Sterilization is not enough for some particles

Materials Management in Health Care

Central Service departments that focus exclusively on sterilizing surgical instruments may be overlooking another problem.

Tiny particulates composed of fibers from clothing and fabrics, powder from latex gloves, dust and other matter cling to instruments. Even when this matter has been completely sterilized, it can cause post-surgical complications as serious as actual infections, according to Wava Truscott, director of scientific affairs & clinical education, Kimberly-Clark Health Care, based in Roswell , Ga.

“The message,” Truscott says, “ is even though it's sterile, it's still a problem.”

Her company makes disposable, one-use surgical gowns, drapes and other material that produce a relatively few particulates. But Truscott is also interested in the role of particulates in central services and mapped out the problem in a presentation at the annual conference of the American Society of Healthcare Central Service Professionals in Orlando last September.

Truscott says hospitals are rightly more interested in stopping pathogens that can be destroyed by sterilization, but she argues that CS departments should also be vigilant about particulates.

“A lot of CS people say, ‘No big deal, it's going to be sterilized,' ” she says. “But sterilizing instruments does not fix the problem.”

What can go wrong in central services

Truscott says CS managers get very interested when she shows them exactly where in the sterilization process that instruments can be contaminated. Here are a few examples:

* Paper or cloth towels, which are put on the bottom of instrument trays to sop up moisture from condensation, deposit lint on instruments. The same thing happens when instruments go through sterilization wrapped in cloth.

* W iping off instruments with a lint-laden cloth can actually mean wiping on particulates.

* Heavy traffic or air flow can spread fibers onto an exposed instrument.

* A dry climate produces static, attracting more particulates onto instruments, and produces dry skin, which creates more particulates.

* Bits of human tissue not removed from instruments pose the same threat as other particulates.

* The delinting machine for reusable fabrics may not have proper venting, bringing lint back into the room.

Truscott says quite a few people approached her after her ASHCSP presentation. “They know how critical the central services department is to the outcome of the patient,” she said.

After another presentation, a sterilization manager explained to Truscott how his hospital linked eye surgery complications to particulates in central services. Clinicians were finding little bits of blue lint in patients' eyes and noticed that CS was using blue towels to hold open forceps during sterilization.

Frank Sizemore , a past president of the ASHCSP who has attended a Truscott presentation, says he thinks she has a point. “If we don't do our job right, this is a very plausible outcome,” he said, referring to surgical complications.

Ernesto Gonzalez , an ASHCSP board member, had mixed feelings after attending the September presentation.

“Worrying about fibers that do not have pathogens is important, but it is a lower priority than worrying about pathogens,” he said. “So far, we're not doing a good enough job with infections. Once we have them solidly in retreat, then this could be the next frontier.”

How big of a problem?

Truscott, who holds a PhD in comparative pathology, says she first learned of particulates years ago while studying latex allergies. She found that the protein from latex gloves could cause wound-healing problems in addition to generating allergies.

She says particulates create several kinds of complications that can slow the healing process, add extra patient days, and, in some cases, lead to death:

* Amplified inflammations, where the skin turns red and exudes pus.

* Granulomas, which are inflammatory lesions. Like pearls, they form around a foreign object and sop up fluids and white blood cells.

* Adhesions, or abnormal joinings of bodily tissues. When the body tries to wall them off, they tend to get thicker, sometimes requiring a risky second surgery to remove them.

* Complementary infections, which are allowed to grow because white blood cells are busy fighting foreign particles.

Amplifying the last point, the CDC's 1999 Guidelines for Prevention of Surgical Site Infection state that “Any foreign body…may increase the probability of surgical site infection after otherwise benign levels of tissue contamination.”

Experts still debate the threat

Some experts, however, dispute some of the links Truscott has made between sterile particulates and surgical complications.

Barbara Trattler, RN, administrator of perioperative services at Monmouth Medical Center, Monmouth, N.J., questioned the connection in a recent two-part article, Prevention of Surgical Site Infections, in the December 2004 and January 2005 issues of the publication Managing Infection Control.

“The literature does not identify lint or granulomas as a factor in surgical site infections where the causative factor/etiology of the granulomas was lint,” Trattler wrote, though she conceded that “the literature is quite extensive on the relationship of glove powder and the development of granuloma.”

Trattler was not available for an interview.

Truscott, in response, points to several scientific studies that link surgical complications with lint and other particulates. Here are the findings from three of them:

* A 1997 study of coronary stent implants in the journal Catheterization and Cardiovascular Diagnosis found that 42 percent of patients with stent thrombosis had particulates enmeshed in the thrombi.

* In a 1984 study in the American Journal of Surgery, c ellulose fibers induced granulomatous reactions and adhesion formation, and six of those cases involved severe granulomatous peritonitis, with one leading to death.

