Neuroanesthesia practice during COVID-19: A single-center experience

The coronavirus disease 2019 (COVID-19) pandemic is a challenge for all health care providers (HCPs). Anesthesiologists are vulnerable to acquiring the disease during aerosol-generating procedures in operating theater and intensive care units. High index of suspicion, detailed history including travel history, strict hand hygiene, use of face masks, and appropriate personal protective equipment are some ways to minimize the risk of exposure to disease. Neurologic manifestations of COVID-19, modification of anesthesia regimen based on the procedure performed, and HCP safety are some implications relevant to a neuroanesthesiologist. National and international guidelines, recommendations, and position statements help in risk stratification, prioritization, and scheduling of neurosurgery and neurointervention procedures. Institutional protocols can be formulated based on the guidelines wherein each HCP has a definite role in this ever-changing scenario. Mental and physical well-being of HCPs is an integral part of successful management of patients. We present our experience in managing 143 patients during the lockdown period in India.Copyright © 2020 Wolters Kluwer Medknow Publications. All rights reserved.

Management of the Normal and Difficult Pediatric Airway: Unique Challenges in the Time of COVID-19.

Purpose of Review: This review focuses on the challenges faced by acute care healthcare workers in the management of the normal and difficult pediatric airway during the COVID-19 pandemic and how these protocols and practices evolved during the pandemic. The current state of knowledge on timing of surgery and anesthesia is also discussed. Recent Findings: In the early days of the pandemic, information about the SARS-CoV-2 virus and disease process was scarce. Governmental, healthcare, and professional organizations created several guidelines to protect invaluable healthcare workers from the contagious virus while also delivering appropriate care to children with COVID-19. With the emergence of new studies and the deployment of new life-saving COVID-19 vaccines and other therapies, these guidelines evolved. The use of aerosol containment devices such as aerosol boxes and flexible barrier techniques was found to be ineffective in reliably containing virus particles while posing potential harm to both healthcare workers and patients. Also, the definition of aerosol-generating and dispersing medical procedures was vastly broadened. To date, use of appropriate personal protection equipment and COVID-19 vaccination are the most effective ways to protect healthcare workers and safely manage children infected with SARS-CoV-2 who require airway intervention. Summary: Evidence-based public health measures and appropriate personal protective equipment remain the best way to protect both healthcare workers and patients. As the virus and population evolve and COVID-19 vaccines become more widely available, clinicians must be willing to adapt to the emerging evidence of their impact on how safe pediatric perioperative care is delivered.

Practices During Intubation in COVID-19 Intensive Care Units in India: A Cross-Sectional Questionnaire-Based Survey.

Background Healthcare workers are committed to learning from each other's experience to safely optimize patient management of COVID-19. Acute hypoxemic failure is common in COVID-19 patients, and nearly 3.2% may require intubation. Intubation is an aerosol-generating procedure (AGP) that might predispose the performer to COVID-19 infection. This survey was intended to evaluate the practices during tracheal intubation in COVID-19 intensive care units (ICUs) and analyze them against the recommendations of the All India Difficult Airway Association (AIDAA) for safe practice. Methodology It was a web-based, multicentric cross-sectional survey. The choices in the questions were based on guidelines for airway management in COVID-19. Survey questions were divided into two parts - the first part consisted of demographics and general information, and the second part focused on safe intubation practices. Results A total of 230 responses were obtained from physicians all over India, presuming their active involvement in COVID-19 cases, of which 226 responses were taken into account. Two-thirds of responders did not receive any training before ICU posting. The Indian Council of Medical Research (ICMR) guideline was followed by 89% of responders for personal protective equipment use. Intubation in COVID-19 patients was predominantly conducted by a senior anesthesiologist/intensivist in the team and a senior resident (37.2%). Rapid sequence intubation (RSI) and modified RSI were preferable among the responder's hospitals (46.5% vs. 33.6%). In most centers, responders used direct laryngoscope for intubation (62.8%), whereas video laryngoscope was used by 34%. Most responders confirmed the endotracheal tube (ETT) position by visual inspection (66.3%) over end-tidal carbon dioxide (EtCO2) concentration tracing (53.9%). Conclusions Safe intubation practices were followed in most of the centers across India. However, teaching and training, preoxygenation methods, alternative ventilation strategies, and confirmation of intubation pertinent to COVID-19 airway management need more attention.

