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1.
PLoS Negl Trop Dis ; 16(3): e0010221, 2022 03.
Article in English | MEDLINE | ID: covidwho-1793647

ABSTRACT

Low-cost improvised continuous positive airway pressure (CPAP) device is safe and efficacious in neonatal respiratory distress. There is a great necessity for similar device in adults, and this has been especially made apparent by the recent Coronavirus Disease 2019 (COVID-19) pandemic, which is unmasking the deficiencies of healthcare system in several low-resource countries. We propose a simplified and inexpensive model of improvised CPAP in adults using locally available resources including aquarium air pumps and a novel pressure release mechanism. Although the safety and efficacy of improvised CPAP in adults are not established, the conceptual model we propose has the potential to serve as a lifesaving technology in many low-resource settings during this ongoing pandemic and thus calls for expedited research.


Subject(s)
COVID-19/therapy , Continuous Positive Airway Pressure/instrumentation , Equipment Design/economics , Respiratory Therapy/instrumentation , Adult , Humans , Noninvasive Ventilation/instrumentation , SARS-CoV-2
2.
Chest ; 160(1): 175-186, 2021 07.
Article in English | MEDLINE | ID: covidwho-1525725

ABSTRACT

BACKGROUND: SARS-CoV-2 aerosolization during noninvasive positive-pressure ventilation may endanger health care professionals. Various circuit setups have been described to reduce virus aerosolization. However, these setups may alter ventilator performance. RESEARCH QUESTION: What are the consequences of the various suggested circuit setups on ventilator efficacy during CPAP and noninvasive ventilation (NIV)? STUDY DESIGN AND METHODS: Eight circuit setups were evaluated on a bench test model that consisted of a three-dimensional printed head and an artificial lung. Setups included a dual-limb circuit with an oronasal mask, a dual-limb circuit with a helmet interface, a single-limb circuit with a passive exhalation valve, three single-limb circuits with custom-made additional leaks, and two single-limb circuits with active exhalation valves. All setups were evaluated during NIV and CPAP. The following variables were recorded: the inspiratory flow preceding triggering of the ventilator, the inspiratory effort required to trigger the ventilator, the triggering delay, the maximal inspiratory pressure delivered by the ventilator, the tidal volume generated to the artificial lung, the total work of breathing, and the pressure-time product needed to trigger the ventilator. RESULTS: With NIV, the type of circuit setup had a significant impact on inspiratory flow preceding triggering of the ventilator (P < .0001), the inspiratory effort required to trigger the ventilator (P < .0001), the triggering delay (P < .0001), the maximal inspiratory pressure (P < .0001), the tidal volume (P = .0008), the work of breathing (P < .0001), and the pressure-time product needed to trigger the ventilator (P < .0001). Similar differences and consequences were seen with CPAP as well as with the addition of bacterial filters. Best performance was achieved with a dual-limb circuit with an oronasal mask. Worst performance was achieved with a dual-limb circuit with a helmet interface. INTERPRETATION: Ventilator performance is significantly impacted by the circuit setup. A dual-limb circuit with oronasal mask should be used preferentially.


Subject(s)
COVID-19 , Continuous Positive Airway Pressure , Disease Transmission, Infectious/prevention & control , Noninvasive Ventilation , Air Filters , Benchmarking/methods , COVID-19/therapy , COVID-19/transmission , Continuous Positive Airway Pressure/adverse effects , Continuous Positive Airway Pressure/instrumentation , Continuous Positive Airway Pressure/methods , Critical Pathways/standards , Critical Pathways/trends , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Noninvasive Ventilation/adverse effects , Noninvasive Ventilation/instrumentation , Noninvasive Ventilation/methods , Research Design , Respiratory Function Tests/methods , SARS-CoV-2 , Treatment Outcome , Ventilators, Mechanical
3.
Clin Respir J ; 14(3): 214-221, 2020 Mar.
Article in English | MEDLINE | ID: covidwho-1455532

ABSTRACT

BACKGROUND: Patients with neuromuscular disorders (NMDs) are likely to develop respiratory failure which requires noninvasive ventilation (NIV). Ventilation via a mouthpiece (MPV) is an option to offer daytime NIV. OBJECTIVES: To determine the preferred equipment for MPV by patients with NMDs. METHODS: Two MPV equipment sets were compared in 20 patients with NMDs. Set 1, consisted of a non-dedicated ventilator for MPV (PB560, Covidien) with a plastic angled mouthpiece. Set 2, consisted of a dedicated MPV ventilator (Trilogy 100, Philips Respironics) without backup rate and kiss trigger combined with a silicone straw mouthpiece. The Borg dyspnea score, ventilator free time, transcutaneous oxygen saturation (SpO2) and carbon dioxide tension (TcCO2 ) were recorded with and without MPV. Patient perception was assessed by a 17-items list. RESULTS: Carbon dioxide tension measurements and total perception score were not different between the two MPV sets. Dyspnea score was lower with the non-dedicated versus dedicated equipment, 1 (0.5) versus 3 (1-6), P < 0.01. All patients with a ventilator free time lower than 6 hours preferred a set backup rate rather than a kiss trigger. Sixty five percent of patients preferred the commercial arm support and 55% preferred the plastic angled mouthpiece. CONCLUSIONS: Dedicated and non-dedicated MPV equipment are deemed effective and comfortable. Individualization of arm support and mouthpiece is advised to ensure success of MPV. A ventilator free time lower than 6 hours seems to be a useful indicator to a priori set a backup rate rather than a rate at zero associated to the kiss trigger.


