High-flow Nasal Therapy Research Articles

Physiological effects of standard oxygen therapy, high-flow nasal cannula, and helmet CPAP in acute bronchiolitis: a randomized cross-over study

ObjectivesAcute viral bronchiolitis (AVB) is a major cause of hospitalization for children in developed and developing countries. Nasal high flow (NHF) therapy improves oxygenation and reduces respiratory drive by enhancing carbon dioxide wash-out. However, little is known about the physiological effects of non-invasive helmet continuous positive airway pressure (h-CPAP) and NHF on respiratory work of breathing (WOB) in pediatric patients with AVB. The present study measured esophageal pressure time product over 1 min (PTPes*min−1), as a close surrogate for WOB during standard oxygen therapy (SOT), NHF delivered at incremental flow rates, and h-CPAP in hospitalized patients with AVB.MethodsThis is a physiological randomized crossover study with four 20-min steps: SOT delivered by a Venturi mask; NHF2 set at 2L/kg*min−1PBW; NHF3 set at 3L/kg*min−1PBW; and h-CPAP with PEEP 7 cmH2O. PTPes *min−1, pressure rate product (PRP), respiratory and other physiological parameters were collected towards the end of each step.ResultsTen hypoxemic children with AVB were enrolled. PTPes*min−1, respiratory rate (RR), PRP, and heart rate (HR) decreased progressively from h-CPAP to NHF3, NHF2, and SOT (p < 0.01). Transcutaneous carbon dioxide tension (tcCO2) was lower during h-CPAP, NHF3, and NHF2 than during SOT (p < 0.001). SpO2:FiO2 was higher during h-CPAP than with all other support (p < 0.01).ConclusionsIn pediatric patients with AVB, h-CPAP was associated with lower WOB, better oxygenation, and lower tcCO2 than with SOT and NHF trials.Trial registrationClinicaltrials.gov NCT03689686 Registered 1 August 2018.

COVID-19 in Patients with Pre-Existing Interstitial Lung Disease: Potential Value of a Steroid-Based Treatment Strategy.

The prognosis of patients with coronavirus disease 2019 (COVID-19) and pre-existing interstitial lung disease (preILD) is poor, and no effective treatment strategy has been determined. The aim of this study was to assess the effectiveness of a steroid-based treatment strategy for patients with COVID-19 and preILD. We retrospectively reviewed the medical records of 610 consecutive patients with COVID-19 treated at our institution between 1 March 2020 and 30 October 2021 and identified 7 patients with preILD, all of whom were treated with corticosteroids and remdesivir. All the patients were men with a median age of 63 years. Three of four patients with severe disease required invasive positive-pressure ventilation (n = 2) or nasal high-flow therapy (n = 1). All three patients could be weaned from respiratory support; however, one died in hospital. The remaining patient with severe COVID-19 had a do-not-resuscitate order in place and died while hospitalized. All three patients with moderate COVID-19 were discharged. The 30-day mortality was 0%, and the mortality rate during the entire observation period was 28.5%. The prognosis of our patients with COVID-19 and preILD has been better than in previous reports. Our management strategy using corticosteroids may have improved these patients' prognosis.

Organisation, staffing and resources of critical care units in Kenya.

To describe the organisation, staffing patterns and resources available in critical care units in Kenya. The secondary objective was to explore variations between units in the public and private sectors. An online cross-sectional survey was used to collect data on organisational characteristics (model of care, type of unit, quality- related activities, use of electronic medical records and participation in the national ICU registry), staffing and available resources for monitoring, ventilation and general critical care. The survey included 60 of 75 identified units (80% response rate), with 43% (n = 23) located in government facilities. A total of 598 critical care beds were reported with a median of 6 beds (interquartile range [IQR] 5-11) per unit, with 26% beds (n = 157) being non functional. The proportion of ICU beds to total hospital beds was 3.8% (IQR 1.9-10.4). Most of the units (80%, n = 48) were mixed/general units with an open model of care (60%, n = 36). Consultants-in-charge were mainly anesthesiologists (69%, n = 37). The nurse-to-bed ratio was predominantly 1:2 with half of the nurses formally trained in critical care. Most units (83%, n = 47) had a dedicated ventilator for each bed, however 63% (n = 39) lacked high flow nasal therapy. While basic multiparametric monitoring was ubiquitous, invasive blood pressure measurement capacity was low (3% of beds, IQR 0-81%), and capnography moderate (31% of beds, IQR 0-77%). Blood gas analysers were widely available (93%, n = 56), with 80% reported as functional. Differences between the public and private sector were narrow. This study shows an established critical care network in Kenya, in terms of staffing density, availability of basic monitoring and ventilation resources. The public and private sector are equally represented albeit with modest differences. Potential areas for improvement include training, use of invasive blood pressure and functionality of blood gas analysers.

