Measurement of airborne particle exposure during simulated tracheal intubation using various proposed aerosol containment devices during the COVID-19 pandemic

Aerosol Box Use in Reducing Health Care Worker Contamination During Airway Procedures (AIRWAY) Study: Secondary Workload and Provider Outcomes in a Simulation-Based Trial

OBJECTIVES

An aerosol box aims to reduce the risk of healthcare provider (HCP) exposure to infections during aerosol generating medical procedures (AGMPs), but little is known about its impact on workload of team members. We conducted a secondary analysis of data from a prospective, multicenter, randomized controlled trial evaluating the impact of aerosol box use on patterns of HCP contamination during AGMPs. The objectives of this study are to: 1) evaluate the effect of aerosol box use on HCP workload, 2) identify factors associated with HCP workload when using an aerosol box, and 3) describe the challenges perceived by HCPs of aerosol box use.

DESIGN

Simulation-based randomized trial, conducted from May to December 2021.

SETTING

Four pediatric simulation centers.

SUBJECTS

Teams of two HCPs were randomly assigned to control (no aerosol box) or intervention groups (aerosol box).

INTERVENTIONS

Each team performed three scenarios requiring different pediatric airway management (bag-valve-mask [BVM] ventilation, laryngeal mask airway [LMA] insertion, and endotracheal intubation [ETI] with video laryngoscopy) on a simulated COVID-19 patient. National Aeronautics and Space Administration-Task Load Index (NASA-TLX) is a standard tool that measures subjective workload with six subscales.

MEASUREMENTS AND MAIN RESULTS

A total of 64 teams (128 participants) were recruited. The use of aerosol box was associated with significantly higher frustration during LMA insertion (28.71 vs. 17.42; mean difference, 11.29; 95% CI, 0.92-21.66; p = 0.033). For ETI, there was a significant increase in most subscales in the intervention group, but there was no significant difference for BMV. Average NASA-TLX scores were all in the "low" range for both groups (range: control BVM 23.06, sd 13.91 to intervention ETI 38.15; sd 20.45). The effect of provider role on workloads was statistically significant only for physical demand ( p = 0.001). As the complexity of procedure increased (BVM → LMA → ETI), the workload increased in all six subscales ( p < 0.05).

CONCLUSIONS

The use of aerosol box increased workload during ETI but not with BVM and LMA insertion. Overall workload scores remained in the "low" range, and there was no significant difference between airway provider and assistant.

Effectiveness of a suction device for containment of pathogenic aerosols and droplets

BACKGROUND

As the global community begins recovering from the COVID-19 pandemic, the challenges due to its aftermath remain. This health crisis has highlighted challenges associated with airborne pathogens and their capacity for rapid transmission. While many solutions have emerged to tackle this challenge, very few devices exist that are inexpensive, easy to manufacture, and versatile enough for various settings.

METHODS

This paper presents a novel suction device designed to counteract the spread of aerosols and droplets and be cost-effective and adaptable to diverse environments. We also conducted an experimental study to evaluate the device's effectiveness using an artificial cough generator, a particle counter, and a mannequin in an isolated system. We measured droplet removal rates with simulated single and repeated cough incidents. Also, measurements were taken at four distinct areas to compare its effectiveness on direct plume versus indirect particle removal.

RESULTS

The device reduced airborne disease transmission risk, as evidenced by its capacity to decrease the half-life of aerosol volume from 23.6 minutes to 15.6 minutes, effectively capturing aerosol-sized droplets known for their extended airborne persistence. The suction device lessened the peak total droplet volume from peak counts. At 22 minutes post peak droplet count, the count had dropped 24% without the suction device and 43% with the suction device.

CONCLUSIONS

The experiment's findings confirm the suction device's capability to effectively remove droplets from the environment, making it a vital tool in enhancing indoor air quality. Given the sustained performance of the suction device irrespective of single or multiple cough events, this demonstrates its potential utility in reducing the risk of airborne disease transmission. 3D printing for fabrication opens the possibility of a rapid iterative design process, flexibility for different configurations, and rapid global deployment for future pandemics.

Quantitative measurement of airborne particles during endoscopic and microscopic ear surgery in the operating room

OBJECTIVE

This study aimed to quantitatively investigate airborne particle load in the operating room during endoscopic or microscopic epitympanectomy or mastoidectomy.

METHOD

In the transcanal endoscopic ear surgery group, drilling was performed underwater. A particle counter was used to measure the particle load before, during and after drilling during transcanal endoscopic ear surgery or microscopic ear surgery. The device counted the numbers of airborne particles of 0.3, 0.5 or 1.0 μm in diameter.

RESULTS

The particle load during drilling was significantly higher in the microscopic ear surgery group (n = 5) than in the transcanal endoscopic ear surgery group (n = 11) for all particle sizes (p < 0.01). In the transcanal endoscopic ear surgery group, no significant differences among the particle load observed before, during and after drilling were seen for any of the particle sizes.

CONCLUSION

Bone dissection carries a lower risk of airborne infection if it is performed using the endoscopic underwater drilling technique.

An Individual Barrier Enclosure Actively Removing Aerosols for Airborne Isolation: A Vacuum Tent

BACKGROUND

Aerosol barrier enclosure systems have been designed to prevent airborne contamination, but their safety has been questioned. A vacuum tent was designed with active continuous suctioning to minimize risks of aerosol dispersion. We tested its efficacy, risk of rebreathing, and usability on a bench, in healthy volunteers, and in an ergonomic clinical assessment study.

METHODS

First, a manikin with airway connected to a breathing simulator was placed inside the vacuum tent to generate active breathing, cough, and CO2 production; high-flow nasal cannula (HFNC) was applied in the manikin's nares. Negative pressure was applied in the vacuum tent's apex port using wall suction. Fluorescent microparticles were aerosolized in the vacuum tent for qualitative assessment. To quantify particles inside and around vacuum tent (aerosol retention), an airtight aerosol chamber with aerosolized latex microparticles was used. The vacuum tent was tested on healthy volunteers breathing with and without HFNC. Last, its usability was assessed in 5 subjects by 5 different anesthesiologists for delivery of full anesthesia, including intubation and extubation.

RESULTS

The vacuum tent was adjusted until no leak was visualized using fluorescent particles. The efficacy in retaining microparticles was confirmed quantitatively. CO2 accumulation inside the vacuum tent showed an inverse correlation with the suction flow in all conditions (normal breathing and HFNC 30 or 60 L/min) in bench and healthy volunteers. Particle removal efficacy and safe breathing conditions (CO2, temperature) were reached when suctioning was at least 60 L/min or 20 L/min > HFNC flow. Five subjects were successfully intubated and anesthetized without ergonomic difficulties and with minimal interference with workflow and an excellent overall assessment by the anesthesiologists.

CONCLUSIONS

The vacuum tent effectively minimized aerosol dispersion. Its continuous suction system set at a high suction flow was crucial to avoid the spread of aerosol particles and CO2 rebreathing.

Development and demonstration of the protective efficacy of a convertible respiratory barrier enclosure: a simulation study

OBJECTIVE

The efficacy of previously developed respiratory barrier enclosures to limit healthcare workers' exposure to aerosols from COVID-19 patients remains unclear; in addition, the design of these devices is unsuitable for transportation or other emergency procedures. Therefore, we developed a novel negative pressure respiratory isolator to improve protection from patient-generated aerosols and evaluated its protective effect in conversion to systemic isolator.

METHODS

This in vitro study simulated droplets by nebulizing 1% glycerol + 99% ethanol solution. We performed cardiopulmonary resuscitation (CPR) and converted a respiratory barrier enclosure into a systemic isolator with a respiratory barrier as well as a respiratory barrier with negative pressure generator (NPG), which were compared with control and room air. During the procedure, particles were counted for 30 seconds and the count was repeated 10 times.

RESULTS

During CPR, the total number of particles in the respiratory barrier with NPG (280,529; interquartile range [IQR], 205,263-359,195; P=0.970) was similar to that in the control (308,789; IQR, 175,056-473,276). Using NPG with a respiratory barrier reduced the number of particles to 27,524 (IQR, 26,703- 28,905; P=0.001). Particle number during conversion of the respiratory barrier into a systemic isolator was also lower than in the control (25,845; IQR, 19,391- 29,772; P=0.001).