Subject(s)
Neuromuscular Diseases/complications , Noninvasive Ventilation/instrumentation , Respiratory Insufficiency/therapy , Ventilators, Mechanical/statistics & numerical data , Adolescent , Adult , Blood Gas Monitoring, Transcutaneous/methods , Carbon Dioxide/metabolism , Case-Control Studies , Cross-Over Studies , Dyspnea/diagnosis , Equipment Design , Female , Humans , Male , Perception , Time Factors , Ventilators, Mechanical/trends , Young Adult
4.
Crit Care ; 25(1): 327, 2021 09 08.
Article in English | MEDLINE | ID: covidwho-1403254

ABSTRACT

A helmet, comprising a transparent hood and a soft collar, surrounding the patient's head can be used to deliver noninvasive ventilatory support, both as continuous positive airway pressure and noninvasive positive pressure ventilation (NPPV), the latter providing active support for inspiration. In this review, we summarize the technical aspects relevant to this device, particularly how to prevent CO2 rebreathing and improve patient-ventilator synchrony during NPPV. Clinical studies describe the application of helmets in cardiogenic pulmonary oedema, pneumonia, COVID-19, postextubation and immune suppression. A section is dedicated to paediatric use. In summary, helmet therapy can be used safely and effectively to provide NIV during hypoxemic respiratory failure, improving oxygenation and possibly leading to better patient-centred outcomes than other interfaces.


Subject(s)
Interactive Ventilatory Support/methods , Noninvasive Ventilation/methods , Work of Breathing/physiology , COVID-19 , Humans , Monitoring, Physiologic/methods , Noninvasive Ventilation/instrumentation , Respiratory Insufficiency/therapy
5.
Chest ; 160(1): 175-186, 2021 07.
Article in English | MEDLINE | ID: covidwho-1298651

ABSTRACT

BACKGROUND: SARS-CoV-2 aerosolization during noninvasive positive-pressure ventilation may endanger health care professionals. Various circuit setups have been described to reduce virus aerosolization. However, these setups may alter ventilator performance. RESEARCH QUESTION: What are the consequences of the various suggested circuit setups on ventilator efficacy during CPAP and noninvasive ventilation (NIV)? STUDY DESIGN AND METHODS: Eight circuit setups were evaluated on a bench test model that consisted of a three-dimensional printed head and an artificial lung. Setups included a dual-limb circuit with an oronasal mask, a dual-limb circuit with a helmet interface, a single-limb circuit with a passive exhalation valve, three single-limb circuits with custom-made additional leaks, and two single-limb circuits with active exhalation valves. All setups were evaluated during NIV and CPAP. The following variables were recorded: the inspiratory flow preceding triggering of the ventilator, the inspiratory effort required to trigger the ventilator, the triggering delay, the maximal inspiratory pressure delivered by the ventilator, the tidal volume generated to the artificial lung, the total work of breathing, and the pressure-time product needed to trigger the ventilator. RESULTS: With NIV, the type of circuit setup had a significant impact on inspiratory flow preceding triggering of the ventilator (P < .0001), the inspiratory effort required to trigger the ventilator (P < .0001), the triggering delay (P < .0001), the maximal inspiratory pressure (P < .0001), the tidal volume (P = .0008), the work of breathing (P < .0001), and the pressure-time product needed to trigger the ventilator (P < .0001). Similar differences and consequences were seen with CPAP as well as with the addition of bacterial filters. Best performance was achieved with a dual-limb circuit with an oronasal mask. Worst performance was achieved with a dual-limb circuit with a helmet interface. INTERPRETATION: Ventilator performance is significantly impacted by the circuit setup. A dual-limb circuit with oronasal mask should be used preferentially.


