Staff perceptions of military chemical-biological-radiological-nuclear (CBRN) air-purifying masks during a simulated clinical task in the context of SARS-CoV-2.

Air-purifying full-face masks, such as military chemical-biological-radiological-nuclear masks, might offer superior protection against severe acute respiratory syndrome coronavirus 2 compared to disposable polypropylene P2 or N95 masks. In addition, disposable masks are in short supply, while military chemical-biological-radiological-nuclear masks can be disinfected then reused. It is unknown whether such masks might be appropriate for civilians with minimal training in their use. Accordingly, we compared the Australian Defence Force in-service chemical-biological-radiological-nuclear Low Burden Mask (AirBoss Defense, Newmarket, Canada) with polypropylene N95 masks and non-occlusive glasses worn during simulated tasks performed by civilian clinicians in an Australian tertiary referral hospital intensive care unit. After brief training in the use of the Low Burden Mask, participants undertook a simulated cardiac arrest scenario. Previous training with polypropylene N95 masks had been provided. Evaluation of 10 characteristics of each mask type were recorded, and time to mask application was assessed. Thirty-three participants tested the Low Burden Mask, and 28 evaluated polypropylene N95 masks and glasses. The Low Burden Mask was donned more quickly: mean time 7.0 (standard deviation 2.1) versus 18.3 (standard deviation 6.7) seconds; P = 0.0076. The Low Burden Mask was rated significantly higher in eight of the 10 assessed criteria, including ease of donning, comfort (initially and over a prolonged period), fogging, seal, safety while removing, confidence in protection, and overall. Visibility and communication ability were rated equally highly for both systems. We conclude that this air-purifying full-face mask is acceptable to clinicians in a civilian intensive care unit. It enhances staff confidence, reduces waste, and is likely to be a lower logistical burden during a prolonged pandemic. Formal testing of effectiveness is warranted.

Increasing ventilator surge capacity in COVID 19 pandemic: design, manufacture and in vitro-in vivo testing in anaesthetized healthy pigs of a rapid prototyped mechanical ventilator.

OBJECTIVE: The advent of new technologies has made it possible to explore alternative ventilator manufacturing to meet the worldwide shortfall for mechanical ventilators especially in pandemics. We describe a method using rapid prototyping technologies to create an electro-mechanical ventilator in a cost effective, timely manner and provide results of testing using an in vitro-in vivo testing model. RESULTS: Rapid prototyping technologies (3D printing and 2D cutting) were used to create a modular ventilator. The artificial manual breathing unit (AMBU) bag connected to wall oxygen source using a flow meter was used as air reservoir. Controlled variables include respiratory rate, tidal volume and inspiratory: expiratory (I:E) ratio. In vitro testing and In vivo testing in the pig model demonstrated comparable mechanical efficiency of the test ventilator to that of standard ventilator but showed the material limits of 3D printed gears. Improved gear design resulted in better ventilator durability whilst reducing manufacturing time (< 2-h). The entire cost of manufacture of ventilator was estimated at 300 Australian dollars. A cost-effective novel rapid prototyped ventilator for use in patients with respiratory failure was developed in < 2-h and was effective in anesthetized, healthy pig model.