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Randomized Controlled Trial
. 2021 Feb;38(2):111-117.
doi: 10.1136/emermed-2020-210514. Epub 2020 Nov 20.

COVID-19 aerosol box as protection from droplet and aerosol contaminations in healthcare workers performing airway intubation: a randomised cross-over simulation study

Muhaimin Noor Azhar  1 , Aida Bustam  2 , Khadijah Poh  1 , Ahmad Zulkarnain Ahmad Zahedi  1 , Mohd Zahir Amin Mohd Nazri  1 , Mohammad Aizuddin Azizah Ariffin  1 , Mohd Hafyzuddin Md Yusuf  1 , Aliyah Zambri  1 , Johnathan Y O Chong  3 , Anhar Kamarudin  1 , Bin Ting Ang  3 , Affan Iskandar  3 , Keng Sheng Chew  4
Affiliations
Randomized Controlled Trial

COVID-19 aerosol box as protection from droplet and aerosol contaminations in healthcare workers performing airway intubation: a randomised cross-over simulation study

Muhaimin Noor Azhar et al. Emerg Med J. 2021 Feb.

Abstract

Background: Concerns over high transmission risk of SARS-CoV-2 have led to innovation and usage of an aerosol box to protect healthcare workers during airway intubation in patients with COVID-19. Its efficacy as a barrier protection in addition to the use of a standard personal protective equipment (PPE) is not fully known. We performed a simulated study to investigate the relationship between aerosol box usage during intubation and contaminations on healthcare workers pre-doffing and post-doffing of PPE.

Methods: This was a randomised cross-over study conducted between 9 April to 5 May 2020 in the ED of University Malaya Medical Centre. Postgraduate Emergency Medicine trainees performed video laryngoscope-assisted intubation on an airway manikin with and without an aerosol box in a random order. Contamination was simulated by nebulised Glo Germ. Primary outcome was number of contaminated front and back body regions pre-doffing and post-doffing of PPE of the intubator and assistant. Secondary outcomes were intubation time, Cormack-Lehane score, number of intubation attempts and participants' feedback.

Results: Thirty-six trainees completed the study interventions. The number of contaminated front and back body regions pre-doffing of PPE was significantly higher without the aerosol box (all p values<0.001). However, there was no significant difference in the number of contaminations post-doffing of PPE between using and not using the aerosol box, with a median contamination of zero. Intubation time was longer with the aerosol box (42.5 s vs 35.5 s, p<0.001). Cormack-Lehane scores were similar with and without the aerosol box. First-pass intubation success rate was 94.4% and 100% with and without the aerosol box, respectively. More participants reported reduced mobility and visibility when intubating with the aerosol box.

Conclusions: An aerosol box may significantly reduce exposure to contaminations but with increased intubation time and reduced operator's mobility and visibility. Furthermore, the difference in degree of contamination between using and not using an aerosol box could be offset by proper doffing of PPE.

Keywords: SARS; airway; emergency department; infectious diseases.

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Conflict of interest statement

Competing interests: None declared.

Figures

Figure 1
Figure 1
The aerosol box design and dimensions.
Figure 2
Figure 2
Participant enrolment and randomisation.
Figure 3
Figure 3
Frequency of contamination based on body regions of intubators (A) pre-doffing and (B) post-doffing of PPE. McNemar test: **p<0.005, *p<0.05.
See this image and copyright information in PMC

Comment in

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