Subject(s)
COVID-19 , Continuous Positive Airway Pressure , Disease Transmission, Infectious/prevention & control , Noninvasive Ventilation , Air Filters , Benchmarking/methods , COVID-19/therapy , COVID-19/transmission , Continuous Positive Airway Pressure/adverse effects , Continuous Positive Airway Pressure/instrumentation , Continuous Positive Airway Pressure/methods , Critical Pathways/standards , Critical Pathways/trends , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Noninvasive Ventilation/adverse effects , Noninvasive Ventilation/instrumentation , Noninvasive Ventilation/methods , Research Design , Respiratory Function Tests/methods , SARS-CoV-2 , Treatment Outcome , Ventilators, Mechanical
6.
Medicine (Baltimore) ; 100(4): e24443, 2021 Jan 29.
Article in English | MEDLINE | ID: covidwho-1298407

ABSTRACT

ABSTRACT: The main aim of this study is to compare the use of non-invasive ventilation (NIV) via helmet versus face mask where different interfaces and masks can apply NIV. However, some of the limitations of the NIV face mask were air leak, face mask intolerance, and requirement of high positive end expiratory pressure, which could be resolved with the use of the helmet NIV. NIV facemask will be applied as per the facial contour of the patient. NIV helmet is a transparent hood and size will be measured as per the head size. Both groups will have a standard protocol for titration of NIV.Patients aged more than 18 years old and diagnosed with acute respiratory distress syndrome as per Berlin definition will be enrolled in the study after signing the informed consent. Subjects who met the inclusion criteria will receive 1 of the 2 interventions; blood gases, oxygenation status [Po2/Fio2] will be monitored in both groups. The time of intubation will be the main comparison factor among the 2 groups. The primary and secondary outcomes will be measured by the number of patients requiring endotracheal intubation after application of helmet device, Improvement of oxygenation defined as PaO2/FiO2 ≥ 200 or increase from baseline by 100, duration of mechanical ventilation via an endotracheal tube, intensive care unit length of stay, death from any cause during hospitalization at the time of enrolment, need for proning during the hospital stay, intensive care unit mortality, and the degree to which overt adverse effects of a drug can be tolerated by a patient including feeding tolerance. TRIAL REGISTRATION NUMBER: NCT04507802. PROTOCOL VERSION: May 2020.


Subject(s)
Head Protective Devices , Masks , Noninvasive Ventilation/instrumentation , Respiratory Distress Syndrome/therapy , Adolescent , Adult , Clinical Trials, Phase III as Topic , Critical Care Outcomes , Female , Humans , Intensive Care Units , Length of Stay , Male , Middle Aged , Randomized Controlled Trials as Topic , Treatment Outcome , Young Adult
7.
Ther Adv Respir Dis ; 15: 17534666211019555, 2021.
Article in English | MEDLINE | ID: covidwho-1247557

ABSTRACT

BACKGROUNDS: High flow nasal cannula (HFNC) is an alternative therapy for acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19). This study aimed first to describe outcomes of patients suffering from COVID-19-related ARDS treated with HFNC; secondly to evaluate safety of HFNC (patients and healthcare workers) and compare patients according to respiratory outcome. METHODS: A retrospective cohort was conducted in French general hospital intensive care unit (ICU). Patients were included if receiving HFNC for hypoxemia (saturation pulse oxygen (SpO2) <92% under oxygen ⩾6 L/min) associated with ARDS and positive SARS-CoV-2 polymerase chain reaction (PCR). Main clinical characteristics and outcomes are described in patients: (a) with do not intubate order (HFNC-DNIO); (b) who did not need intubation (HFNC-only); and (c) eventually intubated (HFNC-intubation). Medians are presented with (1st-3rd) interquartile range. RESULTS: From 26 February to 30 June 2020, 46 patients of median age 75 (70-79) years were included. In the HFNC-DNIO group (n = 11), partial arterial oxygen pressure (PaO2)/inhaled fraction of oxygen (FiO2) ratio median worst PaO2/FiO2 ratio was 109 (102-172) and hospital mortality was 54.5%. Except the HFNC-DNIO patients (n = 35), 20 patients (57%) were eventually intubated (HFNC-intubation group) and 15 were only treated by HFNC (HFNC-only). HFNC-intubation patients presented higher worst respiratory rates per minute in ICU [37 (34-41) versus 33 (24-34) min, p < 0.05] and worsened ICU admission PaO2/FiO2 ratios [121 (103-169) versus 191 (162-219), p < 0.001] compared with HFNC-only patients. Hospital mortality was 35% (n = 7/20) in HFNC-intubation group, 0% in HFNC-only group with a global mortality of these two groups of 20% (n = 7/35). Among tests performed in healthcare workers, 1/12 PCR in symptomatic healthcare workers and 1.8% serologies in asymptomatic healthcare workers were positive. After review of each case, COVID-19 was likely to be acquired outside hospital. CONCLUSIONS: HFNC seems to be useful for COVID-19-related ARDS and safe for healthcare workers. ARDS severity with PaO2/FiO2 <150 associated with respiratory rate >35/min could be regarded as a predictor of intubation.The reviews of this paper are available via the supplemental material section.


