Infection Control Today - 08/2003: Technologies

Technologies, New Guidelines Work to ReduceInvasive Device-Related Infections

By Kelli M. Donley

Infections related to invasive devices arereceiving unprecedented attention since the release of a Centers for DiseaseControl and Prevention (CDC) guideline that updated the topic.

The Guidelines for the Prevention ofIntravascular Catheter-Related Infections, was prepared by numerous infectioncontrol experts, including CDC director Julie L. Geberding, MD, MPH. The updatehighlights five significant methods of reducing such infections:

• Increased education of those inserting such devices

• Using sterile barrier precautions during device insertion

• Using 2 percent chlorhexidine preparation for skin antisepsis before insertion

• Preventing replacing central venous catheters regularly

• Using catheters impregnated with antiseptic/antibiotics¹

The guidelines use several methods ofcategorizing invasive catheters: by type of occupied vessel (peripheral venous,central venous, arterial); life span (temporary, short-term, long-term,permanent); insertion site (subclavian, femoral, internal jugular, peripheral,peripherally inserted central catheter); type of skin to vessel pathway(tunneled, nontunneled); physical length (short, long); or special feature(cuff, antibiotic impregnation). Rates of infection associated with invasivecatheters are divided among these subgroups. However, the research shows morethan 80,000 central venous catheter (CVC)-related infections are reported eachyear from American intensive care units alone. The average cost of eachinfection varies from $34,000 to $56,000; depending on the research figuresused, these infections incur an annual financial burden of $296 million to $2.3billion to the American healthcare system.

CVC-related infections reported hospitalwidetotal more than 250,000 annually in the United States, costing the healthcaresystem an estimated $25,000 per infection. Such high rates of infection andcosts have fueled medical device companies to develop innovative methods ofpreventing infections associated with their devices.

Kelly Powers, vice president of research anddevelopment at CR Bard, based in Murray Hill, N.J., says the companys AccessDivision specializes in long-term vascular access products.

Long-term vascular access devices aretypically given for chemotherapy treatment, he says. These cancer patientsneed long-term infusions of chemotherapeutic drugs. There are four majorcategories that these devices fall into.

Implanted ports can be placed and left in placefor several years. In general, those patients either die from their cancer orthey recover and the ports are removed. The next is peripherally insertedcentral catheters. Those are called PICC lines and they are long-term centralcatheters that are placed in the arm.

Also, there are chronic catheters, placed in thejugular vein and used primarily for the same thing. The final category oflong-term vascular access is for dialysis used for hemodialysis treatment.

Patricia Johnson, RN, MSN, senior marketingmanager at Arrow Medical, based in Libertyville, Ill., says these devices areused for a variety of patients.

They are used many times by critically illpatients, she says. Sometimes these are patients that need total perinatalnutrition. They cant be fed through their stomach or mouth and they need toget the proteins, fats and carbohydrates through the veins. If you do that inthe peripheral aspect, through the arm, you can cause a lot of phlebitis orthrombosis just because of the osmolarity and pH of the medications you areinfusing.

Many times trauma patients, burn patients andpatients with major surgery are candidates for a central venous catheter.

However, Johnson warns, central venous cathetersare not inserted without considerable thought.

These devices remain inserted on average from5 to 10 days, she says. Most people have an average of 7 days. There arecertainly patients who have them in for 2 to 3 weeks because they are just thatcritically ill.

Yet, I think any practitioner today only usesthese catheters as they are needed and tries to get them out as soon as theypossibly can.

She says this rush is due to infectionsassociated with the devices. The challenge for manufacturers has been developinginfection control technologies that last for the entire use of long-termcatheters.

We know there is an average 5 percentinfection rate associated with central venous catheters, she says. In1991, we introduced a technology to help decrease the risk of catheter-relatedblood stream infections. This included silver sulfadiazine and chlorhexidinebeing impregnated onto the external surface of the catheter.

Within the last few years, she says companyofficials have also been able to impregnate internal lumens, extension line andthe hub of the catheter with the antimicrobials. Research has shown thistechnology is effective for 10 to 14 days. Other studies, Johnson says, reporteffectiveness of 45 to 54 days after implantation. Further research is needed.

There are different ways of managingcatheters, the most important focusing on sterile technique when they are beingplaced, says Powers. From a technology standpoint, we have a majorresearch and development focus to develop anti-infective coatings. There is alot of science working on this right now, but no one has completely masteredlong-term effectiveness.

Short-term effectiveness has been demonstrated.

Our devices are in there anywhere from 30 days to24 months. Nothing has shown that you can put on a catheter to prevent infection(for that long).

The primary technology is antibiotics, but thisis less preferred because of bacterial resistance. Silver ion eluding coatingsare fairly promising, but difficult to control the kinetics to be effective forvery long.

