Barrier enclosure device: More scientific evidence is required.

Sir,

We read with interest the use of “novel” barrier enclosure for patient preparation before bronchoscopy.[1] Many methods are being tried to increase the safety of health-care workers during high-risk procedures like endotracheal intubation and bronchoscopy. Some authors have described barrier enclosures which can reduce droplet exposure during endotracheal intubation.[2] However, there are further studies which had shown that barrier enclosure devices can potentially increase the infection risk.

Simpson et al. using a simulation model studied laryngoscopist exposure of airborne particles sized 0.3–5.0 µ using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape).[3] They demonstrated that the use of the aerosol box resulted in a marked increase in airborne particle exposure during coughing compared with no device use. Only a sealed aerosol box with negative pressure kept the airborne particle count at baseline; however, its design will make effective clinical use difficult. The authors hypothesize that there could be increased dispersion of particles escaping from the arm access holes in the aerosol box because of the Bernoulli principle.

Another in situ simulation study evaluated the impact of two types of aerosol boxes on intubations in patients with severe coronavirus disease 2019.[4] The authors concluded that aerosol boxes may increase procedures times and may cause damage to conventional personal protective equipment and therefore place of health-care workers at risk of infection. The box added complexity to the procedures that ideally should be done quickly to reduce exposure times. There is also some concern that the box would concentrate infectious material confined within the box with added risk at the time of box removal and cleaning.[5]

In our own experience, we had tried an enclosure device for performing bronchoscopy. After using it, the bronchoscope developed channel air leak, and one of the reasons could be sharp angulation of the scope at the hole of the box during the procedure.

Due to these reasons, we feel that these enclosure boxes even though have biologically plausible rationale, they should be scientifically tested before use.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.