Subject(s)
COVID-19/complications , Cannula , Noninvasive Ventilation/instrumentation , Oxygen Inhalation Therapy/instrumentation , Respiratory Distress Syndrome/therapy , Respiratory Distress Syndrome/virology , Aged , COVID-19/mortality , COVID-19/therapy , Critical Care , Female , France , Hospital Mortality , Humans , Male , Respiratory Distress Syndrome/mortality , Retrospective Studies
8.
JAMA ; 325(17): 1731-1743, 2021 05 04.
Article in English | MEDLINE | ID: covidwho-1241490

ABSTRACT

Importance: High-flow nasal oxygen is recommended as initial treatment for acute hypoxemic respiratory failure and is widely applied in patients with COVID-19. Objective: To assess whether helmet noninvasive ventilation can increase the days free of respiratory support in patients with COVID-19 compared with high-flow nasal oxygen alone. Design, Setting, and Participants: Multicenter randomized clinical trial in 4 intensive care units (ICUs) in Italy between October and December 2020, end of follow-up February 11, 2021, including 109 patients with COVID-19 and moderate to severe hypoxemic respiratory failure (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen ≤200). Interventions: Participants were randomly assigned to receive continuous treatment with helmet noninvasive ventilation (positive end-expiratory pressure, 10-12 cm H2O; pressure support, 10-12 cm H2O) for at least 48 hours eventually followed by high-flow nasal oxygen (n = 54) or high-flow oxygen alone (60 L/min) (n = 55). Main Outcomes and Measures: The primary outcome was the number of days free of respiratory support within 28 days after enrollment. Secondary outcomes included the proportion of patients who required endotracheal intubation within 28 days from study enrollment, the number of days free of invasive mechanical ventilation at day 28, the number of days free of invasive mechanical ventilation at day 60, in-ICU mortality, in-hospital mortality, 28-day mortality, 60-day mortality, ICU length of stay, and hospital length of stay. Results: Among 110 patients who were randomized, 109 (99%) completed the trial (median age, 65 years [interquartile range {IQR}, 55-70]; 21 women [19%]). The median days free of respiratory support within 28 days after randomization were 20 (IQR, 0-25) in the helmet group and 18 (IQR, 0-22) in the high-flow nasal oxygen group, a difference that was not statistically significant (mean difference, 2 days [95% CI, -2 to 6]; P = .26). Of 9 prespecified secondary outcomes reported, 7 showed no significant difference. The rate of endotracheal intubation was significantly lower in the helmet group than in the high-flow nasal oxygen group (30% vs 51%; difference, -21% [95% CI, -38% to -3%]; P = .03). The median number of days free of invasive mechanical ventilation within 28 days was significantly higher in the helmet group than in the high-flow nasal oxygen group (28 [IQR, 13-28] vs 25 [IQR 4-28]; mean difference, 3 days [95% CI, 0-7]; P = .04). The rate of in-hospital mortality was 24% in the helmet group and 25% in the high-flow nasal oxygen group (absolute difference, -1% [95% CI, -17% to 15%]; P > .99). Conclusions and Relevance: Among patients with COVID-19 and moderate to severe hypoxemia, treatment with helmet noninvasive ventilation, compared with high-flow nasal oxygen, resulted in no significant difference in the number of days free of respiratory support within 28 days. Further research is warranted to determine effects on other outcomes, including the need for endotracheal intubation. Trial Registration: ClinicalTrials.gov Identifier: NCT04502576.


Subject(s)
COVID-19/complications , Intubation, Intratracheal/statistics & numerical data , Noninvasive Ventilation/instrumentation , Oxygen Inhalation Therapy/methods , Respiratory Insufficiency/therapy , Aged , COVID-19/mortality , COVID-19/therapy , Female , Hospital Mortality , Humans , Hypoxia/etiology , Male , Middle Aged , Noninvasive Ventilation/methods , Respiratory Insufficiency/etiology , Treatment Failure
9.
Respir Med ; 185: 106474, 2021.
Article in English | MEDLINE | ID: covidwho-1240604

ABSTRACT

Hypoxemic respiratory failure is a common manifestation of COVID-19 pneumonia. Early in the COVID-19 pandemic, patients with hypoxemic respiratory failure were, at times, being intubated earlier than normal; in part because the options of heated humidified high flow nasal cannula (HFNC) and non-invasive ventilation (NIV) were considered potentially inadequate and to increase risk of virus aerosolization. To understand the benefits and factors that predict success and failure of HFNC in this population, we evaluated data from the first 30 sequential patients admitted with COVID-19 pneumonia to our center who were managed with HFNC. We conducted Cox Proportional Hazards regression models to evaluate the factors associated with high flow nasal cannula failure (outcome variable), using time to intubation (censoring variable), while adjusting for comorbidities and immunosuppression. In the majority of our patients (76.7%), the use of HFNC failed and the patients were ultimately placed on mechanical ventilation. Those at increased risk of failure had a higher sequential organ failure assessment score, and at least one comorbidity or history of immunosuppression. Our data suggest that high flow nasal cannula may have a role in some patients with COVID-19 presenting with hypoxemic respiratory failure, but careful patient selection is the likely key to its success.