Exhaled patient derived aerosol dispersion during awake tracheal intubation with concurrent high flow nasal therapy.

Awake Tracheal Intubation (ATI) can be performed in cases where there is potential for difficult airway management. It is considered an aerosol generating procedure and is a source of concern to healthcare workers due to the risk of transmission of airborne viral infections, such as SARS-CoV-2. At present, there is a lack of data on the quantities, size distributions and spread of aerosol particles generated during such procedures. This was a volunteer observational study which took place in an operating room of a university teaching hospital. Optical particle sizers were used to provide real time aerosol characterisation during a simulated ATI performed with concurrent high-flow nasal oxygen therapy. The particle sizers were positioned at locations that represented the different locations of clinical staff in an operating room during an ATI. The greatest concentration of patient derived aerosol particles was within 0.5-1.0 m of the subject and along their midline, 2242 #/cm3. As the distance, both radial and longitudinal, from the subject increased, the concentration decreased towards ambient levels, 36.9 ± 5.1 #/cm3. Patient derived aerosol particles < 5 µm in diameter remained entrained in the exhaled aerosol plume and fell to the floor or onto the subject. Patient derived particles > 5 µm in diameter broke away from the exhaled plume and spread radially throughout the operating room. Irrespective of distance and ventilation status, full airborne protective equipment should be worn by all staff when ATI is being performed on patients with suspected viral respiratory infections.

Tracheostomy insertion in COVID-19: insertion practice and factors leading to unplanned tube exchange.

Background: Tracheostomy insertion in patients with coronavirus disease 2019 (COVID-19) presents unique challenges. Patients frequently have high ventilatory requirements, and as an aerosol generating procedure, tracheostomy insertion creates the potential for staff transmission. Problems with tracheostomies contribute to morbidity and mortality, and tracheostomy changes may increase risks of staff transmission. We sought to quantify the incidence of clinically necessitated tracheostomy changes, establish the indications for change and investigate the incidence of staff transmission. Methods: We conducted a single institution, retrospective, observational cohort study of all intensive care unit (ICU) patients with COVID-19 who had a tracheostomy between March 2020 and April 2021. The institution is a large tertiary referral centre in Ireland. Results: Forty-three patients had a tracheostomy during the study period. All were a Shiley™ Flexible Adult Taperguard or Shiley™ XLT Tracheostomy. 14 patients (33%) required a tracheostomy change, with the majority (57%) involving a change from a standard size to an extended length tracheostomy. Persistent leak was the most common indication for change (71.6%). Other indications included patient-ventilator dyssynchrony, persistent cough and accidental decannulation. No staff transmission of COVID-19 occurred during this study. Conclusions: The incidence of tracheostomy change was 33%, highlighting the importance of selecting the right tracheostomy for each patient. We discuss how key characteristics of tracheostomies such as type, size, length and inner diameter may impact flow, resistance and work of breathing, leading to unplanned tracheostomy change. No staff transmission occurred arising from tracheostomy insertion, adding to increasing evidence that tracheostomy insertion in COVID-19 appears safe with adherence to guidelines describing the correct use of personal protective equipment.

Dental team member compliance with personal protective equipment and aerosol generating procedure recommendations during the COVID-19 pandemic in Israel - An observational study.