CONCLUSION

The novel isolator was converted to a systemic isolator without air leakage. The aerosol-blocking effect of the isolator was quantified using a particle counter during CPR. Further studies comparing the barrier effect of isolators within various pressure differentials are warranted.

Effectiveness of SplashGuard Caregiver prototype in reducing the risk of aerosol transmission in intensive care unit rooms of SARS-CoV-2 patients: a prospective and simulation study

BACKGROUND

The contagiousness of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is known to be linked to the emission of bioaerosols. Thus, aerosol-generating procedures (AGPs) could increase the risk of infection among healthcare workers (HCWs).

AIM

To investigate the impact of an aerosol protection box, the SplashGuard Caregiver (SGGC) with suction system, by direct analysis of the presence of viral particles after an AGP, and by using the computational fluid dynamics (CFD) simulation method.

METHODS

This prospective observational study investigated HCWs caring for patients with SARS-CoV-2 admitted to an intensive care unit (ICU). Rooms were categorized as: SGCG present and SGCG absent. Virus detection was performed through direct analysis, and using a CFD model to simulate the movement dynamics of airborne particles produced by a patient's respiratory activities.

FINDINGS

Of the 67 analyses performed, three samples tested positive on quantitative polymerase chain reaction: one of 33 analyses in the SCCG group (3%) and two of 34 analyses in the non-SGCG group (5.9%). CFD simulations showed that: (1) reduction of the gaps of an SGCG could decrease the number of emitted particles remaining airborne within the room by up to 70%; and (2) positioning HCWs facing the opposite direction to the main air flow would reduce their exposure.

CONCLUSIONS

This study documented the presence of SARS-CoV-2 among HCWs in a negative pressure ICU room of an infected patient with or without the use of an SGCG. The simulation will help to improve the design of the SGCG and the positioning of HCWs in the room.

Robust and self-lubricating polyvinyl alcohol tubes with a mucosa-like hierarchical architecture for endotracheal intubation

Mechanical mismatch between interventional intubation tubes and human tissues often triggers inevitable friction and causes secondary injury to patients during interventional therapy. Herein, we propose a fabrication strategy of a self-lubricating polyvinyl alcohol (PVA) tube by industrial extrusion technology followed by simple infiltration with water. First, biocompatible glycerin was introduced to weaken the intrinsic hydrogen interaction of PVA by new molecular complexation, broadening the gap between the melting and decomposition temperatures and enabling the stable extrusion of the PVA tube. Subsequently, the as-prepared PVA tube was infiltrated with an aqueous solution to construct a strong hydrogen bonding network between PVA and water molecules, forming a soft hydration layer similar to the upper epithelium layer of mucosa. Benefiting from the solid and liquid properties of the hydration layer as well as the small proportion relative to the whole, the infiltrated PVA tube exhibited excellent hydration lubrication behavior and robust mechanical property. The friction coefficient, tensile strength and elongation at break were measured to be 0.05, 26.2 MPa and 654%, respectively, surpassing the values of 0.5, 16.4 MPa and 240% observed in a commercial polyvinyl chloride tube. In vitro, the PVA intubation tube demonstrated significant biocompatibility, and short-term exposure exhibited minimal impacts on the morphology and proliferation of L929 cells. Ultimately, the potential of the infiltrated PVA tube for interventional intubation was demonstrated successfully using an in vivo rabbit model, providing a new idea for the follow-up development of interventional intubation tubes.

Does doffing the FEES Box generate a significant cloud of particles after aerosol-generating procedures? A proof-of-concept study

PURPOSE

The spread of airborne diseases, including coronaviruses, remains a widespread public health concern. Published studies outline the use of protective barriers to limit the spread of pathogenic particles and droplets resulting from coughing, sneezing, and talking. The findings suggest a role for these barriers during aerosol-generating procedures, such as flexible endoscopic evaluation of swallowing (FEES). However, the question remains of whether doffing a protective barrier will create a concentrated cloud of particles that will increase health professionals' exposure.

METHOD

We simulated four clinical scenarios of coughing and sneezing, talking, eating and drinking, and delivering supplemental oxygen to test whether doffing the FEES Box protective barrier would result in a particle cloud.

RESULT

For all scenarios simulated, doffing the FEES Box did not result in a significant increase in mean particle count. Further, the manner of FEES Box removal did not significantly influence mean particle counts on a consistent basis.

CONCLUSION

These results suggest that doffing the FEES Box does not increase exposure to airborne particles. Although more research is needed to confirm these findings, FEES Box usage should be considered during aerosol-generating procedures, to protect and reassure healthcare professionals who work with patients with COVID-19 or other airborne diseases.

The Effect of a Plastic Barrier Drape on Resuscitation Performance and Provider Contamination: A Randomized Controlled Simulation-Based Pilot Trial

BACKGROUND

Patient barriers to protect health care workers from COVID-19 exposure have been studied for airway management. Few are tested for cardiopulmonary resuscitation (CPR). We sought to determine whether a plastic drape barrier affects resuscitation performance and contamination risks for a simulated cardiopulmonary arrest scenario.

METHODS

This pilot trial randomized in-hospital resuscitation teams of 4 to 6 participants to a plastic drape or without a drape in an in situ cardiopulmonary arrest simulation. The mannequin's airway emanated simulated virus particles (GloGerm, Moab, UT), detectable through UV light. Primary outcomes included airway management and CPR quality measures. Secondary outcomes included visible contamination on personal protective equipment (PPE). We used the Non-Technical Skills (NO-TECHS) instrument to measure perceived team performance and the NASA Task Load Index (NASA-TLX) to measure individual workload. Outcome variables were analyzed using an analysis of covariance (ANCOVA) with participant number as a covariate.

RESULTS

Seven teams were allocated to the intervention (plastic drape) group and 7 to the control. Intubation and ventilation performance (η 2 = 0.09, P > 0.3) and chest compression quality (η 2 = 0.03-0.19, P > 0.14) were not affected by the plastic drape. However, mean contaminated PPE per person decreased with the drape (2.8 ± 0.3 vs. 3.7 ± 0.3, partial η 2 = 0.29, P = 0.05). No differences in perceived workload nor team performance were noted ( P > 0.09).

CONCLUSIONS

In this pilot study, the use of a plastic drape barrier seems not to affect resuscitation performance on simulated cardiopulmonary arrest but decreases health care worker contamination risk. Further implementation trials could characterize the true risk reduction and any effect on resuscitation outcomes.

Quantifying Simulated Contamination Deposition on Healthcare Providers Using Image Analysis

INTRODUCTION

Simulation-based research has played an important role in improving care for communicable diseases. Unfortunately, few studies have attempted to quantify the level of contamination in these simulation activities. We aim to assess the feasibility and provide validity evidence for using integrated density values and area of contamination (AOC) to differentiate various levels of simulated contamination.

METHODS

An increasing number of simulated contamination spots using fluorescent marker were applied on a manikin chest to simulate a contaminated healthcare provider. An ultraviolet light was used to illuminate the manikin to highlight the simulated contamination. Images of increasing contamination levels were captured using a camera with different exposure settings. Image processing software was used to measure 2 outcomes: (1) natural logarithm of integrated density; and (2) AOC. Mixed-effects linear regression models were used to assess the effect of contamination levels and exposure settings on both outcome measures. A standardized "proof-of-concept" exercise was set up to calibrate and formalize the process for human subjects.

RESULTS

A total of 140 images were included in the analyses. Dose-response relationships were observed between contamination levels and both outcome measures. For each increment in the number of contaminated simulation spots (ie, simulated contaminated area increased by 38.5 mm 2 ), on average, log-integrated density increased by 0.009 (95% confidence interval, 0.006-0.012; P < 0.001) and measured AOC increased by 37.8 mm 2 (95% confidence interval, 36.7-38.8 mm 2 ; P < 0.001), which is very close to actual value (38.5 mm 2 ). The "proof-of-concept" demonstration further verified results.

CONCLUSIONS

Integrated density and AOC measured by image processing can differentiate various levels of simulated, fluorescent contamination. The AOC measured highly agrees with the actual value. This method should be optimized and used in the future research to detect simulated contamination deposited on healthcare providers.

