Respiratory Support Devices Research Articles

Use of a gas-operated ventilator as a noninvasive bridging respiratory therapy in critically Ill COVID-19 patients in a middle-income country.

During the COVID-19 pandemic, there was a notable undersupply of respiratory support devices, especially in low- and middle-income countries. As a result, many hospitals turned to alternative respiratory therapies, including the use of gas-operated ventilators (GOV). The aim of this study was to describe the use of GOV as a noninvasive bridging respiratory therapy in critically ill COVID-19 patients and to compare clinical outcomes achieved with this device to conventional respiratory therapies. Retrospective cohort analysis of critically ill COVID-19 patients during the first local wave of the pandemic. The final analysis included 204 patients grouped according to the type of respiratory therapy received in the first 24h, as follows: conventional oxygen therapy (COT), n = 28 (14%); GOV, n = 72 (35%); noninvasive ventilation (NIV), n = 49 (24%); invasive mechanical ventilation (IMV), n = 55 (27%). In 72, GOV served as noninvasive bridging respiratory therapy in 42 (58%) of these patients. In the other 30 patients (42%), 20 (28%) presented clinical improvement and were discharged; 10 (14%) died. In the COT and GOV groups, 68% and 39%, respectively, progressed to intubation (P ≤ 0.001). Clinical outcomes in the GOV and NIV groups were similar (no statistically significant differences). GOV was successfully used as a noninvasive bridging respiratory therapy in more than half of patients. Clinical outcomes in the GOV group were comparable to those of the NIV group. These findings support the use of GOV as an emergency, noninvasive bridging respiratory therapy in medical crises when alternative approaches to the standard of care may be justifiable.

Aerosol drug therapy in critically ill patients (Aero-in-ICU study): A multicentre prospective observational cohort study.

In recent years, a significant understanding of delivering optimal aerosol therapy and the availability of various drugs and devices have led to an increase in its use in clinical practice. There are only a few studies available regarding their use in critically ill patients from a few parts of the world. We aimed to study the practice pattern of aerosol therapy in critically ill patients from Indian intensive care units (ICUs). After ethical approval, this multi-centric prospective observational study was performed over a study period of four weeks. Newly admitted adult patients considered who had an artificial airway and/or ventilation (including non-invasive). Patients were followed up for the next 14 days or until ICU discharge/death (whichever came first) for details of each aerosol therapy, including ongoing respiratory support, drug type, and aerosol-generating device. From the nine participating centers across India, 218 patients were enrolled. Of 218 enrolled patients, 72.48% received 4884 aerosols with 30.91 ± 27.15 (95%CI: 26.6-35.1) aerosols per patient over 1108 patient days. Approximately 62.7% during IMV, 30.2% during NIV, 2.3% in spontaneously breathing patients with an artificial airway during weaning, and 4.7% were given without an artificial airway after weaning or decannulation. In 59%, a single drug was used, and bronchodilators were the most frequent. The jet nebulizer was the most common, followed by the ultrasonic and vibrating mesh aerosol generator. The ventilator setting was changed in only 6.6% of the aerosol sessions with IMV and none with NIV. Aerosol therapy is frequently used with a wide variation in practices; bronchodilators are the most commonly used drugs, and jet nebulizers are the most widely used.

Ongoing exposure to endocrine disrupting phthalates and alternative plasticizers in neonatal intensive care unit patients