Subject(s)
COVID-19/complications , Cannula/adverse effects , Noninvasive Ventilation/adverse effects , Oxygen Inhalation Therapy/adverse effects , Pandemics , Respiratory Insufficiency/therapy , Aged , Aged, 80 and over , COVID-19/epidemiology , Equipment Failure , Female , Humans , Male , Middle Aged , Noninvasive Ventilation/instrumentation , Oxygen Inhalation Therapy/instrumentation , Respiratory Insufficiency/etiology , SARS-CoV-2
10.
JAMA ; 325(17): 1731-1743, 2021 05 04.
Article in English | MEDLINE | ID: covidwho-1148761

ABSTRACT

Importance: High-flow nasal oxygen is recommended as initial treatment for acute hypoxemic respiratory failure and is widely applied in patients with COVID-19. Objective: To assess whether helmet noninvasive ventilation can increase the days free of respiratory support in patients with COVID-19 compared with high-flow nasal oxygen alone. Design, Setting, and Participants: Multicenter randomized clinical trial in 4 intensive care units (ICUs) in Italy between October and December 2020, end of follow-up February 11, 2021, including 109 patients with COVID-19 and moderate to severe hypoxemic respiratory failure (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen ≤200). Interventions: Participants were randomly assigned to receive continuous treatment with helmet noninvasive ventilation (positive end-expiratory pressure, 10-12 cm H2O; pressure support, 10-12 cm H2O) for at least 48 hours eventually followed by high-flow nasal oxygen (n = 54) or high-flow oxygen alone (60 L/min) (n = 55). Main Outcomes and Measures: The primary outcome was the number of days free of respiratory support within 28 days after enrollment. Secondary outcomes included the proportion of patients who required endotracheal intubation within 28 days from study enrollment, the number of days free of invasive mechanical ventilation at day 28, the number of days free of invasive mechanical ventilation at day 60, in-ICU mortality, in-hospital mortality, 28-day mortality, 60-day mortality, ICU length of stay, and hospital length of stay. Results: Among 110 patients who were randomized, 109 (99%) completed the trial (median age, 65 years [interquartile range {IQR}, 55-70]; 21 women [19%]). The median days free of respiratory support within 28 days after randomization were 20 (IQR, 0-25) in the helmet group and 18 (IQR, 0-22) in the high-flow nasal oxygen group, a difference that was not statistically significant (mean difference, 2 days [95% CI, -2 to 6]; P = .26). Of 9 prespecified secondary outcomes reported, 7 showed no significant difference. The rate of endotracheal intubation was significantly lower in the helmet group than in the high-flow nasal oxygen group (30% vs 51%; difference, -21% [95% CI, -38% to -3%]; P = .03). The median number of days free of invasive mechanical ventilation within 28 days was significantly higher in the helmet group than in the high-flow nasal oxygen group (28 [IQR, 13-28] vs 25 [IQR 4-28]; mean difference, 3 days [95% CI, 0-7]; P = .04). The rate of in-hospital mortality was 24% in the helmet group and 25% in the high-flow nasal oxygen group (absolute difference, -1% [95% CI, -17% to 15%]; P > .99). Conclusions and Relevance: Among patients with COVID-19 and moderate to severe hypoxemia, treatment with helmet noninvasive ventilation, compared with high-flow nasal oxygen, resulted in no significant difference in the number of days free of respiratory support within 28 days. Further research is warranted to determine effects on other outcomes, including the need for endotracheal intubation. Trial Registration: ClinicalTrials.gov Identifier: NCT04502576.


Subject(s)
COVID-19/complications , Intubation, Intratracheal/statistics & numerical data , Noninvasive Ventilation/instrumentation , Oxygen Inhalation Therapy/methods , Respiratory Insufficiency/therapy , Aged , COVID-19/mortality , COVID-19/therapy , Female , Hospital Mortality , Humans , Hypoxia/etiology , Male , Middle Aged , Noninvasive Ventilation/methods , Respiratory Insufficiency/etiology , Treatment Failure
11.
J Occup Environ Hyg ; 18(3): 118-127, 2021 03.
Article in English | MEDLINE | ID: covidwho-1066172

