COVID-19: minimising risk to healthcare workers during aerosol-producing respiratory therapy using an innovative constant flow canopy

Generation of Aerosols by Noninvasive Respiratory Support Modalities: A Systematic Review and Meta-Analysis

Importance

Infection control guidelines have historically classified high-flow nasal oxygen and noninvasive ventilation as aerosol-generating procedures that require specialized infection prevention and control measures.

Objective

To evaluate the current evidence that high-flow nasal oxygen and noninvasive ventilation are associated with pathogen-laden aerosols and aerosol generation.

Data Sources

A systematic search of EMBASE and PubMed/MEDLINE up to March 15, 2023, and CINAHL and ClinicalTrials.gov up to August 1, 2023, was performed.

Study Selection

Observational and (quasi-)experimental studies of patients or healthy volunteers supported with high-flow nasal oxygen or noninvasive ventilation were selected.

Data Extraction and Synthesis

Three reviewers were involved in independent study screening, assessment of risk of bias, and data extraction. Data from observational studies were pooled using a random-effects model at both sample and patient levels. Sensitivity analyses were performed to assess the influence of model choice.

Main Outcomes and Measures

The main outcomes were the detection of pathogens in air samples and the quantity of aerosol particles.

Results

Twenty-four studies were included, of which 12 involved measurements in patients and 15 in healthy volunteers. Five observational studies on SARS-CoV-2 detection in a total of 212 air samples during high-flow nasal oxygen in 152 patients with COVID-19 were pooled for meta-analysis. There was no association between high-flow nasal oxygen and pathogen-laden aerosols (odds ratios for positive samples, 0.73 [95% CI, 0.15-3.55] at the sample level and 0.80 [95% CI, 0.14-4.59] at the patient level). Two studies assessed SARS-CoV-2 detection during noninvasive ventilation (84 air samples from 72 patients). There was no association between noninvasive ventilation and pathogen-laden aerosols (odds ratios for positive samples, 0.38 [95% CI, 0.03-4.63] at the sample level and 0.43 [95% CI, 0.01-27.12] at the patient level). None of the studies in healthy volunteers reported clinically relevant increases in aerosol particle production by high-flow nasal oxygen or noninvasive ventilation.

Conclusions and Relevance

This systematic review and meta-analysis found no association between high-flow nasal oxygen or noninvasive ventilation and increased airborne pathogen detection or aerosol generation. These findings argue against classifying high-flow nasal oxygen or noninvasive ventilation as aerosol-generating procedures or differentiating infection prevention and control practices for patients receiving these modalities.

Quantifying the reduction of airborne infectious virus load using a ventilated patient hood

BACKGROUND

Healthcare workers treating SARS-CoV-2 patients are at risk of infection by respiratory exposure to patient-emitted, virus-laden aerosols. Source control devices such as ventilated patient isolation hoods have been shown to limit the dissemination of non-infectious airborne particles in laboratory tests, but data on their performance in mitigating the airborne transmission risk of infectious viruses are lacking.

AIM

We used an infectious airborne virus to quantify the ability of a ventilated hood to reduce infectious virus exposure in indoor environments.

METHODS

We nebulized 10⁹ plaque forming units (pfu) of bacteriophage PhiX174 virus into a ∼30-m³ room when the hood was active or inactive. The airborne concentration of infectious virus was measured by BioSpot-VIVAS and settle plates using plaque assay quantification on the bacterial host Escherichia coli C. The airborne particle number concentration (PNC) was also monitored continuously using an optical particle sizer.

FINDINGS

The median airborne viral concentration in the room reached 1.41 × 10⁵ pfu/m³ with the hood inactive. When active, the hood reduced infectious virus concentration in air samples by 374-fold. The deposition of infectious virus on the surface of settle plates was reduced by 87-fold. This was associated with a 109-fold reduction in total airborne particle number escape rate.

