Investigation of the efficiency of different reprocessing methods on disposable laryngeal masks contaminated with HBV...

The use of laryngeal masks (LM) has increased widely today, both in anesthesia and in emergency cases. LM are available as reusable and disposable. Although reuse of disposable LM is not recommended, they are reused again after decontamination with different methods in anesthesia units in some countries. The reprocessing of single-use LM was therefore investigated. The hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) are pathogens that can pass into saliva. It is known that the HBV is more resistant to decontamination methods as compared to HCV and HIV.

In this study, it was aimed to investigate the effectiveness of different decontamination methods on disposable and reusable LM and to evaluate the reusability of disposable LM after they were treated with simulated saliva samples containing HBV DNA.

The observational study was carried out in Medical Microbiology Department of Erciyes University Medicine Faculty between March 2016 and Mach 2018.

Simulated saliva samples were prepared, and plasma samples of patients with plasma HBVDNA levels of 10⁸IU/mL were inoculated into these samples. HBV DNA levels in saliva samples were investigated by the real-time PCR (Qiagen, Germany). Reusable and disposable LMs were placed into HBV DNA-positive simulated saliva samples. The LM were kept in saliva at 37°C for 1 hour, then dried for 24 hours at room temperature. After cleaning in the automatic washer, different decontamination methods were applied to the LMs. Decontamination methods applied to reusable and disposable LM were thermal disinfection 1 minute at 90°C (A₀600), thermal disinfection 5 minutes at 90°C (A₀3000), thermal disinfection (A₀600) + hydrogen peroxide gas plasma sterilization, thermal disinfection (A₀600) + ethylene oxide sterilization, and disinfection with high-level disinfectant with 2% peracetic acid without cleaning in the automatic washer. Also, thermal disinfection (A₀3000) +5 minutes steam sterilization at 134°C was implemented only to reusable LM. At least three LM were used for each group. Control samples were also used. After the decontamination procedures, the LM were kept in phosphate buffer (PBS) solution for 1 hour at 37°C with shaking. The presence of HBV DNA was investigated by the real-time PCR by taking samples from PBS. The polyethylene glycol procedure was used for saliva and nucleic acid isolation. After the decontamination procedures, the functioning control of the LM was controlled.

The HBV DNA level in the simulated saliva samples was 100,000 IU/mL (lg 5). No HBV DNA was detected in reusable and disposable LM after A₀600 thermal disinfection + ethylene oxide and A₀600 thermal disinfection + hydrogen peroxide. No HBV DNA was detected in reusable LM after A₀3000 thermal disinfection+ steam sterilization. However, HBV DNA was detected in LM after A₀600 or A₀3000 thermal disinfection alone and disinfection with peracetic acid.While no deformation was observed in reusable LM after reprocessing, deformation was observed in disposable LM.

Reuse with high-level disinfection, which is frequently applied to disposable LM, is an incorrect and dangerous practice, therefore disposable LM should not be reused. Reusable LM can be reused after being reprocessing with thermal disinfection + steam or thermal disinfection + hydrogen peroxide low temperature sterilization after effective cleaning.