Infection Control Today - 08/2003: Rolling Reservoirs

August 1, 2003

Rolling Reservoirs: Maintaining AsepticTechnique for Carts

By Kathy Dix

Picture a clean, pristine hospital environment floors, walls and doors that are pathogen-free, furniture that has beenappropriately cleaned, even office equipment that has been sanitized within aninch of its life.

Now picture a cart medical supply cart,janitorial cart, laundry cart cutting a swath of filth through the spotlesshallway. This cart has been used to transport medical waste to the incinerator;to carry soiled laundry to the laundry room; or to carry new medical supplies tothe operating room.

If the cart originated in the janitors closet,it was surrounded by mops, buckets and bottles of disinfectant or sanitizer. Ifthese materials have not been cleaned properly, they will transmit whateverpathogens they carry to the cart, regardless of whether or not it has beenappropriately cleaned after its last sojourn through the hospital. This carttravels into reception areas, including the emergency room (populated withplenty of pathogens); operating rooms; intensive care units; pre-op and post-oprecovery areas; the cafeteria and break rooms; restrooms and laboratories.

If the cart originated in the medical supplycloset, it will have to advance through the hallways to reach the operating roomor patient room. What pathogens is it being exposed to in the halls? Or is itcovered so that clean or sterile items remain clean or sterile?

If the cart started in the patient room or the ORand is now carrying soiled linens to the laundry, the laundry may be bagged, buthas the cart been exposed to the pathogens it carried pre-bagging?

Is the cart and its contents being cleanedbetween areas? If not, why not? Arent staff members required to change gloveswhen moving from one area of the hospital to another? Certainly humans are onemode of transmission, but so too are inanimate objects. Although their method oftransmission is passive rather than active, they can still be a source ofinfection.

Theory

Barry Michaels, senior staff scientist at GeorgiaPacific, maintains that personnel are the worst offenders, not inanimateobjects.

But carts especially those carrying cleaningsupplies can certainly be a problem.

Theyve frequently been found to becontaminated and the cause of various infection outbreaks, Michaels says. Youwouldnt think that cleaning items transport pathogens, but it stands toreason ... Carts become an issue certainly when youre talking aboutconstruction, and, in fact, fallout from construction has been associated withoutbreaks. If you have carts they should be covered if theyre anywhere nearthose areas or being transported through those areas.

Another ubiquitous item throughout the hospitalis floor-cleaning equipment and polishing equipment. Michaels references aposter presentation at last months Association for Professionals in InfectionControl and Epidemiology (APIC) meeting, which documented high particle countsin the air from use of the floor waxer. This (head researcher) was in chargeof infection control at the specific hospital (at which the tests occurred),said, Were starting to wonder if we dont need our floors waxed becauseit represents such a great hazard, he says.

Michaels points out that particles on the floorcan become particles in the air, which can settle on surfaces and then betouched by medical personnel or patients and transferred to other people orobjects. And wet surfaces only complicate the problem. This applies to alltypes of equipment, whether its a cart or surgical tools or equipment orhands. Wet objects ... can pick up and then transfer more microorganisms thandry objects. This is one of the main principles of cross contamination theefficiency of transfer is much greater when things are wet. Wet acts likeflypaper when you think about it ... Anything that comes into contact (with wetobjects) and thus becomes wet is carrying a microbial load with it as well,he says.

We frequently find wet surfaces with bacteriasurviving well, of the type that can cause infections, says Michaels. Typicallywhen you see people that are infectious with, say, methicillin- resistant Staphylococcusaureus (MRSA) or some of the other multi-drug resistant microorganisms,anything in their environment will tend to be contaminated,

he points out. Its easy to imagine that acart in one of these rooms could become contaminated, and if its wet, if itwere just wiped down with a wiper and not an antimicrobial compound, then itcould represent a hazard.

Transport of patients also creates othercross-contamination issues. Whether its in a wheelchair or varioustherapy-related carts or chairs, (such an object) certainly runs risk oftransfer to another patient if its not cleaned and disinfected properly.

Michaels recalls another APIC presentation aboutthe newer vancomycin-resistant Staphylococcus aureus (VRSA) and aretrospective of how only a few initial cases of MRSA led to a widespreadproblem in many hospitals. The feeling is that unless they do somethingdrastic, its only going to be a matter of time before we see another repeatof MRSA, he says. And VRSA could be much more drastic.

