Performance Analysis of Exam Gloves Used for Aseptic Rodent Surgery

Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP–PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham ‘exertion’ activity. According to these criteria, 94% of HP–PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP–PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries.Abbreviations: HP–PA, hydrogen peroxide and peracetic acidThe Guide for the Care and Use of Laboratory Animals (the Guide) states that “general principles of aseptic technique should be followed for all survival surgical procedures.”⁹‘Aseptic technique’ refers to practices that reduce microbial contamination to the lowest possible practical level and includes: preparation of the patient; preparation of the surgeon including decontaminated surgical attire, surgical scrub, and sterile surgical gloves; sterilization of instruments, supplies, and implanted materials; and careful tissue handling during surgery to reduce the likelihood of infection. The Guide also states that “The species of animal may influence the manner in which principles of aseptic technique are achieved.”⁹ Therefore, although aseptic technique should be followed for survival surgeries in rodents, flexibility exists in the means by which asepsis is achieved. Aseptic approaches that are more economical or efficient yet maintain performance standards should be acceptable to the IACUC overseeing the animal care program. The recommendation to wear sterile surgical gloves for survival surgeries in rodents exists to limit contamination of the surgical site by bacteria on the surgeon''s hands and thus reduce the likelihood of a postsurgical infection. Under the Association for Practitioners in Infection Control guidelines, sterilization is defined as “the complete elimination or destruction of all forms of microbial life.”^19-21 However, many laboratory workers fail to wear the recommended type of gloves for rodent surgery, primarily due to the high cost of sterile surgical gloves.⁴The purpose of the current study was to evaluate the performance of more economical and efficient alternatives to sterile surgical gloves for use in rodent survival surgery. The alternatives chosen were surface disinfection with 70% alcohol, HP–PA, and autoclaving for preparation of standard nitrile and latex exam gloves. We evaluated latex and nitrile exam gloves because both are commonly available in the laboratory. Disinfectants are readily available in most animal use areas, inactivate most pathogenic microorganisms, and therefore represent a convenient option for aseptic glove preparation for rodent survival surgeries.²⁰ Isopropyl alcohol (70%) is used as an antiseptic for a variety of procedures in a medical setting including injection site preparation and as part of surgical site preparation. The Guide, however, states that “alcohol is neither a sterilant nor a high-level disinfectant.”⁹ Alcohol is classified as an intermediate-level disinfectant, meaning that it does not kill bacterial spores or hydrophilic viruses.¹⁷ Nonetheless, alcohols at concentrations ranging from 60% to 90% are reported to have excellent microbicidal properties² and significantly reduce the microbial load on contaminated surfaces,⁷ hands,^{15,17,18, 22} and gloves inoculated with test organisms.⁵ A recent study found that soaking the fingertips of sterile surgical gloves in 70% isopropyl alcohol for 30 s between 5 serial mouse laparotomies effectively disinfected the gloves and prevented bacterial contamination.¹⁰ Because unused exam gloves presumably have low levels of bacterial contamination, alcohol might render them aseptic.HP–PA solutions are common disinfectants within the animal vivarium for the disinfection of biosafety cabinets and gloves when working with SPF rodents. A solution comprising 1.00% hydrogen peroxide and 0.08% peracetic acid is considered to be a chemical sterilant suitable for use on critical items that come into contact with sterile patient tissues, as in surgery.²¹ Product availability to animal users and use applications make HP–PA solution a reasonable choice for exam glove disinfection.In addition to chemical disinfection of exam gloves, another readily available option in most animal facilities is steam sterilization in an autoclave. The surgical instruments used for rodent surgery are commonly prepared by using autoclaving, and the addition of standard exam gloves to the surgical pack is another possible alternative to sterile surgical gloves for rodent surgeries. The existing reports on autoclaving of medical gloves date back to the 1960s and refer to reusable surgical gloves. These studies found that autoclaving methods made the gloves unusable or increased breakage;^6,14 however ,glove materials, manufacturing practices, and quality control criteria have changed greatly since then,²³and the most recent updates to test procedures and acceptance criteria for medical gloves in the United States were made in 2006.³ The gloves we selected for evaluation conform to industry standards regarding leaks and visual defects, according to the manufacturer.For this study, we hypothesized that surface disinfection of exam gloves with 70% isopropyl alcohol or HP–PA solution would effectively decrease microbial contamination of exam gloves to a level equivalent to that of sterile surgical gloves and that the disinfection process would not predispose the gloves to contamination from the surgeon''s hands during use. In addition, we hypothesized that autoclaving of exam gloves would have a detrimental effect on performance compared with that of sterile surgical gloves and that autoclaving could render exam gloves unwearable, cause defects in the gloves, or increase the porosity of the glove materials.