catheter will significantly reduce risk in high-risk settings.


ICT: Are there any drawbacks to
antimicrobial coatings?


DM: There are very, very rare
anaphylactic reactions with the silver sulfadiazine chlorhexidine-coated
catheter. Its occurred almost exclusively in Japan, where about one out of
every 10,000 to 15,000 exposed patients had an anaphylactic reaction. That has
not been seen in the United States, and there have been probably 5 million of
these catheters used here, with virtually none of these reactions. These coated
catheters have been remarkably well tolerated.


ICT: Is there a preferred length
of CVC catheter?


DM: I think it depends on the use of
the catheter.


ICT: Is there evidence to suggest
a preferred method of catheter securement with CVCs?


DM: I firmly believe that sutureless
securement devices are preferred. They immobilize the catheter more securely,
theres less risk of losing the catheter, and we obviate the risk of
needlesticks. Ive gotten a hepatitis C-positive needlestick myself when
assisting a resident who was sewing in a catheter, and he stuck me in the thumb.
So Im not an enthusiast for suturing in catheters. But long before that, Ive
not cared for suturing, only for the simple reason that the suture site in the
skin festers, and I think its a source of microorganisms that can invade the
insertion site and cause infection. There are no studies to prove that the infecting
microorganisms actually arise from suture wound infections, but Ive been
suspicious of it for a long time. I think that securement devices obviate that
theoretical concern.

ICT: Tell us about your research in suture causing catheter-related
bloodstream infections.


DM: We published a meta-analysis of
new technologies for prevention of infection of the vascular access area. Some
of it was our research, much of it was researched by others all over the world.
We analyzed several published studies that had looked at the needleless
securement device as compared with suturing catheters in place. And those
studies, in aggregate, showed a statistically significant reduction in the risk
of infection when using the needleless device. I think theres growing data to
suggest that a sutureless securement device is going to result in not only
more comfort for the patient but less infiltration and phlebitis with
peripheral venous catheters, and they may very well reduce the risk of infection
to a central venous catheter.


ICT: Given that suture is cheap,
is a securement device cost prohibitive?


DM: Suture is not cheap. You have to
get sterile suture attached to a needle and you have a sterile needle holder
that has to be autoclaved and cleansed and re-processed. You must use xylocaine.
If all that costs $10, then the cost of suturing the catheter is not cheap at
all. And, suturing is not comfortable for the patient. Theres another issue
to think about the risk of a needlestick injury. If you have a needlestick,
that costs $1,000 or more to work up, evaluate and deliver post-exposure
prophylaxis. And if you have a lot of needlestick occurrences . I would be
willing to bet that the cost of suturing in a central venous catheter is
probably no different than the cost of a securement device.


ICT: Is there a preferred
insertion site dressing with CVCs and why?


DM: I think you can use either gauze
or a transparent dressing. Either is acceptable. And everything I said regarding
peripheral venous catheter in regard to dressings, also applies to central
venous catheters.


ICT: To summarize, are there
three or four cost-effective measures that best protect patients and healthcare
workers relative to both peripheral IVs and CVCs?


DM: Let me first address
peripherals, and then centrals. I think with peripheral venous catheters, its
important to use safety catheters that have a system that automatically shields
the sharp once youve gained access to the vein, thus eliminating that as a
source of a dangerous needlestick injury. Healthcare workers must be trained to
protect themselves from sharps injuries. Also, we should try to use needleless
systems as much as we can.

In terms of protecting patients, well-trained people who can
establish access reliably and safely, such as an IV team, will have the lowest
risk of all. I believe that hospitals ought to have IV teams for peripheral IV
catheters. Theyd have much better results, and a much lower risk of
complications.

They also should use chlorhexidine for the prep. Good aseptic
technique performed by gloved personnel, and using a fenestrated drape is
essential.

Lastly, patients with peripheral venous catheters should be
seen and evaluated every day, and their site examined and palpated. Do they have unexplained fever? Do they have local pain and
discomfort that might indicate early infection or phlebitis or infiltration?
Thats obviously very important.

In terms of central venous catheters, everything I said with
regard to sharps, I would reaffirm is very important. To protect from sharps
injuries, it comes down to both technology and training.

In terms of protecting the patient, first you start by
whenever possible using the subclavian rather than the internal jugular
route; second, using chlorhexidine for the prep; third, using maximal
sterile barriers; fourth, putting on the chlorhexidine impregnated dressing, as
I think it will significantly reduce infection risk. If you dont do that, you may choose to use a coated
catheter. I cant tell you which one is more cost-effective. I suspect the
chlorhexidine impregnated dressing is more cost-effective than coating, but I
dont have randomized trials to prove that.

I think a securement device can fit in the equation in both
types of catheters, peripheral IVs and CVCs. I think it will reduce premature
loss of peripheral catheters. If we reduce premature loss, theres going to be
less need to put in catheters, and there will be a reduction in potential risk
of exposure to sharps and greater comfort for patients.

Securement devices for central venous catheters might reduce
risk of infection. We dont know that with certainty, but we believe that they
may, and were gathering more information on that question as we speak. I
firmly believe that sutureless securement devices are preferred. So, I think
that securement devices can play a role in both types of catheters.

I dont think it matters whether you use a transparent
dressing or gauze dressing, but we use transparent dressings for all of the
advantages I listed.

Lastly, with central catheters, the same kind of monitoring
for complications as with peripheral IVs is very important.


ICT: Thank you very much, Dr.
Maki. We are sure that if infection control professionals around the world
implement your thoughtful recommendations, patients and healthcare workers alike
will assuredly benefit.