scholarly journals Passive Tracer Visualization to Simulate Aerodynamic Virus Transport in Noninvasive Respiratory Support Methods

Respiration ◽  
2021 ◽  
pp. 1-12
Author(s):  
Rutger Hendrik Johan Hebbink ◽  
Judith Elshof ◽  
Steven Wanrooij ◽  
Walter Lette ◽  
Mariëtte Lokate ◽  
...  
Keyword(s):  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
Respiratory Support ◽  
Droplet Dispersion ◽  
Bilevel Positive Airway Pressure ◽  
Increased Risk ◽  
Exhaled Air ◽  
Support Methods ◽  
Jet Velocities

<b><i>Background:</i></b> Various forms of noninvasive respiratory support methods are used in the treatment of hypoxemic CO­VID-19 patients, but limited data are available about the corresponding respiratory droplet dispersion. <b><i>Objectives:</i></b> The aim of this study was to estimate the potential spread of infectious diseases for a broad selection of oxygen and respiratory support methods by revealing the therapy-induced aerodynamics and respiratory droplet dispersion. <b><i>Methods:</i></b> The exhaled air-smoke plume from a 3D-printed upper airway geometry was visualized by recording light reflection during simulated spontaneous breathing, standard oxygen mask application, nasal high-flow therapy (NHFT), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP). The dispersion of 100 μm particles was estimated from the initial velocity of exhaled air and the theoretical terminal velocity. <b><i>Results:</i></b> Estimated droplet dispersion was 16 cm for unassisted breathing, 10 cm for Venturi masks, 13 cm for the nebulizer, and 14 cm for the nonrebreathing mask. Estimated droplet spread increased up to 34 cm in NHFT, 57 cm in BiPAP, and 69 cm in CPAP. A nonsurgical face mask over the NHFT interface reduced estimated droplet dispersion. <b><i>Conclusions:</i></b> During NHFT and CPAP/BiPAP with vented masks, extensive jets with relatively high jet velocities were observed, indicating increased droplet spread and an increased risk of droplet-driven virus transmission. For the Venturi masks, a nonrebreathing mask, and a nebulizer, estimated jet velocities are comparable to unassisted breathing. Aerosols are transported unboundedly in all these unfiltered therapies. The adequate use of protective measures is of vital importance when using noninvasive unfiltered therapies in infectious respiratory diseases.

scholarly journals A Retrospective Analysis of Feeding Practices and Complications in Patients with Critical Bronchiolitis on Non-Invasive Respiratory Support

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 410
Author(s):  
Ariann Lenihan ◽  
Vannessa Ramos ◽  
Nichole Nemec ◽  
Joseph Lukowski ◽  
Junghyae Lee ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Enteral Nutrition ◽  
Acute Respiratory Failure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Severity Of Illness ◽  
Respiratory Support ◽  
Early Enteral Nutrition ◽  
Non Invasive ◽  
Bilevel Positive Airway Pressure

Limited data exist regarding feeding pediatric patients managed on non-invasive respiratory support (NRS) modes that augment oxygenation and ventilation in the setting of acute respiratory failure. We conducted a retrospective cohort study to explore the safety of feeding patients managed on NRS with acute respiratory failure secondary to bronchiolitis. Children up to two years old with critical bronchiolitis managed on continuous positive airway pressure, bilevel positive airway pressure, or RAM cannula were included. Of the 178 eligible patients, 64 were reportedly nil per os (NPO), while 114 received enteral nutrition (EN). Overall equivalent in severity of illness, younger patients populated the EN group, while the NPO group experienced a higher incidence of intubation. Duration of stay in the pediatric intensive care unit and non-invasive respiratory support were shorter in the NPO group, though intubation eliminated the former difference. Within the EN group, ninety percent had feeds initiated within 48 h and 94% reached full feeds within 7 days of NRS initiation, with an 8% complication and <1% aspiration rate. Reported complications did not result in escalation of respiratory support. Notably, a significant improvement in heart rate and respiratory rate was noted after feeds initiation. Taken together, our study supports the practice of early enteral nutrition in patients with critical bronchiolitis requiring NRS.

Physiological Responses and Perceived Comfort to High Flow Nasal Cannula Therapy in Awake Adults: Effects of Flow Magnitude and Temperature

2021 ◽  
Author(s):  
Indra Narang ◽  
Jayne C. Carberry ◽  
Jane E. Butler ◽  
Simon C. Gandevia ◽  
Alan K.I. Chiang ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
High Flow ◽  
Nasal Cannula ◽  
Respiratory Support ◽  
High Flow Nasal Cannula ◽  
Genioglossus Muscle ◽  
Obstructive Sleep