CONCLUSION

A personal ventilation hood significantly reduced airborne particle escape, considerably lowering infectious virus contamination in an indoor environment. Our findings support the further development of source control devices to mitigate nosocomial infection risk among healthcare workers exposed to airborne viruses in clinical settings.

Lessons from COVID-19 in the management of acute respiratory failure

Accumulated evidence supports the efficacy of noninvasive respiratory support therapies in coronavirus disease 2019 (COVID-19)-related acute hypoxaemic respiratory failure, alleviating admissions to intensive care units. Noninvasive respiratory support strategies, including high-flow oxygen therapy, continuous positive airway pressure via mask or helmet and noninvasive ventilation, can be alternatives that may avoid the need for invasive ventilation. Alternating different noninvasive respiratory support therapies and introducing complementary interventions, like self-proning, may improve outcomes. Proper monitoring is warranted to ensure the efficacy of the techniques and to avoid complications while supporting transfer to the intensive care unit. This article reviews the latest evidence on noninvasive respiratory support therapies in COVID-19-related acute hypoxaemic respiratory failure.

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.

Reorganization of Intensive Care Units for the COVID-19 pandemic: effects on nursing sensitive outcomes

BACKGROUND

Since the first months of 2020 COVID-19 patients who were seriously ill due to the development of ARDS, required admission to the intensive care unit to ensure potentially life-saving mechanical ventilation and support for vital functions. To cope with this emergency, an extremely rapid reorganization of premises, services and staff, to dedicate an entire intensive care unit exclusively to SARS-CoV-2 patients and increasing the number of beds was essential. The aim of the study was to evaluate the effects of reorganization of the COVID-19 intensive care unit in terms of nursing sensitive outcomes.

METHODS

a retrospective observational study was conducted to compare nursing sensitive outcomes between pre-COVID period and COVID period.

RESULTS

Falls (0.0 and 0.4%, respectively), physical restraint (1.8 and 1.1%, respectively), and pressure ulcers (8.0 and 3.0%, respectively) were similar in the COVID and in the pre-COVID group. After adjusting for gender, age, BMI, and number of comorbidities, the incidence of bloodstream infections was significantly higher in the COVID group than in the pre-COVID group. There were no statistically significant differences in the incidence between the two groups regarding other evaluated outcomes.

CONCLUSION

The selected nursing sensitive outcomes maintained similar values in the pre-COVID and COVID patient groups. Healthcare-related infections rate must be considered an important alarm signal of quality of nursing care especially in conditions of excessive workload, stress and the presence of less experienced staff increase.

Vented Individual Patient (VIP) Hoods for the Control of Infectious Airborne Diseases in Healthcare Facilities

By providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers (HCWs), vented individual patient (VIP) hoods, a form of local exhaust ventilation (LEV), offer a new approach to reduce hospital-acquired infection (HAI). Results from recent studies have demonstrated that, for typical patient-emitted aerosols, VIP hoods provide protection at least equivalent to that of an N95 mask. Unlike a mask, hood performance can be easily monitored and HCWs can be alerted to failure by alarms. The appropriate use of these relatively simple devices could both reduce the reliance on personal protective equipment (PPE) for infection control and provide a low-cost and energy-efficient form of protection for hospitals and clinics. Although the development and deployment of VIP hoods has been accelerated by the coronavirus disease 2019 (COVID-19) pandemic, these devices are currently an immature technology. In this review, we describe the state of the art of VIP hoods and identify aspects in need of further development, both in terms of device design and the protocols associated with their use. The broader concept of individual patient hoods has the potential to be expanded beyond ventilation to the provision of clean conditions for individual patients and personalized control over other environmental factors such as temperature and humidity.

Development and efficacy testing of a portable negative pressure enclosure for airborne infection containment

OBJECTIVES

To overcome the shortage of personal protective equipment and airborne infection isolation rooms (AIIRs) in the COVID-19 pandemic, a collaborative team of research engineers and clinical physicians worked to build a novel negative pressure environment in the hopes of improving healthcare worker and patient safety. The team then sought to test the device's efficacy in generating and maintaining negative pressure. The goal proved prescient as the US Food and Drug Administration (FDA) later recommended that all barrier devices use negative pressure.