In preterm infants, how does nasal high-flow (nHF) therapy compare with continuous positive airway pressure (CPAP) or with nasal intermittent positive pressure ventilation (NIPPV)?

In preterm infants, how does nasal high-flow (nHF) therapy compare with continuous positive airway pressure (CPAP) or with nasal intermittent positive pressure ventilation (NIPPV)?

State of the art on neonatal noninvasive respiratory support: How physiological and technological principles explain the clinical outcomes.

Noninvasive respiratory support has gained significant popularity in neonatal units because of its potential to reduce lung injury associated with invasive mechanical ventilation. To minimize lung injury, clinicians aim to apply fornoninvasive respiratory support as early as possible. However, the physiological background and the technology behind such support modes are not always clear, and many open questions remain regarding the indications of use and clinical outcomes. This narrative review discusses the currently available evidence for various noninvasive respiratory support modes applied in Neonatal Medicine in terms of physiological effects and indications. Reviewed modes include nasal continuous positive airway pressure, nasal high-flow therapy, noninvasive high-frequency oscillatory ventilation, nasal intermittent positive pressure ventilation (NIPPV), synchronized NIPPV and noninvasive neurally adjusted ventilatory assist. To enhance clinicians' awareness of each support mode's strengths and limitations, we summarize technical features related to the functioning mechanisms of devices and the physical properties of the interfaces commonly used for providing noninvasive respiratory support to neonates. We finally address areas of current controversy and suggest possible areas of research for implementing noninvasive respiratory support in neonatal intensive care units.

International Survey of High-Flow Nasal Therapy Use for Respiratory Failure in Adult Patients.

(1) Background: High-flow nasal therapy (HFNT) has shown several benefits in addressing respiratory failure. However, the quality of evidence and the guidance for safe practice are lacking. This survey aimed to understand HFNT practice and the needs of the clinical community to support safe practice. (2) Method: A survey questionnaire was developed and distributed to relevant healthcare professionals through national networks in the UK, USA and Canada; responses were collected between October 2020 and April 2021. (3) Results: In the UK and Canada, HFNT was used in 95% of hospitals, with the highest use being in the emergency department. HNFT was widely used outside of a critical care setting. HFNT was mostly used to treat acute type 1 respiratory failure (98%), followed by acute type 2 respiratory failure and chronic respiratory failure. Guideline development was felt to be important (96%) and urgent (81%). Auditing of practice was lacking in 71% of hospitals. In the USA, HFNT was broadly similar to UK and Canadian practice. (4) Conclusions: The survey results reveal several key points: (a) HFNT is used in clinical conditions with limited evidence; (b) there is a lack of auditing; (c) it is used in wards that may not have the appropriate skill mix; and (d) there is a lack of guidance for HFNT use.

Same but Different? Comparing the Epidemiology, Treatments and Outcomes of COVID-19 and Non-COVID-19 ARDS Cases in Germany Using a Sample of Claims Data from 2021 and 2019.

