Effectiveness of high flow nasal Cannula (HFNC) therapy compared to standard oxygen therapy (SOT) and continuous positive airway pressure (CPAP) in bronchiolitis.

High Flow Nasal Cannula therapy (HFNC) is a form of respiratory support for bronchiolitis. Recent evidence confirms HFNC reduces the risk of treatment escalation by nearly half (45%) compared to standard oxygen therapy (SOT), although most patients (75%) with mild-moderate respiratory distress manage well on SOT. The majority of children (60%) failing SOT respond well to HFNC making rescue use of HFNC a more cost-effective approach compared to its first-line use. HFNC is compared toCPAP in the setting of moderate to severe bronchiolitis. Patients on HFNC have a slightly elevated risk of treatment failure especially in severe bronchiolitis, but this does not translate to a significant difference in patient or healthcare centred outcomes. HFNC has improved tolerance, a lower complication rate and is more easily available in peripheral hospitals. It is therefore the preferred first line option followed by rescue CPAP. HFNC is clinically effective and safe to use in bronchiolitis of all severities.

The impact of an autonomous nurse-led high-flow nasal cannula oxygen protocol on clinical outcomes of infants with bronchiolitis.

OBJECTIVE: To investigate the relationship of the implementation of a nurse-led high-flow nasal cannula oxygen protocol on the clinical outcomes of infants with bronchiolitis in a regional paediatric unit. BACKGROUND: Bronchiolitis is a common lower respiratory illness and is the leading cause for hospitalisation of infants globally. Standard care involves the provision of supportive measures. Historically, supplemental oxygen was provided by low-flow nasal cannula. High-flow nasal cannula oxygen has been increasingly adopted despite limited evidence of its efficacy. METHODS: This study employed non-equivalent, post-implementation only design to explore clinical outcomes of infants with bronchiolitis admitted for high-flow nasal cannula oxygen therapy. The study compared infants in the 24 months before and after the initiation of a high-flow nasal cannula protocol. The primary clinical outcome was length of stay, secondary outcomes included time on high flow, weaning time, escalation of care and time outside of physiological parameters. Implementation strategy evaluation was measured by compliance with applying the protocol, reported as episodes of variance, and duration of variance. The StaRI checklist was selected as the most appropriate reporting guideline. RESULTS: A total of 80 patients were admitted with bronchiolitis and received high-flow nasal cannula oxygen therapy during a 48-month period; 37 patients were prior, and 43 after, the introduction of a nurse-led high-flow nasal cannula protocol. Length of stay was significantly reduced in the post-implementation group compared to the historical control group (83.8 vs. 61.3 h). Time on high flow and weaning time was decreased in the post-implementation group compared to the control group (33.5 vs. 26.7 h and 26 vs.12.25 h, respectively); however, these did not reach statistical significance. There was varied application of the HFNC protocol. CONCLUSIONS: The implementation of a nurse-led high-flow nasal cannula protocol was associated with a reduced length of stay. RELEVANCE TO CLINICAL PRACTICE: This study demonstrated that infants with bronchiolitis that were treated with a nurse-led high-flow nasal cannula (HFNC) therapy protocol had positive effects on clinical outcomes including a shorter length of stay than compared with those with physician-directed care in a regional paediatric unit. A weight-based (2 L/kg) HFNC therapy was safely administered to infants with bronchiolitis in a regional hospital paediatric ward with no paediatric intensive care unit (PICU).

Efficacy of prophylactic high-flow nasal cannula therapy for postoperative pulmonary complications after pediatric cardiac surgery: a prospective single-arm study.

PURPOSE: This study investigated the incidence of postoperative pulmonary complications (PPC) when high-flow nasal cannula therapy (HFNC) is used prophylactically after pediatric cardiac surgery, and evaluated its efficacy. METHODS: This was a single-arm prospective interventional study that was conducted in a tertiary teaching hospital with eight beds in the pediatric cardiac ICU after approval by the Ethics Committee. One-hundred children under the age of 48 months who were scheduled for cardiac surgery for congenital heart disease were recruited. HFNC was used for 24 h after extubation at a 2 L/kg/min flow rate. The primary outcome was the incidence of PPC within 48 h after extubation. PPC was defined as atelectasis and acute respiratory failure meeting certain criteria. We considered prophylactic HFNC as effective if the prevalence of PPC was < 10%, based on previous reports of reintubation rates of 6%-9% after pediatric cardiac surgery. RESULTS: A total of 91 patients were finally included in the analysis. The incidence of PPC within 48 h after extubation was 18.7%, whereas atelectasis was observed in 13.2%, and acute respiratory failure in 8.8%. Reintubation rate within 48 h after extubation was 0%. CONCLUSIONS: We found the incidence of PPC with prophylactic HFNC after planned extubation after pediatric cardiac surgery. However, the incidence was > 10%; therefore, we could not demonstrate its efficacy in this single-arm study. Further studies are needed to investigate whether the HFNC could be adapted as first-line oxygen therapy after pediatric cardiac surgery.