Due to endocrine disrupting effects, di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices, was restricted in the EU Medical Devices Regulation (EU MDR 2017/745) and gradually replaced by alternative plasticizers. Neonates hospitalized in the neonatal intensive care unit (NICU) are vulnerable to toxic effects of plasticizers. From June 2020 to August 2022, urine samples (n = 1070) were repeatedly collected from premature neonates (n = 132, 4–10 samples per patient) born at <31 weeks gestational age and/or <1500 g birth weight in the Antwerp University Hospital, Belgium. Term control neonates (n = 21, 1 sample per patient) were included from the maternity ward. Phthalate and alternative plasticizers’ metabolites were analyzed using liquid-chromatography coupled to tandem mass spectrometry. Phthalate metabolites were detected in almost all urine samples. Metabolites of alternative plasticizers, di-(2-ethylhexyl)-adipate (DEHA), di-(2-ethylhexyl)-terephthalate (DEHT) and cyclohexane-1,2-dicarboxylic-di-isononyl-ester (DINCH), had detection frequencies ranging 30–95 %. Urinary phthalate metabolite concentrations were significantly higher in premature compared to control neonates (p = 0.023). NICU exposure to respiratory support devices and blood products showed increased phthalate metabolite concentrations (p < 0.001). Phthalate exposure increased from birth until four weeks postnatally. The estimated phthalate intake exceeded animal-derived no-effect-levels (DNEL) in 10 % of samples, with maximum values reaching 24 times the DNEL. 29 % of premature neonates had at least once an estimated phthalate intake above the DNEL. Preterm neonates are still exposed to phthalates during NICU stay, despite the EU Medical Devices Regulation. NICU exposure to alternative plasticizers is increasing, though currently not regulated, with insufficient knowledge on their hazard profile.

Asymmetrical high-flow nasal cannula performs similarly to standard interface in patients with acute hypoxemic post-extubation respiratory failure: a pilot study

BackgroundStandard high-flow nasal cannula (HFNC) is a respiratory support device widely used to manage post-extubation hypoxemic acute respiratory failure (hARF) due to greater comfort, oxygenation, alveolar recruitment, humidification, and reduction of dead space, as compared to conventional oxygen therapy. On the contrary, the effects of the new asymmetrical HFNC interface (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) is still under discussion. Our aim is investigating whether the use of asymmetrical HFNC interface presents any relevant difference, compared with the standard configuration, on lung aeration (as assessed by end-expiratory lung impedance (EELI) measured by electrical impedance tomography (EIT)), diaphragm ultrasound thickening fraction (TFdi) and excursion (DE), ventilatory efficiency (estimated by corrected minute ventilation (MV)), gas exchange, dyspnea, and comfort.MethodsPilot physiological crossover randomized controlled study enrolling 20 adults admitted to the Intensive Care unit, invasively ventilated for at least 24 h, and developing post-extubation hARF, i.e., PaO2/set FiO2 < 300 mmHg during Venturi mask (VM) within 120 min after extubation. Each HFNC configuration was applied in a randomized 60 min sequence at a flow rate of 60 L/min.ResultsGlobal EELI, TFdi, DE, ventilatory efficiency, gas exchange and dyspnea were not significantly different, while comfort was greater during asymmetrical HFNC support, as compared to standard interface (10 [7–10] and 8 [7–9], p-value 0.044).ConclusionsIn post-extubation hARF, the use of the asymmetrical HFNC, as compared to standard HFNC interface, slightly improved patient comfort without affecting lung aeration, diaphragm activity, ventilatory efficiency, dyspnea and gas exchange.Clinical trial numberClinicalTrial.gov. Registration number: NCT05838326 (01/05/2023).New & noteworthyThe asymmetrical high-flow nasal cannula oxygen therapy (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) provides greater comfort as compared to standard interface; while their performance in term of lung aeration, diaphragm activity, ventilatory efficiency, dyspnea, and gas exchange is similar.

A Novel CPAP Device With an Integrated Oxygen Concentrator for Low Resource Countries: In Vitro Validation and Usability Test in Field.

Goal: To develop and validatea novel neonatal non-invasive respiratory support device prototype designed to operate in low-resource settings. Methods: The device integrates a blower-based ventilator and a portable oxygen concentrator. A novel control algorithm was designed to achieve the desired fraction of inspired oxygen (FiO2) while minimizing power consumption. The accuracy of the delivered FiO2 and the device power consumption were evaluated in vitro, and a formative usability test was conducted in a rural hospital in Uganda. Results: The agreement between the set and delivered FiO2 was high (limit of agreement:-5.6 ÷ 3.8%). For FiO2 below 60%, the control algorithm reduced the power drain by 50%. The device was also appreciated by intended users. Conclusion: The prototype proved effective in delivering oxygen-enriched continuous positive airway pressure in the absence of compressed air and oxygen, holding promise for a sustainable and effective implementation of neonatal respiratory support in low-resource settings.