METHODS

Initially, engineers observed simulations of various aerosol- and droplet-generating procedures using hospital beds and stretchers to determine the optimal working dimensions of the containment device. Several prototypes were made based on these dimensions which were combined with filters and various flow-generating devices. Then, the airflow generated and the pressure differential within the device during simulated patient care were measured, specifically assessing its ability to create a negative pressure environment consistent with standards published by the Centers for Disease Control and Prevention (CDC).

RESULTS

The portable fans were unable to generate any airflow and were dropped from further testing. The vacuums tested were all able to generate a negative pressure environment with the magnitude of pressure differential increasing with the vacuum horsepower. Only the 3.5-horsepower Shop-Vac, however, generated a -3.0 pascal (Pa) pressure gradient, exceeding the CDC-recommended minimum of -2.5 Pa for AIIRs.

CONCLUSION

A collaborative team of physicians and engineers demonstrated the efficacy of a prototype portable negative pressure environment, surpassing the negative pressure differential recommended by the CDC.

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.

Q-DEPICT: Qatar Determining Emergency Physician Incidence of COVID-Positive Testing

Despite protective measures such as personal protective equipment (PPE) and a COVID airway management program (CAMP), some emergency physicians will inevitably test positive for COVID. We aim to develop a model predicting weekly numbers of emergency physician COVID converters to aid operations planning.

The data were obtained from the electronic medical record (EMR) used throughout the national healthcare system. Hamad Medical Corporation's internal emergency medicine workforce data were used as a source of information on emergency physician COVID conversion and numbers of emergency physicians completing CAMP training. The study period included the spring and summer months of 2020 and started on March 7 and ran for 21 whole weeks through July 31. Data were extracted from the system's EMR database into a spreadsheet (Excel, Microsoft, Redmond, USA). The statistical software used for all analyses and plots was Stata (version 16.1 MP, StataCorp, College Station, USA). All data definitions were made a priori.

A total of 35 of 250 emergency physicians (14.0%, 95% CI 9.9%–19.9%) converted to a positive real-time reverse transcriptase-polymerase chain reaction (PCR) during the study's 21-week period. Of these. only two were hospitalized for having respiratory-only disease, and none required respiratory support. Both were discharged within a week of admission. The weekly number of newly COVID-positive emergency physicians was zero and was seen in eight of 21 (38.1%) weeks. The peak weekly counts of six emergency physicians with new COVID-positive were seen in week 14. The mean weekly number of newly COVID-positive emergency physicians was 1.7 ± 1.9, and the median was 1 (IQR, 0 to 3).

This study demonstrates that in the State of Qatar's Emergency Department (ED) system, knowing only four parameters allows the reliable prediction of the number of emergency physicians likely to convert COVID PCR tests within the next week. The results also suggest that attention to the details of minimizing endotracheal intubation (ETI) risk can eliminate the expected finding of the association between ETI numbers and emergency physician COVID numbers.

A prospective clinical evaluation of a patient isolation hood during the COVID-19 pandemic

Background

Healthcare workers (HCWs) have frequently become infected with severe acute respiratory syndrome coronavirus 2 whilst treating patients with coronavirus disease 2019 (COVID-19). A variety of novel devices have been proposed to reduce COVID-19 cross-contamination.

Objectives

The aim of the study was (i) to test whether patients and HCWs thought that a novel patient isolation hood was safe and comfortable and (ii) to obtain COVID-19 infection data of hospital HCWs.

Methods

This is a prospective cohort study of 20 patients, entailing HCW/patient questionnaires and safety aspects of prototype isolation hoods. COVID-19 data of HCWs were prospectively collected. Assessment of the hood's safety and practicality and adverse event reporting was carried out.

