Application of a Modified Endoscopy Face Mask for Flexible Laryngoscopy During the COVID-19 Pandemic

COVID-19 in the Clinic: Trial of an Aerosol Containment Mask for Endoscopic Clinic Procedures

OBJECTIVE

Create an aerosol containment mask (ACM) for common otolaryngologic endoscopic procedures which also provides nanoparticle-level protection to patients.

STUDY DESIGN

Prospective feasibility study.

SETTING

In-person testing with a novel ACM.

METHODS

The mask was designed in Solidworks and 3-dimensional printed. Measurements were made on 100 consecutive clinic patients who underwent medically necessarily endoscopy, 50 rigid nasal and 50 flexible, by 9 surgeons.

RESULTS

Of the 50 patients who underwent rigid nasal endoscopy with the ACM, 0 of 25 patients with the suction off and 0 of 25 patients with the suction on had evidence of leakage of 0.3 μm particles. Of the 50 patients who underwent flexible endoscopy with the ACM, 0 of 25 patients with the suction off and 0 of 25 patients with the suction on had evidence of leakage of 0.3 μm particles. In terms of comfort, 73% of patients found the ACM somewhat or very comfortable without suction, compared to 86% with the suction on. Surgeons were able to visualize all necessary anatomic areas in 98% of procedures. In 97% of procedures, the masks were able to be placed easily.

CONCLUSION

ACM can accommodate rigid nasal and flexible endoscopes and may prevent leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions.

LEVEL OF EVIDENCE

The level of evidence is 2.

On the Design and Testing of an Origami Inspired Nasal Cover: Mitigating Aerosol Risks During Endoscopic Sinus Procedures

Aerosols generated during endoscopic sinus procedures present a concern to the health and safety of healthcare personnel especially with the presence of COVID-19. The purpose of this study is to describe the design and testing of a nasal cover to restrict aerosolized pathogens. The nasal cover was designed to sit overtop the nose with conformal slits for insertion of endoscopic instrumentation. Polydimethylsiloxane (PDMS) was chosen as the nasal mask material and its composition, thickness, and slit geometry were selected using a Taguchi experimental design and survey with clinical collaborators at Penn State Milton S. Hershey Medical Center. The nasal cover was designed using principles of origami engineering to be manufactured flat then folded into its operating state. Form and functionality were evaluated by surgeons, fellows, and residents in the aforementioned survey. Aerosol containment was evaluated by measuring smoke, representative of surgical aerosols, with an optical particle counter. A 25:1 composition PDMS with 3mm thickness and vertical slit geometry was chosen for the nasal cover design. Survey results demonstrated that the origami cover sat well on the nose and did not significantly impact the surgical conditions with single instrumentation. On average, this nasal cover was found to restrict more than 93% of 0.3µm aerosols, and more than 99% of all aerosols larger than 0.5µm in size. Use of a patient worn nasal cover has the potential to drastically reduce the risk to hospital personnel during endonasal surgeries by reducing aerosol generation and potential pathogen spread.

Development of protective equipment for endoscopic treatment and surgery in otorhinolaryngology

Objective

The coronavirus disease pandemic has raised concerns regarding the transmission of infections to healthcare workers. We developed a new protective device to reduce the risk of aerosol diffusion and droplet infection among healthcare workers. Here, we report the results of a theoretical evaluation of the efficacy of this device.

Methods

We used suction-capable masks with and without rubber slits, sleeves for the insertion section of endoscopes and treatment tools, and a cover for the control section of the endoscope. To simulate droplet spread from patients, we created a droplet simulation model and an aerosol simulation model. The results with and without the devices attached and with and without the suction were compared.

Results

The droplet simulation model showed a 95% reduction in droplets with masks with rubber slits; furthermore, a reduction of 100% was observed when the insertion sleeve was used. Evaluation of aerosol simulation when suction was applied revealed an aerosol reduction of 98% and >99% with the use of the mask without rubber slits and with the combined use of the mask and insertion sleeve, respectively. The elimination of droplet emission upon instrument removal confirmed that the instrument sleeve prevented the diffusion of droplets. The elimination of droplets upon repeated pressing of the suction button confirmed that the cover prevented the diffusion of droplets.

Conclusion

We developed a device for infection control, in collaboration with a gastrointestinal endoscopist and Olympus Medical Systems Corporation, that was effective in reducing droplet and aerosol diffusion in this initial theoretical assessment.

COVID-19 and laryngological surgery

In 2019, the emergence of the novel SARS-CoV-2 virus in Wuhan, China transformed society and caused major changes in medical care. Efforts to implement protocols to keep providers and their staffs safe during care of all patients ensued. Within the field of laryngology, the risk of aerosol generation and viral spread was among the highest in medicine. It is important to understand the impact of COVID-19 on presurgical and surgical laryngoscopic care as well as the evolution of knowledge that led to our current practices and protocols.