Epidemiology, Pathogenesis of Catheter-RelatedInfections

Officials at the CDC have been monitoring thetypes of infections reported in the United States since 1970. The NationalNosocomial Infection Surveillance System (NNIS) data shows infections in thisarena have changed in reaction to developing antibacterial resistance patterns.The following timeline denotes the most prevalent catheter-related infections:

• 1986-1989: Coagulase-negative staphylococci, Staphylococcus aureus, Candida

• 1992-1999: Coagulase-negative staphylococci, enterococci, Staphylococcus aureus

CDC researchers highlight in 1999 they receivedthe first data showing Staphylococcus aureus isolates resistant tooxacillin and Candida albincans isolates were resistant to fluconazole.Other Candida strains have since become resistant to itraconazole aswell. Also, ICU-related Enterobacteriaceae infections, Klebsiellapneumoniae in particular, have become increasingly resistant toextended-spectrum cephalosporins and broad spectrum antimicrobial agents.¹

Short-term catheter insertion sites primarilydevelop infections because of migration of skin organisms near the area. Howeverlong-term catheter sites more frequently cause infections because of hubcontamination.¹

We know the pathogenesis of catheter-relatedinfections is that the longer the catheters are left in place, the moreprominent it becomes as being the source of an infection, says Johnson.

Paul Blackburn, RN, senior product manager ofclinical information at CR Bard, says besides the complex antimicrobialimpregnation technologies, there are simple methods healthcare workers (HCWs)can use to reduce these infections.

Follow the CDC-recommended guidelines for notonly site preparation, but for insertion of the device, he says. Werecommend that HCWs use Chloraprep as the antimicrobial for the site and then werecommend that they use full sterile barrier precautions during insertion.

Once insertion is complete and HCWs begin thecare and maintenance regime, again we recommend that they use sterile gloveswhen cleaning the site. Also, they should use chlorhexidine gluconate and theyshould follow their hospitals policy. Chloraprep is manufactured by Medi-FlexInc., based in Overland Park, Kan.

Johnson is not as quick to provide companyinfection control recommendations.

A manufacturer is responsible to tell you whattheir product does, how it works, limitations as we know it, but to say topeople that you need to use this or that, no, she says. We know there ismore than one way to approach things. As long as they are within practiceguidelines and should be research driven, we dont make such recommendations.We will certainly refer them to the guidelines we try to help people docritical thinking. What you tell one group of practitioners depending on theirpractices in their hospital is not applicable. Currently, we think Chloraprep isan excellent skin prep and we have it in many of our kits. But we do have somekits with betadine.

She says it would be presumptuous for amanufacturer to tell HCWs how to do their jobs.

There are some people who havent moved frombetadine to Chloraprep yet, she says. Some of that is because of financialaspects in their hospitals they dont want to incur increased costs. Somehave not made the intellectual leap into chlorhexidine and Chloraprep as a skinpreparation. We cant mandate that. As a manufacturer, we are responsible forour technology and we follow the latest information, guidelines and standards ofpractice concerning catheter-related infections; we do not set those standards.Practitioners, through their research, set the standards they are expected topractice.

Guidelines, Recommendations

CDC officials report a variety of qualitymeasures HCWs should be following to minimize catheter-related infections. Theirinitial findings should come as no surprise: the shortage of HCWs and criticallevel staffing leads to higher rates of infection. They found specialized IVteams have shown unequivocal effectiveness in reducing the incidence ofcatheterrelated infections and associated complications and costs.¹

Recommendations concerning the site of catheterinsertion, type of catheter material, hand hygiene and aseptic technique,site-dressing regimens, skin antisepsis, securement devices, in-line filters,and others can be found in detail in the report. Notably, the researchers dorecommend the use of 2 percent aqueous chlorhexidine gluconate instead of thepreviously accepted use of povidone iodine for skin preparation.

Additional Invasive Devices

Foley catheter manufacturers are also investingin antimicrobial impregnation technologies. Anthony Conway, president and CEO ofRochester Medical, based in Stewartville, Minn., says catheter-associatedurinary tract infections are a proverbial thorn in his companys side.

Yet, they may have found an effective tool tofight this elusive enemy.

Nitrofurazone has been used for many years,he says. It is used topically for burn patients, for example, and has beenused in the last three of four wars in the field topically to prevent infectionin wounded soldiers.

With the drugs history on the market, Conwaysays its apparent durability led to its selection as companys antimicrobialof choice for their antiinfective line of Foley catheters.

The reason we selected nitrofurazone is thatit hasnt show resistance, he says. During 50 years of use, there hasbeen essentially no build up of resistance whatsoever. It is not an antibiotic it is a chemosynthetic. TI is a chemical. It has multiple kill mechanism andinterferes with not just cell walls but with enzyme production of cells in anumber of other ways. It is thought that the reasons for lack of resistantbuildup are because of this multiple kill mechanism. Also, it is notsystemically absorbed.

Because it isnt absorbed into the system,Conway says, resistance is also prevented.

The drug is not being exposed to bacteriathrough the rest of the body, which would increase chance for resistance, hesays. It seems to be the perfect fit. Many experts feel that urinary tractinfections create the largest reservoir in hospitals of potential bacteria poolsthat can help generate resistance. By reducing this pool with a topicalapplication, we certainly feel that it is a positive advancement.

The company specializes in anti-infective Foleyand intermittent catheters.

The best practice standards for infection controlremain critical: hand hygiene, appropriate personal protective equipment,protection of the sterile field and HCW education concerning invasive devicesshould be of utmost concern. HCWs should also keep their eyes open for moreproducts, both intravascular catheters and Foley catheters, that featureantimicrobial technologies.