A hood shield reduces postdoffing contamination during simulated COVID-19 airway management: an exploratory, simulation-based randomized study

PURPOSE

SARS-CoV-2 poses a significant occupational health threat to health care workers performing aerosol-generating medical procedures, with a threefold increased risk of a positive test and predicted infection compared with the general population. Nevertheless, the personal protective equipment (PPE) configuration that provides better protection with lower contamination rates is still unknown.

METHODS

We enrolled 40 practitioners with airway management training (anesthesiologists, anesthesia assistants/nurses) in an exploratory, simulation-based randomized study. We evaluated the performance of a novel, locally designed hood (n = 20) in terms of protection from surrogate contamination using an ultraviolet (UV) marker during a standardized urgent intubation procedure and a simulated episode of coughing in a high-fidelity simulation setting compared with standard PPE (n = 20). The primary outcome was the presence of residual UV fluorescent contamination on any base clothing or exposed skin of the upper body after doffing PPE assessed by a blinded evaluator.

RESULTS

The proportion of participants with residual contamination on any base clothing or exposed skin of the upper body after doffing was less than half in the hood PPE group compared with the standard PPE group (8/20 [40%] vs 18/20 [90%], respectively; P = 0.002).

CONCLUSIONS

Compared with standard PPE, enhanced PPE with a locally designed prototype hood was associated with reduced contamination of the upper torso and fewer body areas being exposed to droplets after a simulated aerosol-generating scenario without designed airflow.

STUDY REGISTRATION

ClinicalTrials.gov (NCT04373096); registered 4 May 2020.

A novel negative pressure isolation device reduces aerosol exposure: A randomized controlled trial

Background and aim

The COVID-19 pandemic has led to a proliferation of intubation barriers designed to protect healthcare workers from infection. We developed the Suction-Assisted Local Aerosol Containment Chamber (SLACC) and tested it in the operating room. The primary objectives were to determine the ease and safety of airway management with SLACC, and to measure its efficacy of aerosol containment to determine if it significantly reduces exposure to health care workers.

Methods

In this randomized clinical trial, adult patients scheduled to undergo elective surgery with general endotracheal anesthesia were screened and informed consent obtained from those willing to participate. Patients were randomized to airway management either with or without the SLACC device. Patients inhaled nebulized saline before and during anesthesia induction to simulate the size and concentration of particles seen with severe symptomatic SARS-CoV-2 infection.

Results

79 patients were enrolled and randomized. Particle number concentration (PNC) at the patients' and healthcare workers' locations were measured and compared between the SLACC vs. control groups during airway management. Ease and success of tracheal intubation were recorded for each patient. All intubations were successful and time to intubation was similar between the two groups. Healthcare workers were exposed to significantly lower particle number concentrations (#/cm3) during airway management when SLACC was utilized vs. control. The particle count outside SLACC was reduced by 97% compared to that inside the device.

Conclusions

The SLACC device does not interfere with airway management and significantly reduces healthcare worker exposure to aerosolized particles during airway management.

Assessment of the use and Safety of Protection Box for Intubation and Extubation Among Anaesthesiologists During COVID-19 Pandemic- A Cross-sectional Survey

Introduction

Covid 19 epidemic has affected the people making them undergo emergency procedures requiring intubation. A protective box was innovated at our tertiary care centre to safeguard the HCW during intubation and/or extubation and the study was planned to assess its use and safety among the anaesthesiologists.

Methods

A cross sectional, questionnaire base survey was done among anaesthesiologists in various strata of residency. The intubation box was used on the patient for intubation and extubation. The experience of participants was recorded via a Google Form and one response per participant was restricted. Participants were divided into two groups, Group 1(1stand 2nd year junior residents) and Group 2 (Senior resident and 3rd year junior resident). A valid response, was received from 25 anaesthesiologists who were either performing or assisting the intubation. The residents were evaluated based on the ease of use and safety features of the box.

Results

There was a significant difference in the time taken to intubate between the two groups (p = 0.048) and it was found that Group 2 with more experience took less time to intubate than Group 1. Also, more respondents in Group 2 found it easier to manoeuvre the hands to handle instruments than Group 1(p = 0.024).

Conclusion

We recommend that usage of intubation box during intubation or extubation is a non-harmful and necessary compromise that we must make to protect the /safeguard the well-being of Health Care Worker without affecting patient care in our fight with COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03692-7.

The effect of clinical face shields on aerosolized particle exposure

Background

Face shields protect healthcare workers (HCWs) from fluid and large droplet contamination. Their effect on smaller aerosolized particles is unknown.

Materials & methods

An ultrasonic atomizer was used to simulate particle sizes equivalent to human breathing and forceful cough. Particles were measured at positions correlating to anesthetic personnel in relation to a patient inside an operating theatre environment. The effect of the application of face shields on HCW exposure was measured.

Results & Conclusion

Significant reductions in particle concentrations were measured after the application of vented and enclosed face shields. Face shields appear to reduce the concentration of aerosolized particles that HCWs are exposed to, thereby potentially conferring further protection against exposure to aerosolized particles in an operating theatre environment.

Use of a Negative Pressure Containment Pod Within Ambulance-Workspace During Pandemic Response

Emergency medical service (EMS) providers have a higher potential exposure to infectious agents than the general public (Nguyen et al., 2020, "Risk of COVID-19 Among Frontline Healthcare Workers and the General Community: A Prospective Cohort Study," Lancet Pub. Health, 5(9), pp. e475-e483; Brown et al., 2021, "Risk for Acquiring Coronavirus Disease Illness Among Emergency Medical Service Personnel Exposed to Aerosol-Generating Procedures," Emer. Infect. Disease J., 27(9), p. 2340). The use of protective equipment may reduce, but does not eliminate their risk of becoming infected as a result of these exposures. Prehospital environments have a high risk of disease transmission exposing EMS providers to bioaerosols and droplets from infectious patients. Field intubation procedures may be performed causing the generation of bioaerosols, thereby increasing the exposure of EMS workers to pathogens. Additionally, ambulances have a reduced volume compared to a hospital treatment space, often without an air filtration system, and no control mechanism to reduce exposure. This study evaluated a containment plus filtration intervention for reducing aerosol concentrations in the patient module of an ambulance. Aerosol concentration measurements were taken in an unoccupied research ambulance at National Institute for Occupational Safety and Health (NIOSH) Cincinnati using a tracer aerosol and optical particle counters (OPCs). The evaluated filtration intervention was a containment pod with a high efficiency particulate air (HEPA)-filtered extraction system that was developed and tested based on its ability to contain, capture, and remove aerosols during the intubation procedure. Three conditions were tested (1) baseline (without intervention), (2) containment pod with HEPA-1, and (3) containment pod with HEPA-2. The containment pod with HEPA-filtered extraction intervention provided containment of 95% of the total generated particle concentration during aerosol generation relative to the baseline condition, followed by rapid air cleaning within the containment pod. This intervention can help reduce aerosol concentrations within ambulance patient modules while performing aerosol-generating procedures.

Simulation Method for Testing Aerosol Mitigation Strategies: An Observational Study

BACKGROUND

Frontline health care workers who perform potentially aerosol-generating procedures, such as endotracheal intubations, in patients with coronavirus disease 2019 may be at an increased risk of exposure to severe acute respiratory syndrome coronavirus 2. To continue to care for patients with coronavirus disease 2019, minimizing exposure is paramount. Using simulation, we devised a testing method to evaluate devices that may mitigate the spread of aerosol and droplet-sized particles.

METHODS

In this prospective single-center study, participants intubated a manikin 3 times using standard personal protective equipment, once with no barrier device, once with an acrylic box, and once with a modified horizontal drape. The micrometer-sized particle count, generated by a nebulization model, was recorded before and after each intubation. The first-pass intubation rate and time to intubation were recorded. Each operator completed a postsimulation survey about their experience using the barrier devices.

RESULTS

Thirty airway proceduralists completed the simulation and survey. There was no significant difference in particle counts (aerosols or droplets) or first-pass intubation, but the horizontal drape was found to significantly increase intubation time ( P = 0.01). Most participants preferred the drape over the acrylic box or no barrier device.

CONCLUSIONS

The acrylic box and plastic drape did not mitigate particle spread. However, our testing method can be used to test barrier designs using negative pressure or other mitigation strategies for particle spread.

The effect of using personal protective equipment and aerosol box in the emergency department on the intubation times

Background

Endotracheal intubation is a procedure commonly performed in the emergency department (ED). Endotracheal intubation poses a risk of exposure to infectious aerosol droplets.

