Key Clinical Points Evaluation and Management of Severe Covid-19 Patients with severe coronavirus disease 2019 (Covid-19) may become critically ill with acute respiratory distress syndrome that typ...

https://www.nejm.org/doi/pdf/10.1056/NEJMcp2009575?articleTools=true

Severe Covid-19

Clinical pathways are optimal patient care processes that have been developed to improve the quality of care for patients. Anecdotal evidence has suggested that patients presenting to the healthcar...

Using the modified delphi method to establish clinical consensus for the diagnosis and treatment of patients with rotator cuff pathology

Respirable aerosols ( 5 µm) precautions at other times. However, emerging evidence indicates respiratory activities may be a more important source of aerosols than clinical procedures such as tracheal intubation. We aimed to measure the size, total number and volume of all human aerosols exhaled during respiratory activities and therapies. We used a novel chamber with an optical particle counter sampling at 100 l.min-1 to count and size-fractionate close to all exhaled particles (0.5-25 µm). We compared emissions from ten healthy subjects during six respiratory activities (quiet breathing; talking; shouting; forced expiratory manoeuvres; exercise; and coughing) with three respiratory therapies (high-flow nasal oxygen and single or dual circuit non-invasive positive pressure ventilation). Activities were repeated while wearing facemasks. When compared with quiet breathing, exertional respiratory activities increased particle counts 34.6-fold during talking and 370.8-fold during coughing (p < 0.001). High-flow nasal oxygen 60 at l.min-1 increased particle counts 2.3-fold (p = 0.031) during quiet breathing. Single and dual circuit non-invasive respiratory therapy at 25/10 cm.H2 O with quiet breathing increased counts by 2.6-fold and 7.8-fold, respectively (both p < 0.001). During exertional activities, respiratory therapies and facemasks reduced emissions compared with activities alone. Respiratory activities (including exertional breathing and coughing) which mimic respiratory patterns during illness generate substantially more aerosols than non-invasive respiratory therapies, which conversely can reduce total emissions. We argue the risk of aerosol exposure is underappreciated and warrants widespread, targeted interventions.

https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/pdf/10.1111/anae.15475

The effect of respiratory activity, non-invasive respiratory support and facemasks on aerosol generation and its relevance to COVID-19.

Aerosol generating procedures: are they of relevance for transmission of SARS-CoV-2?

OBJECTIVE: The aim of this study was to assess the outcomes of tracheostomy in patients with COVID-19 respiratory failure. SUMMARY BACKGROUND DATA: Tracheostomy has an essential role in managing COVID-19 patients with respiratory failure who require prolonged mechanical ventilation. However, limited data are available on how tracheostomy affects COVID-19 outcomes, and uncertainty surrounding risk of infectious transmission has led to divergent recommendations and practices. METHODS: It is a multicenter, retrospective study; data were collected on all tracheostomies performed in COVID-19 patients at 7 hospitals in 5 tertiary academic medical systems from February 1, 2020 to September 4, 2020. RESULT: Tracheotomy was performed in 118 patients with median time from intubation to tracheostomy of 22âdays (Q1-Q3: 18-25). All tracheostomies were performed employing measures to minimize aerosol generation, 78.0% by percutaneous technique, and 95.8% at bedside in negative pressure rooms. Seventy-eight (66.1%) patients were weaned from the ventilator and 18 (15.3%) patients died from causes unrelated to tracheostomy. No major procedural complications occurred. Early tracheostomy (≤14âdays) was associated with decreased ventilator days; median ventilator days (Q1-Q3) among patients weaned from the ventilator in the early, middle and late groups were 21 (21-31), 34 (26.5-42), and 37 (32-41) days, respectively with P = 0.030. Compared to surgical tracheostomy, percutaneous technique was associated with faster weaning for patients weaned off the ventilator [median (Q1-Q3): 34 (29-39) vs 39 (34-51) days, P = 0.038]; decreased ventilator-associated pneumonia (58.7% vs 80.8%, P = 0.039); and among patients who were discharged, shorter intensive care unit duration [median (Q1-Q3): 33 (27-42) vs 47 (33-64) days, P = 0.009]; and shorter hospital length of stay [median (Q1-Q3): 46 (33-59) vs 59.5 (48-80) days, P = 0.001]. CONCLUSION: Early, percutaneous tracheostomy was associated with improved outcomes compared to surgical tracheostomy in a multi-institutional series of ventilated patients with COVID-19.

Tracheostomy for COVID-19 Respiratory Failure: Multidisciplinary, Multicenter Data on Timing, Technique, and Outcomes.