Efficacy of high-flow nasal cannula therapy in bedridden patients.

BACKGROUND: A growing number of studies have demonstrated the efficacy of high-flow nasal cannula therapy (HFNC) for treating children with acute respiratory distress. However, it remains unknown whether HFNC is effective in bedridden patients with acute respiratory distress. METHOD: We retrospectively reviewed the medical records of bedridden patients with acute respiratory distress who were treated with HFNC using a home ventilator in continuous positive airway pressure mode at our center between March 2014 and August 2016. We assessed heart rate, respiratory rate, oxygen saturation measured using a pulse oximeter, the partial pressure of venous carbon dioxide, or the transcutaneous partial pressure of carbon dioxide, and symptoms of respiratory distress before and after the initiation of HFNC. RESULTS: During the 2-year-study period, 25 patients were treated with HFNC. The patients' mean heart rate, respiratory rate, oxygen saturation measured using a pulse oximeter, and pressure of venous carbon dioxide/the transcutaneous partial pressure of carbon dioxide values improved significantly (P < 0.05). Symptoms of respiratory distress were considerably ameliorated at 1-3 h after the HFNC initiation, except in two patients. In these two patients, the HFNC was replaced with non-invasive positive pressure ventilation. Non-invasive positive pressure was also required at 16 to 168 h after the initiation of HFNC in five of the 28 episodes in which the patient was initially responsive to HFNC, as the patients' respiratory symptoms gradually deteriorated. CONCLUSION: Performing HFNC with a home ventilator in continuous positive airway pressure mode is effective at treating bedridden patients with acute respiratory distress. However, it is essential that the HFNC can be switched to non-invasive positive pressure if needed.

High-flow nasal cannula therapy reduced the respiratory rate and respiratory distress in a standard model simulator and in patients with hypoxemic respiratory failure.

High-flow nasal cannula (HFNC) therapy has been increasingly applied to treat patients with severe hypoxemic respiratory failure. We investigated whether vital signs reflect the reduction of work of breathing in a simulator study and a clinical study. In the simulator study, a standard model high-fidelity human patient simulator (HPS) directly received 35 L/minute of 100% O2 via the HFNC. In the clinical study, the medical records of patients with hypoxemic respiratory failure who received HFNC therapy between January 2013 and May 2015 were retrospectively reviewed. Statistical analysis was performed using a one-way repeated analysis of variance followed by Bonferroni post-hoc testing. In the HPS, HFNC therapy significantly reduced the partial pressure of alveolar CO2, respiratory rate, and tidal volume (p < 0.001), and all values returned to baseline following HFNC therapy termination (p < 0.001). In the clinical study including 48 patients, the respiratory rate was significantly reduced from 27 ± 9 (baseline) to 24 ± 8 (3 hours), 24 ± 8 (5 hours), and 24 ± 8.0 (6 hours) (p < 0.05). The heart rate also decreased significantly (p < 0.05). Our results suggested that HFNC therapy reduced work of breathing and assessing vital signs can be important.

FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): a multicentre pilot randomised controlled trial of high-flow nasal cannula therapy versus continuous positive airway pressure in paediatric critical care.