ABSTRACT

During the beginning of the SARS-CoV-2 pandemic, there was a shortage of masks and respirators for the protection of health care professionals. Masks for noninvasive ventilation (NIV) in combination with viral-proof filters, worn by healthcare workers, could serve as an alternative protection measure. We determined the simulated protection factor (SPF) of such devices in comparison to conventional surgical masks, N95, and FFP3 respirators. Masks and respirators were mounted on a ventilated mannequin head in a test-chamber. Isotonic saline containing 150 MBq 99mTC-DTPA (99mTc-diethylenetriamine pentaacetate (DTPA) was nebulized inside the box. The aerosol had a mass median aerodynamic diameter of 0.6 ± 0.4 µm. SPFs were measured using radioactive DTPA particles in the mannequin test system by calculating the ratio of unfiltered particles (Pu) and filtered particles (Pf) for each tested device (SPF = Pu/Pf). Simulated protection factors were 15.6 ± 3.6 for a ResMed AcuCare mask plus filter, 3.5 ± 0.2 for a ResMed Mirage Quattro FX mask plus filter, 9.5 ± 0.8 for a Loewenstein JOYCEclinc FF mask plus filter, 1.9 ± 0.2 for a surgical mask with a rubber band, 2.7 ± 0.7 for a surgical mask with ribbons, 2.3 ± 0.3 for an FFP3 respirator, and 3.6 ± 1.3 for an N95 respirator. The ResMed AcuCare and the Loewenstein JOYCEclinic FF mask were more effective than any other of the tested devices (p < 0.001). In conclusion, masks normally used for NIV with viral-proof filters can effectively filter respirable particles.


Subject(s)
COVID-19/prevention & control , Masks , Respiratory Protective Devices , Filtration/instrumentation , Manikins , N95 Respirators , Noninvasive Ventilation/instrumentation , Occupational Exposure/prevention & control , SARS-CoV-2 , Technetium Tc 99m Pentetate
12.
J Biomech ; 118: 110302, 2021 03 30.
Article in English | MEDLINE | ID: covidwho-1062446

ABSTRACT

The coronavirus disease 2019 (COVID-19) is a potentially severe acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2. The potential for transmission of this disease has led to an important scarcity of health-care resources. Consequently, alternative solutions have been explored by many physicians and researchers. Non-invasive Ventilation has been revealed as one alternative for patients with associated acute respiratory distress syndrome. This technique is being used in combination with helmet-like interfaces because of their versatility and affordability. However, these interfaces could experience important problems of CO2 rebreathing, especially under low flow rate conditions. This work proposes a Computational Fluid Dynamics method to accurately characterize the fluid flow in a pre-design environment of helmet-like interfaces. Parameters as effective dead space, rebreathing, pressure, or temperature field distribution are quantified and analysed in detail in order to study the performance and feasibility of such devices to relieve the effects of respiratory infections.


Subject(s)
COVID-19/therapy , Noninvasive Ventilation/instrumentation , Respiratory Distress Syndrome/therapy , SARS-CoV-2 , COVID-19/epidemiology , Humans , Hydrodynamics , Pandemics , Respiration
13.
Pulmonology ; 27(5): 413-422, 2021.
Article in English | MEDLINE | ID: covidwho-1057245

ABSTRACT

Helmet CPAP (H-CPAP) has been recommended in many guidelines as a noninvasive respiratory support during COVID-19 pandemic in many countries around the world. It has the least amount of particle dispersion and air contamination among all noninvasive devices and may mitigate the ICU bed shortage during a COVID surge as well as a decreased need for intubation/mechanical ventilation. It can be attached to many oxygen delivery sources. The MaxVenturi setup is preferred as it allows for natural humidification, low noise burden, and easy transition to HFNC during breaks and it is the recommended transport set-up. The patients can safely be proned with the helmet. It can also be used to wean the patients from invasive mechanical ventilation. Our article reviews in depth the pathophysiology of COVID-19 ARDS, provides rationale of using H-CPAP, suggests a respiratory failure algorithm, guides through its setup and discusses the issues and concerns around using it.


Subject(s)
COVID-19/therapy , Continuous Positive Airway Pressure/instrumentation , Noninvasive Ventilation/instrumentation , Respiratory Insufficiency/therapy , Ventilator Weaning/methods , COVID-19/diagnosis , COVID-19/physiopathology , COVID-19/transmission , Head Protective Devices , Humans , Noninvasive Ventilation/methods , Oxygen Inhalation Therapy/instrumentation , Oxygen Inhalation Therapy/methods , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/nursing , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification
14.
Expert Rev Med Devices ; 17(11): 1211-1220, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-1003456

ABSTRACT

Background: The current SARS-CoV-2 pandemic has provoked the collapse of some health systems due to insufficient intensive care unit capacity. The use of continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) therapies has been limited in consideration of the risk of occupational infection in health-care professionals. Aims: In preclinical experimental simulations, evaluate occupational and environmental safety of the newly developed isolation system for aerosol-transmitted infections (ISATI). Method: Simulations were conducted to test ISATI's capability to isolate aerosolized molecular (caffeine), and biological (SARS-CoV-2 synthetic RNA) markers. Caffeine deposition was analyzed on nitrocellulose sensor discs by proton nuclear magnetic resonance spectroscopy. Synthetic SARS-CoV-2 detection was performed by reverse transcription-polymerase chain reaction. Results: ISATI demonstrated efficacy in isolating molecular and biological markers within the enclosed environment in simulated conditions of CPAP, HFNO and mechanical ventilation therapy. Neither the molecular marker nor substantial amounts of synthetic SARS-CoV-2 RNA were detected in the surrounding environment, outside ISATI, indicating appropriate occupational safety for health-care professionals. Conclusion: Aerosolized markers were successfully contained within ISATI in all experimental simulations, offering occupational and environmental protection against the dissemination of aerosolized microparticles under CPAP or HFNO therapy conditions, which are indicated for patients with acute respiratory infections.