Determining the incidence and risk factors of medical device-related pressure injury in intensive care patients

AimThis study aims to determine the incidence and risk factors of Medical Device-Related Pressure Injury (MDRPI) in Intensive Care Unit (ICU) patients. Material and methodsThis descriptive cross-sectional study involved 300 patients who did not have an MDRPI at the time of admission to the ICU of a university hospital in Turkey. The data was collected using the Patient Information Form, the Medical Device-Related Pressure Injury Follow-Up Chart, and the Jackson/Cubbin Risk Assessment Scale. ResultsThe mean age of the patients was 71.88 ± 14.82 years old. Precisely 31% of patients were found to be at risk for pressure injuries, and MDRPI occurred in 18% of them. It was found that patients most commonly experienced stage 1 MDRPI in the hand-finger region due to pulse oximetry. It was also determined that nasal cannulas caused MDRPI the fastest. Patients with MDRPI had low Jackson/Cubbin scores, low albumin and hematocrit levels, and longer hospitalization durations (p < .05). Dependence on -respiratory support device, bedridden, and experiencing non-device-related pressure injuries were associated with MDRPI (p < .05). ConclusionIt was found that factors causing non-device-related pressure injuries may also pose an MDRPI risk for patients in intensive care. It was also observed that devices used in ICU could cause pressure injuries even in very short periods in cases where necessary precautions are not taken. Periodic evaluation of the area the medical devices are in contact with, removal of unused devices as quickly as possible, and the use of prophylactic dressings can play an important role in preventing MDRPI.

A New Global Definition of Acute Respiratory Distress Syndrome.

Background: Since publication of the 2012 Berlin definition of acute respiratory distress syndrome (ARDS), several developments have supported the need for an expansion of the definition, including the use of high-flow nasal oxygen, the expansion of the use of pulse oximetry in place of arterial blood gases, the use of ultrasound for chest imaging, and the need for applicability in resource-limited settings. Methods: A consensus conference of 32 critical care ARDS experts was convened, had six virtual meetings (June 2021 to March 2022), and subsequently obtained input from members of several critical care societies. The goal was to develop a definition that would 1) identify patients with the currently accepted conceptual framework for ARDS, 2) facilitate rapid ARDS diagnosis for clinical care and research, 3) be applicable in resource-limited settings, 4) be useful for testing specific therapies, and 5) be practical for communication to patients and caregivers. Results: The committee made four main recommendations: 1) include high-flow nasal oxygen with a minimum flow rate of ⩾30 L/min; 2) use PaO2:FiO2 ⩽ 300 mm Hg or oxygen saturation as measured by pulse oximetry SpO2:FiO2 ⩽ 315 (if oxygen saturation as measured by pulse oximetry is ⩽97%) to identify hypoxemia; 3) retain bilateral opacities for imaging criteria but add ultrasound as an imaging modality, especially in resource-limited areas; and 4) in resource-limited settings, do not require positive end-expiratory pressure, oxygen flow rate, or specific respiratory support devices. Conclusions: We propose a new global definition of ARDS that builds on the Berlin definition. The recommendations also identify areas for future research, including the need for prospective assessments of the feasibility, reliability, and prognostic validity of the proposed global definition.

Hair as an alternative matrix to assess exposure of premature neonates to phthalate and alternative plasticizers in the neonatal intensive care unit

Due to adverse health effects, di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices (PMDs), was restricted, and gradually replaced by alternative plasticizers (APs). Up to this date, urine was the sole matrix studied for plasticizer exposure in neonates hospitalized in the neonatal intensive care unit (NICU), a population highly vulnerable to toxic effects of plasticizers. The primary aim of this study was to assess simultaneous measurement of phthalate and AP metabolites in neonatal scalp hair. In addition, we aimed to use this matrix to investigate exposure of premature neonates to plasticizers during their stay in the NICU.Hair samples in this study were collected from premature neonates and their mothers included in a prospective birth cohort study in a tertiary NICU at the Antwerp University Hospital (UZA), Belgium. Samples from premature neonates (n = 45) and their mothers (n = 107) as well as from control neonates (n = 24) and mothers (n = 29) were analyzed using liquid-chromatography coupled to tandem mass spectrometry.This is the first study reporting metabolites of phthalate and alternative plasticizers in neonatal hair samples as biomarkers for exposure to these plasticizers. Results showed that hair sampled from premature neonates after a NICU stay contained significantly higher metabolite concentrations of both phthalates (DEHP, DiBP, and DnBP; 9.0–2500, 9.3–2200, and 24.7–5300 ng/g), and alternative plasticizers (DEHA, DEHT, and TOTM; 38.8–3400, 127.5–5700, and 10.8–8700 ng/g) – when compared to healthy control neonates. Besides, DEHP and DEHT metabolite concentrations were significantly higher than in hair sampled from adult populations. In addition, prolonged NICU exposure to non-invasive respiratory support devices and gastric tubes was correlated with increased concentrations in hair samples, indicating accumulation of plasticizers in this alternative matrix.In conclusion, our data indicate that preterm neonates are still highly exposed to phthalate and alternative plasticizers during NICU stay, despite the EU Medical Devices Regulation.

