An evaluation of varying protocols for high-level disinfection of flexible fiberoptic laryngoscopes

The Effectiveness of Ultraviolet Smart D60 in Reducing Contamination of Flexible Fiberoptic Laryngoscopes

OBJECTIVE

To compare the effectiveness of disinfection protocols utilizing a ultraviolet (UV) Smart D60 light system with Impelux™ technology with a standard Cidex ortho-phthalaldehyde (OPA) disinfection protocol for cleaning flexible fiberoptic laryngoscopes (FFLs).

METHODS

Two hundred FFLs were tested for bacterial contamination after routine use, and another 200 FFLs were tested after disinfection with one of four methods: enzymatic detergent plus Cidex OPA (standard), enzymatic detergent plus UV Smart D60, microfiber cloth plus UV Smart D60, and nonsterile wipe plus UV Smart D60. Pre- and post-disinfection microbial burden levels and positive culture rates were compared using Kruskal-Wallis ANOVA and Fisher's two-sided exact, respectively.

RESULTS

After routine use, approximately 56% (112/200) of FFLs were contaminated, with an average contamination level of 9,973.7 ± 70,136.3 CFU/mL. The standard reprocessing method showed no positive cultures. The enzymatic plus UV, microfiber plus UV, and nonsterile wipe plus UV methods yielded contamination rates of 4% (2/50), 6% (3/50), and 12% (6/50), respectively, with no significant differences among the treatment groups (p > 0.05). The pre-disinfection microbial burden levels decreased significantly after each disinfection technique (p < 0.001). The average microbial burden recovered after enzymatic plus UV, microfiber plus UV, and nonsterile wipe plus UV were 0.40 CFU/mL ± 2, 0.60 CFU/mL ± 2.4, and 12.2 CFU/mL ± 69.5, respectively, with no significant difference among the treatment groups (p > 0.05). Micrococcus species (53.8%) were most frequently isolated, and no high-concern organisms were recovered.

CONCLUSION

Disinfection protocols utilizing UV Smart D60 were as effective as the standard chemical disinfection protocol using Cidex OPA.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:3512-3519, 2023.

A cost comparison between reusable flexible and disposable laryngoscopes

OBJECTIVES

To compare the costs of disposable laryngoscopes to reusable scopes in outpatient and inpatient settings.

METHODS

The total variable and fixed costs involved in flexible scope reprocessing were collected from two general otolaryngology clinics, a pediatric otolaryngology clinic, and a children's hospital. Variable costs of disposable materials and labor were collected from 65 scope reprocessing events to identify the cost of reprocessing. Fixed costs of scope maintenance, monitors, video towers, and storage equipment were collected from financial records. Fixed and variable costs were analyzed to identify the cost per scope event. The costs were then compared to a theoretical model where disposable scopes were used to meet the volume demands of each clinic and children's hospital setting. The model of disposable scopes was generated after obtaining volume costs specific to each setting from a disposable scope company.

RESULTS

The average cost of a reusable scope model per scope event was $66.02 ± 4.49 at the three clinics and $130.66 at the children's hospital. The average cost of the disposable scope model per scope event was $152.55 ± 0.55 in the three clinics and $172.61 in the children's hospital. The cost differences were $86.53 ± 3.96 and $41.95 respectively.

CONCLUSIONS

In an outpatient clinic, reusable scopes are less expensive than a disposable scope model. In children's hospital inpatient setting, the difference in costs between disposable and reusable scopes is lower. When considering other non-economic factors, disposable scopes may be a feasible option, especially in the children's hospital setting.

Efficacy of Disinfection of Rigid Endoscope by Ethyl Alcohol 70%

Introduction  Currently, there is no safe, affordable, and ecologically-sustainable guideline that helps prevent contamination through endoscopy. We evaluated the safety of intermediate-level disinfection with 70% ethyl alcohol (w/v) based on biological-load recovery from rigid endoscopes after nasal endoscopy.