Acute respiratory distress syndrome (ARDS) is a severe lung condition that can be caused by a variety of underlying illnesses. Due to SARS-CoV-2, the number of cases with ARDS has increased worldwide, making it essential to compare this form of acute respiratory failure with classical causes of ARDS. While there have been several studies investigating the differences between COVID-19 and non-COVID-19 ARDS in early stages of the pandemic, little is known about the differences in later phases, especially in Germany. The aim of this study is to characterize and compare the comorbidities, treatments, adverse events, and outcomes of COVID-19-associated ARDS and non-COVID-19 ARDS using a representative sample of German health claims data from the years 2019 and 2021. We compare percentages and median values of the quantities of interest from the COVID-19 and non-COVID-19 ARDS group, with p-values calculated after conducting Pearson's chi-squared test or the Wilcoxon rank sum test. We also run logistic regressions to access the effect of comorbidities on mortality for COVID-19 ARDS and non-COVID-19 ARDS. Despite many similarities, we find that that there are some remarkable differences between COVID-19 and non-COVID-19 ARDS cases in Germany. Most importantly, COVID-19 ARDS cases display fewer comorbidities and adverse events, and are more often treated with non-invasive ventilation and nasal high-flow therapy. This study highlights the importance of comprehending the contrasting epidemiological features and clinical outcomes of COVID-19 and non-COVID-19 ARDS. This understanding can aid in clinical decision making and guide future research initiatives aimed at enhancing the management of patients afflicted with this severe condition.

Nasal high flow therapy for primary respiratory support in preterm infants.

Nasal high flow therapy for primary respiratory support in preterm infants.

PO-1388 Clinical implementation and evaluation of liver SBRT in breath-hold using nasal high flow therapy

PO-1388 Clinical implementation and evaluation of liver SBRT in breath-hold using nasal high flow therapy

Comparison of High Flow Nasal Therapy with Non-Invasive Ventilation and Conventional Oxygen Therapy for Acute Hypercapnic Respiratory Failure: A Meta-Analysis of Randomized Controlled Trials.

We aimed to evaluate whether high flow nasal cannula (HFNC) is an effective and safe method for adult patients with acute hypercapnic respiratory failure (AHRF). We searched the Cochrane Library, Embase, and PubMed databases from inception to August 2022 to obtain randomized controlled trials (RCTs) that compared HFNC with conventional oxygen treatment (COT) or non-invasive ventilation (NIV) in patients with AHRF, and then performed a meta-analysis. A total of ten parallel RCTs with 1265 individuals were identified. Of them, two studies compared HFNC with COT and eight studies compared HFNC with NIV. In terms of intubation rate, mortality, and arterial blood gas (ABG) improvement, HFNC showed comparable effects to NIV and COT. However, HFNC was more comfortable (mean difference [MD] -1.87, 95% confidence interval [CI] =-2.59, -1.15, P <0.00001, I2 =0%) and resulted in fewer adverse events (odds ratio [OR] 0.12, 95% CI=0.06, 0.28, P<0.00001, I2 = 0%), compared with NIV. In comparison to NIV, HFNC could significantly lower heart rate (HR) (MD -4.66, 95% CI=-6.82, -2.50, P <0.0001, I2 =0%), respiratory rate (RR) (MD -1.17, 95% CI=-2.03, -0.31, P =0.008, I2 =0%), and hospital stay length (MD -0.80, 95% CI=-1.44, -0.16, P =0.01, I2 =0%). NIV showed a decreased frequency in the treatment crossover rate, compared with HFNC in patients with pH<7.30 (OR 5.78, 95% CI=1.50, 22.31, P = 0.01, I2: not applicable). Contrary to COT, HFNC could considerably reduce the need for NIV (OR 0.57, 95% CI=0.35, 0.91, P=0.02, I2=0%). HFNC was effective and safe in patients with AHRF. However, in patients with pH <7.30, HFNC may result in a higher incidence of treatment crossover, compared with NIV. Compared to COT, HFNC may decrease the need for NIV in patients with compensated hypercapnia.

Chest Physiotherapy Interventions for Children During SARS-COV-2 Pandemic.

Since the first case of Severe Acute Respiratory Syndrome Coronavirus-2/Coronavirus Disease 2019 (SARS-COV-2/COVID-19) was discovered in Wuhan, China, it spread to vast limits globally and became a public health disaster, affecting nearly all countries around the globe. Along with mainstream medical treatment, alternative medicine desperately was the need of the hour for youngsters to manage their symptoms while being self-quarantined and ultimately to improve their chances of survival and recovery from COVID-19. Since the beginning of SARS-COV-2, few studies address the clinical-functional presentation of viral infection and management with physiotherapy for children. Major online electronic databases PubMed, PEDro, and Google Scholar were researched to identify, organize and commission the current review. To create a search strategy, Medical Subject Headings and Descriptors of Science and Health were utilized. The authors looked for other studies by screening the references list of the potentially pertinent papers. These computerized searches turned up studies and those studies' bibliographies with pertinent citations were examined. Personal protective equipment was a crucial component for protection and contact precaution. Following hypoxia, effective oxygen therapy is administered right away. When necessary, under the right circumstances, nasal high-flow oxygen therapy, non-invasive ventilation, lung-protective breathing methods, and prone positioning can be used. Children with SARS-CoV-2/COVID-19 may benefit from physiotherapy interventions with a focus on ventilatory management, airway clearance procedures, early activities, and mobilization.