Outcome measures

The outcome measures are as follows: questionnaire responses, adverse event reporting, rates of infections in HCWs during the study period (20/6/2020 to 21/7/2020), and COVID-19 infections in HCWs reported until the last recorded diagnosis of COVID-19 in HCWs (20/6/2020 to 27/9/2020).

Results

Of the 64 eligible individual HCW surveys, 60 surveys were overall favourable (>75% questions answered in favour of the isolation hood). HCWs were unanimous in perceiving the hood as safe (60/60), preferring its use (56/56), and understanding its potential COVID-19 cross-contamination minimisation (60/60). All eight patients who completed the questionnaire thought the isolation hood helped prevent COVID-19 cross infection and was safe and comfortable. There were no reported patient safety adverse events. The COVID-19 attack rate from 20/6/2020 to 27/9/2020 among registered nurses was as follows: intensive care units (ICUs), 2.2% (3/138); geriatric wards, 13.2% (26/197); and COVID-19 wards, 18.3% (32/175). The COVID-19 attack rate among medical staff was as follows: junior staff, 2.1% (24/932); senior staff, 0.7% (4/607); aged care/rehabilitation, 6.7% (2/30); and all ICU medical staff, 8.6% (3/35).

Conclusions

The isolation hood was preferred to standard care by HCWs and well tolerated by patients, and after the study, isolation hoods became part of standard ICU therapy. There was an association between being an ICU nurse and a low COVID-19 infection rate (no causality implied). ICU HCWs feel safer when treating patients with COVID-19 using an isolation hood.

Feasibility of Pediatric Non-Invasive Respiratory Support in Low- and Middle-Income Countries

Non-Invasive respiratory support can be viewed as mechanical respiratory support without endotracheal intubation and it includes continuous positive airway pressure, bi-level positive airway pressure, high flow nasal cannula, and non-invasive positive pressure ventilation. Over past few years, non-invasive respiratory support is getting more popular across pediatric intensive care units for acute respiratory failure as well as for long-term ventilation support at home. It reduces the need for invasive mechanical ventilation, decreases the risk of nosocomial pneumonia as well as mortality in selected pediatric and adult population. Unfortunately, majority of available studies on non-invasive respiratory support have been conducted in high-income countries, which are different from low-and middle-income countries (LMICs) in terms of resources, manpower, and the disease profile. Hence, we need to consider disease profile, severity at hospital presentation, availability of age-appropriate equipment, ability of healthcare professionals to manage patients on non-invasive respiratory support, and cost-benefit ratio. In view of the relatively high cost of equipment, there is a need to innovate to develop indigenous kits/devices with available resources in LMICs to reduce the cost and potentially benefit health system. In this review, we highlight the role of non-invasive respiratory support in different clinical conditions, practical problems encountered in LMICs setting, and few indigenous techniques to provide non-invasive respiratory support.

Management of hospitalised adults with coronavirus disease 2019 (COVID-19): a European Respiratory Society living guideline

INTRODUCTION

Hospitalised patients with coronavirus disease 2019 (COVID-19) as a result of SARS-CoV-2 infection have a high mortality rate and frequently require noninvasive respiratory support or invasive ventilation. Optimising and standardising management through evidence-based guidelines may improve quality of care and therefore patient outcomes.

METHODS

A task force from the European Respiratory Society and endorsed by the Chinese Thoracic Society identified priority interventions (pharmacological and non-pharmacological) for the initial version of this "living guideline" using the PICO (population, intervention, comparator, outcome) format. The GRADE approach was used for assessing the quality of evidence and strength of recommendations. Systematic literature reviews were performed, and data pooled by meta-analysis where possible. Evidence tables were presented and evidence to decision frameworks were used to formulate recommendations.