Aim

The present study aims to test the effect of using an aerosol box (AB) and personal protective equipment (PPE) on the intubation time while performing endotracheal intubation manikin.

Subjects and Methods

The study participants (11 emergency specialists, 11 emergency physicians, and 11 general practitioners) performed endotracheal intubation on a training manikin in three different airway simulations. Simulation 1 had neither PPE nor AB, simulation 2 had PPE, and simulation 3 had both PPE and AB. The intubation times, the number of intubation attempts, and the discomfort caused by the AB were recorded.

Results

There was no significant difference in the number of intubation attempts between the physicians according to their position and airway simulations (p > 0.05). There was a significant difference at all time points except for the time to endotracheal tube cuff inflation in three different airway simulations using PPE and an AB (p < 0.05). The median intubation times were longer using PPE and an AB.

Conclusion

The use of PPE and an AB significantly increases the total intubation time.

Design and quantitative evaluation of 'Aerosol Bio-Containment Device (ABCD)' for reducing aerosol exposure during infectious aerosol-generating events

The Coronavirus Disease 2019 (COVID-19) pandemic renewed interest in infectious aerosols and reducing risk of airborne respiratory pathogen transmission, prompting development of devices to protect healthcare workers during airway procedures. However, there are no standard methods for assessing the efficacy of particle containment with these protective devices. We designed and built an aerosol bio-containment device (ABCD) to contain and remove aerosol via an external suction system and tested the aerosol containment of the device in an environmental chamber using a novel, quantitative assessment method. The ABCD exhibited a strong ability to control aerosol exposure in experimental and computational fluid dynamic (CFD) simulated scenarios with appropriate suction use and maintenance of device seals. Using a log-risk-reduction framework, we assessed device containment efficacy and showed that, when combined with other protective equipment, the ABCD can significantly reduce airborne clinical exposure. We propose this type of quantitative analysis serves as a basis for rating efficacy of aerosol protective enclosures.

Aerosol generation during paediatric procedural sedation with continuous-flow nitrous oxide suggests a low risk of airborne viral transmission to health-care workers

AIM

Inhaled nitrous oxide is a common form of procedural sedation in paediatric care. During the COVID-19 pandemic, concerns about potential aerosol generation and associated viral transmission to health-care workers have led to controversy regarding its use. We aimed to measure the degree of aerosol generation during continuous flow nitrous oxide sedation to inform future guidelines.

METHODS

Aerosol numbers in the respirable range were measured using a particle counter during 30 procedures undertaken in children under nitrous oxide sedation in the Emergency Department.

RESULTS

Changes from baseline measurements were greatest in particles in the 0.3 μm range. The mean increase from baseline in 0.3 μm particles per cubic metre was 18 022 (95% confidence interval (CI) 5949-30 096) after the child entered the room, and 2931 (95% CI -4407 to 10 269) during nitrous oxide administration.

CONCLUSION

Variation of respirable particle numbers from baseline levels was no greater during nitrous oxide administration than for breathing and talking asymptomatic children. These results suggest the additional risk of airborne viral transmission to staff during inhaled nitrous oxide sedation is low.

Improving safety and communication for healthcare providers caring for SARS-COV-2 patients

Background

Decreasing healthcare provider (HCP) exposure to the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) virus in emergency departments (EDs) is crucial. Approaches include limiting the HCP presence and ensuring sealed isolation rooms, which can result in communication difficulties. This quality improvement (QI) initiative aimed to decrease by 50% duration of isolation room door opening and increasing HCP-perceived communication clarity by one point on a five-point Likert scale.

Methods

This was a prospective, multi-stage project with three Plan-Do-Study-Act (PDSA) cycles between May and July 2020: (1) an educational intervention, (2) the introduction of a novel transceiver communication device, and (3) utilizing a clinical champion. Statistical Process Control XbarR charts were used to assess for special cause variation, and two-tailed Mann-Whitney U tests were used for statistical significance between Likert survey means. Qualitative responses underwent thematic analysis.

Results

Observation of 174 patient encounters was completed over 33 days, with 95 meeting the inclusion criteria. Door opening decreased from baseline (n=40; mean 72.97%) to PDSA 3 (n=21; mean 1.58%; p<0.0001). HCP-perceived communication clarity improved from baseline (n=36; mean 3.36) to PDSA-3 (n=49; mean 4.21; p<0.001). Survey themes included positive effects on communication and workflow, with some challenges on the integration of the new device into the clinical workflow. HCP-perceived errors, workarounds, and workflow pauses showed significant improvements.

Conclusion

This QI initiative with a novel transceiver showed significant decreases in isolation room door opening and increases in communication clarity. Future work will expand to operating rooms and intensive care units.

Evaluation of the conventional and modified aerosol boxes during tracheal intubation in normal and difficult airways: a randomized, crossover, manikin simulation study

The aim of this study was to evaluate conventional and modified aerosol boxes in terms of intubation time, first-pass intubation success, and mouth-to-mouth distance between the laryngoscopist and patient during tracheal intubation in simulated patients with normal and difficult airways. Sixteen anesthesiologists performed tracheal intubations with direct laryngoscope or three different videolaryngoscopes (McGRATH MAC videolaryngoscope, C-MAC videolaryngoscope, and Pentax-AWS) without an aerosol box or with a conventional or a modified aerosol boxes in simulated manikins with normal and difficult airways. Intubation time, first-pass intubation success, and mouth-to-mouth distance during tracheal intubation were recorded. Compared to no aerosol box, the use of a conventional aerosol box significantly increased intubation time in both normal and difficult airways (Bonferroni-corrected P-value (P_corrected) = 0.005 and P_corrected = 0.003, respectively). Intubation time was significantly shorter with the modified aerosol box than with the conventional one for both normal and difficult airways (P_corrected = 0.003 and P_corrected = 0.011, respectively). However, no significant differences were found in intubation time between no aerosol box and the modified aerosol box for normal and difficult airways (P_corrected = 0.336 and P_corrected = 0.112, respectively). The use of conventional or modified aerosol boxes significantly extended the mouth-to-mouth distances compared to not using an aerosol box during tracheal intubation with each laryngoscope (all P_corrected < 0.05), and the distances were not different between the conventional and modified boxes in normal and difficult airways. The use of modified aerosol box did not increase intubation time and could help maintain a distance from the simulated patients with normal and difficult airways.

Efficacy of an aerosol suction device Free-100 M in removing aerosols produced by coughing to minimize COVID-19 infection

PURPOSE

The healthcare workers are at the greatest risk of being exposed to viral infection during airway management of a patient with coronavirus disease 2019 (COVID-19). An air extractor which suctions air around the patient's face would reduce the spread of viral aerosols during coughing, but no study has confirmed this. We assessed whether or not an air extractor reduces the amount of aerosols spreading toward the operator's face, during coughing of simulated patients.

METHODS

After obtained approval of the study by a research ethics committee and written informed consent from 20 volunteers (and additional 20 volunteers), we asked each volunteer to lie supine on a table in a positive-pressure management operating room. As a cross-over design, we used an airborne particle counter (Handheld 3016, SGY company, Tokyo) to measure the aerosols approximately 30 cm above the participant's mouth, while the volunteer was coughing, with and without the use of an air extractor Free-100 M (Forest-one, Funabashi), facing the participant's mouth. In another 20 volunteers, the aerosols were measured, while each volunteer was lying supine, without coughing, and without the use of the air extractor.

RESULTS

The aerosol count during coughing was significantly lower when the air extractor was used [median: 55 (interquartile range: 15-128)] than when it was not used [73 (44-201)] [p = 0.001, difference: 19 (95%CI: 4-70)].

CONCLUSIONS

The Free-100 M air extractor would reduce, but do not remove all, aerosols produced by coughing of a patient, and thus may reduce the risk of infection of COVID-19.

