If you're adhering properly to AORN guidelines, your nurses are cleaning horizontal surfaces in the operative field between every case, every day. The group argues, quite rightly, that "although it is difficult to define the level of contamination necessary to increase surgical wound infection rates, a clean surgical environment will reduce the number of microbial flora present."1

That adds up to a lot of cleaning and disinfecting. While it's not an especially demanding task, you must ensure staff are thorough and provide them with efficacious tools for the job. Here's what you need to know about surface disinfectants to help you choose what's best for your ORs.

Determining your needs The Association for Professionals in Infection Control's guidelines on disinfection call for you to remove all organic matter, such as blood, tissue and mucous, from equipment that comes into contact with patients. You should do this by first mechanically cleaning those surfaces - even if they look clean - and then disinfecting them by scrubbing or mopping with a good old-fashioned combination of water and some form of detergent or disinfectant. The idea is to kill as many microbes as possible in order to reduce the chance they'll find their ways into the patient and cause a surgical site infection.

Because disinfectants are designed to kill bacteria and viruses, they are toxic (as well as corrosive, irritant and, in some cases, carcinogenic), so you should use the minimum level of microbe kill that meets your needs. Low-level disinfectants are all you need to deal with the OR floor and non-critical patient care equipment such as the OR table and its attachments.2

APIC lists five types of disinfectant "solutions for use on non-critical patient care equipment." Contact time should be 10 minutes or less on each, again because of the potential risks they pose:

• ethyl or isopropyl alcohol (70% to 90% concentration)
• sodium hypochlorite (5.2% household bleach) at 1:500 dilution (100ppm free choline)
• phenolic germicidal detergent solution (check your product's label for use-dilution)
• iodophor germicidal detergent solution (check label) and
• quaternary ammonium germicidal detergent solution (check label).2

Before you buy a disinfectant, review the labeling information with the sales rep or on the manufacturer's Web site to ensure that the solution you're considering is compatible with the surfaces you'll be using it on and will handle the microbes you need to kill. For example, if you work in a GI center or do a lot of colonoscopies, buy a product that's effective against C. difficile (the vegetative form, not the spores, which are highly resistant to chemical inactivation and for which there are as yet no approved options in the United States).

Let's take a look at each kind of disinfectant.

• Alcohol solutions. As you know, alcohol produces a broad-spectrum microbe kill in a relatively short amount of time (10 minutes). That's why alcohol-based gel rubs are being recommended left and right for spot disinfection of the hands in the operative setting. The duration of the kill is short, though this might not be a problem if your room turnovers are speedy, such as in cataract surgery. In addition, alcohol is harsh and tends to break down the pads on the OR table fairly quickly. (Hand rubs have added compounds to ameliorate both these problems.)
• Sodium hypochlorite (bleach) solutions. Even more harsh than alcohol, but it gets the job done with a broad-spectrum kill in a shorter contact time - as little as two minutes. Recommended by the CDC for disinfecting surfaces that have come into contact with blood. Some products are formulated as cleaner-disinfectants. Staff are going to have to take care to wear the proper personal protective equipment, because of the potential for eye, nose and throat irritation; make sure the OR has been well ventilated before patients arrive for their procedures.
• Phenolic solutions. These are efficacious for killing bacteria, viruses and fungi, with a contact time similar to alcohol's. They have the added advantage of killing tuberculosis, pseudomonas and staphylococcus. Highly irritating to skin, eyes, noses and throats, phenol-based products are also hard on whatever they're used on. They may be formulated as a two-in-one cleaner-disinfectant.
• Quarternary solutions. What you give up in harshness, you lose in efficacy: Many of these products don't kill tuberculosis or hepatitis B. Solutions that contain both alcohol and quarternary amines are especially effective at ridding an OR surface of bioburden. They may also be a cleaner-disinfectant.

These aren't your only options, just the ones that are tried-and-true. The EPA has recently approved several surface disinfectants that don't contain corrosive hypochlorites or caustic phenols. One's active ingredient is non-toxic citric acid; the other's active mechanism is oxidization, which destroys rather than poisons pathogens' membranes to kill them.

Waste not, want not Your procedures surrounding storage and handling of disinfectants can standardize cleaning to make it more efficacious, while also helping to ensure you don't waste solution. A few tips:

• Don't disinfect if you don't have to. If the surface never came into contact with body fluids, bioburden or broken skin, cleaning solution may suffice.
• Dilute properly. I've said it before and I'll say it again: More is not always better when it comes to killing microbes. Too high a disinfectant-to-water ratio throws off its ability to do what you want it to - not to mention, it'll leave a residue and it wastes expensive solution. You should also track the dilution: Record the name and date it was performed, along with the expiration date.
• Use only what you need. Just as you want to meet the minimum level of microbe kill that meets your needs, you want to use the minimum amount of solution to cover the surface. Throwing away nearly a gallon because all you needed was a quart is just wasteful.
• Store, dispense and apply conscientiously. Keep containers where they won't be knocked over. Make sure the mechanism for dilution and dispensing doesn't put you at risk for spills - pumps, spigots and spray nozzles (instead of pouring) can all help keep this to a minimum. Don't soak a surface when just a coating will do.
• Keep up with par levels. Stock your disinfectants as you would any other high-use supply in your facility. Maintaining par levels according to what your needs are can help you avoid having to dispose of extra or outdated containers; this can be expensive because, at original high concentrations, unused disinfectants usually have to be disposed of as hazardous waste. You pay for that by the pound - and you know how heavy those containers can be.

Disinfectant-impregnated wipes (towelettes) are being touted as a solution to many of the causes of disinfectant waste. Not only do they make for safer delivery, because you're not spraying potentially hazardous chemicals into the air, but they also potentially offer convenience by saving you a step in the cleaning process. (They also usually come in a few sizes, so you can use what suits the surface you're cleaning or disinfecting.)

Depending on the formulation of disinfectant, the towelettes will possess the same microbial kill features as their liquid-only counterparts. Keep in mind that the EPA requires producers of commercially prepared pre-moistened wipes to modify label-use instructions to reflect the steps necessary to assure complete disinfection of inanimate patient care surfaces. EPA-required instructions state that "the surface must remain visibly wet for the prescribed contact time in order to produce disinfection."

If the disinfection time listed on the label is 10 minutes, the surface must remain visibly wet for the entire 10 minutes - letting the solution evaporate and air dry before the required contact time required for the product to work puts patients and staff at risk. This is because microorganisms, such as HBV and staphylococcus aureus, are able to survive for long periods of time on dry surfaces.

Remember, no matter what solution you choose, the label is there for a reason: to guide you on dilution ratios, contact time and methods of application. Have a written policy that covers all these factors, and ensure staff are trained in each of these practices.

>References
1. "Recommended practices for environmental cleaning in the surgical practice setting." AORN Journal 1998 Feb. Accessed at http://findarticles.com/p/articles/mi_m0FSL/is_n2_v67/ai_20651299
2. Association for Professionals in Infection Control and Epidemiology, Inc. "APIC guideline for selection and use of disinfectants." Am J Infect Control 1996 Aug;24(4):313-42. Accessed at http://www.guideline.gov/summary/summary.aspx??ss=6&nbr=1454&doc_id=2228