BACKGROUND: Although high-flow nasal cannula therapy (HFNC) has become a popular mode of non-invasive respiratory support (NRS) in critically ill children, there are no randomised controlled trials (RCTs) comparing it with continuous positive airway pressure (CPAP). We performed a pilot RCT to explore the feasibility, and inform the design and conduct, of a future large pragmatic RCT comparing HFNC and CPAP in paediatric critical care. METHODS: In this multi-centre pilot RCT, eligible patients were recruited to either Group A (step-up NRS) or Group B (step-down NRS). Participants were randomised (1:1) using sealed opaque envelopes to either CPAP or HFNC as their first-line mode of NRS. Consent was sought after randomisation in emergency situations. The primary study outcomes were related to feasibility (number of eligible patients in each group, proportion of eligible patients randomised, consent rate, and measures of adherence to study algorithms). Data were collected on safety and a range of patient outcomes in order to inform the choice of a primary outcome measure for the future RCT. RESULTS: Overall, 121/254 eligible patients (47.6%) were randomised (Group A 60%, Group B 44.2%) over a 10-month period (recruitment rate for Group A, 1 patient/site/month; Group B, 2.8 patients/site/month). In Group A, consent was obtained in 29/33 parents/guardians approached (87.9%), while in Group B 84/118 consented (71.2%). Intention-to-treat analysis included 113 patients (HFNC 59, CPAP 54). Most reported adverse events were mild/moderate (HFNC 8/59, CPAP 9/54). More patients switched treatment from HFNC to CPAP (Group A: 7/16, 44%; Group B: 9/43, 21%) than from CPAP to HFNC (Group A: 3/13, 23%; Group B: 5/41, 12%). Intubation occurred within 72 h in 15/59 (25.4%) of HFNC patients and 10/54 (18.5%) of CPAP patients (p = 0.38). HFNC patients experienced fewer ventilator-free days at day 28 (Group A: 19.6 vs. 23.5; Group B: 21.8 vs. 22.2). CONCLUSIONS: Our pilot trial confirms that, following minor changes to consent procedures and treatment algorithms, it is feasible to conduct a large national RCT of non-invasive respiratory support in the paediatric critical care setting in both step-up and step-down NRS patients. TRIAL REGISTRATION: clinicaltrials.gov, NCT02612415 . Registered on 23 November 2015.

Treatment options for patients with severe COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic has affected the world for over 3 years. Treatment options have improved substantially during this period, including antiviral drugs, antibody drugs, immune-based agents, and vaccination. While these improvements have reduced mortality rates in patients with COVID-19, some patients still develop severe illness. In this review, we aimed to provide an overview of treatments for patients with severe COVID-19 from study reports and clinical experience. We discussed the treatments from two perspectives: respiratory care and drug treatments. In the respiratory care section, we discussed the usefulness of high-flow nasal cannula therapy and non-invasive ventilation as an alternative to invasive ventilation. In the drug treatments section, we focused on three classes for severe COVID-19 treatment: antiviral drugs, immune-based agents, and anticoagulation therapy. We did not discuss antibody drugs and vaccination, as they are not used for severe COVID-19 treatment.

Efficacy and safety of high-flow nasal cannula therapy in elderly patients with acute respiratory failure.

INTRODUCTION: To assess the efficacy and safety of high-flow nasal cannula (HFNC) in elderly patients with acute respiratory failure (ARF) not due to COVID-19, refractory to treatment with conventional oxygen therapy and/or intolerant to noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) and without criteria for admission to intensive care units (ICU). METHODS: Prospective observational study of patients with ARF treated with HFNC who presented clinical and arterial blood gas deterioration after 24 h of medical treatment and oxygenation by conventional systems. The degree of dyspnoea, gas exchange parameters (arterial O2 pressure/inspired O2 fraction ratio (PaO2/FiO2); oxygen saturation measured by oximetry/ inspired fraction of oxygen (Sp02/Fi02), ROX index), degree of patient tolerance and mortality were evaluated. These were measured at discharge from the emergency department (ED), 24 h after treatment with conventional oxygenation and 60, 120 min and 24 h after initiation of HFNC. The results were analyzed for all patients as a whole and for patients with hypercapnia (arterial carbon dioxide tension (PaCO2) < 45 mmHg) separately. RESULTS: 200 patients were included in the study between November 2019 and November 2020, with a mean age of 83 years, predominantly women (61.9%), obese (Body Mass Index (BMI) 31.1), with high comorbidity (Charlson index 4) and mild-moderate degree of dependence (Barthel 60). A number of 128 patients (64%) were hypercapnic. None had respiratory acidosis (pH 7.39). Evaluation at 60 min, 120 min and 24 h showed significant improvement in all patients and in the subgroup of hypercapnic patients with respect to baseline parameters in respiratory rate (RR), dyspnoea, ROX index, PaO2/FiO2, SpO2/FiO2 and patient comfort. No changes in PaCO2 or level of consciousness were observed. HFNC was well tolerated. Ten patients (5%) died due to progression of the disease causing ARF. CONCLUSIONS: HFNC is an effective and safe alternative in elderly patients with ARF not due to COVID-19, refractory to treatment with conventional oxygen therapy and/or intolerant to NIV or CPAP and without criteria for admission to ICU.

High-flow nasal cannula oxygen versus conventional oxygen therapy for acute respiratory failure due to COVID-19: a systematic review and meta-analysis.