Prevention of submicron aerosolized particle dispersion: evaluation of an aerosol box using a pediatric simulation model

Background and Aim: The SplashGuard CG (SG) is a barrier enclosure developed to protect healthcare workers from SARS-CoV-2 transmission during aerosol-generating procedures. Our objective was to evaluate the protection provided by the SG against aerosolized particles (AP), using a pediatric simulation model of spontaneous ventilation (SV) and noninvasive ventilation (NIV). Methods: An aerosol generator was connected to the airways of a pediatric high-fidelity manikin with a breathing simulator. AP concentrations were measured both in SV and NIV in the following conditions: with and without SG, inside and outside the SG, with and without suction applied to the device. Results: In the SV simulated setting, AP peaks were lower with SG: 0.1 × 10⁵ particles/L compared to without: 1.6 × 10⁵, only when the ports were closed and suction applied. In the NIV simulated setting, AP peaks outside the SG were lower than without SG (20.5 × 10⁵ particles/L), whatever the situation, without suction (14.4 × 10⁵particles/L), with suction and ports open or closed: 10.3 and 0.7 × 10⁵ particles/L. In SV and NIV simulated settings, the AP peaks measured within the SG were much higher than the AP peaks measured without SG, even when suction was applied to the device. Conclusions: The SG seems to decrease peak AP exposure in the 2 ventilation contexts, but only with closed port and suction in SV. However, high concentrations of AP remain inside even with suction and SG should be used cautiously.

Effect of two barrier devices on the time taken and ease of intubation of a paediatric intubation manikin - A randomised cross-over simulation study

Background and Aims

During the present COVID-19 pandemic, several inventions have been employed to protect personnel involved in intubation from inhalational exposure to the virus. In this study, we compared the effect of two barrier devices, Intubation Box versus Plastic Drape, on the time taken and difficulty in intubating a pediatric manikin.

Material and Methods

Nineteen experienced anesthesiologists performed six different intubations: without barrier, with intubation box, with plastic drape; with and without a bougie, using the Latin Square Design for randomizing order of intubations. The time taken for intubation (TTI) was compared using Student's t test, and nonparametric values were analyzed using Chi-square test with Yates correction.

Results

Both barrier devices increased the TTI from 14.8 (3.5) s to 19.8 (6.8) s with intubation box (P = 0.068) and 19.3 (8.9) s with plastic drape (P = 0.099). Use of bougie significantly prolonged TTI to 25.8 (6.7) s without barrier (P = 0.000), 32.5 (13.3) with intubation box (P = 0.000), and 29.8 (7.3) s with plastic drape (P = 0.000). The number of attempts was not different (P = 0.411), and the visibility was slightly impaired with both barriers (P = 0.047). The ease of intubation, even without the bougie, was significantly different compared to default, with P values of 0.009 and 0.042 for intubation box and plastic drape, respectively. The highest significance was with intubation box with bougie with a P value of 0.00017.

Conclusion

Both the intubation box and plastic drape increased the time taken as well as difficulty in intubation. The extra protection afforded should be balanced against risks of hypoxia in the patient.

Mitigating the Spread of Covid-19 During Extubation: Assessing the Impact of a Barrier Device

COVID-19 is a novel virus spread via airborne particles. Given the inherent risk to the anesthesia provider, intubation and airway management guidelines have been recently established. Various studies have been published advocating and detailing the results of different intubation devices designed to decrease the number of airborne particles. Currently, little literature exists regarding devices designed to mitigate the spread of COVID-19 airborne particles during extubation. The purpose of this prospective in situ simulated manikin study was to measure the effectiveness of an aerosolized containment device during passive (deep) and forced (simulated coughing) extubation. Airborne particles were measured at the 0.3, 0.5, 1, 2, 5, 10-micron level. Statistically significant decreases were seen with the use of a barrier device during both passive and forced extubation.

Aerosol boxes for airway management in coronavirus disease patients: a clinical retrospective study in Mexico

INTRODUCTION

Significant concerns raise for the healthcare workers involved in airway management of patients diagnosed with coronavirus 2019 disease (COVID-19). Due to shortages of personal protective equipment (PPE), barrier enclosure systems such as aerosol box (AB) have been proposed worldwide. The aim of this study was to evaluate our experience using AB as protective equipment in patients with COVID-19 in a third-level center in Mexico.

METHODS

A retrospective study of COVID-19 patients requiring airway management using an AB in the Hospital Central Sur de Alta Especialidad de Pemex in Mexico City from March 1 to June 1, 2020. Antropometric data, pre-intubation vital signs, and laboratory tests were recorded; the primary endpoints were intubation success rate and complications associated with AB and patients' mortality. As a secondary endpoint, AB subjective evaluation was explored by administering a survey after airway management procedures.

RESULTS

Thirty-nine patients for a total of 40 intubations were documented. Thirty-one (77.5%) were men, with a mean age of 61.65 years; successful intubation occurred in 39 (97.55%) of the procedures, and AB was used in 36 (90%) of intubations, with success in 28 (70.0%); A Cormack-Lehane grade 3 view was recorded in 18 patients (46.2%), and during the procedure, the AB had to be removed in 8 (22.2%) cases, with migration documented in 91.6% of cases. The 30-day mortality was 48.71%, with 23.0% of patients discharged. 83.3% of surveyed anesthesiologists reported significant limitations in manipulating airway devices with AB used.

CONCLUSION

Our data indicate that in clinical practice, the use of AB may hinder airway management and decrease the intubation success rate and may also result in patients' injury. Further studies are necessary to validate the use of AB in clinical practice, and they should not replace certified PPE.

Design and testing of the safety of the SARUS-CPR hood for novice resuscitators

BACKGROUND AND AIMS

Bystanders should be protected against aerosols, droplets, saliva, blood and vomitus during resuscitation after cardiac arrest The SARUS (safer - airway - resuscitation) CPR airway hood™ is a clear plastic cover and integrated mask that envelopes the head and torso. Our objectives were to test leakage using saline aerosol generation tests, then assess the performance of the hood during mock cardio-pulmonary resuscitation on a manikin.

METHODS

A checklist was validated by comparing the performance of 10 novices against 10 experts during mock resuscitation. Thereafter, 15 novices were tested with and without the hood, in a randomised cross-over study, one week apart.

RESULTS

Laboratory analysis showed a > 99% reduction of saline particles detected 5 cm, 75 cm and 165 cm above volunteers wearing the hood. On manikins, experts scored better compared to novices, 8.5 (0.7) vs 7.6 (1.2), difference (95%CI) 0.9 (0.4-1.3), P = 0.0004. Novice performance was equivalent using the hood and standard equipment, 7.3 (1.4) vs 7.3 (1.1) respectively, difference (90%CI) 0.0 (-0.3 - 0.3), P = 0.90.

CONCLUSION

Aerosol transmission reduced in the breathing zone. Simulated resuscitation by novices was equivalent with and without the hood.

Prevention of droplet dispersal with 'e-mask': A new daily use endoscopic mask during bronchoscopy

BACKGROUND AND OBJECTIVE

Bronchoscopy is an airborne particle-generating procedure. However, few methods for safe bronchoscopy have been developed. To reduce airborne particles during bronchoscopy, we created an 'e-mask', which is a simple, disposable mask for patients. Our objective was to evaluate the e-mask's protective ability against airborne particles and to assess respiratory adverse events and complications.

METHODS

Patients with stage 2-4 chronic obstructive pulmonary disease were excluded. We performed visualization and quantifying experiments on airborne particles with and without the e-mask. We prospectively evaluated whether wearing the e-mask during bronchoscopy was associated with the incidence of patients requiring >5 L/min oxygen to maintain >90% oxygen saturation, and patients with >45 mm Hg end-tidal carbon dioxide (EtCO₂ ) elevation, in addition to complications, compared to historical controls.

RESULTS

In the visualization experiment, more than ten thousand times of airborne particles were generated without the e-mask than with the e-mask. The volume of airborne particles was significantly reduced with the e-mask, compared to that without the e-mask (p = 0.011). Multivariate logistic regression analysis revealed that wearing the e-mask had no significant effect on the incidence of patients requiring >5 L/min oxygen to maintain >90% oxygen saturation, (p = 0.959); however, wearing the e-mask was a significant factor in >45 mm Hg EtCO₂ elevation (p = 0.026). No significant differences in complications were observed between the e-mask and control groups (5.8% vs. 2.5%, p = 0.395).

CONCLUSION

Wearing the e-mask during bronchoscopy significantly reduced the generation of airborne particles during bronchoscopy without increasing complications.