INTRODUCTION: Coronaviruses which have been responsible for numerous epidemics worldwide, share common transmission modalities and pose a risk within dental clinics. Updated, COVID-19 specific infection control and personal protective equipment (PPE) guidelines for dental settings, including minimizing aerosol generating procedures (AGPs), were issued by the Israeli Ministry of Health (MoH) in spring 2020. This study investigated dental team members (dentists, dental assistants and hygienists) compliance with MoH recommendations exposed to asymptomatic COVID-19 positive patients. METHODS: The MoH analyzed exposure reports from dental clinics to asymptomatic SARS-CoV-2 positive patients following their reopening (April 2020). Exposure reports were verified against a COVID-19 national database. A cumulative transmission rate was calculated and compared to the rate in the population. RESULTS: 1323 exposure reports were received (May 1st - December 31st 2020) regarding dental team members who treated asymptomatic SARS-CoV-2 positive patients: 525 (39.7%) were dentists, 656 (49.6%) dental assistants, and 126 (9.5%) hygienists. Practitioner type was not reported in 16 (1.2%) cases. Most dental team members reported full PPE use and performance of short/non-aerosol generating procedures. Dentists and hygienists reported higher compliance compared with dental assistants. 8 (0.6%) dental team members (4 dentists, 4 dental assistants) were positive post-exposure, with an average of 5.4 days (median 5 days, SD = 4.8) from dental treatment to a positive COVID-19 test. PRINCIPAL CONCLUSIONS: Most dental team members complied fully with the MoH recommendations. Differences were found between the dental team members (hygienists being most adherent). Further efforts are required to encourage full compliance.

Exposure to airborne SARS-CoV-2 in four hospital wards and ICUs of Cyprus. A detailed study accounting for day-to-day operations and aerosol generating procedures.

In any infectious disease, understanding the modes of transmission is key to selecting effective public health measures. In the case of COVID-19 spread, the strictness of the imposed measures outlined the lack of understanding on how SARS-CoV-2 transmits, particularly via airborne pathways. With the aim to characterize the transmission dynamics of airborne SARS-CoV-2, 165 and 62 air and environmental samples, respectively, were collected in four COVID-19 wards and ICUs in Cyprus and analyzed by RT-PCR. An alternative method for SARS-CoV-2 detection in air that provides comparable results but is less cumbersome and time demanding, is also proposed. Considering that all clinics employed 14 regenerations per hour of full fresh air inside patient rooms, it was hypothesized that the viral levels and the frequency of positive samples would be minimum outside of the rooms. However, it is shown that leaving the door opened in patient rooms hinders the efficiency of the ventilation system applied, allowing the virus to escape. As a result, the highest observed viral levels (135 copies m-3) were observed in the corridor of a ward and the frequency of positive samples in the same area was comparable to that inside a two-bed cohort. SARS-CoV-2 in that corridor was found primarily to lie in the coarse mode, at sizes between 1.8 and 10 µm. Similar to previous studies, the frequency of positive samples and viral levels were the lowest inside intensive care units. However, if a patient with sufficient viral load (Ct-value 31) underwent aerosol generating procedures, positive samples with viral levels below 45 copies m-3 were acquired within a 2 m distance of the patient. Our results suggest that a robust ventilation system can prevent unnecessary exposure to SARS-CoV-2 but with limitations related to foot traffic or the operations taking place at the time.

A Multimodal Approach to Training COVID-19 Processes Across Four Intensive Care Units.

Coronavirus disease (COVID-19) required innovative training strategies for emergent aerosol generating procedures (AGPs) in intensive care units (ICUs). This manuscript summarizes institutional operationalization of COVID-specific training, standardized across four ICUs. An interdisciplinary team collaborated with the Simulator Program and OpenPediatrics refining logistics using process maps, walkthroughs and simulation. A multimodal approach to information dissemination, high-volume team training in modified resuscitation practices and technical skill acquisition included instructional videos, training superusers, small-group simulation using a flipped classroom approach with rapid cycle deliberate practice, interactive webinars, and cognitive aids. Institutional data on application of this model are presented. Success was founded in interdisciplinary collaboration, resource availability and institutional buy in.

Environmental Contamination by SARS-CoV-2 During Noninvasive Ventilation in COVID-19.

