Paediatric headbox as aerosol and droplet barrier.

Background: High-flow nasal oxygen (HFNO) is frequently used in hospitals, producing droplets and aerosols that could transmit SARS-CoV-2.

Aim: To determine if a headbox could reduce droplet and aerosol transmission from patients requiring HFNO.

Methods: The size and dispersion of propylene glycol (model for patient-derived infectious particles) was measured using a spectrometer and an infant mannequin receiving 10-50 L/min of HFNO using (1) no headbox, (2) open headbox, (3) headbox-blanket or (4) headbox with a high-efficiency particulate (HEP) filter covering the neck opening.