Subject(s)
COVID-19/therapy , Noninvasive Ventilation , Aerosols , Continuous Positive Airway Pressure/instrumentation , Continuous Positive Airway Pressure/methods , Health Personnel , Humans , Noninvasive Ventilation/instrumentation , Noninvasive Ventilation/methods , Oxygen , Oxygen Inhalation Therapy , SARS-CoV-2
15.
Air Med J ; 40(1): 16-19, 2021.
Article in English | MEDLINE | ID: covidwho-986987

ABSTRACT

Helmet-based noninvasive ventilation (NIV) is a viable option for the safe transport of potential or known coronavirus disease 2019 patients. Given the most likely modes of transmission through droplets, aerosols, and fomite contact, airway procedures such as endotracheal intubation place air medical crews and other health care providers at high risk for exposure. This, together with data that suggest that a large cohort of coronavirus disease 2019 patients have better outcomes if we can avoid intubating them, creates a need for a safe method of NIV or high-flow oxygen delivery during transport. Commonly used and successful in-hospital regimens for these patients are high-flow nasal cannula and continuous positive airway pressure or bilevel positive airway pressure. In some studies, helmet NIV has been shown to be a viable, if not superior, alternative to these therapies for patients with acute hypoxemic respiratory failure. Furthermore, because it is a sealed and closed space that completely isolates the patient's airway and breathing, it provides a very high degree of protection from exposure to pathogens transmitted through droplets or aerosols. This article discusses practical implementation of helmet NIV in air medical transport.


Subject(s)
Air Ambulances , COVID-19/therapy , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Noninvasive Ventilation/instrumentation , COVID-19/transmission , Humans , Noninvasive Ventilation/methods
16.
Artif Organs ; 45(7): 754-761, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-978685

ABSTRACT

Noninvasive continuous positive airway pressure (NIV-CPAP) is effective in patients with hypoxemic respiratory failure. Building evidence during the COVID-19 emergency reported that around 50% of patients in Italy treated with NIV-CPAP avoided the need for invasive mechanical ventilation. Standard NIV-CPAP systems operate at high gas flow rates responsible for noise generation and inadequate humidification. Furthermore, open-configuration systems require a high concentration of oxygen to deliver the desired FiO2 . Concerns outlined the risk for aerosolization in the ambient air and the possible pressure drop in hospital supply pipes. A new NIV-CPAP system is proposed that includes automatic control of patient respiratory parameters. The system operates as a closed-loop breathing circuit that can be assembled, combining a sleep apnea machine with existing commercially available components. Analytical simulation of a breathing patient and simulation with a healthy volunteer at different FiO2 were performed. Inspired and expired oxygen fraction and inspired and expired carbon dioxide pressure were recorded at different CPAP levels with different oxygen delivery. Among the main findings, we report (a) a significant (up to 30-fold) reduction in oxygen feeding compared to standard open high flow NIV-CPAP systems, to assure the same FiO2 levels, and (b) a negligible production of the noise generated in ventilatory systems, and consequent minimization of patients' discomfort. The proposed NIV-CPAP circuit, reshaped in closed-loop configuration with the blower outside of the circuit, has the advantages of minimizing aerosol generation, environmental contamination, oxygen consumption, and noise to the patient. The system is easily adaptable and can be implemented using standard CPAP components.


Subject(s)
COVID-19/therapy , Continuous Positive Airway Pressure/instrumentation , Lung/virology , Noise/prevention & control , Noninvasive Ventilation/instrumentation , Oxygen/administration & dosage , SARS-CoV-2/pathogenicity , Ventilators, Mechanical , Aerosols , COVID-19/physiopathology , COVID-19/transmission , COVID-19/virology , Computer Simulation , Continuous Positive Airway Pressure/adverse effects , Equipment Design , Filtration/instrumentation , Humans , Lung/physiopathology , Noise/adverse effects , Noninvasive Ventilation/adverse effects , Numerical Analysis, Computer-Assisted , Oxygen/adverse effects
17.
Am J Emerg Med ; 39: 158-161, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-838183

