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

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.

Evaluation of face shields used during aerosol generating procedures

Transnasal flexible laryngoscopy is considered an aerosol generating procedure. A negative pressure face shield (NPFS) was developed to control aerosol from the patient during laryngoscopy. The purpose of this study was to determine the effectiveness of the NPFS at controlling virus aerosol compared to a standard disposable plastic face shield. The face shields were placed on a simulated patient coughing machine. MS2 bacteriophage was used as a surrogate for SARS-CoV-2 and was aerosolized using the coughing machine. The aerosolized virus was sampled on the inside and outside of the face shields. The virus aerosol concentration was not significantly different between the inside and outside of the traditional plastic face shield (p = 0.12). However, the particle concentrations across all particle sizes measured were significantly decreased outside the face shield. The virus and particle concentrations were significantly decreased (p < 0.01) outside the NPFS operating at a flow rate of 38.6 L per minute (LPM). When the NPFS was operated at 10 LPM, virus concentrations were not significantly different (p = 0.09) across the face shield. However, the number particle concentrations across all particle sizes measured were significantly different (p < 0.05).

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.

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.

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.

Pediatric otolaryngology in the coronavirus disease 2019 pandemic: what have we learned?

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) has changed the face of healthcare. The current review is to discuss the major aspects that have changed in pediatric otolaryngology, from surgical operations management, to clinic workflow, to procedural precautions.

RECENT FINDINGS

There have been many studies over the past year describing different ways to improve the safety of healthcare delivery in pediatric otolaryngology amidst a global pandemic, as well as ways to improve clinic and surgical logistics along with guidelines for telehealth of a surgical specialty.

SUMMARY

COVID-19 has forever altered how healthcare is viewed and practiced, and pediatric otolaryngology was not exempt. With an increased focus on provider safety, as well as novel ways of utilizing changes in methods of communication, the practice of pediatric otolaryngology has evolved with the rest of healthcare to take on the new challenges brought on by this global pandemic.

Utility of Point-of-Care COVID-19 Testing in an Outpatient Otolaryngology clinic

OBJECTIVE

To evaluate the utility of point-of-care COVID-19 testing for identifying infected patients in an otolaryngology practice.

STUDY DESIGN

Retrospective review of 947 patients tested with a point-of-care nucleic acid amplification test for SARS-CoV-2 (Abbott ID Now).

SETTING

Tertiary otolaryngology clinic setting from July to November 2020.

METHODS

Tests were characterized by provider-specified indication (symptomatic, preprocedural, and universal), subspecialty, provider type, and contemporaneous regional COVID-19 positivity rate, defined as 12%. Positive results were further classified as true or false positive (TP or FP) based on repeat polymerase chain reaction testing wherever available, and true positivity rates were compared among groups by multiway chi-square and Fisher's exact tests. FP rates within 48 hours of a TP result were also evaluated to assess for batch contamination.

RESULTS

A total of 947 SARS-CoV-2 nucleic acid amplification tests were performed, yielding 9 TPs (0.95%) and 5 FPs (0.53%). TP rates were significantly different by testing indication, with higher rates among symptomatic patients (P = .012; vs universal, odds ratio = 7.86 [95% CI, 1.27-83.52]; vs preprocedural, odds ratio = 4.91 [95% CI, 0.79-52.17]); by subspecialty (P = .011), as driven by higher positivity rates in laryngology; and by encounter, with higher rates among advanced practice practitioners than physicians (P = .002; odds ratio = 9.97 [95% CI, 2.11-51.16]). TP rates were not significantly different during periods of uncontrolled local outbreak (P = .660). FP rates were not significantly higher within a 48-hour window of a TP (P = .192).

CONCLUSION

Point-of-care COVID-19 nucleic acid amplification tests in an outpatient otolaryngology clinic identified a low TP rate (<1%) with most cases being clinically suspected. Laryngology and advanced practice practitioner encounters may have higher positivity rates.Level of evidence: 3.

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.

Laser plume containment during flexible transnasal laryngoscopy

Objective

To evaluate a negative pressure microenvironment designed to contain laser plume during flexible transnasal laryngoscopy.

Methods

The Negative Pressure Face Shield (NPFS) was previously reported as well tolerated with initial use on 30 patients. Diagnostic transnasal laryngoscopy was performed on an additional 108 consecutive patients who were evaluated by questionnaires and sequential pulse oximetry. Further study addressed operative transnasal potassium‐titanyl‐phosphate (KTP) laser laryngoscopy with biopsy done on four patients employing the NPFS.

Results

The previously described NPFS version 3 (v.3), a transparent acrylic barrier with two anterior instrumentation ports, was modified by repositioning the side suction port closer to the level of the nose and deepening the lateral sides, squaring off the lower projection. A post‐procedure questionnaire employing a 5‐point Likert scale ranging from no symptoms (rating of 1) to intolerable (rating of 5) identified excellent patient tolerance of the new design (v.4), among 22 patients evaluated and similar in the comparison to the 116 patients using version 3. Among the 138 patients analyzed, only one patient rated the experience as greater than “mild claustrophobia.” 100% of patients answered either “none” or “mild” to the pain and shortness of breath questions. The NPFS (v.4) was then successfully used in four patients for laser laryngoscopy with biopsy of laryngeal papilloma (3/4) and hemorrhagic polyp (1/4). Post‐procedure questionnaire identified no shortness of breath (4/4), no claustrophobia (4/4), no pain (4/4) and no significant changes in pulse oximetry during use.

Conclusion

Extensive experience in performing diagnostic laryngoscopy with the NPFS directed design changes leading to successful use for transnasal flexible laser laryngoscopy with biopsy in a negative pressure microenvironment.

Level of Evidence

Level 2b (Cohort Study).

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.