Optimizing Tracheal Oxygen Tension and Diffusion Ratio When Choosing High-Flow Oxygen Therapy or CPAP for the Treatment of Hypoxemic Respiratory Failure: Insights from Ex Vivo Physiologic Modelling.

This article is a review of the physiological and technological processes underpinning high-flow nasal therapy with oxygen (HFNT or HFOT) for the treatment of hypoxemic respiratory failure. A mathematical model was carefully built to represent the relationships between the settings on the HFNT device and the resultant diffusion of oxygen into hypoxemic, arterial blood. The analysis was used to recommend a strategy for setting the flow rate at or above the patient's peak inspiratory flow when HFNT is used with a blender and equal to the patient's peak inspiratory rate when bleed-in oxygen is used. The analysis also teaches how to titrate the settings to achieve a desired fraction of inhaled oxygen, (FiO2), in the trachea using a simple ratio when bleed-in oxygen is used. The model was used to compare HFNT as a method to improve oxygen diffusion efficacy with other forms of oxygen therapy. The analysis in this article relates the efficacy of HFOT/HFNT to that of CPAP with supplemental oxygen by computing the diffusion ratio of oxygen therapy versus breathing room air. We predicted that in non-atelectatic lungs, when considering oxygenation, HFNT can be equally effective as CPAP with supplemental oxygen therapy for treating hypoxemic respiratory failure.

High-Flow Nasal Therapy in Acute and Chronic Respiratory Failure: Past, Present, and Future

High-flow nasal therapy (HFNT) was introduced into clinical practice in the early 2000s as a form of noninvasive respiratory support (NIRS) [...].

Impact of high- and low-flow nebulised saline on airway hydration and mucociliary transport.

Nebulised drugs, including osmotic agents and saline, are increasingly used during noninvasive respiratory support, including nasal high-flow therapy. The authors conducted an in vitro study to compare the hydration effect of nebulised isotonic 0.9% and hypertonic 7.0% saline on mucociliary transport. In a perfused organ bath, 10 sheep tracheas were exposed to 7.5 mL nebulised 0.9% and 7.0% saline entrained into heated (38°C) and humidified air delivered at high and low flow (20 and 7 L·min-1, respectively). Simultaneous measurements of the airway surface liquid height, mucus transport velocity, cilia beat frequency and surface temperature were made over time. The data are presented as mean±sd. The airway surface liquid height increased significantly with both 0.9% and 7.0% saline: at low-flow by 37.2±10.0 µm and 152.7±10.9 µm, respectively, and at high-flow by 62.3±5.6 µm and 163.4±25.4 µm, respectively (p<0.001). Mucus velocity was increased by both 0.9% and 7.0% saline from a baseline of 8.2±0.8 mm·min-1 to 8.8±0.7 mm·min-1 and 17.1±0.5 mm·min-1, respectively, with low-flow and at high-flow to 9.8±0.02 mm·min-1 (p=0.04) and 16.9±0.5 mm·min-1 (p<0.05), respectively. Ciliary beating did not change with 0.9% saline, but declined from 13.1±0.6 Hz to 10.2±0.6 Hz and 11.1±0.6 Hz (p<0.05) with 7.0% saline at low- and high-flow, respectively. The findings demonstrate that nebulised isotonic 0.9% saline, like hypertonic 7.0% saline, significantly stimulates basal mucociliary transport, and the use of high-flow delivery had no significantly different hydration effects compared with low-flow delivery. Hypertonic 7.0% saline suppressed ciliary beating, indicating an increase in airway surface liquid osmolarity, which may have negative effects on the airway surface with frequent use.