Diagnostic and surgical innovations in otolaryngology for adult and paediatric patients during the COVID-19 era

During the Coronavirus Disease 2019 (COVID-19) pandemic, otolaryngology has been shown to be a high-risk specialty due to the exposure to aerosol-generating physical examinations, procedures and surgical interventions on the head and neck area, both in adult and paediatric patients. This has prompted the issue of updating the guidelines by International Health Authorities in the Ear Nose and Throat (ENT) field and, at the same time, has stimulated engineers and healthcare professionals to develop new devices and technologies with the aim of reducing the risk of contamination for physicians, nurses and patients.

Methods

A review of the literature published on PubMed, Ovid/Medline and Scopus databases was performed from January 01, 2020 to December 31, 2021.

Results

73 articles were eligible to be included, which were subdivided into 4 categories: ("Artificial Intelligence (AI)"; "Personal Protective Equipment (PPE)"; "Diagnostic tools"; "Surgical tools").

Conclusions

All of the innovations that have been developed during the COVID-19 pandemic have laid the foundation for a radical technological change of society, not only in medicine but also from a social, political and economical points of view that will leave its mark in the coming decades.

Particle scattering during otolaryngological examinations

PURPOSE

We aimed to analyze particle scattering during common otolaryngology examination procedures which are associated with aerosol-generating procedures.

MATERIALS AND METHODS

This study was conducted with 109 volunteer patients who have participated between October 2020 and January 2021. We measured aerosol and droplet production during oropharyngeal examination, anterior rhinoscopy, rigid nasopharyngoscopy, and rigid laryngoscopy. Measurements were calculated at the beginning of the examinations and during the otolaryngological examination procedures.

RESULTS

There was no significant increase when we compared the particle scattering in each examination procedure with the basal measurements. But at the end of all examination methods for each patient, there was a significant increase at each micrometer. When all examination methods are compared with each other, particle increases in the oropharyngeal examination with larger particle sizes than 0,5 μm were found to be higher than other examination methods. We analyzed six patients' measurements, who coughed, gagged, or sneezed during the nasal endoscopy procedure, there was a significant increase in terms of 0,3 μm particle scattering.

CONCLUSION

When all examination methods are performed together, there is a significant particle increase in all particle sizes in the examination room at the end of the examinations. This causes otolaryngologists to be exposed to a significant particle increase at each micrometer. Because of this reason, otolaryngologists should be careful and should wear personal protective equipment while examining patients.

Patient-worn endoscopy mask to protect against viral transmission

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.

COVID-19 in the Clinic: Human Testing of an Aerosol Containment Mask for Endoscopic Clinic Procedures

OBJECTIVE

To create an aerosol containment mask (ACM) for common otolaryngologic endoscopic procedures that also provides nanoparticle-level protection to patients.

STUDY DESIGN

Prospective feasibility study .

SETTING

In-person testing with a novel ACM.

METHODS

The mask was designed in Solidworks and 3D printed. Measurements were made on 10 healthy volunteers who wore the ACM while reading the Rainbow Passage repeatedly and performing a forced cough or sneeze at 5-second intervals over 1 minute with an endoscope in place.

RESULTS

There was a large variation in the number of aerosol particles generated among the volunteers. Only the sneeze task showed a significant increase compared with normal breathing in the 0.3-µm particle size when compared with a 1-tailed t test (P = .013). Both the 0.5-µm and 2.5-µm particle sizes showed significant increases for all tasks, while the 2 largest particle sizes, 5 and 10 µm, showed no significant increase (both P < .01). With the suction off, 3 of 30 events (2 sneeze events and 1 cough event) had increases in particle counts, both inside and outside the mask. With the suction on, 2 of 30 events had an increase in particle counts outside the mask without a corresponding increase in particle counts inside the mask. Therefore, these fluctuations in particle counts were determined to be due to random fluctuation in room particle levels.

CONCLUSION

ACM will accommodate rigid and flexible endoscopes plus instruments and may prevent the leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions.

LEVEL OF EVIDENCE

2.

COVID-19 in the Clinic: Aerosol Containment Mask for Endoscopic Otolaryngologic Clinic Procedures

Objective

To create an aerosol containment mask (ACM) that contains aerosols during common otolaryngologic endoscopic procedures while protecting patients from environmental aerosols.

Study Design

Bench testing.

Setting

Mannequin testing.

Methods

The mask was designed in SolidWorks and 3-dimensional printed. Mannequins were fitted with a nebulizer to generate aerosols. Commercial particle counters were used to measure mask performance.

