A quantitative evaluation of aerosol generation from upper airway suctioning during tracheal intubation and extubation sequences.

Background: Open respiratory suctioning is considered to be an aerosol generating procedure (AGP) and laryngopharyngeal suction, used to clear secretions during anaesthesia, is widely managed as an AGP. It is uncertain whether such upper airway suctioning should be designated an aerosol generating procedure (AGP) because of a lack of both aerosol and epidemiological evidence of risk. Aim: To assess the relative risk of aerosol generation by upper airway suction during tracheal intubation and extubation in anaesthetised patients. Methods: Prospective environmental monitoring study in ultraclean operating theatres to assay aerosol concentration during intubation and extubation sequences including upper airway suctioning for patients undergoing surgery (n=19 patients). An Optical Particle Sizer (particle size 300nm-10μm) was used to sample aerosol 20cm above the mouth of the patient. Baseline recordings (background, tidal breathing and volitional coughs) were followed by intravenous induction of anaesthesia with neuromuscular blockade. Four periods of oropharyngeal suction were performed with a Yankauer sucker: pre-laryngoscopy, post-intubation and pre- and post-extubation. Findings: Aerosol from breathing was reliably detected (65[39-259] particles.L-1 (median[IQR])) above background (4.8[1-7] particles.L-1, p<0.0001 Friedman). The procedure of upper airway suction was associated with much lower average concentrations of aerosol than breathing (6.0[0-12] particles.L-1, P=0.0007) and was indistinguishable from background (P>0.99). The peak aerosol concentration recorded during suctioning (45[30-75] particles.L-1) was much lower than both volitional coughs (1520[600-4363] particles.L-1, p<0.0001, Friedman) and tidal breathing (540[300-1826] particles.L-1, p<0.0001, Friedman). Conclusion: The procedure of upper airway suction during airway management is associated with no higher concentration of aerosol than background and much lower than breathing and coughing. Upper airway suction should not be designated as a high risk AGP.

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Identification of the source events for aerosol generation during oesophago-gastro-duodenoscopy

Gut ◽

10.1136/gutjnl-2021-324588 ◽

2021 ◽

pp. gutjnl-2021-324588

Author(s):

Florence K A Gregson ◽

Andrew J Shrimpton ◽

Fergus Hamilton ◽

Tim M Cook ◽

Jonathan P Reid ◽

...

Keyword(s):

Particle Concentration ◽

Particle Number ◽

Protective Equipment ◽

Average Particle ◽

Respiratory Pathogens ◽

Tidal Breathing ◽

Aerosol Generation ◽

Wide Range ◽

Monitoring Study ◽

Particle Sizer

ObjectiveTo determine if oesophago-gastro-duodenoscopy (OGD) generates increased levels of aerosol in conscious patients and identify the source events.DesignA prospective, environmental aerosol monitoring study, undertaken in an ultraclean environment, on patients undergoing OGD. Sampling was performed 20 cm away from the patient’s mouth using an optical particle sizer. Aerosol levels during OGD were compared with tidal breathing and voluntary coughs within subject.ResultsPatients undergoing bariatric surgical assessment were recruited (mean body mass index 44 and mean age 40 years, n=15). A low background particle concentration in theatres (3 L−1) enabled detection of aerosol generation by tidal breathing (mean particle concentration 118 L−1). Aerosol recording during OGD showed an average particle number concentration of 595 L−1 with a wide range (3–4320 L−1). Bioaerosol-generating events, namely, coughing or burping, were common. Coughing was evoked in 60% of the endoscopies, with a greater peak concentration and a greater total number of sampled particles than the patient’s reference voluntary coughs (11 710 vs 2320 L−1 and 780 vs 191 particles, n=9 and p=0.008). Endoscopies with coughs generated a higher level of aerosol than tidal breathing, whereas those without coughs were not different to the background. Burps also generated increased aerosol concentration, similar to those recorded during voluntary coughs. The insertion and removal of the endoscope were not aerosol generating unless a cough was triggered.ConclusionCoughing evoked during OGD is the main source of the increased aerosol levels, and therefore, OGD should be regarded as a procedure with high risk of producing respiratory aerosols. OGD should be conducted with airborne personal protective equipment and appropriate precautions in those patients who are at risk of having COVID-19 or other respiratory pathogens.

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Methods of systemic and regional lymphotropic therapy in otorhinolaryngology

Russian otorhinolaryngology ◽

10.18692/1810-4800-2020-4-82-89 ◽

2020 ◽

Vol 19 (4) ◽

pp. 82-89

Author(s):

S. Yu. Krotov ◽

◽

I. N. Putalova ◽

Yu. A. Krotov ◽

◽

...

