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Renowned Expert Dennis Maki, MD, Continues Discussion of IVsand Central Venous Catheters
Second part of a two-part interview
This second part of ICTs interview with Dr. Dennis Makicenters on his views regarding central venous catheter care and maintenance. Asbefore, Maki amplifies upon current CDC guidelines with his own knowledge ofscientific facts established since the Guidelines were adopted in 2002. Theinterview ends with Maki summarizing his position on key elements of care andmaintenance of both peripheral IVs and central venous catheters.
ICT:Are there any specific recommendations you wouldmake with regard to central venous catheter-related bloodstream infections?
DM: Most certainly. With long-termcentral devices, theres overwhelming evidence that an anti-infective locksolution will significantly reduce the risk of infection. The Centers forDisease Control and Prevention (CDC) guideline committee was cautious aboutforming a consensus to recommend these be used routinely. But anti-infectivelocks can be used selectively in individual patients and in certain settings. Ithink the evidence is very compelling that these anti-infective lock solutionscould become standard care in many settings and would reduce risk to patients. Imconfident that in the next draft of the guidelines, that will be the case.
A second area is a novel technology called BioPatch, which isa chlorhexidine-impregnated synthetic disk that is affixed around centralcatheters, peripheral inserted catheters, and arterial catheters. This appearsto reduce risk of bacteremia significantly. Again, the guidelines committee tooka 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 nextdraft of the guidelines, there will be a strong recommendation for use of theBioPatch.
ICT: Lets discuss siteselection. Is there any evidence to suggest a preferred insertion site betweenthe internal jugular vs. the subclavian?
DM: The subclavian has a lower riskof infection than the internal jugular. I think the evidence is pretty convincing of that.
ICT: I understand from ourpreceding discussion that you strongly recommend chlorhexidine as a skinpreparation prior to CVC placement. How often should a skin antiseptic like chlorhexidine be usedafter CVC placement and why?
DM: I think every time that youre-dress the device you should use chlorhexidine antiseptic. However, there areno good studies that tell us how often we need to re-dress these devices. Ithink if we use some of the technology we have already talked about, such astransparent dressings or the BioPatch (the chlorhexidine-impregnated disc),theres probably not a need to change most of these dressings more often thanabout every five to seven days.
ICT: Regarding the catheter, isthere a preferred kind of CVC antimicrobial vs. non-antimicrobial?
DM: I thinkantimicrobial-impregnated or coated catheters do reduce risk of infection. Whatsnot clear is whether we get any significant added reduction in risk if we usechlorhexidine for the skin prep, or if we use something like achlorhexadine-impregnated dressing. If we use those two technologies, its notclear that we get much added reduction in risk with a coated catheter. Ifchlorhexidine for prep of the skin is not used, then I think an anti-infectedcoated catheter will significantly reduce risk in high-risk settings.
ICT: Are there any drawbacks toantimicrobial coatings?
DM: There are very, very rareanaphylactic reactions with the silver sulfadiazine chlorhexidine-coatedcatheter. Its occurred almost exclusively in Japan, where about one out ofevery 10,000 to 15,000 exposed patients had an anaphylactic reaction. That hasnot been seen in the United States, and there have been probably 5 million ofthese catheters used here, with virtually none of these reactions. These coatedcatheters have been remarkably well tolerated.
ICT: Is there a preferred lengthof CVC catheter?
DM: I think it depends on the use ofthe catheter.
ICT: Is there evidence to suggesta preferred method of catheter securement with CVCs?
DM: I firmly believe that suturelesssecurement devices are preferred. They immobilize the catheter more securely,theres less risk of losing the catheter, and we obviate the risk ofneedlesticks. Ive gotten a hepatitis C-positive needlestick myself whenassisting 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, Ivenot cared for suturing, only for the simple reason that the suture site in theskin festers, and I think its a source of microorganisms that can invade theinsertion site and cause infection. There are no studies to prove that the infectingmicroorganisms actually arise from suture wound infections, but Ive beensuspicious of it for a long time. I think that securement devices obviate thattheoretical concern.
ICT: Tell us about your research in suture causing catheter-related bloodstream infections.
DM: We published a meta-analysis ofnew technologies for prevention of infection of the vascular access area. Someof 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 needlelesssecurement device as compared with suturing catheters in place. And thosestudies, in aggregate, showed a statistically significant reduction in the riskof infection when using the needleless device. I think theres growing data tosuggest that a sutureless securement device is going to result in not onlymore comfort for the patient but less infiltration and phlebitis withperipheral venous catheters, and they may very well reduce the risk of infectionto a central venous catheter.
ICT: Given that suture is cheap,is a securement device cost prohibitive?
DM: Suture is not cheap. You have toget sterile suture attached to a needle and you have a sterile needle holderthat 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 atall. And, suturing is not comfortable for the patient. Theres another issueto 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-exposureprophylaxis. And if you have a lot of needlestick occurrences . I would bewilling to bet that the cost of suturing in a central venous catheter isprobably no different than the cost of a securement device.
ICT: Is there a preferredinsertion site dressing with CVCs and why?
DM: I think you can use either gauzeor a transparent dressing. Either is acceptable. And everything I said regardingperipheral venous catheter in regard to dressings, also applies to centralvenous catheters.
ICT: To summarize, are therethree or four cost-effective measures that best protect patients and healthcareworkers relative to both peripheral IVs and CVCs?
DM: Let me first addressperipherals, and then centrals. I think with peripheral venous catheters, itsimportant to use safety catheters that have a system that automatically shieldsthe sharp once youve gained access to the vein, thus eliminating that as asource of a dangerous needlestick injury. Healthcare workers must be trained toprotect themselves from sharps injuries. Also, we should try to use needlelesssystems as much as we can.
In terms of protecting patients, well-trained people who canestablish access reliably and safely, such as an IV team, will have the lowestrisk of all. I believe that hospitals ought to have IV teams for peripheral IVcatheters. Theyd have much better results, and a much lower risk ofcomplications.
They also should use chlorhexidine for the prep. Good aseptictechnique performed by gloved personnel, and using a fenestrated drape isessential.
Lastly, patients with peripheral venous catheters should beseen and evaluated every day, and their site examined and palpated. Do they have unexplained fever? Do they have local pain anddiscomfort that might indicate early infection or phlebitis or infiltration?Thats obviously very important.
In terms of central venous catheters, everything I said withregard to sharps, I would reaffirm is very important. To protect from sharpsinjuries, 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 jugularroute; second, using chlorhexidine for the prep; third, using maximalsterile barriers; fourth, putting on the chlorhexidine impregnated dressing, asI think it will significantly reduce infection risk. If you dont do that, you may choose to use a coatedcatheter. I cant tell you which one is more cost-effective. I suspect thechlorhexidine impregnated dressing is more cost-effective than coating, but Idont have randomized trials to prove that.
I think a securement device can fit in the equation in bothtypes of catheters, peripheral IVs and CVCs. I think it will reduce prematureloss of peripheral catheters. If we reduce premature loss, theres going to beless need to put in catheters, and there will be a reduction in potential riskof exposure to sharps and greater comfort for patients.
Securement devices for central venous catheters might reducerisk of infection. We dont know that with certainty, but we believe that theymay, and were gathering more information on that question as we speak. Ifirmly believe that sutureless securement devices are preferred. So, I thinkthat securement devices can play a role in both types of catheters.
I dont think it matters whether you use a transparentdressing or gauze dressing, but we use transparent dressings for all of theadvantages I listed.
Lastly, with central catheters, the same kind of monitoringfor 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 worldimplement your thoughtful recommendations, patients and healthcare workers alikewill assuredly benefit.