In the context of covid-19, aerosol generating procedures have been highlighted as requiring a higher grade of personal protective equipment. We investigated how official guidance documents and academic publications have classified procedures in terms of whether or not they are aerosol-generating. We performed a rapid systematic review using preferred reporting items for systematic reviews and meta-analyses standards. Guidelines, policy documents and academic papers published in english or french offering guidance on aerosol-generating procedures were eligible. We systematically searched two medical databases (medline, cochrane central) and one public search engine (google) in march and april 2020. Data on how each procedure was classified by each source were extracted. We determined the level of agreement across different guidelines for each procedure group, in terms of its classification as aerosol generating, possibly aerosol-generating, or nonaerosol-generating. 128 documents met our inclusion criteria; they contained 1248 mentions of procedures that we categorised into 39 procedure groups. Procedures classified as aerosol-generating or possibly aerosol-generating by ≥90% of documents included autopsy, surgery/postmortem procedures with high-speed devices, intubation and extubation procedures, bronchoscopy, sputum induction, manual ventilation, airway suctioning, cardiopulmonary resuscitation, tracheostomy and tracheostomy procedures, non-invasive ventilation, high-flow oxygen therapy, breaking closed ventilation systems, nebulised or aerosol therapy, and high frequency oscillatory ventilation. Disagreements existed between sources on some procedure groups, including oral and dental procedures, upper gastrointestinal endoscopy, thoracic surgery and procedures, and nasopharyngeal and oropharyngeal swabbing. There is sufficient evidence of agreement across different international guidelines to classify certain procedure groups as aerosol generating. However, some clinically relevant procedures received surprisingly little mention in our source documents. To reduce dissent on the remainder, we recommend that (a) clinicians define procedures more clearly and specifically, breaking them down into their constituent components where possible; (b) researchers undertake further studies of aerosolisation during these procedures; and (c) guideline-making and policy-making bodies address a wider range of procedures.

https://bmjopenrespres.bmj.com/content/bmjresp/7/1/e000730.full.pdf

Classification of aerosol-generating procedures: a rapid systematic review.

Objectives:We aimed to evaluate the effects of cannabis on workplace safety outcomes and road traffic collisions (using operation of a motor vehicle as a proxy for other safety-sensitive tasks) via a systematic literature review and meta-analysis.Methods:We searched MEDLINE and the reference

Impact of Cannabis Use on Road Traffic Collisions and Safety at Work: Systematic Review and Meta-analysis

Background Drug- and alcohol-related impairment in the workplace has been linked to an increased risk of injury for workers. Randomly testing populations of workers for these substances has become a practice in many jurisdictions, with the intention of reducing the risk of workplace incidents and accidents. Despite the proliferation of random drug and alcohol testing (RDAT), there is currently a lack of consensus about whether it is effective at preventing workplace injury, or improving other non-injury accident outcomes in the work place. Objectives To assess the effectiveness of workplace RDAT to prevent injuries and improve non-injury accident outcomes (unplanned events that result in damage or loss of property) in workers compared with no workplace RDAT. Search methods We conducted a systematic literature search to identify eligible published and unpublished studies. The date of the last search was 1 November 2020. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, two other databases, Google Scholar, and three trials registers. We also screened the reference lists of relevant publications known to us. Selection criteria Study designs that were eligible for inclusion in our review included randomised controlled trials (RCTs), cluster-randomised trials (CRTs), interrupted time-series (ITS) studies, and controlled before-after (CBA) studies. Studies needed to evaluate the effectiveness of RDAT in preventing workplace injury or improving other non-injury workplace outcomes. We also considered unpublished data from clinical trial registries. We included employees working in all safety-sensitive occupations, except for commercial drivers, who are the subject of another Cochrane Review. Data collection and analysis Independently, two review authors used a data collection form to extract relevant characteristics from the included study. They then analysed a line graph included in the study of the prevalence rate of alcohol violations per year. Independently, the review authors completed a GRADE assessment, as a means of rating the quality of the evidence. Main results Although our searching originally identified 4198 unique hits, only one study was eligible for inclusion in this review. This was an ITS study that measured the effect of random alcohol testing (RAT) on the test positivity rate of employees of major airlines in the USA from 1995 to 2002. The study included data from 511,745 random alcohol tests, and reported no information about testing for other substances. The rate of positive results was the only outcome of interest reported by the study. The average rate of positive results found by RAT increased from 0.07% to 0.11% when the minimum percentage of workers who underwent RAT annually was reduced from 25% to 10%. Our analyses found this change to be a statistically significant increase (estimated change in level, where the level reflects the average percentage points of positive tests = 0.040, 95% confidence interval 0.005 to 0.075; P = 0.031). Our GRADE assessment, for the observed effect of lower minimum testing percentages associating with a higher rate of positive test results, found the quality of the evidence to be 'very low' across the five GRADE domains. The one included study did not address the following outcomes of interest: fatal injuries; non-fatal injuries; non-injury accidents; absenteeism; and adverse effects associated with RDAT. Authors' conclusions In the aviation industry in the USA, the only setting for which the eligible study reported data, there was a statistically significant increase in the rate of positive RAT results following a reduction in the percentage of workers tested, which we deem to be clinically relevant. This result suggests an inverse relationship between the proportion of positive test results and the rate of testing, which is consistent with a deterrent effect for testing. No data were reported on adverse effects related to RDAT. We could not draw definitive conclusions regarding the effectiveness of RDAT for employees in safety-sensitive occupations (not including commercial driving), or with safety-sensitive job functions. We identified only one eligible study that reflected one industry in one country, was of non-randomised design, and tested only for alcohol, not for drugs or other substances. Our GRADE assessment resulted in a 'very low' rating for the quality of the evidence on the only outcome reported. The paucity of eligible research was a major limitation in our review, and additional studies evaluating the effect of RDAT on safety outcomes are needed.

Graeme Wyatt

Papers

Classification of aerosol-generating procedures: a rapid systematic review.

Impact of Cannabis Use on Road Traffic Collisions and Safety at Work: Systematic Review and Meta-analysis

Random drug and alcohol testing for preventing injury in workers