Quantitative evaluation of aerosol generation during manual facemask ventilation.

Manual facemask ventilation, a core component of elective and emergency airway management, is classified as an aerosol-generating procedure. This designation is based on one epidemiological study suggesting an association between facemask ventilation and transmission during the SARS-CoV-1 outbreak in 2003. There is no direct evidence to indicate whether facemask ventilation is a high-risk procedure for aerosol generation. We conducted aerosol monitoring during routine facemask ventilation and facemask ventilation with an intentionally generated leak in anaesthetised patients. Recordings were made in ultraclean operating theatres and compared against the aerosol generated by tidal breathing and cough manoeuvres. Respiratory aerosol from tidal breathing in 11 patients was reliably detected above the very low background particle concentrations with median [IQR (range)] particle counts of 191 (77-486 [4-1313]) and 2 (1-5 [0-13]) particles.l-1 , respectively, p = 0.002. The median (IQR [range]) aerosol concentration detected during facemask ventilation without a leak (3 (0-9 [0-43]) particles.l-1 ) and with an intentional leak (11 (7-26 [1-62]) particles.l-1 ) was 64-fold (p = 0.001) and 17-fold (p = 0.002) lower than that of tidal breathing, respectively. Median (IQR [range]) peak particle concentration during facemask ventilation both without a leak (60 (0-60 [0-120]) particles.l-1 ) and with a leak (120 (60-180 [60-480]) particles.l-1 ) were 20-fold (p = 0.002) and 10-fold (0.001) lower than a cough (1260 (800-3242 [100-3682]) particles.l-1 ), respectively. This study demonstrates that facemask ventilation, even when performed with an intentional leak, does not generate high levels of bioaerosol. On the basis of this evidence, we argue facemask ventilation should not be considered an aerosol-generating procedure.

Factors Predicting Admission in Pediatric and Young Adults With COVID-19

Study Objectives: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and COVID-19- its associated disease in humans- appears to cause more severe morbidity and mortality in older adults and geriatric patients than in children and young adults. There is growing recognition of the association between both race and obesity and disease severity in hospitalized patients with COVID-19.However, the impact of age, race, and other major comorbidities on COVID-19 course in children and younger adults is not as well understood. Methods: We conducted a retrospective analysis of 2656 patients under the age of 36 years with COVID-19 between March 1, 2020 and August 6, 2020 as reported to HEALTHeLINK, a regional health information system for western New York State. Subjects were split into pediatric (0-19 years) and young adult (20- 36 years) datasets. We evaluated the association between candidate risk factors (age, sex, race, calculated BMI/BMI percentile, smoking status, diabetes, pre-existing respiratory disease, hypertension, and sickle cell disease) using recursive partitioning and linear regression. The primary outcome was hospital admission, with length of stay being the secondary outcome Results: There were 2129 young adults and 527 pediatric patients who tested positive for COVID-19 during our study period. In our young adult population, race was the most significant predictor of admission, followed by BMI. African Americans with a BMI > 23 had the highest rate of admission (66%, p<0.001). Interestingly, Asian race was a strong predictor of outpatient management, regardless of BMI. Smoking status and hypertension were less significant predictors of admission, whereas sex, diabetes, preexisting respiratory conditions, and sickle cell disease were not significant. For our pediatric population, race was also the most significant predictor of admission, with African Americans being admitted at higher rates than Whites and Asians. In the pediatric population, however, BMI percentile for age was not a predictor of admission. In regards to the secondary outcome, admitted young adult with COVID-19 had an average length of stay of 1.4 days (SD ±2) while the admitted pediatric COVID-19 patients had an average length of stay of 1 day (SD ±1.1). African American race was associated with longer length of stay in both populations however, BMI was only significant in the young adult population. Conclusions: In a regional population of young adult and pediatric patients with COVID-19, race was strongly predictive of admission and length of stay. African American patients were most likely to be admitted, while Asian race was a strong predictor of outpatient management. For African American young adults, a BMI > 23 was the strongest additional predictor of admission. For younger patients with COVID-19 a simple decision tree that incorporates age, race, and BMI can help identify those patients least likely to need inpatient management. [Formula presented]

Aerosolisation during tracheal intubation and extubation in an operating theatre setting.

Aerosol-generating procedures such as tracheal intubation and extubation pose a potential risk to healthcare workers because of the possibility of airborne transmission of infection. Detailed characterisation of aerosol quantities, particle size and generating activities has been undertaken in a number of simulations but not in actual clinical practice. The aim of this study was to determine whether the processes of facemask ventilation, tracheal intubation and extubation generate aerosols in clinical practice, and to characterise any aerosols produced. In this observational study, patients scheduled to undergo elective endonasal pituitary surgery without symptoms of COVID-19 were recruited. Airway management including tracheal intubation and extubation was performed in a standard positive pressure operating room with aerosols detected using laser-based particle image velocimetry to detect larger particles, and spectrometry with continuous air sampling to detect smaller particles. A total of 482,960 data points were assessed for complete procedures in three patients. Facemask ventilation, tracheal tube insertion and cuff inflation generated small particles 30-300 times above background noise that remained suspended in airflows and spread from the patient's facial region throughout the confines of the operating theatre. Safe clinical practice of these procedures should reflect these particle profiles. This adds to data that inform decisions regarding the appropriate precautions to take in a real-world setting.