Objectives

To design and evaluate patient-worn personal protective equipment (PPE) that allows providers to perform endoscopy while protecting against droplet and airborne disease transmission.

Study design

Single subject study.

Methods

Mask efficacy was evaluated using a cough simulator that sprays dye visible under ultra-violet light. User-testing was performed on an airway trainer mannequin where each subject performed the endoscopy with and without the mask in random orders. Their time to completion and number of attempts before successful completion were recorded, and each subject was asked to fill out a NASA Task Load Index (TLX) form with respect to their experience.

Results

The mask has a filtration efficiency of 97.31% and eliminated any expelled particles with the cough simulator. Without the mask, a simulated cough is visualized as it progresses away from the cough origin. Subjects who performed trans-nasal endoscopy spent 27.8 ± 8.0 s to visualize the vocal cords for the no mask condition and 28.7 ± 13.6 s for the mask condition (mean ± SD, p > .05). There was no statistically significant difference found in the mental demand, physical demand, temporal demand, performance, effort, and frustration of endoscopy under the no mask and mask conditions (all p > .05).

Conclusion

The designed PPE provides an effective barrier for viral droplet and airborne transmission while allowing the ability to perform endoscopy with ease.

Level of evidence

3 Laryngoscope, 2021.

N95 decontamination protocols and KN95 respirators have been described as solutions to a lack of personal protective equipment. However, there are a few material science studies that characterize the charge distribution and physical changes accompanying disinfection treatments, particularly heating. Here, we report the filtration efficiency, dipole charge density, and fiber integrity of N95 and KN95 respirators before and after various decontamination methods. We found that the filter layers in N95 and KN95 respirators maintained their fiber integrity without any deformations during disinfection. The filter layers of N95 respirators were 8-fold thicker and had 2-fold higher dipole charge density than that of KN95 respirators. Emergency Use Authorization (EUA)-approved KN95 respirators showed filtration efficiencies as high as N95 respirators. Interestingly, although there was a significant drop in the dipole charge in both respirators during decontamination, there was no remarkable decrease in the filtration efficiencies due to mechanical filtration. Cotton and polyester face masks had a lower filtration efficiency and lower dipole charge. In conclusion, a loss of electrostatic charge does not directly correlate to the decreased performance of either respirator.

Objective

Endotracheal tubes (ETTs) are commonly associated with laryngeal injury that may be short lasting and temporary or more severe and life altering. Injury is believed to result from forces that these ETTs exert on the larynx. Here we quantify the forces of ETTs of various sizes on the laryngotracheal complex to gain a more quantitative understanding of these potential damaging forces. Here we also perform preclinical testing of a novel support device to offload these forces.

Methods

Endotracheal intubation was performed on a fresh human cadaver using various ETT sizes. A strain-sensitive graphene nanosheet sensor and a commercially available force sensing resistor were secured behind the larynx, anterior to the prevertebral fascia. The forces exerted on the larynx were measured for each of the commonly used ETTs. A novel support device, ETT clip (Endo Clip), was attached to the ETTs and changes in these forces were observed.

Results

Forces exerted on the laryngotracheal complex by various ETTs were observed to increase with increasing tube size. This pressure can be significantly reduced with a novel ETT clip.

Conclusion

Here we demonstrate the first quantitative measurement of forces that ETTs exert on the larynx. We demonstrate a novel device that can easily clip onto an ETT reducing pressure on the laryngotracheal complex. This preclinical test paves the way for a human clinical trial.

Level of evidence

5.