Aerosol and Droplet Dispersion During Gastrointestinal Motility Investigations

COVID-19: The Study of Aerosol Generation and Droplet Dispersion and Deposition During Naso-gastric Intubation for Gastrointestinal Motility Investigations

To obtain more knowledge about the generation of aerosol and droplet dispersion and deposition during naso-gastric intubation for gastrointestinal motility investigations

Health care workers (HCW) at the endoscopy unit are at constant occupational risk for many infectious diseases as they perform daily procedures that are believed to generate aerosol and droplets, which may harvest respiratory pathogens. These daily procedures include for example High Resolution Impedance Manometry (HRiM), 24h multichannel intraluminal impedance-pH monitoring (MII-pH) and endoscopic investigations. It is well-known that these procedures may induce cough, and can generate aerosol and droplets (1). Previous research showed that respiratory pathogens can remain dispersed in aerosol for up to 3 hours and droplets with a viral load remain stable on plastic and stainless steel surfaces (2). Furthermore, it is known that high viral loads may be present in the nasal cavity, nasopharynx and the oropharynx (3). The impact of the occupational risk for HCW at the endoscopy unit was confirmed during the peak of the severe acute respiratory syndrome -coronavirus (SARS-CoV) outbreak, as confirmed in an online survey from 39 motility centers in Europe. This survey showed that 35 out of 39 centers reduced their capacity during the SARS-CoV outbreak in the month of March 2020 with a median of 100% (range 50-100%) for esophageal HRiM and with a median of 100% (range 80-100%) for MII-pH (4).

Therefore, with resumption of clinical activities during the recovery phase of the SARS-CoV outbreak, a number of guidelines and measures are taken to protect patients and personnel from viral spread. Patients are screened for SARS-CoV infection by reverse transcription polymerase chain reaction ((RT-)PCR) testing on a nasopharyngeal swab specimen prior to invasive investigations and they are required to wear a chirurgical facemask in the hospital at all times. Staff of the endoscopy and function testing units are wearing a chirurgical facemask, standard gloves, goggles, hairnet and a water-resistant gown. Moreover, patients are required to keep a surgical mask over their mouth during the naso-gastric probe positioning, and the bed is lowered so that the head of the patient is below the neck level of the technician. Throughout the procedure, the technician positions him- or herself to the side and back of the patient. However, there is a lack of scientific evidence on the amount of aerosol and droplet spread when these procedures are being performed, with the safety measures that are outlined (1, 4).

Inclusion Criteria:

Aged >18 years old;

• Male or female patients;
• Patients undergoing elective gastrointestinal motility investigations (MII-pH and HRiM);
• Negative PCR on nasopharyngeal swab 24 hours prior to the test;
• No anatomical deformity of nose and throat, no known diseases of nose and throat;
• Signed informed consent.

Exclusion Criteria:

• Females who are pregnant or lactating;
• Use of anticoagulant medication;
• Known allergy to fluorescein.