Keyword(s):

Tracheal Intubation ◽

Middle Ear ◽

Human Body ◽

Upper Airway ◽

Preventive Therapy ◽

Review Of The Literature ◽

Number Of Patients ◽

Key Concepts ◽

Post Intubation ◽

General Connection

The present article is devoted to the review of the literature data about the use of clinical lymphology methods in otorhinolaryngology. The first part of the article outlines the key concepts and terms regarding the general connection of the lymphatic and lymphoid systems of the human body and methods of influence on them of drugs and physical technologies to achieve the effect of lymphatic recovery (lymphatic stimulation, lymphatic correction, lymphatic protection, and lymphatic suppression). The article also gives the concept of “lymphatic region”, main links, and considers the features of different methods of lymphotropic therapy. The second part presents specific results of the use of lymphotropic therapy in different forms of acute and chronic inflammatory pathology of pharynx, nose, paranasal sinuses, larynx, ear, and also preventive therapy to reduce post intubation laryngeal morbidity in younger children after prolonged tracheal intubation. The authors conclude about the prevailing studies aimed at developing methods of regional lymphotropic (indirect) therapy. Currently, they are considered as effective methods to stop a variety of forms of inflammatory pathology of the middle ear and the upper airway. Methods of systemic (direct lymphotropic) therapy in otorhinolaryngology are not yet widely used, they are used much less often and in a small number of patients. Both directions require further research and technical development, since today the potential of ENT pathology is far from being exhausted, where they could find their application.

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AEROSOL GENERATION DURING COUGHING - QUANTITATIVE DEFINITION FOR AEROSOL GENERATING PROCEDURES: OBSERVATIONAL STUDY

10.1101/2021.08.24.21262520 ◽

2021 ◽

Author(s):

Enni Sanmark ◽

Lotta-Maria Oksanen ◽

Noora Rantanen ◽

Mari Lahelma ◽

Veli-Jukka Anttila ◽

...

Keyword(s):

High Risk ◽

Operating Room ◽

Aerosol Particles ◽

Aerosol Concentration ◽

Medical Procedures ◽

Aerosol Generation ◽

Limit Value ◽

Aerosol Exposure ◽

Particle Sizer ◽

Quantitative Definition

ABSTRACT Aim: The purpose of the study was to determine aerosol exposure generated by coughing in operation room environments to create a quantitative limit value for high risk aerosol generating medical procedures. Background: Coughing is known to produce a significant amount of aerosols and is thus commonly used as a best reference for high-risk aerosol-generation. Accordingly, procedures during which aerosol generation exceeds the amount of aerosol generated in instances of coughing are seen as high risk aerosol generating procedures. However, no reliable quantitative values are available for high risk aerosol-generation. Methods: Coughing was measured from 37 healthy volunteers in the operating room environment. Aerosol particles generated during coughing within the size range of 0.3 - 10 microm were measured with Optical Particle Sizer from 40cm, 70cm, and 100cm distances. The distances reflected potential exposure distances where personnel are during surgeries. Results: A total of 306 coughs were measured. Average aerosol concentration during coughing was 1.580 +/- 13.774 particles/cm3 (range 0.000 - 195.528). Discussion: The aerosol concentration measured in this study can be used as a limit for high-risk aerosol generation in the operating room environment when assessing the aerosol generating procedures and the risk of operating room staff s exposure for aerosol particles. AUTHOR APPROVAL:All authors have approved the manuscript and have made significant contributions.

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Basics of Airway and Oxygen Delivery Devices

Mayo Clinic Critical and Neurocritical Care Board Review ◽

10.1093/med/9780190862923.003.0114 ◽

2019 ◽

pp. 835-839

Author(s):

Andrew W. Murray

Keyword(s):

Tracheal Intubation ◽

Brain Death ◽

Difficult Airway ◽

Brain Damage ◽

Oxygen Delivery ◽

Upper Airway ◽

Patent Airway ◽

Definition Of ◽

Facemask Ventilation

One of the greatest responsibilities in managing an airway is to maintain a continuously patent airway. Any loss of patency of the patient’s airway is critical, and if the ability to provide ventilatation is lost, brain damage can rapidly develop potentially lead to brain death. The definition of difficult airway is not standardized in the anesthesiology literature, but it has been described as the situation when “a conventionally trained anesthesiologist experiences difficulty with facemask ventilation of the upper airway, difficulty with tracheal intubation, or both”

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Effects Of Endotracheal And Upper Airway Suctioning On Physiological Parameters Of Premature Infants At Neonatal Intensive Care Unit