Aerosol therapy in adult critically ill patients: a consensus statement regarding aerosol administration strategies during various modes of respiratory support

BackgroundClinical practice of aerosol delivery in conjunction with respiratory support devices for critically ill adult patients remains a topic of controversy due to the complexity of the clinical scenarios and limited clinical evidence.ObjectivesTo reach a consensus for guiding the clinical practice of aerosol delivery in patients receiving respiratory support (invasive and noninvasive) and identifying areas for future research.MethodsA modified Delphi method was adopted to achieve a consensus on technical aspects of aerosol delivery for adult critically ill patients receiving various forms of respiratory support, including mechanical ventilation, noninvasive ventilation, and high-flow nasal cannula. A thorough search and review of the literature were conducted, and 17 international participants with considerable research involvement and publications on aerosol therapy, comprised a multi-professional panel that evaluated the evidence, reviewed, revised, and voted on recommendations to establish this consensus.ResultsWe present a comprehensive document with 20 statements, reviewing the evidence, efficacy, and safety of delivering inhaled agents to adults needing respiratory support, and providing guidance for healthcare workers. Most recommendations were based on in-vitro or experimental studies (low-level evidence), emphasizing the need for randomized clinical trials. The panel reached a consensus after 3 rounds anonymous questionnaires and 2 online meetings.ConclusionsWe offer a multinational expert consensus that provides guidance on the optimal aerosol delivery techniques for patients receiving respiratory support in various real-world clinical scenarios.

Reported Complications of Bubble Continuous Positive Airway Pressure Systems in Low-Resource Settings: An International Survey.

Lower respiratory tract infections (LRTIs) are the leading cause of death in young children globally. Most of the global burden of mortality from LRTIs occurs in low-resource settings (LRSs), where obtaining and maintaining respiratory support devices such as commercial bubble continuous positive airway pressure (bCPAP) can be prohibitive. Low-cost bCPAP devices exist, such as the homemade WHO-style bCPAP design, but the safety of this design has been called into question. Based on our team's experience with homemade bCPAP, the side effects of the high pressures described in recent studies are not commonly encountered. Therefore, we sought feedback via an international survey about various complications including pneumothorax from practitioners in LRSs who use two forms of homemade bCPAP. In our qualitative survey, we did not find a convincing pattern in the recall of complications between commercial bCPAP and homemade bCPAP with narrow- or wide-bore expiratory limb in neonates or older children.

High flow nasal oxygen in frail COVID-19 patients hospitalized in intermediate care units and non-eligible to invasive mechanical ventilation