Comparison of endotracheal intubation with Macintosh versus King Vision video laryngoscope using coronavirus disease 2019 barrier box on manikins: A randomized crossover study

BACKGROUND:

Coronavirus disease 2019 (COVID-19) virus usually spreads through aerosol and close contact. Frontline health-care workers handle aerosol-generating procedures like endotracheal intubation. To reduce this risk, COVID-19 barrier box came into the picture. However, the COVID-19 barrier box may compromise easy and successful intubation, and their limitation must be studied.

OBJECTIVES:

The objective of this study was to assess the time to successful intubation with or without the COVID-19 barrier box using the Macintosh laryngoscope and King Vision video laryngoscope (KVVL). We also assessed the first-pass success rate, ease of intubation, Cormack–Lehane (CL) grade, and requirement of external laryngeal manipulation.

METHODS:

We conducted this manikin-based randomized crossover study to assess the time to successful intubation by anesthesiologists (22) and emergency physicians (11) having 1 year or more experience with or without COVID-19 barrier box by using the Macintosh laryngoscope and KVVL. Our study randomized the sequence of the four different intubation scenarios.

RESULTS:

The comparison of mean duration of intubation between KVVL (13.21 ± 4.05 s) and Macintosh laryngoscope (12.89 ± 4.28 s) with COVID-19 barrier box was not statistically significant (95% confidence interval: 1.21–0.97). The ease of intubation, number of attempts, and requirement of external laryngeal manipulation were not statistically significant. Intubations were statistically significant more difficult with barrier box in view of higher CL grade.

CONCLUSION:

Time to intubation was longer with COVID-19 barrier box using KVVL as compared to Macintosh laryngoscope which was statistically not significant.

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.

Modeling of nursing care-associated airborne transmission of SARS-CoV-2 in a real-world hospital setting

Respiratory transmission of SARS-CoV-2 from one older patient to another by airborne mechanisms in hospital and nursing home settings represents an important health challenge during the COVID-19 pandemic. However, the factors that influence the concentration of respiratory droplets and aerosols that potentially contribute to hospital- and nursing care-associated transmission of SARS-CoV-2 are not well understood. To assess the effect of health care professional (HCP) and patient activity on size and concentration of airborne particles, an optical particle counter was placed (for 24 h) in the head position of an empty bed in the hospital room of a patient admitted from the nursing home with confirmed COVID-19. The type and duration of the activity, as well as the number of HCPs providing patient care, were recorded. Concentration changes associated with specific activities were determined, and airway deposition modeling was performed using these data. Thirty-one activities were recorded, and six representative ones were selected for deposition modeling, including patient's activities (coughing, movements, etc.), diagnostic and therapeutic interventions (e.g., diagnostic tests and drug administration), as well as nursing patient care (e.g., bedding and hygiene). The increase in particle concentration of all sizes was sensitive to the type of activity. Increases in supermicron particle concentration were associated with the number of HCPs (r = 0.66; p < 0.05) and the duration of activity (r = 0.82; p < 0.05), while submicron particles increased with all activities, mainly during the daytime. Based on simulations, the number of particles deposited in unit time was the highest in the acinar region, while deposition density rate (number/cm2/min) was the highest in the upper airways. In conclusion, even short periods of HCP-patient interaction and minimal patient activity in a hospital room or nursing home bedroom may significantly increase the concentration of submicron particles mainly depositing in the acinar regions, while mainly nursing activities increase the concentration of supermicron particles depositing in larger airways of the adjacent bed patient. Our data emphasize the need for effective interventions to limit hospital- and nursing care-associated transmission of SARS-CoV-2 and other respiratory pathogens (including viral pathogens, such as rhinoviruses, respiratory syncytial virus, influenza virus, parainfluenza virus and adenoviruses, and bacterial and fungal pathogens).

Experiences of healthcare providers with a novel emergency response intubation team during COVID-19

OBJECTIVES

In the early stages of the COVID-19 pandemic, there were significant concerns about the infectious risks of intubation to healthcare providers. In response, a dedicated emergency response intubation team (ERIT) consisting of anesthesiologists and allied health providers was instituted for our emergency department (ED). Given the high-risk nature of intubations and the new interprofessional team dynamics, we sought to assess health-care provider experiences and potential areas of improvement.

METHODS

Surveys were distributed to healthcare providers at the University Health Network, a quaternary healthcare centre in Toronto, Canada, which includes two urban EDs seeing over 128,000 patients per year. Participants included ED physicians and nurses, anesthesiologists, anesthesia assistants, and operating room nurses. The survey included free-text questions. Responses underwent thematic analysis using grounded theory and were independently coded by two authors to generate descriptive themes. Discrepancies were resolved with a third author. Descriptive themes were distilled through an inductive, iterative process until fewer main themes emerged.

RESULTS

A total of 178 surveys were collected (68.2% response rate). Of these, 123 (69%) participated in one or more ERIT activations. Positive aspects included increased numbers of staff to assist, increased intubation expertise, improved safety, and good team dynamics within the ERIT team. Challenges included a loss of scope (primarily ED physicians and nurses) and unfamiliar workflows, perceived delays to ERIT team arrival or patient intubation, role confusion, handover concerns, and communication challenges between ED and ERIT teams. Perceived opportunities for improvement included interprofessional training, developing clear guidelines on activation, inter-team role clarification, and guidelines on handover processes post-intubation.

CONCLUSIONS

Healthcare providers perceived that a novel interprofessional collaboration for intubations of COVID-19 patients presented both benefits and challenges. Opportunities for improvement centred around interprofessional training, shared decision making between teams, and structured handoff processes.

Effectiveness of a novel semi-closed barrier device with a personalized exhaust in cough aerosol simulation according to particle counts and visualization of particles

Oxygen therapy is an essential treatment for patients with coronavirus disease 2019, although there is a risk of aerosolization of additional viral droplets occurring during this treatment that poses a danger to healthcare professionals. High-flow oxygen through nasal cannula (HFNC) is a vital treatment bridging low-flow oxygen therapy with tracheal intubation. Although many barrier devices (including devices without negative pressure in the barrier) have been reported in the literature, few barrier devices are suitable for HFNC and aerosol infection control procedures during HFNC have not yet been established. Hence, we built a single cough simulator model to examine the effectiveness of three protective measures (a semi-closed barrier device, a personalized exhaust, and surgical masks) administered in isolation as well as in combination using particle counter measurements and laser sheet visualization. We found that the addition of a personalized exhaust to a semi-closed barrier device reduced aerosol leakage during HFNC without negative pressure. This novel combination may thus reduce aerosol exposure during oxygen therapy, enhance the protection of healthcare workers, and likely reduce nosocomial infection risk.

Evaluation of aerosol box use for ultrasound-guided internal jugular vein cannulation in patients with COVID-19: A short-term randomised study

Background and Aims:

During the coronavirus disease 2019 (COVID-19) pandemic, health care workers are at a high risk of infection from aerosols. In this study, we compared the ease of using the aerosol box (AB) with the traditional method during internal jugular vein cannulation attempts (IJVCA).

Methods:

The study included 40 patients with COVID-19 who required central venous catheterisation during treatment in the ward. The patients were randomly allocated to one of the two protective equipment (PPE) groups and then randomly assigned to one of the five anaesthesiologists with at least 5 years of experience. Group P and A had both PPE and AB used, whereas Group P included patients where PPE was used alone. The physicians completed a survey after performing the procedure to evaluate the use of the AB.

Results:

The preparation for the procedure and procedure durations were observed to be statistically longer in Group P and A (P = 0.002 and P = 0.001, respectively). The first attempt in Group P and A was unsuccessful in six patients, whereas the first attempt in Group P was unsuccessful in only two patients (P = 0.235). Anaesthesiologists described difficulty with manipulation during the procedure, discomfort using the box, and resulting cognitive load increase in Group P and A.

Conclusion:

The IJVCA procedures were faster and easier and had greater satisfaction for physicians when the AB was not used. Also, the high complication rate, including carotid artery punctures and disruption of sterility and PPE, albeit not statistically significant, has clinical implications. Therefore, we do not recommend the use of ABs for IJVCA.