RESULTS

Based on the available evidence at the time of guideline development (20 February, 2021), the panel makes a strong recommendation in favour of the use of systemic corticosteroids in patients requiring supplementary oxygen or ventilatory support, and for the use of anticoagulation in hospitalised patients. The panel makes a conditional recommendation for interleukin (IL)-6 receptor antagonist monoclonal antibody treatment and high-flow nasal oxygen or continuous positive airway pressure in patients with hypoxaemic respiratory failure. The panel make strong recommendations against the use of hydroxychloroquine and lopinavir-ritonavir. Conditional recommendations are made against the use of azithromycin, hydroxychloroquine combined with azithromycin, colchicine, and remdesivir, in the latter case specifically in patients requiring invasive mechanical ventilation. No recommendation was made for remdesivir in patients requiring supplemental oxygen. Further recommendations for research are made.

CONCLUSION

The evidence base for management of COVID-19 now supports strong recommendations in favour and against specific interventions. These guidelines will be regularly updated as further evidence becomes available.

Endotracheal intubation of COVID-19 patients by paramedics using a box barrier: A randomized crossover manikin study

BACKGROUND

In the prehospital setting, endotracheal intubation (ETI) may be required to secure the coronavirus disease 2019 (COVID-19) patient airway. It has been suggested that the use of a protective barrier can reduce possible aerosol delivery from patients to clinicians during ETI. We sought to assess the performance of ETI by paramedics wearing personal protective equipment with and without the use of a box barrier.

METHODS

A randomized, crossover simulation study was performed in a simulation laboratory. Study participants were 18 paramedics actively working in the clinical environment. Participants' performance of ETI via direct laryngoscopy (DL) with and without the use of a box barrier was assessed. The sequence of intubation was randomized to either BoxDL-first or DL-first. The primary outcome was the success rate of ETI on first-attempt. The secondary and tertiary outcomes were ETI success rates on three attempts and total intubation time, respectively.

RESULTS

There were no differences between the DL group and the BoxDL group in one-attempt success rates (14/18 vs 12/18; P = 0.754), and in overall success rates (16/18 vs 14/18; P = 0.682). The mean (standard deviation) of the total intubation times for the DL group and the BoxDL group were 27.3 (19.7) seconds and 36.8 (26.2) seconds, respectively (P < 0.015).

CONCLUSIONS

The findings of this pilot study suggest that paramedics wearing personal protective equipment can successfully perform ETI using a barrier box, but the intubation time may be prolonged. The applicability of these findings to the care of COVID-19 patients remain to be investigated.

Tracheostomies after SARS-CoV-2 intubation, performed by academic otorhinolaryngologists in the Paris area of France: Preliminary results

Objective

To analyse tracheostomies after intubation for SARS-Cov-2 infection performed by otorhinolaryngologists in 7 university hospitals in the Paris area of France during the month March 24 to April 23, 2020.

Material and methods

A multicentre retrospective observational study included 59 consecutive patients. The main goals were to evaluate the number, characteristics and practical conditions of tracheostomies, and the COVID-19 status of the otorhinolaryngologists. Secondary goals were to analyse tracheostomy time, decannulation rate, immediate postoperative complications and laryngotracheal axis status.

Results

Tracheostomy indications were for ventilatory weaning and extubation failure in 86% and 14% of cases, respectively. The technique was surgical, percutaneous or hybrid in 91.5%, 3.4% and 5.1% of cases, respectively. None of the operators developed symptoms consistent with COVID-19. Postoperative complications occurred in 15% of cases, with no significant difference between surgical and percutaneous/hybrid techniques (P = 0.33), although no complications occurred after percutaneous or hybrid tracheostomies. No procedures or complications resulted in death. The decannulation rate was 74.5% with a mean tracheostomy time of 20 ± 12 days. In 55% of the patients evaluated by flexible endoscopy after decannulation, a laryngeal abnormality was found. On univariate analysis, no clinical features had a significant influence on tracheostomy time, decannulation rate or occurrence of laryngeal lesions.