BackgroundIn COVID-19 patients, older age (sixty or older), comorbidities, and frailty are associated with a higher risk for mortality and invasive mechanical ventilation (IMV) failure. It therefore seems appropriate to suggest limitations of care to older and vulnerable patients with severe COVID-19 pneumonia and a poor expected outcome, who would not benefit from invasive treatment. HFNO (high flow nasal oxygen) is a non-invasive respiratory support device already used in de novo acute respiratory failure. The main objective of this study was to evaluate the survival of patients treated with HFNO outside the ICU (intensive care unit) for a severe COVID-19 pneumonia, otherwise presenting limitations of care making them non-eligible for IMV. Secondary objectives were the description of our cohort and the identification of prognostic factors for HFNO failure. MethodsWe conducted a retrospective cohort study. We included all patients with limitations of care making them non-eligible for IMV and treated with HFNO for a severe COVID-19 pneumonia, hospitalized in a COVID-19 unit of the pulmonology department of Lyon Sud University Hospital, France, from March 2020 to March 2021. Primary outcome was the description of the vital status at day-30 after HFNO initiation, using the WHO (World Health Organization) 7-points ordinal scale. ResultsFifty-six patients were included. Median age was 83 years [76.3–87.0], mean duration for HFNO was 7.5 days, 53% had a CFS score (Clinical Frailty Scale) >4. At day-30, 73% of patients were deceased, one patient (2%) was undergoing HFNO, 9% of patients were discharged from hospital. HFNO failure occurred in 66% of patients. Clinical signs of respiratory failure before HFNO initiation (respiratory rate >30/min, retractions, and abdominal paradoxical breathing pattern) were associated with mortality (p = 0.001). ConclusionsWe suggest that HFNO is an option in non-ICU skilled units for older and frail patients with a severe COVID-19 pneumonia, otherwise non-suitable for intensive care and mechanical ventilation. Observation of clinical signs of respiratory failure before HFNO initiation was associated with mortality.

Leaching of Phthalates from Medical Supplies and Their Implications for Exposure.

In this study, 72 single-use medical products, grouped into four categories, namely, creams/liquids (n = 8), medical devices (n = 46; 15 of 46 labeled "di(2-ethylhexyl)phthalate (DEHP)-free"), first aid products (n = 13), and intravenous (IV) infusion/irrigation fluids (n = 5), were collected from an intensive care unit in a hospital in New York State in 2015 and analyzed for the migration of 10 phthalates in ethanol/water (1:1) mixture for 1 h. The total phthalate concentration (Σphthalates) leached from medical products ranged from 0.04 to 54,600 μg. DEHP was the major phthalate found in 99% of the samples analyzed, with the highest amount leached from respiratory support devices (median: 6560 μg). DEHP was also found at notable concentrations in products labeled as "DEHP-free". Direct exposure to phthalates from the use of medical devices and first aid supplies and dermal intake from the use of creams/lotions were calculated. The highest DEHP exposure dose of 730 μg/kg bw/day was determined from the use of cannula for neonates. This is the first study to document the amount of phthalates leached from various medical supplies and associated exposures.

Detection of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in the air near patients using noninvasive respiratory support devices

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Bubble CPAP respiratory support devices for infants in low-resource settings.

Approximately 46% of the 5.2 million annual under-5 deaths derive from neonatal conditions commonly associated with hypoxemia or acute respiratory distress. It has been estimated that 98% of these deaths occur in low- and middle-income countries (LMICs).Effective implementation of noninvasive respiratory support at all levels of healthcare could significantly reduce neonatal mortality. Several factors limit the widespread and effective implementation of noninvasive respiratory support in LMICs, including inadequate infrastructure, lack of proper instrumentation, shortage of skilled staff, costly disposables, and difficulties in the supply of consumables and spare parts. The aim of this state-of-the-art paper is to provide a detailed evaluation of the commercially available devices providing noninvasive respiratory support in LMICs, focusing on bubblecontinuous positive airway pressure(bCPAP). bCPAP might be administrated using a variety of different commercial devices, including devices specifically designed for LMICs, as well as using self-made systems. We described all the equipment required for safe and effective implementation of bCPAP, including air and oxygen sourced, pressure-reducing valves and flowmeters, air-oxygen blending systems, humidifiers, respiratory support devices, patient circuits, and airway interfaces. Specifically, we critically evaluated the advantages and disadvantages of various existing solutions within the context of low-resource settings.

Abstract 9704: Role of Arterial Blood Gas Variables in the Prognostication of Patients With Acute Decompensated Heart Failure Admitted to Cardiac Intensive Care Unit

