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.