BACKGROUND: Environmental contamination by SARS-CoV-2 from patients with COVID-19 undergoing noninvasive ventilation (NIV) in the ICU is still under investigation. This study set out to investigate the presence of SARS-CoV-2 on surfaces near subjects receiving NIV in the ICU under controlled conditions (ie, use of dual-limb circuits, filters, adequate room ventilation). METHODS: This was a single-center, prospective, observational study in the ICU of a tertiary teaching hospital. Four surface sampling areas, at increasing distance from subject's face, were identified; and each one was sampled at fixed intervals: 6, 12, and 24 h. The presence of SARS-CoV-2 was detected with real-time reverse transcriptase-polymerase-chain-reaction (RT-PCR) test on environmental swabs; the RT-PCR assay targeted the SARS-CoV-2 virus nucleocapsid N1 and N2 genes and the human RNase P gene as internal control. RESULTS: In a total of 256 collected samples, none were positive for SARS-CoV-2 genetic material, whereas 21 samples (8.2%) tested positive for RNase P, thus demonstrating the presence of genetic material unrelated to SARS-CoV-2. CONCLUSIONS: Our data show that application of NIV in an appropriate environment and with correct precautions leads to no sign of surface environmental contamination. Accordingly, our data support the idea that use of NIV in the ICU is safe both for health care workers and for other patients.

Reduction in cycle time for a rapid polymerase chain reaction diagnostic test at the point of care.

Background: Rapid testing facilitates safe and effective diagnosis, but the true speed of the process is the time from collection of a sample to delivery of an accurate and reliable test result - 'end-to-end' time. Transport, unpacking and relaying of information can extend this time considerably beyond the minimum laboratory turnaround times as stipulated by PCR testing protocols. Aim/Objective: This study aimed to minimise time needed to ascertain SARS-CoV-2 status prior to treatment in a UK Dental Hospital using a novel, mobile, direct to polymerase chain reaction (PCR) workflow. Methods: Process flow analysis and PDSA (Plan, Do, Study, Act) cycles for rapid continuous improvement were employed in a service improvement programme. Primerdesign™ q16 rapid PCR instruments and PROmate® COVID-19 direct assays were used for molecular testing. Findings/Results: We showed a reduction in real-world end-to-end time for a diagnostic test from 240 min to 85 min (65% reduction) over a 4-week period. Discussion: New rapid technologies have become available that reduce analytical time to under 90 min, but the real-world clinical implementation of the test requires a fully integrated workflow from clinic to reporting.

Pharmacologic methods to minimise coughing during extubation in the era of COVID-19.

BACKGROUND/AIM: Given the current severe acute respiratory syndrome coronavirus 2 pandemic, coughing at the time of extubation is at risk of creating aerosolisation. This may place health care workers at risk of nosocomial infection during the perioperative period. This study aims to summarise the current pharmacologic methods to minimise cough at the time of extubation, and to determine whether some strategies could be more beneficial than others. METHODS: This is a summary of systematic reviews. A comprehensive search through MEDLINE was performed. Thirty-three publications were screened for eligibility. Only the manuscripts discussing pharmacologic methods to minimise coughing on extubation were included in this review. FINDINGS: Many pharmacological agents have been proposed to decrease the incidence of cough at the time of extubation. Of these, intravenous administration of dexmedetomidine (relative risk 0.4; 95% CI: 0.4-0.5) or remifentanil (RR 0.4; 95% CI: 0.4-0.5) seems to have the largest effect to reduce cough on extubation. CONCLUSION: The available data in the current literature is sparse. Yet, dexmedetomidine and remifentanil seem to be the most efficient agents to decrease the incidence of emergence coughing.

Estimation of the risk of COVID-19 transmission through aerosol-generating procedures.

BACKGROUND: The outbreak of the coronavirus disease 2019 (COVID-19) pandemic was associated with the provision of multiple guidelines for the dental profession. All elective procedures were restricted, and only emergency procedures were performed. There was fear and anxiety among dentists while performing aerosol-generating procedures (AGPs), as they were considered to pose a high risk of COVID-19 transmission. OBJECTIVES: The aim of this study was to assess the risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during AGPs, and to examine the association between risk severity and the number of AGPs performed per day. The efficacy of personal protective equipment (PPE) was also assessed. MATERIAL AND METHODS: This cross-sectional cohort study was based on an online questionnaire form completed by 629 general and specialized dentists between January 1 and February 28, 2021. The collected data referred to the sources of COVID-19 infection, the type of PPE used and the number of AGPs performed each day by dental healthcare professionals (DHCPs). For each question, the absolute numbers of responses as well as percentages were calculated. RESULTS: Among the 629 DHCPs, 113 (17.97%) contracted COVID-19. The risk of contracting COVID-19 during AGPs was the same as in the case of non-AGPs, and the infection risk was not associated with the number of AGPs performed per day. The efficacy of a surgical mask with a face shield/eye goggles was higher in comparison with all other types of PPE. Differences in the infection risk across the different types of PPE used were statistically significant (p < 0.001). CONCLUSIONS: The risk of COVID-19 transmission during AGPs is the same as in the case of non-AGPs. Thus, restrictions on the performance of elective AGPs should be lifted. On the other hand, the best protection during AGPs is provided by a surgical mask with a face shield/eye goggles.