ABSTRACT

BACKGROUND: Initial recommendations discouraged high flow nasal cannula (HFNC) in COVID-19 patients, driven by concern for healthcare worker (HCW) exposure. Noting high morbidity and mortality from early invasive mechanical ventilation, we implemented a COVID-19 respiratory protocol employing HFNC in severe COVID-19 and HCW exposed to COVID-19 patients on HFNC wore N95/KN95 masks. Utilization of HFNC increased significantly but questions remained regarding HCW infection rate. METHODS: We performed a retrospective evaluation of employee infections in our healthcare system using the Employee Health Services database and unit records of employees tested between March 15, 2020 and May 23, 2020. We assessed the incidence of infections before and after the implementation of the protocol, stratifying by clinical or non-clinical role as well as inpatient COVID-19 unit. RESULTS: During the study period, 13.9% (228/1635) of employees tested for COVID-19 were positive. Forty-six percent of infections were in non-clinical staff. After implementation of the respiratory protocol, the proportion of positive tests in clinical staff (41.5%) was not higher than that in non-clinical staff (43.8%). Of the clinicians working in the high-risk COVID-19 unit, there was no increase in infections after protocol implementation compared with clinicians working in COVID-19 units that did not use HFNC. CONCLUSION: We found no evidence of increased COVID-19 infections in HCW after the implementation of a respiratory protocol that increased use of HFNC in patients with COVID-19; however, these results are hypothesis generating.


Subject(s)
COVID-19/epidemiology , COVID-19/therapy , Health Personnel/statistics & numerical data , Noninvasive Ventilation/methods , Occupational Diseases/epidemiology , Cannula , Humans , Massachusetts/epidemiology , Noninvasive Ventilation/instrumentation , Occupational Exposure , Retrospective Studies , Tertiary Care Centers
18.
Eur J Cancer ; 138: 109-112, 2020 10.
Article in English | MEDLINE | ID: covidwho-739806
19.
Am J Emerg Med ; 46: 276-281, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-684311

ABSTRACT

BACKGROUND: The use of high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) in patients with COVID-19 is debated. METHODS: This study was performed in four hospitals of China from January to March 2020. We retrospectively enrolled 23 and 13 COVID-19 patients who used HFNC and NIV as first-line therapy, respectively. RESULTS: Among the 23 patients who used HFNC as first-line therapy, 10 experienced HFNC failure and used NIV as rescue therapy. Among the 13 patients who used NIV as first-line therapy, one (8%) used HFNC as rescue therapy due to NIV intolerance. The duration of HFNC + NIV (median 7.1, IQR: 3.5-12.2 vs. 7.3, IQR: 5.3-10.0 days), intubation rate (17% vs. 15%) and mortality (4% vs. 8%) did not differ between patients who used HFNC and NIV as first-line therapy. In total cohorts, 6 (17%) patients received intubation. Time from initiation of HFNC or NIV to intubation was 8.4 days (IQR: 4.4-18.5). And the time from initiation of HFNC or NIV to termination in patients without intubation was 7.1 days (IQR: 3.9-10.3). Among all the patients, C-reactive protein was independently associated with intubation (OR = 1.04, 95% CI: 1.01-1.07). In addition, no medical staff got nosocomial infection who participated in HFNC and NIV management. CONCLUSIONS: In critically ill patients with COVID-19 who used HFNC and NIV as first-line therapy, the duration of HFNC + NIV, intubation rate and mortality did not differ between two groups. And no medical staff got nosocomial infection during this study.


Subject(s)
COVID-19/therapy , Cannula/statistics & numerical data , Noninvasive Ventilation/instrumentation , Oxygen Inhalation Therapy/instrumentation , Aged , COVID-19/epidemiology , China/epidemiology , Equipment Design , Female , Humans , Male , Middle Aged , Pandemics , SARS-CoV-2
20.
Paediatr Respir Rev ; 35: 61-63, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-608739

ABSTRACT

There are significant logistical challenges to providing respiratory support devices, beyond simple oxygen flow, when centres run out of supplies or do not have these devices at all, such as in low resource settings. At the peak of the COVID-19 crisis, it was extremely difficult to import medical equipment and supplies, because most countries prohibited the medical industry from selling outside of their own countries. As a consequence, engineering teams worldwide volunteered to develop emergency devices, and medical experts in mechanical ventilation helped to guide the design and evaluation of prototypes. Although regulations vary among countries, given the emergency situation, some Regulatory Agencies facilitated expedited procedures. However, laboratory and animal model testing are crucial to minimize the potential risk for patients when treated with a device that may worsen clinical outcome if poorly designed or misused.


Subject(s)
Continuous Positive Airway Pressure/instrumentation , Coronavirus Infections/therapy , Medical Device Legislation , Pneumonia, Viral/therapy , Respiratory Distress Syndrome/therapy , Respiratory Insufficiency/therapy , Ventilators, Mechanical/supply & distribution , Betacoronavirus , COVID-19 , Device Approval , Education, Professional, Retraining , Equipment Design , Equipment and Supplies/supply & distribution , Humans , Noninvasive Ventilation/instrumentation , Pandemics , Personnel Staffing and Scheduling , Respiration, Artificial/instrumentation , SARS-CoV-2 , Spain
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