Infection Control Today - 08/2003: Rolling Reservoirs

Rolling Reservoirs: Maintaining Aseptic Technique for Carts

By Kathy Dix

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

Now picture a cart medical supply cart, janitorial cart, laundry cart cutting a swath of filth through the spotless hallway. 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 to the operating room.

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

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

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

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


Barry Michaels, senior staff scientist at Georgia Pacific, maintains that personnel are the worst offenders, not inanimate objects.

But carts especially those carrying cleaning supplies can certainly be a problem.

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

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

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

We frequently find wet surfaces with bacteria surviving well, of the type that can cause infections, says Michaels. Typically when you see people that are infectious with, say, methicillin- resistant Staphylococcus aureus (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 a cart in one of these rooms could become contaminated, and if its wet, if it were just wiped down with a wiper and not an antimicrobial compound, then it could represent a hazard.

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

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

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

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

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

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

The concept of cross-contamination, he notes, isnt well understood, however. Its kind of nebulous. You hear it so much and every time you hear it, it diminishes the power of the concept ... You hear it quite frequently at conferences, yet the person thats right on the line constantly battling this, the healthcare personnel, I dont know if it really gets through to them. You constantly see review of hand hygiene or even surface disinfection and its lacking, because I dont think this concept has transported them into an understanding of how important it is to prevent it, continues Michaels.

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

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

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

In the end, good hand and surface hygiene is the best means of preventing infection. If you look at the ways of killing microorganisms, you can kill them by kinetic energy, you can kill them by chemical energy (in disinfectants) or by thermal energy, Michaels says. By kinetic, were talking good old-fashioned elbow grease. As you rub a surface that is contaminated, you entrap (pathogens) in the product but you also expose the ones that were lying tight against the surface to fresh disinfectant ... The part that cant be standardized is (that) everybody wipes a surface with more or 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 wiping or rubbing.

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

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

Michaels explains that cross-contamination will skew any risk assessment.

The fact is that cross-contamination will just undermine the mathematics because it can be so powerful. Its almost like a bomb; you dont know when its going to go off. Its extremes-driven. Its not based on an average amount, but on the extreme event because it can have such catastrophic results.


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

Innovatives Axen is a use dilution (12 parts per million) of the concentrate Axenohl, composed of one molecule of silver to one molecule of citric acid. Axen 30 is a use dilution of 30 ppm. It has three unique characteristics that should set the market standard for disinfectants, says Auerbach.

It has a 30-second kill on a standard indicator bacteria (Staphylococcus pseudomonas and salmonella) and then it has a two-minute kill on vancomycin-resistant Enterococcus (VRE) and MRSA, and it has a 30- second kill on listeria. It is virucidal and kills athletes foot fungus, (has a) two minute kill on E. coli, and then in viruses 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 be especially useful for killing VRE or MRSA in areas in which it is widespread, points out Brian Sasaki, microbiologist and technical sales manager at Innovative. In northern California, when you talk to ICUs, Ive asked them how high their incidence is, and one hospital said about 40 percent in ICU are suffering from MRSA. That statistic is via word-of-mouth and not documented, he points out.

That ICU is where the 24-hour residual effect would 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 in vitro, not in vivo; the compound is so new that in vivo testing has not yet been done.

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) puff spray instead of aerosol, Singer adds. You can apply it as floor cleaner, (even a) mop treatment.

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

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

Practical Applications

Virginia Abell, RN, is the director of infection control 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 reservoirs of infection, but they usually arent seen as a mode of transmission, she says. The key is back to basics on all that rolling stuff they have to be cleaned on a regular routine and as needed.

It is key to specifically designate who is responsible for cleaning each piece of equipment, whether it be custodial personnel or healthcare personnel. We assign all pieces of equipment to someones responsibility, Abell says. Dietary handles all of the dietary carts.

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

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

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

Asked about antimicrobials, Abell responds, Residual claims are all well and good. But 85 percent of infections are transmitted by the hands of caregivers. And there are not really chronic offenders in terms of equipment. No piece of equipment is particularly problematic unless you instrument the patient with it. If you enter the patients body with a piece of equipment like an endoscope, if that is contaminated, thats problematic.

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

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

Thats the reason for routine cleaning.

Standards vary from place to place. Almost everyones standards say (to perform cleaning) so often, plus as needed. Both JCAHO and APIC say you have to make a schedule. There may be some guidelines to help beginning people to have a feel that the side rails have to be wiped off after they are soiled, that you have to clean every room at discharge of a patient, those standard kinds of things.

There will always be some risk of infection, regardless of how well items are cleaned. Theres hospital-associated infection and it should be brought down to the lowest possible level, agrees Abell. But if you are going to take very sick people and instrument their bodies, the risk of infection is always there. Theres always a risk whenever you instrument a patient, break the barrier of his intact skin or GI tract or respiratory 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 a pretty resilient race and we manage to survive one way or another, Abell says.

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