Caution Regarding Enclosures for Airway Procedures.

To the Editor

Several enclosures made in part of transparent plastic sheets of varying stiffness have been suggested for placement around the head and upper torso.[1-3] During airway procedures, they provide source control to protect the providers. A transparent stiff plastic box is described.[1] Videos describing several similar enclosures are posted on the Internet. Two enclosures made of disposable transparent flexible plastic bags over nondisposable stiff frames are described.[2,3]

None of these devices has received a 510(k) approval from the Food and Drug Administration. Studies of safety, efficacy, and usability of these devices are not available. Several suggestions are presented for altering the systems described by the original authors to ameliorate some of the problems. An alternative system that avoids many of the problems is also described.

These enclosures compromise provider’s visibility of the airway. Combining the described[1,2] 2ports for provider’s arms into a single long port improves maneuverability. If flexible plastic sheet is utilized,[2,3] during airway difficulties, the sheet can be moved to provide complete access to head and neck without emergently doffing the entire enclosure. This can also be done if the patient gets claustrophobic in the enclosure. As described,[1] the wall at the head of a stiff enclosure is also made of stiff plastic. Instead, if it is made of flexible plastic, it can be moved expeditiously in an emergency.

A suction should be placed inside all the enclosures even though the original authors did not include it.[1] The suction should finally discharge into the atmosphere after high-efficiency particulate air (HEPA) filtration. Suction can substantially reduce the amount of pathogen accumulation in the enclosure.

Doffing and decontamination of these enclosures are not described by their authors. Inside of the enclosure should be suctioned well before doffing. It is difficult to decontaminate or dispose of the parts made of stiff material.

In one of the proposed enclosures[2] made of disposable transparent flexible plastic bag over a nondisposable stiff pipe frame, a suction is connected to a HEPA filter through the pipe frame. Inside of the pipe frame may get contaminated and is difficult to decontaminate. This problem can be obviated by sealing the pipe frame and placing the suction near the patient’s airway, inside the enclosure.

Although not yet published, a disposable transparent flexible plastic bag over a low-cost folding adjustable frame is suitable. The adjustable frame may permit enclosures of varying shapes and dimensions to suit different patients and providers. A suction should be placed near the patient’s airway. The bag and the folding frame may be disposed of after 1use.

Source control is already provided by covering the patient’s mouth and nose by an anesthesia breathing circuit mask, oxygen mask, or a surgical or procedure mask. Placement of a drape such as a clear plastic sheet over the mask and the face during extubation and other periods of excessive aerosol generation can be protective. Added protection of the providers by published enclosures[1-3] must be balanced against the risk of disease transmission during doffing, decontamination, and disposal.