10.1164/ajrccm-conference.2011.183.1_meetingabstracts.a3379 ◽

2011 ◽

Author(s):

Riany S. Sena ◽

Andréa L. Barbosa ◽

Maria Vera Lúcia M.L. Cardoso ◽

Thays B. Brasil

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Neonatal Intensive Care Unit ◽

Premature Infants ◽

Neonatal Intensive Care ◽

Upper Airway ◽

Physiological Parameters ◽

Airway Suctioning

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Numerical study of dynamic glottis and tidal breathing on respiratory sounds in a human upper airway model

Sleep And Breathing ◽

10.1007/s11325-017-1588-0 ◽

2017 ◽

Vol 22 (2) ◽

pp. 463-479 ◽

Cited By ~ 9

Author(s):

Jinxiang Xi ◽

Zhaoxuan Wang ◽

Khaled Talaat ◽

Carri Glide-Hurst ◽

Haibo Dong

Keyword(s):

Numerical Study ◽

Upper Airway ◽

Respiratory Sounds ◽

Tidal Breathing ◽

Airway Model

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Experimental Evaluation of Perfluorocarbon Aerosol Generation with Two Novel Nebulizer Prototypes

Pharmaceutics ◽

10.3390/pharmaceutics11010019 ◽

2019 ◽

Vol 11 (1) ◽

pp. 19 ◽

Cited By ~ 4

Author(s):

Iñigo Aramendia ◽

Unai Fernandez-Gamiz ◽

Alberto Lopez-Arraiza ◽

Carmen Rey-Santano ◽

Victoria Mielgo ◽

...

Keyword(s):

Circular Ring ◽

Geometric Standard Deviation ◽

Distilled Water ◽

Aerodynamic Diameter ◽

Mean Values ◽

Non Invasive ◽

Aerosol Generation ◽

Non Invasive Ventilation ◽

Particle Sizer ◽

Invasive Techniques

The potential of non-invasive ventilation procedures and new minimally invasive techniques has resulted in the research of alternative approaches as the aerosolization for the treatment of respiratory distress syndrome (RDS). The aim of this work was to design two nebulizer prototypes and to evaluate them studying the particle size distribution of the inhaled droplets generated with distilled water and two perfluorocarbons (PFCs). Different experiments were performed with driving pressures of 1–3 bar for each compound. An Aerodynamic Particle Sizer was used to measure the aerodynamic diameter (Da), the mass median aerodynamic diameter (MMAD) and the geometric standard deviation (GSD). The results showed that both prototypes produced heterodisperse aerosols with Da mean values in all cases below 5 µm. The initial experiments with distilled water showed MMAD values lower than 9 µm and up to 15 µm with prototype 1 and prototype 2, respectively. Regarding the PFCs, relatively uniform MMAD values close to 12 µm were achieved. The air delivery with outer lumens of prototype 1 presented more suitable mass distribution for the generation and delivery of a uniform aerosol than the two half-circular ring geometry proposed in the prototype 2.

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Endotracheal and upper airways suctioning: changes in newborns’ physiological parameters

Revista Latino-Americana de Enfermagem ◽

10.1590/s0104-11692011000600013 ◽

2011 ◽

Vol 19 (6) ◽

pp. 1369-1376 ◽

Cited By ~ 5

Author(s):

Andréa Lopes Barbosa ◽

Maria Vera Lúcia Moreira Leitão Cardoso ◽

Thays Bezerra Brasil ◽

Carmen Gracinda Silvan Scochi

Keyword(s):

Neonatal Intensive Care ◽

Upper Airway ◽

Physiological Parameters ◽

Public Institution ◽

Pharmacological Interventions ◽

Upper Airways ◽

Nasal Cpap ◽

Before And After ◽

The City ◽

Airway Suctioning

This study investigated which physiological parameters change when endotracheal and upper airway suctioning is performed immediately before, immediately after and five minutes after this procedure is performed in newborns hospitalized in a Neonatal Intensive Care Unit (NICU). This is a quantitative and longitudinal study, before and after type, performed in the NICU of a public institution in the city of Fortaleza, CE, Brazil. The sample was composed of 104 newborns using oxigenotherapy and who needed endotracheal and upper airway suctioning. The results showed significant alterations in respiratory and heart rates (p<0.05) in neonates using Oxyhood and nasal CPAP while the pulse significantly changed (p<0.05) in newborns placed in oxyhood, using nasal CPAP and Mechanical Ventilation; oxygen saturation was the only parameter that did not alter significantly. We propose that nurses develop non-pharmacological interventions to reduce potential alterations caused in newborns’ physiological parameters due to this procedure.

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