Conclusion

The main findings of the present retrospective study were: absence of contamination of the surgeons, heterogeneity of practices between centres, a high rate of complications and laryngeal lesions whatever the technique, and the specificities of the patients.

Recommended Approaches to Minimize Aerosol Dispersion of SARS-CoV-2 During Noninvasive Ventilatory Support Can Cause Ventilator Performance Deterioration: A Benchmark Comparative Study

Background

SARS-CoV-2 aerosolization during noninvasive positive-pressure ventilation may endanger health care professionals. Various circuit setups have been described to reduce virus aerosolization. However, these setups may alter ventilator performance.

Research Question

What are the consequences of the various suggested circuit setups on ventilator efficacy during CPAP and noninvasive ventilation (NIV)?

Study Design and Methods

Eight circuit setups were evaluated on a bench test model that consisted of a three-dimensional printed head and an artificial lung. Setups included a dual-limb circuit with an oronasal mask, a dual-limb circuit with a helmet interface, a single-limb circuit with a passive exhalation valve, three single-limb circuits with custom-made additional leaks, and two single-limb circuits with active exhalation valves. All setups were evaluated during NIV and CPAP. The following variables were recorded: the inspiratory flow preceding triggering of the ventilator, the inspiratory effort required to trigger the ventilator, the triggering delay, the maximal inspiratory pressure delivered by the ventilator, the tidal volume generated to the artificial lung, the total work of breathing, and the pressure-time product needed to trigger the ventilator.

Results

With NIV, the type of circuit setup had a significant impact on inspiratory flow preceding triggering of the ventilator (P < .0001), the inspiratory effort required to trigger the ventilator (P < .0001), the triggering delay (P < .0001), the maximal inspiratory pressure (P < .0001), the tidal volume (P = .0008), the work of breathing (P < .0001), and the pressure-time product needed to trigger the ventilator (P < .0001). Similar differences and consequences were seen with CPAP as well as with the addition of bacterial filters. Best performance was achieved with a dual-limb circuit with an oronasal mask. Worst performance was achieved with a dual-limb circuit with a helmet interface.

Interpretation

Ventilator performance is significantly impacted by the circuit setup. A dual-limb circuit with oronasal mask should be used preferentially.

Feasibility of Pediatric Non-Invasive Respiratory Support in Low- and Middle-Income Countries

Non-Invasive respiratory support can be viewed as mechanical respiratory support without endotracheal intubation and it includes continuous positive airway pressure, bi-level positive airway pressure, high flow nasal cannula, and non-invasive positive pressure ventilation. Over past few years, non-invasive respiratory support is getting more popular across pediatric intensive care units for acute respiratory failure as well as for long-term ventilation support at home. It reduces the need for invasive mechanical ventilation, decreases the risk of nosocomial pneumonia as well as mortality in selected pediatric and adult population. Unfortunately, majority of available studies on non-invasive respiratory support have been conducted in high-income countries, which are different from low- and middle-income countries (LMICs) in terms of resources, manpower, and the disease profile. Hence, we need to consider disease profile, severity at hospital presentation, availability of age-appropriate equipment, ability of healthcare professionals to manage patients on non-invasive respiratory support, and cost-benefit ratio. In view of the relatively high cost of equipment, there is a need to innovate to develop indigenous kits/ devices with available resources in LMICs to reduce the cost and potentially benefit health system. In this review, we highlight the role of non-invasive respiratory support in different clinical conditions, practical problems encountered in LMICs setting, and few indigenous techniques to provide non-invasive respiratory support.

Barrier enclosure use during aerosol-generating medical procedures: A scoping review

INTRODUCTION

Barrier enclosure devices were introduced to protect against infectious disease transmission during aerosol generating medical procedures (AGMP). Recent discussion in the medical community has led to new designs and adoption despite limited evidence. A scoping review was conducted to characterize devices being used and their performance.