Results

The ACM has 2 ports on either side for instruments and endoscopes, a port for a filter, and a port that can evacuate aerosols contained within the mask via a standard suction pump. The mask contained aerosols on a mannequin with and without facial hair when the suction was set to 18.5 L/min. Other types of masks demonstrated substantial aerosol leakage under similar conditions. In a subsequent experiment, the ACM contained aerosols generated by a nebulizer up to the saturation of the particle detector without measurable leakage with or without suction.

Conclusion

The ACM will accommodate rigid and flexible endoscopes plus instruments and prevent leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions.

Level of evidence

2.

Guidelines for Robotic Flexible Endoscopy at the Time of COVID-19

Flexible endoscopy involves the insertion of a long narrow flexible tube into the body for diagnostic and therapeutic procedures. In the gastrointestinal (GI) tract, flexible endoscopy plays a major role in cancer screening, surveillance, and treatment programs. As a result of gas insufflation during the procedure, both upper and lower GI endoscopy procedures have been classified as aerosol generating by the guidelines issued by the respective societies during the COVID-19 pandemic-although no quantifiable data on aerosol generation currently exists. Due to the risk of COVID-19 transmission to healthcare workers, most societies halted non-emergency and diagnostic procedures during the lockdown. The long-term implications of stoppage in cancer diagnoses and treatment is predicted to lead to a large increase in preventable deaths. Robotics may play a major role in this field by allowing healthcare operators to control the flexible endoscope from a safe distance and pave a path for protecting healthcare workers through minimizing the risk of virus transmission without reducing diagnostic and therapeutic capacities. This review focuses on the needs and challenges associated with the design of robotic flexible endoscopes for use during a pandemic. The authors propose that a few minor changes to existing platforms or considerations for platforms in development could lead to significant benefits for use during infection control scenarios.

Innovations in otorhinolaryngology in the age of COVID-19: a systematic literature review

OBJECTIVE

Otolaryngologists are at increased occupational risk of Coronavirus Disease 2019 (COVID-19) infection due to exposure from respiratory droplets and aerosols generated during otologic, nasal, and oropharyngeal examinations and procedures. There have been a variety of guidelines and precautions developed to help mitigate this risk. While many reviews have focused on the personal protective equipment (PPE) and preparation guidelines for surgery in the COVID-19 era, none have focused on the more creative and unusual solutions designed to limit viral transmission. This review aims to fill that need.

DATA SOURCES

PubMed, Ovid/Medline, and Scopus.

METHODS

A comprehensive review of literature was performed on September 28, 2020 using PubMed, Ovid/Medline, and Scopus databases. All English-language studies were included if they proposed or assessed novel interventions developed for Otolaryngology practice during the COVID-19 pandemic. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

A total of 41 papers met inclusion criteria and were organized into 5 categories ('General Recommendations for Otolaryngologic Surgery', 'Equipment Shortage Solutions', 'Airway Procedures', 'Nasal Endoscopy and Skull Base Procedures', and 'Otologic Procedures'). Articles were summarized, highlighting the innovations created and evaluated during the COVID-19 pandemic. Creative solutions such as application of topical viricidal agents, make-shift mask filters, three-dimensional (3-D) printable adapters for headlights, aerosol containing separation boxes, and a variety of new draping techniques have been developed to limit the risk of COVID-19 transmission.

CONCLUSIONS

Persistent risk of COVID-19 exposure remains high. Thus, there is an increased need for solutions that mitigate the risk of viral transmission during office procedures and surgeries, especially given that most COVID-19 positive patients present asymptomatically. This review examines and organizes creative solutions that have been proposed and utilized in the otolaryngology. These solutions have a potential to minimize the risk of viral transmission in the current clinical environment and to create safer outpatient and operating room conditions for patients and healthcare staff.

A novel aerosolisation mitigation device for endoscopic sinus and skull base surgery in the COVID-19 era

Purpose

To provide a novel solution to reduce aerosol exposure in the operating room during endoscopic sinus and skull base procedures in the COVID-19 era.

Methods

We have designed a 3D printable midfacial mask that partially seals the nose, while allowing instrumentation during endoscopic transnasal surgery. The mask when connected to a vacuum system creates a constant negative pressure inside it, sucking out aerosols and gases generated during surgical procedures. Its effectiveness was tested using vapour exhalations by a human volunteer and drilling bone in a head model. The physical barrier effect was measured using fluorescein atomization in a head model.

Results

The pressure and airflow measured remained negative inside it in all the different situations tested. The mask was capable of completely evacuating human adult exhalation, and was more effective than the hand suction instrument. However, it was as effective as hand suction instrument at preventing aerosol spread from bone drilling. The physical barrier effect achieved a 72% reduction in the splatter created from the fluorescein atomization.

Conclusions

The mask effectively prevented the spread of aerosols and reduced droplet spread during simulated transnasal endoscopic skull base surgery in laboratory conditions. This device has potential benefits in protecting surgical personnel against airborne transmission of COVID-19 and could be useful in reducing chronic exposure to the hazard of surgical smoke.