Introduction: Several risk factors and scores have been studied to predict in-hospital mortality [IHM] and rehospitalization [RH] in patients with AHF. Hypothesis: The impact of the initial therapies implemented for AHF on the variables of the acid base gases (ABG) has not been evaluated for prognostication of IHM and RH. Methods: We prospectively evaluated 216 patients admitted in CICU with AHF from 2015 to 2021. Demographic, clinical and ABG variables were analyzed on admission and at 24 hours. Patients were grouped according to whether they presented improvement in respiratory failure, defined as improvement in SaO2, PaO2 and PaCO2 as well as de-escalation of respiratory support devices (NIV or high flow). The aim of the study was to identify whether the improvement in ABG variables, O2 requirement or respiratory support within 24 hours of admission is associated with lower IHM and RH at 60 days. Data was analyzed using bivariate and multivariate analyzes by logistic regression. Results: Mean age was 75 years (44% female), normal EF 62% and reduced 38%. Mean NT-pro-BNP was 9280 ng/dl. RH at 60 days was 25% and IHM was 8.7%. Mean PaO2 on admission was 75 mmHg and at 24 hours 82 mmHg, PaCO2 on admission was 38 mmHg and at 24 hours 40 mmHg, mean SaO2 on admission was 94% and at 24 hours 95%. In bivariate analysis, the highest elevation of the PaCO2 on admission as well as PaCO2 at 24 hours were identified as predictors of IHM (38.42 vs 40.26 mmHg, p = 0.025) and (40.17 vs 46.84 mmHg, p = 0.002) respectively. In multivariate analysis, AKI on CKD (p = 0.03), cardiogenic shock (p = &lt;0.0001), acute myocardial infarction (p = &lt;0.004), emergency PCI (p = &lt;0.001), NIV failure (p = &lt;0.001), NT-pro-BNP (p = &lt;0.01), and elevated PaCO2 at 24 hours (p = 0.02) were identified as independent predictors for IHM. No association between the improvement in ABG variables and RH at 60 days was found. Conclusions: The lack of improvement in PaCO2 at 24 hours of admission to CICU for AHF identifies patients at higher risk for IHM. However, there was no association between the improvement ABG variables at 24 hours and the RH for AHF.

Frequency and Correlates of Pediatric High-Flow Nasal Cannula Use for Bronchiolitis, Asthma, and Pneumonia.

Heated humidified high-flow nasal cannula (HFNC) is a respiratory support device historically used in pediatrics for infants with bronchiolitis. No large-scale analysis has determined the current frequency or demographic distribution of HFNC use in children. The objective of this study was to determine the frequency and correlates of HFNC use in children presenting to the hospital for asthma, bronchiolitis, or pneumonia. This longitudinal observational study was based on electronic health record data from a large regional health information exchange, the Indiana Network for Patient Care (INPC). Subjects were age 0-18 y with recorded hospital encounters at an INPC hospital between 2010-2019 with International Classification of Diseases codes for bronchiolitis, asthma, or pneumonia. Annual proportions of HFNC use among all hospital encounters were assessed using generalized additive models. Log-binomial regression models were used to identify correlates of incident HFNC use and determine risk ratios of specific subjects receiving HFNC. The study sample included 242,381 unique subjects with 412,712 hospital encounters between 2010-2019. The 10-y period prevalence of HFNC use was 2.54% (6,155/242,381) involving 7,974 encounters. Hospital encounters utilizing HFNC increased by 400%, from 326 in 2010 to 1,310 in 2019. This increase was evenly distributed across all 3 diagnostic categories (bronchiolitis, asthma, and pneumonia). Sex, race, age, and ethnicity all significantly influenced the risk of HFNC use. Over the 10-y period, the percentage of all hospital encounters using HFNC increased from 1.11% in 2010 to 3.15% in 2018. Subjects with multiple diagnoses had significantly higher risk of receiving HFNC. The use of HFNC in children presenting to the hospital with common respiratory diseases has increased substantially over the past decade and is no longer confined to treating infants with bronchiolitis. Demographic and diagnostic factors significantly influenced the frequency of HFNC use.