Objective  To demonstrate the efficacy of 70% ethanol in disinfecting rigid endoscopes (REs) to reduce microbial growth in microbiological cultures.

Methods  After a nasal endoscopy examination, the endoscope was swabbed with gauze; this served as the positive-control sample. The standard operating procedure for intermediate-level disinfection with 70% ethyl alcohol (w/v) following prior cleaning was applied. The endoscope was again swabbed; this served as the experimental sample. The collected material from the endoscope was extracted from gauze pieces, filtered through a 0.22-μm cellulose membrane, and cultivated in different means of culture.

Results  The results revealed a significant difference between the positive-control and experimental groups regarding the presence of Streptococcus coagulase (-) ( p  < 0.001), Bacillus spp. ( p  < 0.001), and Staphylococcus aureus ( p  = 0.001). These microorganisms were detected in the control group, but not in the experimental group.

Conclusions  Microorganisms were not recovered from the samples of the experimental group, demonstrating the efficacy and the germicidal action of 70% ethyl alcohol (w/v) as a means of achieving intermediate-level disinfection.

Experimental Study to Develop a Method for Improving Sample Collection to Monitor Laryngoscopes after Reprocessing

BACKGROUND/AIMS

The microbiological surveillance of endoscopes and automated flexible endoscope reprocessing have been proven to be two of the most difficult and controversial areas of infection control in endoscopy. The purpose of this study was to standardize a sampling method for assessing the effectiveness of standard reprocessing operating procedures for flexible fiberoptic laryngoscopes (FFLs).

METHODS

First, the sampling devices were directly inoculated with Bacillus atrophaeus spores; second, tissue non tissue (TNT) wipes were tested on artificially contaminated surfaces and on FFLs.

RESULTS

Comparison of the sponges, cellulose, and TNT wipes indicated that the TNT wipes were more effective in releasing spores (93%) than the sponges (49%) and cellulose wipes (52%). The developed protocol provides a high efficiency for both collection and extraction from the stainless steel surface (87% of the spores were removed and released) and from the FFL (85% of the spores were removed and released), with relatively low standard deviations for recovery efficiency, particularly for the analysis of the FFL.

CONCLUSION

TNT wipes are more efficient for sampling surface areas, thereby aiding in the accuracy and reproducibility of environmental surveillance.

High-Level Disinfection of Otorhinolaryngology Clinical Instruments: An Evaluation of the Efficacy and Cost-effectiveness of Instrument Storage

Objectives

Despite increasing interest in individual instrument storage, risk of bacterial cross-contamination of otorhinolaryngology clinic instruments has not been assessed. This study is the first to determine the clinical efficacy and cost-effectiveness of standard high-level disinfection and clinic instrument storage.

Methods

To assess for cross-contamination, surveillance cultures of otorhinolaryngology clinic instruments subject to standard high-level disinfection and storage were obtained at the start and end of the outpatient clinical workday. Rate of microorganism recovery was compared with cultures of instruments stored in individual peel packs and control cultures of contaminated instruments. Based on historical clinic data, the direct allocation method of cost accounting was used to determine aggregate raw material cost and additional labor hours required to process and restock peel-packed instruments.

Results

Among 150 cultures of standard high-level disinfected and co-located clinic instruments, 3 positive bacterial cultures occurred; 100% of control cultures were positive for bacterial species ( P < .001). There was no statistical difference between surveillance cultures obtained before and after the clinic day. While there was also no significant difference in rate of contamination between peel-packed and co-located instruments, peel packing all instruments requires 6250 additional labor hours, and conservative analyses place the cost of individual semicritical instrument storage at $97,852.50 per year.

Discussion

With in vitro inoculation of >200 otorhinolaryngology clinic instruments, this study demonstrates that standard high-level disinfection and storage are equally efficacious to more time-consuming and expensive individual instrument storage protocols, such as peel packing, with regard to bacterial contamination.

Implications for Practice

Standard high-level disinfection and storage are equally effective to labor-intensive and costly individual instrument storage protocols.