Electronic supplementary material

The online version of this article (10.1007/s00405-020-06462-1) contains supplementary material, which is available to authorized users.

Reducing Aerosolized Particles and Droplet Spread in Endoscopic Sinus Surgery during COVID-19

Objectives

The presence of high SARS‐Cov‐2 viral loads in the upper airway, including the potential for aerosolized transmission of viral particles, has generated significant concern amongst otolaryngologists worldwide, particularly those performing endoscopic sinus surgery (ESS). We evaluated a simple negative‐pressure mask technique to reduce viral exposure.

Methods

Two models simulating respiratory droplets >5–10 μm and fine respiratory nuclei <5 μm using fluorescein dye and wood smoke, respectively, were utilized in a fixed cadaveric study in a controlled environment. Using ultraviolet light, fluorescein droplet spread was assessed during simulated ESS with powered microdebrider and powered drilling. Wood smoke ejection was used to evaluate fine particulate escape from a negative‐pressure mask using digital subtraction image processing.

Results

The use of a negative‐pressure mask technique resulted in 98% reduction in the fine particulate aerosol simulation and eliminated larger respiratory droplet spread during simulated ESS, including during external drill activation.

Conclusions

As global ear, nose & throat (ENT) services resume routine elective operating, we demonstrate the potential use of a simple negative‐pressure mask technique to reduce the risk of viral exposure for the operator and theatre staff during ESS.

Level of Evidence

5 Laryngoscope, 131:956–960, 2021

Multidisciplinary Safety Recommendations After Tracheostomy During COVID-19 Pandemic: State of the Art Review

OBJECTIVE

In the chronic phase of the COVID-19 pandemic, questions have arisen regarding the care of patients with a tracheostomy and downstream management. This review addresses gaps in the literature regarding posttracheostomy care, emphasizing safety of multidisciplinary teams, coordinating complex care needs, and identifying and managing late complications of prolonged intubation and tracheostomy.

DATA SOURCES

PubMed, Cochrane Library, Scopus, Google Scholar, institutional guidance documents.

REVIEW METHODS

Literature through June 2020 on the care of patients with a tracheostomy was reviewed, including consensus statements, clinical practice guidelines, institutional guidance, and scientific literature on COVID-19 and SARS-CoV-2 virology and immunology. Where data were lacking, expert opinions were aggregated and adjudicated to arrive at consensus recommendations.

CONCLUSIONS

Best practices in caring for patients after a tracheostomy during the COVID-19 pandemic are multifaceted, encompassing precautions during aerosol-generating procedures; minimizing exposure risks to health care workers, caregivers, and patients; ensuring safe, timely tracheostomy care; and identifying and managing laryngotracheal injury, such as vocal fold injury, posterior glottic stenosis, and subglottic stenosis that may affect speech, swallowing, and airway protection. We present recommended approaches to tracheostomy care, outlining modifications to conventional algorithms, raising vigilance for heightened risks of bleeding or other complications, and offering recommendations for personal protective equipment, equipment, care protocols, and personnel.

IMPLICATIONS FOR PRACTICE

Treatment of patients with a tracheostomy in the COVID-19 pandemic requires foresight and may rival procedural considerations in tracheostomy in their complexity. By considering patient-specific factors, mitigating transmission risks, optimizing the clinical environment, and detecting late manifestations of severe COVID-19, clinicians can ensure due vigilance and quality care.

Negative pressure face shield for flexible laryngoscopy in the COVID-19 era

OBJECTIVE

Introduce novel methods and materials to limit microdroplet spread when performing transnasal aerosol generating procedures in the COVID-19 era.

METHODS

Prototypes of a negative pressure face shield (NPFS) were tested then used clinically to create a suction-clearing negative pressure microenvironment with controlled access to the nose and mouth. Air pressure measurements within prototypes were followed by prospective evaluation of 30 consecutive patients treated with the device assessed through questionnaires and monitoring oximetry.

RESULTS

The NPFS is a transparent acrylic barrier with two anterior instrumentation ports and a side port to which continuous suction is applied. It is positioned on a stand and employs a disposable antimicrobial wrap to secure an enclosure around the head. This assembly was successfully used to complete transnasal laryngoscopy in all 30 patients studied. Tolerance of the design was excellent, with postprocedure questionnaire identifying no shortness of breath (27/30), no claustrophobia (27/30), no pain (29/30), and no significant changes in pulse oximetry.

CONCLUSION

Diagnostic laryngoscopy was successfully performed in a negative pressure microenvironment created to limit dispersion of aerosols. Further application of the NPFS device is targeted for use with transnasal laryngeal laser and biopsy procedures to be followed by additional modification to enable intranasal and intraoral procedures in a similar protected environment.

LEVEL OF EVIDENCE

Level 2b (Cohort Study).