Radiotherapy for mediastinal lymphoma in breath hold using surface monitoring and nasal high flow oxygen: Clinical experiences and breath hold stability

PurposeIn this study we describe the clinical introduction and evaluation of radiotherapy in mediastinal lymphoma in breath hold using surface monitoring combined with nasal high flow therapy (NHFT) to prolong breath hold duration. Materials and methods11 Patients with mediastinal lymphoma were evaluated. 6 Patients received NHFT, 5 patients were treated in breath hold without NHFT. Breath hold stability as measured by a surface scanning system was evaluated, as well as internal movement based on cone beam computed tomography (CBCT) before and after treatment. Based on internal movement, margins were determined. In a parallel planning study we compared free breathing plans with breath hold plans using the determined margins. ResultsAverage inter breath hold stability was 0.6 mm for NHFT treatments, and 0.5 mm for non-NHFT treatments (p > 0.1). Intra breath hold stability was 0.8 vs. 0.6 mm (p > 0.1) on average. Using NHFT, average breath hold duration increased from 34 s to 60 s (p < 0.01). Residual CTV motion derived from CBCTs before and after each fraction was 2.0 mm for NHFT vs 2.2 mm for non-NHFT (p > 0.1). Combined with inter-fraction motion, a uniform mediastinal margin of 5 mm appears to be sufficient. In breath hold, mean lung dose is reduced by 2.6 Gy (p < 0.001), while mean heart dose is reduced by 2.0 Gy (p < 0.001). ConclusionTreatment of mediastinal lymphoma in breath hold is feasible and safe. The addition of NHFT approximately increases breath hold durations with a factor two while stability is maintained. By reducing breathing motion, margins can be decreased to 5 mm. A considerable dose reduction in heart, lungs, esophagus, and breasts can be achieved with this method.

Effect of High-Flow Nasal Oxygenation on Gastric Insufflation in Patients Undergoing Laryngeal Microsurgery under Tubeless General Anesthesia with Neuromuscular Blockade

High-flow nasal oxygenation is an oxygen delivery method by which high concentrations of heated humidified oxygen are supplied via the nasal cavity. This study aimed to investigate the effect of high-flow nasal oxygenation on gastric volume change in adult patients undergoing laryngeal microsurgery under tubeless general anesthesia with neuromuscular blockade. Patients aged 19-80 years with an American Society of Anesthesiologists physical status 1 or 2 who were scheduled to undergo laryngoscopic surgery under general anesthesia were recruited. Patients received high-flow nasal oxygenation therapy at 70 L/min during surgery under general anesthesia with neuromuscular blockade. The cross-sectional area of the gastric antrum was measured via ultrasound in the right lateral position before and after high-flow nasal oxygenation, and the gastric volume was calculated. The duration of apnea, i.e., the duration of administration of high-flow nasal oxygenation in the paralyzed state, was also recorded. Of the 45 patients enrolled, 44 completed the study. There were no significant differences in the antral cross-sectional area in the right lateral position, gastric volume, and gastric volume per kg between before and after high-flow nasal oxygenation application. The median duration of apnea was 15 (interquartile range, 14-22) min. High-flow nasal oxygenation at 70 L/min during apnea with the mouth open did not influence the gastric volume in patients undergoing laryngeal microsurgery under tubeless general anesthesia with neuromuscular blockade.

Aerosol delivery through high-flow nasal therapy: Technical issues and clinical benefits.