METHODS

We conducted a scoping review of formal databases (MEDLINE, Embase, Cochrane Database of Systematic Reviews, CENTRAL, Scopus), grey literature, and hand-searched relevant journals. Forward and reverse citation searching was completed on included articles. Article/full-text screening and data extraction was performed by two independent reviewers. Studies were categorized by publication type, device category, intended medical use, and outcomes (efficacy - ability to contain particles; efficiency - time to complete AGMP; and usability - user experience).

RESULTS

Searches identified 6489 studies and 123 met criteria for inclusion (k = 0.81 title/abstract, k = 0.77 full-text). Most articles were published in 2020 (98%, n = 120) as letters/commentaries (58%, n = 71). Box systems represented 42% (n = 52) of systems described, while plastic sheet systems accounted for 54% (n = 66). The majority were used for airway management (67%, n = 83). Only half of articles described outcome measures (54%, n = 67); 82% (n = 55) reporting efficacy, 39% (n = 26) on usability, and 15% (n = 10) on efficiency. Efficacy of devices in containing aerosols was limited and frequently dependent on use of suction devices.

CONCLUSIONS

While use of various barrier enclosure devices has become widespread during this pandemic, objective data of efficacy, efficiency, and usability is limited. Further controlled studies are required before adoption into routine clinical practice.

Environmental contamination in a coronavirus disease 2019 (COVID-19) intensive care unit-What is the risk?

Background:

The risk of environmental contamination by severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in the intensive care unit (ICU) is unclear. We evaluated the extent of environmental contamination in the ICU and correlated this with patient and disease factors, including the impact of different ventilatory modalities.

Methods:

In this observational study, surface environmental samples collected from ICU patient rooms and common areas were tested for SARS-CoV-2 by polymerase chain reaction (PCR). Select samples from the common area were tested by cell culture. Clinical data were collected and correlated to the presence of environmental contamination. Results were compared to historical data from a previous study in general wards.

Results:

In total, 200 samples from 20 patient rooms and 75 samples from common areas and the staff pantry were tested. The results showed that 14 rooms had at least 1 site contaminated, with an overall contamination rate of 14% (28 of 200 samples). Environmental contamination was not associated with day of illness, ventilatory mode, aerosol-generating procedures, or viral load. The frequency of environmental contamination was lower in the ICU than in general ward rooms. Eight samples from the common area were positive, though all were negative on cell culture.

Conclusion:

Environmental contamination in the ICU was lower than in the general wards. The use of mechanical ventilation or high-flow nasal oxygen was not associated with greater surface contamination, supporting their use and safety from an infection control perspective. Transmission risk via environmental surfaces in the ICUs is likely to be low. Nonetheless, infection control practices should be strictly reinforced, and transmission risk via droplet or airborne spread remains.

Coronavirus Disease-19: Challenges Associated with the Treatment of Head and Neck Oncology and Laryngology Patients in the Coronavirus Disease-19 Era

This review explores the changes to practice associated with COVID-19 for providers treating patients with head and neck cancer and laryngeal pathology. The aim of the review is to highlight some of the challenges and considerations associated with treating this patient population during the pandemic. Additionally, it seeks to discuss some of the areas of concern related to ramping up clinical volume.

Use of a Novel Negative-Pressure Tent During Bedside Tracheostomy in COVID-19 Patients

Background

Many COVID-19 patients with neurological manifestations and respiratory failure remain dependent on mechanical ventilation and require tracheostomy, which is an aerosol generating procedure (AGP). The risk of SARS-CoV-2 transmission to healthcare staff during AGPs is well documented, and negative-pressure rooms are often unavailable. Innovative techniques to decrease risk to healthcare providers during AGPs are necessary. Our objective was to demonstrate the feasibility of percutaneous dilatational tracheostomy (PDT) performed using a novel prefabricated low-cost negative-pressure tent (AerosolVE).