Clinical use of heated, high flow nasal cannula (HFNC) for non-invasive respiratory support is increasing and may have a therapeutic role in stabilizing the upper airway in obstructive sleep apnea (OSA). However, physiological mechanisms by which HFNC therapy may improve upper-airway function and effects of different temperature modes are unclear. Accordingly, this study aimed to determine effects of incremental flows and temperature modes (heated and non-heated) of HFNC on upper airway muscle activity (genioglossus), pharyngeal airway pressure, breathing parameters and perceived comfort. Six participants (2 females, aged 35±14 years) were studied during wakefulness in supine position and received HFNC at variable flows (0-60 L/min) during heated (37ºC) and non-heated (21ºC) modes. Breathing parameters via calibrated Respitrace inductance bands (chest and abdomen), upper-airway pressures via airway transducers, and genioglossus muscle activity via intra-muscular bipolar fine wire electrodes were measured. Comfort levels during HFNC were quantified using a visual analogue scale. Increasing HFNC flows did not increase genioglossus muscle activation despite increased negative epiglottic pressure swings (p=0.009). HFNC provided ~7cmH2O positive airway pressure at 60 L/min in non-heated and heated modes. In addition, increasing the magnitude of HFNC flow reduced breathing frequency (p=0.045), increased expiratory time (p=0.040), increased peak inspiratory flow (p=0.002), and increased discomfort (p=0.004). Greater discomfort occurred at higher flows in non-heated versus heated mode (p=0.034). These findings provide novel insight into key physiological changes that occur with HFNC for respiratory support and indicate the primary mechanism for improved upper-airway stability is positive airway pressure, not increased pharyngeal muscle activity.

scholarly journals Bilevel Positive Airway Pressure Versus Nasal Continuous Positive Airway Pressure for Prevention of Extubation Failure in Infants After Cardiac Surgery: A Randomized Controlled Trial

2021 ◽  
Author(s):  
yirong zheng ◽  
wenpeng xie ◽  
jianfeng liu ◽  
ning xu ◽  
hua cao ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Septal Defect ◽  
Positive Airway Pressure ◽  
Extubation Failure ◽  
Hospital Length Of Stay ◽  
Respiratory Support ◽  
Failure Rates ◽  
Bilevel Positive Airway Pressure

Abstract Objective: To evaluate the effect of bilevel positive airway pressure (BiPAP) and nasal continuous positive airway pressure (NCPAP) in respiratory support after extubation in infants undergoing cardiac surgery. Methods: A total of 83 infants who underwent repair of atrial septal defect (ASD) or ventricular septal defect (VSD) after extubation were randomized to the BiPAP group (n= 42) or the NCPAP group (n= 41) between January 2020 and December 2020. The primary outcomes were the extubation failure rate and the level of PCO2 within 24 h after extubation. Results: The baseline characteristics between the two groups were similar. The introduction of BiPAP for post-extubation respiratory support did not reduce extubation failure rates compared to NCPAP (P>0.05). The PaCO2 level within 48 h was significantly lower in the BiPAP group (P<0.05). Additionally, the PaO2/FiO2 in the BiPAP group was significantly higher than that in the NCPAP group at 6h, 12h and 24h after treatment (P<0.05).There were no statistically significant differences in duaration on NIV, hospital length of stay, total hospital costs in $ and complications between the two groups (P>0.05). Conclusion: The introduction of BiPAP for post-extubation respiratory support did not reduce extubation failure rates versus NCPAP. However, BiPAP was shown to be superior to NCPAP in improving oxygenation and carbon dioxide clearance.

scholarly journals Bi-level positive airway pressure (biPAP) for non-invasive respiratory support of foals

2020 ◽  
Author(s):  
Sharanne L Raidal ◽  
Lexi Burgmeestre ◽  
Chee Sum Melanie Catanchin ◽  
Chris T Quinn
Keyword(s):  
Respiratory Insufficiency ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Respiratory Support ◽  
Response To Treatment ◽  
Close Monitoring ◽  
Supplementary Oxygen ◽  
Non Invasive ◽  
Bilevel Positive Airway Pressure ◽  
Group 1

AbstractRespiratory insufficiency and pulmonary health are important considerations in equine neonatal care, as the majority of foals are bred for athletic function. The administration of supplementary oxygen is readily implemented in equine practice settings, but this does not address respiratory insufficiency due to inadequate ventilation and is no longer considered optimal care for hypoxia in some settings. Non-invasive ventilatory strategies including continuous or bi-level positive airway pressure are effective in human and veterinary studies, and may offer improved respiratory support in equine clinical practice. The current study was conducted in two parts to investigate the use of a commercial bilevel positive airway pressure (biPAP) ventilator, designed for home care of people with obstructive respiratory conditions, for respiratory support of foals. In Part 1 a prospective observational study was conducted to evaluate the effect of sequential application of supplementary oxygen and then biPAP for respiratory support of five foals ≤ 4 days of age hospitalised with respiratory in sufficiency (Group 1) and four healthy, sedated foals < 28 days of age (Group 2). In Part 2, biPAP and supplementary oxygen were administered to six healthy foals with pharmacologically induced respiratory insufficiency in a two sequence, two phase, cross-over study (Group 3). Non-invasive ventilation by biPAP improved gas exchange and mechanics of breathing (increased tidal volume, decreased respiratory rate and increased peak inspiratory flow) in foals, but modest hypercapnia was observed in healthy, sedated foals (Groups 2 and 3). Clinical cases (Group 1) appeared less likely to develop hypercapnia in response to treatment, however the response in individual foals was variable, and close monitoring is necessary. Clinical observations, pulse oximetry and CO2 monitoring of expired gases were of limited benefit in identification of foals responding inappropriately to biPAP, and improved methods to assess and monitor respiratory function are required in foals.

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