A modified barrier enclosure to prevent viral aerosol transmission during endotracheal intubation and extubation of patients with coronavirus disease

To the editor:

The spread of the new severe acute respiratory syndrome coronavirus 2 has not only affected the global social and economic status but has also challenged the entire healthcare system. In this state of crisis, clinicians and other medical professionals are the frontline workers managing the coronavirus disease (COVID-19) pandemic. To prevent viral exposure and its further spread, clinicians are required to use standard personal protective equipment (PPE). However, several healthcare workers are experiencing a lack of PPE. Certain procedures such as intubation and extubation operations are particularly susceptible to generate potentially infectious aerosols that could infect medical personnel [1]. Therefore, to prevent aerosol-mediated viral infection during intubation/extubation procedures, Robert Canelli et al. recently invented an “aerosol box” [2]. It is a barrier that can be easily fabricated and could help to protect clinicians from aerosol infection during intubation/extubation procedure. It consists of a transparent plastic cube that covers a patient's head and two circular ports through which a clinician could pass their hands to perform airway procedures. However, this box restricts hand mobility and requires prior training before use in actual clinical procedures.

We have devised a lightweight acrylic “Kojima/Sugimura-type (KS type) aerosol box” with improved design and operability (Fig. 1). This can be used to cover a patient's head similar to that with the conventional “aerosol box.” Only a disposable plastic bag is required for its set-up (Movie S1). The box is covered with vinyl and notches are made in the vinyl to access the patient. As this barrier provides flexible access to a patient, the preferred procedure can be planned on a case-by-case basis. Leaks or aerosol exposure can be prevented by making necessary and sufficient cuts. Furthermore, sealing the notches with tape can help to achieve more airtight conditions. Owing to the high mobility of the arm, more complicated nasal intubation and fiber intubation procedures can be performed in addition to conventional oral intubation. Another advantage of this box is that the medical staff who assist with these procedures can also have access to the patient through this barrier enclosure. The device might also be able to prevent exposure to aerosols generated by coughing during extubation. By discarding the tube used for intubation and the vinyl, reduced aerosol generation is expected.

Fig. 1.

Barrier enclosure “Kojima/Sugimura-type (KS type) aerosol box.” This box has a very simple design and is easy to set up.

A: From the superior side.

B: From the inferior side.

C: From the sagittal side.

D: With a mannequin.

We have devised a lightweight acrylic “Kojima/Sugimura-type (KS type) aerosol box” with improved design and operability (Fig. 1). This can be used to cover a patient's head similar to that with the conventional “aerosol box.” Only a disposable plastic bag is required for its set-up (Movie S1). The box is covered with vinyl and notches are made in the vinyl to access the patient. As this barrier provides flexible access to a patient, the preferred procedure can be planned on a case-by-case basis. Leaks or aerosol exposure can be prevented by making necessary and sufficient cuts. Furthermore, sealing the notches with tape can help to achieve more airtight conditions. Owing to the high mobility of the arm, more complicated nasal intubation and fiber intubation procedures can be performed in addition to conventional oral intubation. Another advantage of this box is that the medical staff who assist with these procedures can also have access to the patient through this barrier enclosure. The device might also be able to prevent exposure to aerosols generated by coughing during extubation. By discarding the tube used for intubation and the vinyl, reduced aerosol generation is expected.

In the wake of the relentless spread of COVID-19, asymptomatic transmission remains a grave concern as it is difficult to determine the extent of screening needed by patients scheduled for a surgery [3]. Although it has become indispensable to comply with standard precautions to prevent COVID-19, required medical resources have been depleted. Thus, limited medical resources are a major challenge in the management and spread of COVID-19. By using the “KS-type aerosol box,” anesthesiologists and emergency doctors who perform intubation procedures, and the medical staff who assist with these procedures can protect themselves from infection, even when dealing with patients who are considered infection-free. This use of this box may also reduce PPE usage by minimizing the infected area. However, the extent to which this box prevents aerosol exposure and contamination of medical personnel and the environment needs to be verified. Intubation and extubation are highly specialized and stressful procedures. We believe that this box will be useful to prevent infection while performing these procedures routinely.

The following is the supplementary data related to this article.

Movie S1

Setting:

Place the “Kojima/Sugimura-type aerosol box” over the patient's head. Cover it with vinyl. Ensure that the equipment required for intubation is placed inside the box beforehand. Make a notch to access the patient. After access, seal the notch with tape. Smaller the notch, better the sealing performance.

Intubation

When ready, perform the intubation procedure. Oral intubation can be performed as usual. Nasal intubation is also possible because of limited restrictions on arm movement.

Extubation

The extubation procedure can also be performed as usual. After extubation, an oxygen mask can be placed over the patient mouth, and the tube can be discarded along with the vinyl.

Supplementary data to this article can be found online at https://doi.org/10.1016/j.jclinane.2020.109876.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author contributions

YK and MS invented this Box. YK, KA and KY simulated this box.

Declaration of competing interest

None declared.