According to the study, Michaels says, onedialysis patient with VRSA was handled with kid gloves. They made sure thatthis patient wasnt allowed into the waiting room, didnt sit on any of theseats, wasnt transported on any of the wheelchairs, until every other patientwas out of there and the entire place could be decontaminated after this patientleft ... This person was basically bagged before entering the hospital sotransport through the hospital didnt cause any airborne spread, or anycontact with that foot would not result in leaving infectious material onequipment ...

When you start looking at it in those terms, itmakes this kind of equipment very important and disinfection of this equipmentvery important.

Likewise, severe acute respiratory syndrome (SARS),Michaels says, is also treated harshly. No treatment is considered off-baseor too exorbitant, he adds. You have multiple disinfectant treatments ofanything in these areas;

in fact this kind of exaggerated infectioncontrol has been credited with reducing the size and scope of the outbreakswhere it has been able to be exorcised in a thorough manner.

The concept of cross-contamination, he notes, isntwell understood, however. Its kind of nebulous. You hear it so much andevery time you hear it, it diminishes the power of the concept ... You hear itquite frequently at conferences, yet the person thats right on the lineconstantly battling this, the healthcare personnel, I dont know if it reallygets through to them. You constantly see review of hand hygiene or even surfacedisinfection and its lacking, because I dont think this concept hastransported them into an understanding of how important it is to prevent it,continues Michaels.

Cross contamination can take place in a veryshort period of time, Michaels says. You wheel a cart in, it becomescontaminated with either secretions from a patient or microscopic contaminants(in which) the amount of secretion may be very minimal, but the surfaces arestill contaminated.

A healthcare person touches a surface, touchesthe cart handles handles have been identified as frequently contaminated then goes to the next patient room and touches the patient after touching thecart handle.

Its such a short period of time, perhaps lessthan a minute, that (even in an antimicrobial-coated surface) the antimicrobialsin these kinds of compounds wouldnt be able to act fast enough.

In the end, good hand and surface hygiene is thebest means of preventing infection. If you look at the ways of killingmicroorganisms, you can kill them by kinetic energy, you can kill them bychemical energy (in disinfectants) or by thermal energy, Michaels says. Bykinetic, were talking good old-fashioned elbow grease. As you rub a surfacethat is contaminated, you entrap (pathogens) in the product but you also exposethe ones that were lying tight against the surface to fresh disinfectant ... Thepart that cant be standardized is (that) everybody wipes a surface with moreor less vigor. The more vigor, the more elbow grease, the more kinetic energy,and the better your results.

In many cases, a two-stage process is the answer:wiping or removing the soil, then application of a disinfectant and more wipingor rubbing.

Many organic soils will inactivate sanitizers.By getting rid of that soil first, you make the sanitizer that much moreeffective, Michaels explains.

When quantitative microbial risk assessment isconducted, it reveals that the efficacy of the method or treatment is not theonly factor. Its also the frequency at which that process gets done, andthe idea that youre not introducing cross-contamination, says Michaels.A good example if were talking about carts is that I could disinfect acart often with a disinfectant with high effectiveness. But if the wiper that Imusing is contaminated, then youre contaminating it often. You have toeliminate the cross-contamination part. You could have a highly effectiveprocess but not do it often enough so its always contaminated. Itsfrequency, effectiveness and cross-contamination that you really need to controlall at the same time in order to lower the risk of infection. Likewise, youcould do it a lot and not have an effective method and all youre doing isbasically wasting your energy.

Michaels explains that cross-contamination willskew any risk assessment.

The fact is that cross-contamination will justundermine the mathematics because it can be so powerful. Its almost like abomb; you dont know when its going to go off. Its extremes-driven. Itsnot based on an average amount, but on the extreme event because it can havesuch catastrophic results.

Materials

Asked if there are new materials that can helpclean carts more effectively, Gene Auerbach, chief operations officer atInnovative Medical Services says that a new disinfectant just approved by theEnvironmental Protection Agency (EPA) in March may prove a useful tool.

Innovatives Axen is a use dilution (12 partsper million) of the concentrate Axenohl, composed of one molecule of silver toone molecule of citric acid. Axen 30 is a use dilution of 30 ppm. It hasthree unique characteristics that should set the market standard fordisinfectants, says Auerbach.