Aerosol-generating procedures, how best did anesthesiologists use available personal protective equipment during early COVID-19 pandemic in a tertiary care center of southern India? A prospective cross-sectional study.

Background and Aims: Anesthesiologists are involved in high-risk procedures for transmission of SARS-CoV-2 like aerosol-generating procedures (AGPs). The present study was conducted to assess the compliance toward the use of personal protective equipment (PPE) and proposed modifications in anesthesia techniques to prevent dissemination of the virus among healthcare workers. Material and Methods: This prospective cross-sectional study was conducted during the first wave of the COVID-19 pandemic and included all elective surgeries involving AGPs inside operation theatres and remote areas. Participants were anesthesia consultants and trainees. Trained anesthesia technicians observed and documented all the AGPs and data entry with analysis was done using EPI Data 3.1, SPSS 21.0. Descriptive statistics were reported using mean ± SD for continuous variables. Results: Preoperative COVID-19 test was done in 96.3% of patients. Most (74.8%) of the AGPs were performed by consultants. In our study, compliance for N95 masks usage and hand hygiene was found to be 99.2% and 55.9%, respectively. Avoidance of crowding was followed in only 38.9% during intubation. To contain the aerosol-based spread of virus, modification of anesthesia practices like acrylic boxes (6.4%), plastic sheets (5.5%), video laryngoscopy (39%), rapid sequence intubation (RSI) (42.7%), and 59.3% of deep extubation were incorporated. Conclusion: In our study, we found satisfactory compliance toward usage of N95 masks alone, whereas compliance toward other available PPE and modification in anesthesia practice was found to be unsatisfactory.

A case series of interventional pulmonology in the era of coronavirus disease 2019

The coronavirus disease 2019 (COVID-19) pandemic is still ongoing, and respirology associations globally are updating and releasing guidelines to provide appropriate care for health care workers and patients. The virus can become airborne if aerosol-generating procedures (AGPs) are performed. Interventional pulmonology procedures were performed on 63 patients within the period of March-May 2020. During this pandemic, personnel involved per procedure is limited, personal protective equipment level 3 is utilized in AGPs, and level 2 personal protective equipment is used in non-AGPs. The majority of patients were male (54%) and were aged 30-49 years (35%). Bronchoscopy was the most frequent procedure performed (62%). The most common pulmonary conditions in these patients were pneumonia, pleural effusion, and lung mass/consolidation (all 24%). There were seven (11%) patients diagnosed as having probable COVID-19. Interventional pulmonology procedures can still be performed in the era of COVID-19 pandemic.

Risk of transmission of respiratory viruses during aerosol-generating medical procedures (AGMPs) revisited in the COVID-19 pandemic: a systematic review.