Methods

Retrospective review of consecutive PDT procedures performed by neurointensivists on intubated adult patients with COVID-19 using the AerosolVE tent during the pandemic under an innovative clinical care protocol. The AerosolVE negative-pressure tent consists of a clear plastic canopy with slits for hand access attached to a U-shaped base with air vents. Air within the tent is drawn through a high-efficiency particulate air filter and released outside. Preliminary testing during simulated AGPs demonstrated negligible escape of particulate matter beyond the tent. The main outcome measure was successful completion of PDT and bronchoscopy within the AerosolVE tent, without complications.

Results

The patients were a 53-year-old man with multifocal ischemic stroke and acute respiratory distress syndrome (ARDS), 53-year-old woman with cerebellar hemorrhage and ARDS, and a 69-year-old man with ARDS. Pre-procedure FiO₂ requirement was 40–50% and positive end-expiratory pressure (PEEP) 8–12 cm H₂O. The tent was successfully positioned around the patient and PDT completed with real-time ultrasound guidance in all 3 patients. Bronchoscopy was performed to confirm tube position and perform pulmonary toilet. No complications occurred.

Conclusions

It is feasible to perform PDT on intubated COVID-19 patients using the AerosolVE negative-pressure tent. This is a promising low-cost device to decrease risk to healthcare providers during AGPs.

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

The COVID‐19 pandemic has led to the production of novel devices intended to protect airway managers during the aerosol‐generating procedure of tracheal intubation. Using an in‐situ simulation model, we evaluated laryngoscopist exposure of airborne particles sized 0.3 ‐ 5.0 microns using five aerosol containment devices (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no aerosol containment device. Nebulised saline was used as the aerosol‐generating model for 300 s, at which point, the devices were removed to assess particle spread. Primary outcome was the quantity and size of airborne particles measured at the level of the laryngoscopist’s head at 30, 60, 120 and 300 s, as well as 360 s (60 s after device removal). Airborne particles sizes of 0.3, 0.5, 1.0, 2.5 and 5.0 microns were quantified using an electronic airborne particle counter. Compared with no device use, the sealed intubation box with suction resulted in a decrease in 0.3, 0.5, 1.0 and 2.5 micron, but not 5.0 micron, particle exposure over all time‐periods (p = 0.003 for all time periods). Compared with no device use, the aerosol box showed an increase in 1.0, 2.5 and 5.0 micron airborne particle exposure at 300 s (p = 0.002, 0.008, 0.002, respectively). Compared with no device use, neither horizontal nor vertical drapes showed any difference in any particle size exposure at any time. Finally, when the patient coughed, use of the aerosol box resulted in a marked increase in airborne particle exposure compared with other devices or no device use. In conclusion, novel devices intended to protect the laryngoscopist require objective testing to ensure they are fit for purpose and do not result in increased airborne particle exposure.

A COVID-19 Airway Management Innovation with Pragmatic Efficacy Evaluation: The Patient Particle Containment Chamber

The unique resource constraints, urgency, and virulence of the coronavirus disease 2019 pandemic has sparked immense innovation in the development of barrier devices to protect healthcare providers from infectious airborne particles generated by patients during airway management interventions. Of the existing devices, all have shortcomings which render them ineffective and impractical in out-of-hospital environments. Therefore, we propose a new design for such a device, along with a pragmatic evaluation of its efficacy. Must-have criteria for the device included: reduction of aerosol transmission by at least 90% as measured by pragmatic testing; construction from readily available, inexpensive materials; easy to clean; and compatibility with common EMS stretchers. The Patient Particle Containment Chamber (PPCC) consists of a standard shower liner draped over a modified octagonal PVC pipe frame and secured with binder clips. 3D printed sleeve portals were used to secure plastic sleeves to the shower liner wall. A weighted tube sealed the exterior base of the chamber with the contours of the patient's body and stretcher. Upon testing, the PPCC contained 99% of spray-paint particles sprayed over a 90s period. Overall, the PPCC provides a compact, affordable option that can be used in both the in-hospital and out-of-hospital environments.