Antimicrobial mouthwashes (gargling) and nasal sprays to protect healthcare workers when undertaking aerosol-generating procedures (AGPs) on patients without suspected or confirmed COVID-19 infection.

Abstract

COVID-19 infection poses a serious risk to patients and -due to its contagious nature -to those healthcare workers (HCWs) treating them. The risks of transmission of infection are greater when a patient is undergoing an aerosol-generating procedure (AGP). Not all those with COVID-19 infection are symptomatic, or suspected of harbouring the infection. If a patient who is not known to have orsuspected of having COVID-19 infection is to undergo an AGP, it would nonethelessbe sensible to minimise the risk to those HCWs treating them. If the mouth and nose of anindividual undergoing an AGPare irrigated with antimicrobial solutions, this may be a simple and safe method ofreducingthe risk of any covert infection being passed to HCWs through droplet transmission or direct contact. Alternatively, the use of antimicrobial solutions by the HCWmay decrease the chance of them acquiringCOVID-19 infection.However,the use of such antimicrobial solutions may be associated with harms related to the toxicity of the solutions themselves or alterations in the natural microbial flora of the mouth or nose. To assess the benefits and harms of antimicrobial mouthwashes and nasal sprays administered to HCWs and/or patients when undertaking AGPs on patients without suspected or confirmed COVID-19 infection. Information Specialists from Cochrane ENT and Cochrane Oral Health searchedthe Central Register of Controlled Trials (CENTRAL 2020, Issue 6); Ovid MEDLINE; Ovid Embaseand additional sources for published and unpublished trials. The date of the search was 1 June 2020. SELECTION CRITERIA: This is a question that urgently requires evidence, however at the present time we did not anticipate finding many completed RCTs. We therefore planned to include the following types of studies:randomised controlled trials (RCTs);quasi-RCTs;non-randomised controlled trials;prospective cohort studies;retrospective cohort studies;cross-sectional studies;controlled before-and-after studies. We set no minimum duration for the studies. We sought studies comparing any antimicrobial mouthwash and/or nasal spray (alone or in combination) at any concentration, delivered to the patient or HCW before and/or after an AGP. We used standard Cochrane methodological procedures. Our primary outcomes were: 1) incidence of symptomatic or test-positive COVID-19 infection in HCWs or patients; 2) significant adverse event:anosmia (or disturbance in sense of smell).Our secondary outcomes were: 3)COVID-19 viral content of aerosol (when present); 4)change in COVID-19 viral load at site(s) of irrigation; 5)other adverse events: changes in microbiome in oral cavity, nasal cavity, oro- or nasopharynx; 6)other adverse events: allergy, irritation/burning of nasal, oral or oropharyngeal mucosa (e.g. erosions, ulcers, bleeding), long-term staining of mucous membranes or teeth, accidental ingestion.We planned to use GRADE to assess the certainty of the evidence for each outcome. We found nocompleted studies to include in this review. AUTHORS' CONCLUSIONS: We identified no studies for inclusion in this review, nor any ongoing studies.The absence ofcompleted studiesis not surprising given the relatively recent emergence of COVID-19 infection. However, we are disappointed that this important clinical questionis notbeing addressed by ongoing studies.