BACKGROUND: In many jurisdictions healthcare workers (HCWs) are using respirators for aerosol-generating medical procedures (AGMPs) performed on adult and pediatric populations with all suspect/confirmed viral respiratory infections (VRIs). This systematic review assessed the risk of VRIs to HCWs in the presence of AGMPs, the role respirators versus medical/surgical masks have on reducing that risk, and if the risk to HCWs during AGMPs differed when caring for adult or pediatric patient populations. MAIN TEXT: We searched MEDLINE, EMBASE, Cochrane Central, Cochrane SR, CINAHL, COVID-19 specific resources, and MedRxiv for English and French articles from database inception to September 9, 2021. Independent reviewers screened abstracts using pre-defined criteria, reviewed full-text articles, selected relevant studies, abstracted data, and conducted quality assessments of all studies using the ROBINS-I risk of bias tool. Disagreements were resolved by consensus. Thirty-eight studies were included; 23 studies on COVID-19, 10 on SARS, and 5 on MERS/ influenza/other respiratory viruses. Two of the 16 studies which assessed associations found that HCWs were 1.7 to 2.5 times more likely to contract COVID-19 after exposure to AGMPs vs. not exposed to AGMPs. Eight studies reported statistically significant associations for nine specific AGMPs and transmission of SARS to HCWS. Intubation was consistently associated with an increased risk of SARS. HCWs were more likely (OR 2.05, 95% CI 1.2-3.4) to contract human coronaviruses when exposed to an AGMP in one study. There were no reported associations between AGMP exposure and transmission of influenza or in a single study on MERS. There was limited evidence supporting the use of a respirator over a medical/surgical mask during an AGMP to reduce the risk of viral transmission. One study described outcomes of HCWs exposed to a pediatric patient during intubation. CONCLUSION: Exposure to an AGMP may increase the risk of transmission of COVID-19, SARS, and human coronaviruses to HCWs, however the evidence base is heterogenous and prone to confounding, particularly related to COVID-19. There continues to be a significant research gap in the epidemiology of the risk of VRIs among HCWs during AGMPs, particularly for pediatric patients. Further evidence is needed regarding what constitutes an AGMP.

Aerosol and Droplet Generation During Intubation and Normal Breathing: A Simulation Study

The recent COVID-19 pandemic has made important changes to the everyday practice of anaesthetists. Current research has shown that the virus spreads via respiratory droplets and aerosolisation. The aim of this study was to examine the extent of contact contamination, droplet spread and aerosolisation, which may occur with normal breathing and intubation in a mannequin study. In the first experiment, an Ambu bag was attached to the simulation mannequin’s trachea and an atomiser device was placed into the mannequin’s pharynx. This model simulated normal ventilation as 0.5 ml of luminescent fluid was sprayed through the atomiser. In the second experiment, the mannequin was intubated with a videolaryngoscope while spraying 0.5 ml of luminescent fluid through the atomiser, after which the laryngoscope was removed. The spread of the luminescent aerosol cloud after three full breaths, droplet spread and contact contamination were visualised using ultraviolet light. The extent of spread was evaluated using a 4-point Likert scale (0 to 3) by two observers. Each of the experiments was repeated five times. For the first experiment, aerosol formation, droplet spread and contact contamination were 2.5 (2–3), 1 (0–1), 0 (0–1) points. In the second experiment, aerosol formation, droplet spread and contact contamination were 0.5 (0–1), 1 (0–1), 3 (2–3) points, accordingly. Noticeable contact contamination occurs during laryngoscopy and removal of the laryngoscope, whereas droplet contamination with laryngoscopy and normal breathing is minimal. Normal breathing leads to significant aerosol formation.

Anaesthetists' current practice and perceptions of aerosol-generating procedures: a mixed-methods study.

The evidence base surrounding the transmission risk of 'aerosol-generating procedures' has evolved primarily through quantification of aerosol concentrations during clinical practice. Consequently, infection prevention and control guidelines are undergoing continual reassessment. This mixed-methods study aimed to explore the perceptions of practicing anaesthetists regarding aerosol-generating procedures. An online survey was distributed to the Membership Engagement Group of the Royal College of Anaesthetists during November 2021. The survey included five clinical scenarios to identify the personal approach of respondents to precautions, their hospital's policies and the associated impact on healthcare provision. A purposive sample was selected for interviews to explore the reasoning behind their perceptions and behaviours in greater depth. A total of 333 survey responses were analysed quantitatively. Transcripts from 18 interviews were coded and analysed thematically. The sample was broadly representative of the UK anaesthetic workforce. Most respondents and their hospitals were aware of, supported and adhered to UK guidance. However, there were examples of substantial divergence from these guidelines at both individual and hospital level. For example, 40 (12%) requested respiratory protective equipment and 63 (20%) worked in hospitals that required it to be worn whilst performing tracheal intubation in SARS-CoV-2 negative patients. Additionally, 173 (52%) wore respiratory protective equipment whilst inserting supraglottic airway devices. Regarding the use of respiratory protective equipment and fallow times in the operating theatre: 305 (92%) perceived reduced efficiency; 376 (83%) perceived a negative impact on teamworking; 201 (64%) were worried about environmental impact; and 255 (77%) reported significant problems with communication. However, 269 (63%) felt the negative impacts of respiratory protection equipment were appropriately balanced against the risks of SARS-CoV-2 transmission. Attitudes were polarised about the prospect of moving away from using respiratory protective equipment. Participants' perceived risk from COVID-19 correlated with concern regarding stepdown (Spearman's test, R = 0.36, p < 0.001). Attitudes towards aerosol-generating procedures and the need for respiratory protective equipment are evolving and this information can be used to inform strategies to facilitate successful adoption of revised guidelines.