A Quantitative Study of Particle Dispersion due to Respiratory Support Modalities in PC-12 Aircraft: Prehospital Patient Transport

ObjectiveIt is unclear whether supplemental oxygen and noninvasive ventilation respiratory support devices increase the dispersion of potentially infectious bioaerosols in a pressurized air medical cabin. This study quantitatively compared particle dispersion from respiratory support modalities in an air medical cabin during flight. MethodsDispersion was measured in a fixed wing air ambulance during flight with a breathing medical mannequin simulator exhaling nebulized saline from the lower respiratory tract with the following respiratory support modalities: a nasal cannula with a surgical mask, high-flow nasal oxygen (HFNO) with a surgical mask, and noninvasive bilevel positive airway pressure (BiPAP) ventilation. ResultsNasal cannula oxygen with a surgical mask was associated with the highest particle concentrations. In the absence of mask seal leaks, BiPAP was associated with 1 order of magnitude lower particle concentration compared with a nasal cannula with a surgical mask. Particle concentrations associated with HFNO with a surgical mask were lower than a nasal cannula with a surgical mask but higher than BiPAP. ConclusionsParticle dispersion associated with the use of BiPAP and HFNO with a surgical mask is lower than nasal cannula oxygen with a surgical mask. These findings may assist air medical organizations with operational decisions where little data exist about respiratory particle dispersion.

A Simplified Adult Expiratory Support Device: First Clinical Cases in a Low-Resource Setting

PurposeIn low and middle-income countries, mechanical ventilators or commercially available devices used to offer continuous positive airway pressure are not readily affordable and available. In Ghana, nearly 10% of critically ill patients presenting to the emergency department require ventilator support. DescriptionWe designed, built, and tested a simple expiratory positive airway pressure (EPAP) device to provide adult respiratory support in low resource environments with or without supplemental oxygen and without the need for electricity. EvaluationLaboratory tests demonstrated that the device is capable of delivering EPAP at levels expected to provide significant assistance to some patients. We present the first 2 cases where the use of this simple EPAP device provided critical respiratory support during weaning of patients from mechanical ventilation. ConclusionsA low-cost 3-dimensional printable adult respiratory support device could provide substantial benefit to patients suffering from respiratory distress through the delivery of appropriate levels of EPAP in a low-resource setting with limited infrastructure. Further clinical validation is needed for broader application in low-resource settings.

High-Flow Nasal Cannula and COVID-19: A Clinical Review.

During the coronavirus disease 2019 (COVID-19) pandemic, noninvasive respiratory support has played a central role in managing patients affected by moderate-to-severe acute hypoxemic respiratory failure, despite inadequate scientific evidence to support its usage. High-flow nasal cannula (HFNC) treatment has gained popularity because of its effectiveness in delivering a high fraction of humidified oxygen, which improves ventilatory efficiency and the respiratory pattern, as well as its reported high tolerability, ease of use, and application outside of ICUs. Nevertheless, the risk of infection transmission to health-care workers has raised some concerns about its use in the first wave of the pandemic outbreak, with controversial recommendations provided by different scientific societies. This narrative review provides an overview of the recent evidence on the physiologic rationale, risks, and benefits of using HFNC instead of conventional oxygen therapy and other types of noninvasive respiratory support devices, such as continuous positive airway pressure and noninvasive ventilation in patients affected by COVID-19 pneumonia with associated acute hypoxemic respiratory failure. It also summarizes the available evidence with regard to the clinical use of HFNC during the current pandemic and its reported outcomes, and highlights the risks of bioaerosol dispersion associated with HFNC use.

Automation of oxygen titration in preterm infants: Current evidence and future challenges

For the preterm infant with respiratory insufficiency requiring supplemental oxygen, tight control of oxygen saturation (SpO2) is advocated, but difficult to achieve in practice. Automated control of oxygen delivery has emerged as a potential solution, with six control algorithms currently embedded in commercially-available respiratory support devices. To date, most clinical evaluations of these algorithms have been short-lived crossover studies, in which a benefit of automated over manual control of oxygen titration has been uniformly noted, along with a reduction in severe SpO2 deviations and need for manual FiO2 adjustments. A single non-randomised study has examined the effect of implementation of automated oxygen control with the CLiO2 algorithm as standard care for preterm infants; no clear benefits in relation to clinical outcomes were noted, although duration of mechanical ventilation was lessened. The results of randomised controlled trials are awaited. Beyond the gathering of evidence regarding a treatment effect, we contend that there is a need for a better understanding of the function of contemporary control algorithms under a range of clinical conditions, further exploration of techniques of adaptation to individualise algorithm performance, and a concerted effort to apply this technology in low resource settings in which the majority of preterm infants receive care. Attainment of these goals will be paramount in optimisation of oxygen therapy for preterm infants globally.