Public heatlh practice issue: Assessment of existing environmental controls and occupational exposure risks during high-level chemical disinfection in the outpatient clinic setting.

摘要

In the United States, healthcare clinics such as ambulatory surgery centers and physicians' offices are conducting outpatient surgeries and invasive procedures at an increased rate because of cost benefits, convenience, and advanced technology. Care is being provided in the outpatient setting involving semi-critical or critical instruments such as endoscopes, vaginal probes, and surgical tools which must be disinfected prior to reuse to prevent healthcare-associated infections. Glutaraldehyde and ortho-phthaladehyde (OPA) are widely used high-level disinfectants (HLDs) for semi-critical and critical medical instruments, but these chemicals have been shown to represent a health risk to workers by The National Institute for Occupational Safety and Health (NIOSH)9. While there is published literature on use of these chemicals in the hospital setting, as well as environmental controls and occupational exposure risks, the prevalence and conditions in outpatient clinics has not been well documented. The purpose of this study was to determine which outpatient clinics used high level disinfection, if healthcare workers in these settings had the potential for being exposed to levels at or above regulatory or recommended thresholds and whether the clinics are incorporating recommended environmental controls. Sixteen outpatient clinics were initially assessed for medical instrument reprocessing activities, including the type and volume of chemical disinfectant, type of instrument undergoing reprocessing, type of container used to hold the disinfectant during reprocessing and current engineering controls present. The building was also characterized into one of five defined categories based on building setup. Sample measurements were then recorded for room air changes per hour (ACH) and glutaraldehyde exposure levels (ppm). Sampling for OPA was not performed due to the current absence of both a standardized sampling protocol and an associated recommended exposure limit.14 Only three of the sixteen clinical areas assessed exhibited a mean ACH at or above the standard ACH of 10. Only four of the sixteen clinics used glutaraldehyde based HLDs, the remaining clinics used OPA. These four clinics' measurements resulted in <0.04ppm glutaraldehyde for 15 minute exposure and additionally 15 minutes prior to and post exposure for both the worker breathing zone and work area, which is below the American Conference in Governmental Industrial Hygienists (ACGIH) recommended short term exposure limit of 0.05ppm. The ACGIH short term exposure level was used because the handling of the chemical was general completed within a 15 minute period. Glutaraldehyde does not have an established Permissible Exposure Limit (PEL) set by the Occupational Safety and Health Administration (OSHA), but has a NIOSH Recommended Exposure Level (REL) of 0.2ppm for an 8 hour day. Seventy five percent of the clinics in the study were categorized as being located in medical office buildings. However, no significant relationship between building category and ACH rates was detected. Although no chemical exposures in excess of recommended levels were detected, studies have indicated that reported asthma is significantly greater in nurse professionals involved in instrument cleaning4, and that asthma can develop at levels well below standards in most countries10. Some simple preventive measures can be put in place to control unnecessary exposures, including the acquisition of engineering controls (free-standing vapor capture systems) and neutralization agents for disposal, as well as improvements to the current policies on HLDs. Routine monitoring for chemical exposures in the outpatient clinic work settings should be considered prudent because some sites may not possess recommended engineering controls.