It has a 30-second kill on a standardindicator bacteria (Staphylococcus pseudomonas and salmonella) and thenit has a two-minute kill on vancomycin-resistant Enterococcus (VRE) andMRSA, and it has a 30- second kill on listeria. It is virucidal and killsathletes foot fungus, (has a) two minute kill on E. coli, and then inviruses it has 30-second kill on HIV type 1, one minute on herpes simplex one,and 10 minutes on rhinovirus, influenza A, and poliovirus type 2.

Axenohl (silver dihydrogen citrate) may beespecially useful for killing VRE or MRSA in areas in which it is widespread,points out Brian Sasaki, microbiologist and technical sales manager atInnovative. In northern California, when you talk to ICUs, Ive asked themhow high their incidence is, and one hospital said about 40 percent in ICU aresuffering from MRSA. That statistic is via word-of-mouth and not documented,he points out.

That ICU is where the 24-hour residual effectwould be particularly handy. Related to carts, etc., (that would be useful)on a regular basis, not only for initial protection, but sustained protection,Singer says. However, he points out, testing showing this statistic was done invitro, not in vivo; the compound is so new that in vivo testing has not yet beendone.

Axen is approved as a hard-surface disinfectant.It can be used on carts, tables, floors, plastics, metals, seals or doorknobs,says Donna Singer, executive vice president of Innovative. (Its a) puffspray instead of aerosol, Singer adds. You can apply it as floor cleaner,(even a) mop treatment.

One thing people like about it in a hospitalsituation is its nontoxic, so you dont have to take a patient out of theroom, says Auerbach. A lot have asthmatic problems and if you go in with aquat or phenol it bothers them. (Axen) doesnt bother them.

Axen has the added bonus of being non-corrosiveon carts, Singer points out. And the 24-hour residual effect means that cleaningdoes not have to be done as frequently, adds Auerbach. Use of the disinfectantis relatively simple. Spray it on and wipe it off after two minutes. Thereason is to make sure youve covered the resistant bacteria, Auerbachaffirms.

Practical Applications

Virginia Abell, RN, is the director of infectioncontrol and clinical safety at Summa Health System in Akron, Ohio. I think,first of all, the basic carts do not transmit infection. They may be reservoirsof infection, but they usually arent seen as a mode of transmission, shesays. The key is back to basics on all that rolling stuff they have to becleaned on a regular routine and as needed.

It is key to specifically designate who isresponsible for cleaning each piece of equipment, whether it be custodialpersonnel or healthcare personnel. We assign all pieces of equipment tosomeones responsibility, Abell says. Dietary handles all of the dietarycarts.

Certain supply carts on the nursing unit arenursing personnels responsibility. In our system, its hard to find a spotwhere someone says , Well, I dont know who cleans it, but I dont,because everybody pretty much knows whose responsibility it is for what piecesof equipment.

Some responsibilities may change based on thestatus of the patient room, for example.

The patients bed unit if occupied is nursings responsibility, Abell explains. At discharge, it is theresponsibility of our environmental services.

Asked about antimicrobials, Abell responds, Residualclaims are all well and good. But 85 percent of infections are transmitted bythe hands of caregivers. And there are not really chronic offenders interms of equipment. No piece of equipment is particularly problematic unlessyou instrument the patient with it. If you enter the patients body with apiece of equipment like an endoscope, if that is contaminated, thatsproblematic.

As far as carts, they need to be on a routinecleaning schedule. But as long as theyre on a routine cleaning schedule, theyshouldnt be implicated as an infection reservoir, she points out.

Certainly gram-negative organisms have apropensity for environmental surfaces. Any small amount of material will allowgram-negatives to survive for some amount of time, Abell cautions.

Thats the reason for routine cleaning.

Standards vary from place to place. Almosteveryones standards say (to perform cleaning) so often, plus as needed. BothJCAHO and APIC say you have to make a schedule. There may be some guidelines tohelp beginning people to have a feel that the side rails have to be wiped offafter they are soiled, that you have to clean every room at discharge of apatient, those standard kinds of things.

There will always be some risk of infection,regardless of how well items are cleaned. Theres hospital-associatedinfection and it should be brought down to the lowest possible level, agreesAbell. But if you are going to take very sick people and instrument theirbodies, the risk of infection is always there. Theres always a risk wheneveryou instrument a patient, break the barrier of his intact skin or GI tract orrespiratory tract. (You must) weigh the benefit versus the risk of infection.

Although infection is unlikely to disappear,chances are good that humans will manage to work around the risks. We are apretty resilient race and we manage to survive one way or another, Abellsays.