Design and in-vitro testing of a portable patient isolation chamber for bedside aerosol containment and filtration

The emergence of the SARS-CoV-2 pandemic has imposed a multitude of complications on healthcare facilities. Healthcare professionals had to develop creative solutions to deal with resource shortages and isolation spaces when caring for COVID positive patients. Among many other solutions, facilities have utilized engineering strategies to mitigate the spread of viral contamination within the hospital environment. One of the standard solutions has been the use of whole room negative pressurization (WRNP) to turn a general patient room into an infection isolation space. However, this has not always been easy due to many limitations, such as direct access to the outdoors and the availability of WRNP units. In operating rooms where a patient is likely to go through aerosol-generating procedures, other solutions must be considered because most operating rooms use positive pressure ventilation to maintain sterility. The research team has designed, built, and tested a Covering for Operations during Viral Emergency Response (COVER), a low-cost, portable isolation chamber that fits over a patient's torso on a hospital bed to contain and remove the pathogenic agents at the source (i.e., patient's mouth and nose). This study tests the performance of the COVER system under various design and performance scenarios using particle tracing techniques and compares its efficiency with WRNP units. The results show that COVER can dramatically reduce the concentration of particles within the room, while WRNP is only effective in preventing the room-induced particles from migrating to adjacent spaces.

Investigations into the efficacy of a novel extubation-aerosol shield: a cough model study

Background

Physicians have had to perform numerous extubation procedures during the prolonged coronavirus disease 2019 (COVID 19) pandemic. Future pandemics caused by unknown pathogen may also present a risk of exposure to infectious droplets and aerosols.

Aim

This study evaluated the ability of a newly developed aerosol barrier, “Extubation-Aerosol (EA)-Shield” to provide maximum protection from aerosol exposure during extubation via an aerosolised particle count and high-quality visualisation assessments.

Methods

We employed a cough model having parameters similar to humans and used micron oil aerosol as well as titanium dioxide as aerosol tracers. Aerosol barrier techniques employing a face mask (group M) and EA-Shield (group H) were compared.

Findings

The primary outcome was the difference in the number of particles contacting the physician's face before and after extubation. The maximum distances of aerosol dispersal after extubation were measured as the secondary outcomes. All aerosolised particles of the two tracers were significantly smaller in group H than in group M (p < 0.05). In addition, the sagittal and axial maximum distances and sagittal areas of aerosol dispersal for 3, 5, and 10 s after extubation were significantly smaller in group H than in group M (p < 0.05).

Conclusion

This model indicates that EA-Shield could be highly effective in reducing aerosol exposure during extubation. Therefore, we recommend using it as an aerosol barrier when an infectious aerosol risk is suspected.

Adapted full-face snorkel masks as an alternative for COVID-19 personal protection during aerosol generating procedures in South Africa: A multi-centre, non-blinded in-situ simulation study

INTRODUCTION

SARS-CoV-2 has resulted in increased worldwide demand for personal protective equipment (PPE). With pressure from ongoing epidemic and endemic episodes, we assessed an adapted snorkel mask that provides full-face protection for healthcare workers (HCWs), particularly during aerosol-generating procedures. These masks have a custom-made adaptor which allows the fitment of standard medical respiratory filters. The aim of this study was to evaluate the fit, seal and clinical usability of these masks.

METHODS

This multicentre, non-blinded in-situ simulation study recruited fifty-two HCWs to don and doff the adapted snorkel mask. Negative pressure seal checks and a qualitative fit test were performed. The HCWs completed intubation and extubation of a manikin in a university skills training laboratory, followed by a web-based questionnaire on the clinical usability of the masks.

RESULTS

Whilst fit and usability data were generally satisfactory, two of the 52 participants (3.8%) felt that the mask did not span the correct distance from the nose to the chin, and 3 of 34 participants (8.8%) who underwent qualitative testing with a Bitrex test failed. The majority of users reported no fogging, humidity or irritation. It was reportedly easy to speak while wearing the mask, although some participants perceived that they were not always understood. Twenty-one participants (40%) experienced a subjective physiological effect from wearing the mask; most commonly a sensation of shortness of breath.

DISCUSSION

A fit-tested modified full-face snorkel mask may offer benefit as a substitute for N95 respirators and face shields. It is, however, important to properly select the correct mask based on size, fit testing, quality of the three-dimensional (3D) printed parts and respiratory filter to be used. Additionally, HCWs should be trained in the use of the mask, and each mask should be used by a single HCW and not shared.

Development of a Mannequin for Simulation-Based Trials Involving Respiratory Viral Spread During Respiratory Arrest and Cardiopulmonary Arrest Scenarios

During the coronavirus disease 2019 (COVID-19) pandemic, mannequin models have been developed to mimic viral spread using fluorescent particles. These models use contraptions such as a spray gun or an exploding latex balloon to emanate a sudden acceleration of particles, simulating a "cough" reflex. No models have been developed to mimic passive aerosolization of viral particles during a cardiopulmonary arrest simulation. Our novel approach to aerosolization of simulated viral spread allows for a continuous flow of particles, which allows us to maintain components of high-fidelity team-based simulations. Our simulated model emanated GloGerm (Moab, UT) from the respiratory tract using a continuous nebulization chamber. Uniquely, the construction of our apparatus allowed for the ability to perform full, simulated cardiopulmonary resuscitation scenarios (such as chest compressions, bag-mask ventilation, and endotracheal intubation) on a high-fidelity mannequin while visualizing potential contamination spread at the conclusion of the simulation. Positive feedback from users included the ability to visualize particulate contamination after cardiopulmonary resuscitations in the context of personal protective equipment usage and roles in resuscitation (i.e. physician, respiratory therapist, nurse). Negative criticism towards the simulation included the lack of certain high-fidelity feedback markers of the mannequin (auscultating breath sounds and checking pulses) due to the construction of the particle aerosolization mechanism.

Macintosh laryngoscope versus AMBU King Vision video laryngoscope for endotracheal intubation using a COVID-19 barrier box: A randomized controlled trial

Background

Coronavirus disease 2019 (COVID-19) barrier box is being used by health-care workers for protection against aerosol-transmitted infection. Usually, a Macintosh laryngoscope (MC) or a video laryngoscope (VL) is used for endotracheal intubation (ETI). We aimed to determine the most suitable laryngoscope blade in terms of time to ETI, ease of ETI, and the first-pass success rate.

Methods

American Society of Anesthesiologists Grade I and II patients undergoing surgery under general anesthesia were randomized into the MC and the King Vision VL groups in a 1:1 ratio. ETI was performed using either the MC (the MC group) or the King Vision VL (the VL group) with a COVID-19 barrier box. The first-pass intubation success rate, intubation time, and ease of ETI were analyzed.

Results

The first-pass success rate was higher in the MC group (P = 0.43). The mean duration of ETI was 33 s and 47 s in the MC group and VL group, respectively. The difference was statistically significant between the groups (P = 0.002). The ease of ETI was comparable between the groups (P = 0.57), and the Cormack-Lehane grade was significantly different between the groups (P = 0.0025).

Conclusion

ETI duration was shorter in the MC group than in the VL group. Hence, a MC can be used along with a COVID-19 barrier box by experienced operators for the prevention of aerosol spread.

Simulation with a colour indicator to help reduce contamination during airway management in COVID-19 times: An experience from a tertiary centre in India

BACKGROUND AND AIMS

The coronavirus disease 2019 (COVID-19) pandemic has initiated modified protocols for aerosol-generating procedures. A simulation study using dye was conducted to highlight contamination at intubation and extubation and to encourage adherence to the new COVID-19 protocol among anaesthesia personnel in our institution.

METHODS

A video demonstrating the new COVID-19 protocols was circulated in the Department of Anaesthesiology a week prior to the study. Thirty teams, each comprising an anaesthesia resident and a staff technician, were enroled. Each team was asked to demonstrate the steps of preparation, intubation and extubation on a mannequin in a COVID-19 scenario. Checklists were used to assess points of contamination and adherence to the protocols. Following debriefing, a repeat simulation was conducted. The use of a dye highlighted the points of contamination. The study subjects provided feedback on the usefulness of the session and practical difficulties encountered in adapting to the new protocols.

RESULTS

The average contamination scores decreased by 3.4 (95% confidence interval (CI): 2.4-4.4, P < 0.001) in the post-debrief session. Adherence to the steps of the modified protocol improved by a score of 2.7 (CI: 3.6-1.83) among anaesthesiologists and by 4.3 (CI: 5.3-3.3) among technicians. Further, 93% felt that the use of the colour indicator reinforced awareness of the possible points of contamination.