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.

Reducing aerosol dispersion by high flow therapy in COVID-19: High resolution computational fluid dynamics simulations of particle behavior during high velocity nasal insufflation with a simple surgical mask.

Objective: All respiratory care represents some risk of becoming an aerosol-generating procedure (AGP) during COVID-19 patient management. Personal protective equipment (PPE) and environmental control/engineering is advised. High velocity nasal insufflation (HVNI) and high flow nasal cannula (HFNC) deliver high flow oxygen (HFO) therapy, established as a competent means of supporting oxygenation for acute respiratory distress patients, including that precipitated by COVID-19. Although unlikely to present a disproportionate particle dispersal risk, AGP from HFO continues to be a concern. Previously, we published a preliminary model. Here, we present a subsequent highresolution simulation (higher complexity/reliability) to provide a more accurate and precise particle characterization on the effect of surgical masks on patients during HVNI, low-flow oxygen therapy (LFO2), and tidal breathing. Methods: This in silico modeling study of HVNI, LFO2, and tidal breathing presents ANSYS fluent computational fluid dynamics simulations that evaluate the effect of Type I surgical mask use over patient face on particle/droplet behavior. Results: This in silico modeling simulation study of HVNI (40 L min-1) with a simulated surgical mask suggests 88.8% capture of exhaled particulate mass in the mask, compared to 77.4% in LFO2 (6 L min-1) capture, with particle distribution escaping to the room (> 1 m from face) lower for HVNI+Mask versus LFO2+Mask (8.23% vs 17.2%). The overwhelming proportion of particulate escape was associated with mask-fit designed model gaps. Particle dispersion was associated with lower velocity. Conclusions: These simulations suggest employing a surgical mask over the HVNI interface may be useful in reduction of particulate mass distribution associated with AGPs.

Airborne Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospitals: Effects of Aerosol-Generating Procedures, HEPA-Filtration Units, Patient Viral Load, and Physical Distance.

BACKGROUND: Transmission of coronavirus disease 2019 (COVID-19) can occur through inhalation of fine droplets or aerosols containing infectious virus. The objective of this study was to identify situations, patient characteristics, environmental parameters, and aerosol-generating procedures (AGPs) associated with airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. METHODS: Air samples were collected near hospitalized COVID-19 patients and analyzed by RT-qPCR. Results were related to distance to the patient, most recent patient diagnostic PCR cycle threshold (Ct) value, room ventilation, and ongoing potential AGPs. RESULTS: In total, 310 air samples were collected; of these, 26 (8%) were positive for SARS-CoV-2. Of the 231 samples from patient rooms, 22 (10%) were positive for SARS-CoV-2. Positive air samples were associated with a low patient Ct value (OR, 5.0 for Ct <25 vs >25; P = .01; 95% CI: 1.18-29.5) and a shorter physical distance to the patient (OR, 2.0 for every meter closer to the patient; P = .05; 95% CI: 1.0-3.8). A mobile HEPA-filtration unit in the room decreased the proportion of positive samples (OR, .3; P = .02; 95% CI: .12-.98). No association was observed between SARS-CoV-2-positive air samples and mechanical ventilation, high-flow nasal cannula, nebulizer treatment, or noninvasive ventilation. An association was found with positive expiratory pressure training (P < .01) and a trend towards an association for airway manipulation, including bronchoscopies and in- and extubations. CONCLUSIONS: Our results show that major risk factors for airborne SARS-CoV-2 include short physical distance, high patient viral load, and poor room ventilation. AGPs, as traditionally defined, seem to be of secondary importance.