High-flow nasal cannula (HFNC) therapy is an oxygen delivery method particularly used in patients affected by hypoxemic respiratory failure. In comparison with the conventional "low flow" oxygen delivery systems, it showed several important clinical benefits. The possibility to nebulize drugs via HFNC represents a desirable medical practice because it allows the administration of inhaled drugs, mostly bronchodilators, without the interruption or modification of the concomitant oxygen therapy. HFNC, by itself has shown to exert a small but significant bronchodilator effect and improves muco-ciliary clearance; thus, the nebulization of bronchodilators through the HFNC circuit may potentially increase their pharmacological activity. Several technical issues have been observed which include the type of the nebulizer that should be used, its position within the HFNC circuit, and the optimal gas flow rates to ensure an efficient drug delivery to the lungs both in "quiet" and "distressed" breathing patterns. The aim of this review has been to summarize the scientific evidence coming from "in vitro" studies and to discuss the results of "in vivo" studies performed in adult subjects, mainly affected by obstructive lung diseases. Most studies seem to indicate the vibrating mesh nebulizer as the most efficient type of nebulizer and suggest to place it preferentially upstream from the humidifier chamber. In a quite breathing patterns, the inhaled dose seems to increase with lower flow rates while in a "distressed" breathing pattern, the aerosol delivery is higher when gas flow was set below the patient's inspiratory flow, with a plateau effect seen when the gas flow reaches approximately 50% of the inspiratory flow. Although several studies have demonstrated that the percentage of the loaded dose nebulized via HFNC reaching the lungs is small, the bronchodilator effect of albuterol seems not to be impaired when compared to the conventional inhaled delivery methods. This is probably attributed to its pharmacological activity. Prospective and well-designed studies in different cohort of patients are needed to standardize and demonstrate the efficacy of the procedure.

A case study on how nasal high-flow treatment helps prevent the recurrence of surgical atelectasis by providing respiratory support

Background: Preventing postoperative atelectasis in surgical patients with impaired pulmonary function is preferable. This study presented a case in which the use of nasal high flow treatment to assist the respiratory system prevented the recurrence of postoperative atelectasis. Case Presentation: An urgent laparoscopic procedure was performed on a 68-year-old man who had a perforation in his upper digestive tract. The patient appeared undernourished because of his severe, uncontrolled diabetes mellitus. The scheduled surgery was completed without incident. On the fifth postoperative day, the patient exhibited acute atelectasis of the left lower lobe, with an oxygen saturation of 89%. When tracheal suction and postural draining restored normal oxygenation, positive-pressure ventilation at 8 cm H2O airway pressure was employed to stop recurring atelectasis. On the seventh postoperative day, 15 hours after positive pressure breathing ended, the patient suffered a relapse of acute atelectasis. Once bronchoscopy was utilized to remove a mucous plaque from the tracheobronchial tree, nasal high flow treatment at a rate of 40 l/minute was employed to deliver a modest dose of continuous positive airway pressure rather than positive pressure breathing. The respiratory rehabilitation continued without a hitch, and his health was more stable with nasal high flow therapy&amp;apos;s breathing support than it was with positive pressure ventilation. The nasal high flow therapy also provided gas that was sufficiently humidified, which improved the bronchial secretion. There was no new atelectasis throughout the remainder of the patient&amp;apos;s stay in the intensive care unit. Conclusion: Respiratory support with nasal high flow treatment might help to prevent postoperative atelectasis by providing continuous positive airway pressure in conjunction with progressive respiratory rehabilitation.

EBNEO Commentary: Nasal high-flow therapy during neonatal endotracheal intubation.

EBNEO Commentary: Nasal high-flow therapy during neonatal endotracheal intubation.

Long-Term Domiciliary High-Flow Nasal Therapy in Patients with Bronchiectasis: A Preliminary Retrospective Observational Case-Control Study.

This is a retrospective bicentric case-control study of outpatients with BE on optimized medical treatment with a severe exacerbation requiring hospitalization in the previous year. Patients on long-term home HFNT (cases) and patients on optimized medical treatment alone (controls) were matched by age, sex, bronchiectasis severity index, and exacerbations in the previous year. Data on BE exacerbations, hospitalizations/year, mucus features, respiratory symptoms, and pulmonary function were collected. The primary outcome was the change from baseline in the exacerbation rates at 12 months between groups. 20 patients in the HFNT group and 20 controls were included. A significant reduction in exacerbations [-1.9 (-2.8 to -0.9), p = 0.0005] and hospitalizations [-0.7 (-1.1 to -0.3), p = 0.0006] was found in the HFNT group vs controls. A slight improvement in pulmonary function [FEV1% +6,1% (+1% to +11.3%) (p = 0.0219), FVC% +4.6% (+0.8% to +8.3%) (p = 0.0188) and FEF25-75% +13.4 (+11 to +15.9) (p = 0.0189) was also found in the HFNT group compared to controls. In this preliminary study, long-term domiciliary HFNT improved the clinical course of patients with BE.