CONCLUSION

Simulation with a low-fidelity mannequin by using colour indicator for secretions is an effective teaching tool to reduce health hazards during airway management in COVID-19 times.

Comparative performance of two protective barriers during tracheal intubation of COVID-19 patients: A simulation cross-over study

COVID-19 was declared a pandemic by the WHO in 2020. In light of the global shortage of PPE and concerns regarding the safety of healthcare providers, clinicians have resorted to the use of novel protective barriers, such as aerosol boxes and plastic sheets, during aerosol generating procedures, especially tracheal intubation. We compared the effect of these barriers on the tracheal intubation of simulated patients with severe COVID-19 in a crossover study. The study was approved by the Ethics Committee of King Faisal Specialist Hospital, and the procedures were compliant with the COVID-19 airway management guidelines of the Saudi Anesthesia Society. The time to intubation was our primary outcome. Secondary outcomes included number of optimization maneuvers, number of intubation attempts, time to glottic view and ventilation of the lungs, and damage to PPE. Thirteen consultant anesthetists performed 39 tracheal intubations on a manikin using each of three approaches (aerosol box, plastic sheet, and no-barrier). Data were collected via direct and video observation. The plastic sheet approach demonstrated the highest time to intubation (mean ± StE [95% CI]: 33.3s ± 3.5 [25.8– 40.9]) compared to the aerosol box (22.0s ± 2.5 [16.5 – 27.5], P < 0.01) and no-barrier approaches (16.1s ± 1.1 [13.7 – 18.4], P < 0.0001). Similarly, the plastic sheet approach had the highest time to glottic view, and ventilation intervals compared to the other two approaches, while the no-barrier approach had the shortest time intervals. There were no failed intubations or damage to the PPE sustained during the use of any of the three approaches. The aerosol box does not impose a significant delay in tracheal intubation using video laryngoscopy, unlike the plastic sheet barrier. Further research on the aerosolization risk is warranted before these protective barriers can be considered as mainstay approaches during aerosol generating procedures.

Aerosol box for intubation of patients with suspected COVID-19: simulation study

Introduction. Endotracheal intubation is a procedure associated with a high level of exposure to the COVID-19 virus. This has led to the search of alternatives to reduce the risk of contamination, including the so-called aerosol box. Objective: To compare time and difficulty of orotracheal intubation when using the aerosol box in a simulated setting. Methodology: Observational study conducted with the participation of 33 anesthetist physicians and anesthesia residents; groups were compared in terms of time and intubation difficulty using a conventional Macintosh laryngoscope and the McGRATH™ MAC (Medtronic) videolaryngoscope with or without aerosol box. In order to determine performance with the intubation maneuver, crude hazard ratios were estimated, and a Cox multivariate regression model was built, adjusted by anesthetist years of experience and difficulties during the procedure. Results: On average, the aerosol box increased intubation time by 7.57 seconds (SD 8.33) when the videolaryngoscope was used, and by 6.62 (SD 5.74) with the Macintosh. Overall, 132 intubations were performed, with 121 successful and 6 failed first-time attempts (4 with the use of the aerosol box); 16 participants (48.48%) reported difficulty handling the box. With the use of the Macintosh, intubation was found to be faster than with the videolaryngoscope (cHR: 1.36 [95% CI 0.64-2.88]; adjusted HR: 2.20 [95% CI 0.73-6.62]). Conclusions: The use of the aerosol box and personal protective equipment in a simulation setting hinders the intubation maneuver and may result in protracted execution time.

Lessons from COVID-19: A reflection on the strengths and weakness of early consensus recommendations for pediatric difficult airway management during a respiratory viral pandemic using a modified Delphi method

BACKGROUND

The authors recognized a gap in existing guidelines and convened a modified Delphi process to address novel issues in pediatric difficult airway management raised by the COVID-19 pandemic.

METHODS

The Pediatric Difficult Intubation Collaborative, a working group of the Society for Pediatric Anesthesia, assembled an international panel to reach consensus recommendations on pediatric difficult airway management during the COVID-19 pandemic using a modified Delphi method. We reflect on the strengths and weaknesses of this process and ways care has changed as knowledge and experience have grown over the course of the pandemic.

RECOMMENDATIONS

In the setting of the COVID-19 pandemic, the Delphi panel recommends against moving away from the operating room solely for the purpose of having a negative pressure environment. The Delphi panel recommends supplying supplemental oxygen and using videolaryngoscopy during anticipated difficult airway management. Direct laryngoscopy is not recommended. If the patient meets extubation criteria, extubate in the OR, awake, at the end of the procedure.

REFLECTION

These recommendations remain valuable guidance in caring for children with anticipated difficult airways and infectious respiratory pathology when reviewed in light of our growing knowledge and experience with COVID-19. The panel initially recommended minimizing involvement of additional people and trainees and minimizing techniques associated with aerosolization of viral particles. The demonstrated effectiveness of PPE and vaccination at reducing the risk of exposure and infection to clinicians managing the airway makes these recommendations less relevant for COVID-19. They would likely be important initial steps in the face of novel respiratory viral pathogens.

CONCLUSIONS

The consensus process cannot and should not replace evidence-based guidelines; however, it is encouraging to see that the panel's recommendations have held up well as scientific knowledge and clinical experience have grown.

Recommendations for developing clinical care protocols during pandemics: From theory and practice

In 2019, a novel coronavirus called the severe acute respiratory syndrome coronavirus 2 led to the outbreak of the coronavirus disease 2019, which was deemed a pandemic by the World Health Organization in March 2020. Owing to the accelerated rate of mortality and utilization of hospital resources, health care systems had to adapt to these major changes. This affected patient care across all disciplines and specifically within the perioperative services. In this review, we discuss the strategies and pitfalls of how perioperative services in a large academic medical center responded to the initial onset of a pandemic, adjustments made to airway management and anesthesia specialty services – including critical care medicine, obstetric anesthesiology, and cardiac anesthesiology - and strategies for reopening surgical caseload during the pandemic.

Clinical recommendations for in-hospital airway management during aerosol-transmitting procedures in the setting of a viral pandemic

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can lead to severe pneumonia and multiorgan failure. While most of the infected patients develop no or only mild symptoms, some need respiratory support or even invasive ventilation. The exact route of transmission is currently under investigation. While droplet exposure and direct contact seem to be the most significant ways of transmitting the disease, aerosol transmission appears to be possible under circumstances favored by high viral load. Despite the use of personal protective equipment (PPE), this situation potentially puts healthcare workers at risk of infection, especially if they are involved in airway management. Various recommendations and international guidelines aim to protect healthcare workers, although evidence-based research confirming the benefits of these approaches is still scarce. In this article, we summarize the current literature and recommendations for airway management of COVID-19 patients.

Comparison of the Efficiency and Usability of Aerosol Box and Intubation Tent on Intubation of a Manikin Using Personal Protective Equipment: A Randomized Crossover Study

Background

The aerosol box and intubation tent are improvised barrier-enclosure devices developed during the novel coronavirus pandemic to protect health care workers from aerosol transmission.

Objective

Using time to intubation as a crude proxy, we aimed to compare the efficiency and usability of the aerosol box and intubation tent in a simulated manikin.

Methods

This was a single-center, randomized, crossover manikin study involving 28 participants (9 anesthetists, 16 emergency physicians, and 3 intensivists). Each participant performed rapid sequence intubations in a random sequence of three different scenarios: 1) no device use; 2) aerosol box; 3) intubation tent. We compared the time to intubation between different scenarios.

Results

The median total intubation time with no device use, aerosol box, and intubation tent were 23.7 s (interquartile range [IQR] 19.4–28.4 s), 30.9 s (IQR 24.1–52.5 s), and 26.0 s (IQR 22.1–30.8 s), respectively. Post hoc analysis showed a significantly longer intubation time using the aerosol box compared with no device use (p < 0.001) and compared with the intubation tent (p < 0.001). The difference between the intubation tent and no device use was not significant. The first-pass intubation success rate did not differ between the groups. Only aerosol box use had resulted in breaches of personal protective equipment. Participants considered intubation with the intubation tent more favorable than the aerosol box.

Conclusions

The intubation tent seems to have a better barrier-enclosure design than the aerosol box, with a reasonable balance between efficiency and usability. Further evaluation of its efficacy in preventing aerosol dispersal and in human studies are warranted prior to recommendation of widespread adoption.