* A 1977 study in the American Journal of Surgery found 45 consecutive post-operative cases of cellulose fiber granulomatous disease after switching to cellulose-based drapes.

Some surgery groups recognize the dangers of particulates.

Standards of the Association of Operating Room Nurses focus on the problem of lint from gowns and drapes that carry bacteria. AORN states that “bacteria-carrying lint may settle in surgical sites and wounds with a resulting increase in post-operative patient complications.”

Meanwhile, the Council for Refractive Surgery in Sacramento , Calif. , reports that particulates in LASIK surgery create a condition called diffuse lamellar keratitis, which creates fine white grainy cells in the eye. “Although the infiltrates are sterile,” the Council reports, “the cornea attacks them and, if left unchecked, will destroy itself, causing serious damage and permanent reduction in visual acuity.”

The council says the problem stems from steam-sterilization of ophthalmic instruments. The condensed water cannot be completely emptied and dead infiltrates collect in it, then attach to the next sterilized instrument.

New fabrics give off less lint

While experts continue to debate the role of particulates, makers of disposable health care textiles are already dealing with it.

Manufacturers have been switching from paper-based disposables, which generate a lot of lint, to products made of more expensive polymers, which have very little lint and are also fluid- and flame-resistant.

The industry, which generates $7 billion in sales a year, boarded the non-linting bandwagon because companies are “trying to differentiate themselves in any way they can,” said a representative of one of the manufacturers, who did not wish to be identified. “We use non-linting as a selling feature.”

Curt Koehn, director of marketing for converters at Cardinal Health in Dublin , Ohio , says he is not aware of studies showing a link between lint and surgical complications, but the link makes sense, and Cardinal Health is taking it seriously with a new line of low-linting drapes and gowns.

When nonwovens made out of paper began replacing reusuable fabrics more than a quarter century ago, levels of particulates shot up. An abrasion test reported by AORN shows how. Nonwoven cellulose laminate produced 632 times as much lint as woven fabrics.

While the weave in fabrics helped keep lint from shedding, the wood fibers in paper products are no more than 1/8th of an inch long and can easily fall out, Koehn says. In contrast to wood pulp, he says Cardinal Health's new polymer fibers are as long as a football field and they lint even less than the fabrics.

The polymers are getting better. Cardinal Health reports that its new drape generates 99 particles per cubic foot per minute in a Gelbo flex linting test, while its new surgical gown generates 220 particles per cubic foot. Dupont Medical Fabrics, based in Nashville , and Kimberly-Clark report very roughly the same levels for their polymer drapes and gowns. In contrast, paper-polyester drapes, the older standard, generated 8,660 particles per cubic foot in a Gelbo flex test performed by Dupont.

But while drape and gown manufacturers seem close to eradicating lint in their products, other materials commonly used in ORs are still raining lint and fibers into the OR. Fiber lap sponges generate 10,000 particles per cubic foot in the Dupont test; bath blankets, 60,000 particles; cotton towels, 100,000 particles; and paper towels produce a whopping 180,000 particles in the test.

Paper and cloth are still used because they are more absorbent than plastic, sopping up blood in the OR or condensation in sterilization trays in CS. Similarly, Truscott estimates that about half of OR workers still use p owdered gloves because they are easier to pull on and off.

Meanwhile, a lot of hospitals never switched to nonwovens and still use fabrics. Sizemore, the past ASHCSP president, says his hospital, Wake Forest University Baptist Medical Center in Winston-Salem , N.C. , uses fabrics almost exclusively because it has its own on-site laundry and nonwovens are less expensive.

Groups like AORN say fabrics can generate acceptable levels of lint if they are removed from circulation when they start degrading. Some manufacturers place grids on the fabric that you can check each time they are washed, discarding the article when it has been washed a certain number of times. Rather than use the grids, Sizemore says staff at his hospital check each piece of fabric for signs of deterioration.

Some pointers

Truscott has a checklist of steps you can take to control particulates. Some examples are:

* Close doors and reduce nearby traffic.

* Humidity should be set between 30% and 60%, with 50% the optimal setting.

* Clean your transport carts of lint regularly.

* C lean all surfaces regularly, even those that are across the room, using a non-linting towel or mop.

* Wear hair gear and don't wear sweaters or powdered latex gloves.

* Instead of placing a towel at the bottom of the sterilization tray, use a containerized tray. Instruments are placed in baskets that are elevated above the bottom so that water does not touch the instrument.

And if you are unsure how much lint a fabric is emitting, Truscott recommends a simple test. Rub it three or four times, then turn it 180 degrees and rub it three or four times more. Then affix clear packing tape on the area and pull it off, then check how much lint is on the tape.

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