BACKGROUND: The effectiveness of high-flow nasal cannula oxygen therapy (HFNC) in patients with acute respiratory failure due to COVID-19 remains uncertain. We aimed at assessing whether HFNC is associated with reduced risk of intubation or mortality in patients with acute respiratory failure due to COVID-19 compared with conventional oxygen therapy (COT). METHODS: In this systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Science, and CENTRAL databases for randomized controlled trials (RCTs) and observational studies comparing HFNC vs. COT in patients with acute respiratory failure due to COVID-19, published in English from inception to December 2022. Pediatric studies, studies that compared HFNC with a noninvasive respiratory support other than COT and those in which intubation or mortality were not reported were excluded. Two authors independently screened and selected articles for inclusion, extracted data, and assessed the risk of bias. Fixed-effects or random-effects meta-analysis were performed according to statistical heterogeneity. Primary outcomes were risk of intubation and mortality across RCTs. Effect estimates were calculated as risk ratios and 95% confidence interval (RR; 95% CI). Observational studies were used for sensitivity analyses. RESULTS: Twenty studies were analyzed, accounting for 8383 patients, including 6 RCTs (2509 patients) and 14 observational studies (5874 patients). By pooling the 6 RCTs, HFNC compared with COT significantly reduced the risk of intubation (RR 0.89, 95% CI 0.80 to 0.98; p = 0.02) and reduced length of stay in hospital. HFNC did not significantly reduce the risk of mortality (RR 0.93, 95% CI 0.77 to 1.11; p = 0.40). CONCLUSIONS: In patients with acute respiratory failure due to COVID-19, HFNC reduced the need for intubation and shortened length of stay in hospital without significant decreased risk of mortality. Trial registration The study was registered on the International prospective register of systematic reviews (PROSPERO) at https://www.crd.york.ac.uk/prospero/ with the trial registration number CRD42022340035 (06/20/2022).

Factors influencing health professionals' use of high-flow nasal cannula therapy for infants with bronchiolitis - A qualitative study.

Aim: To explore the factors influencing the use of high-flow nasal cannula (HFNC) therapy for infants with bronchiolitis. Design: Qualitative approach using semi-structured interviews. Methods: The semi-structured interviews (face-to-face or virtual) were conducted between September 2020 and February 2021. Deductive content analysis was used to map key influencing factors for use of HFNC therapy to the Theoretical Domains Framework (TDF). Results: Nineteen interviews were undertaken before reaching thematic saturation (7 nurses, 12 doctors) in emergency departments and paediatric wards from four purposively selected hospitals in Australia and New Zealand. Influencing factors were mapped to eight domains in the TDF with 21 themes identified. Main findings included: (1) Health professionals' expectations of HFNC therapy on patient deterioration, work of breathing and oxygenation; (2) Staff emotions relating to concern and anxiety about deterioration and "need to do something"; (3) Social influences from other health professionals and parents and (4) Environmental factors relating to logistics of care and patient transfer considerations. These factors, combined with the ready availability of HFNC equipment and health professionals having the required skills to administer the therapy, contributed to its initiation. Conclusion: Individual/personal and contextual/environmental factors contribute to the use of HFNC therapy for infants with bronchiolitis. It is evident these influences contribute substantially to increased use, despite evidence-based guidelines recommending a more nuanced approach to this therapy. These findings will inform a targeted implementation intervention to promote evidence-based use of HFNC therapy in infants with bronchiolitis.

Use of high flow nasal cannula oxygen therapy for patients infected with SARS-CoV-2 outside intensive care setting.

Background: In early 2022, there was a sudden surge of patients infected by the Omicron variant of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Hong Kong (HK), resulting in 9,163 deaths as of 29 May 2022. Many of the local population had not been vaccinated before this wave. The number of patients who developed coronavirus disease 2019 (COVID-19) related respiratory failure outnumbered the capacity of intensive care unit (ICU) beds. Some of these patients had to be supported with high flow nasal cannula (HFNC) therapy outside ICU setting. HK was in crisis situation. The primary objective of this study is to assess the 28-day mortality of this group of patients. The secondary objective is to explore any predictors of non-survivors to help clinical decision-making in future crisis. Methods: This is a retrospective observational study of patients suffering from COVID-19 related respiratory failure who received HFNC therapy in general medical wards of two hospitals during the period of 17 Mar to 30 Apr 2022. Survival and risk factors were reviewed. Results: Forty-nine patients were recruited. Twenty-six patients (53%) survived at 28-day after initiation of HFNC support. Three clinical parameters were found to be significantly associated with mortality at 28-day: (I) SpO2/FiO2 (SF) ratio <160 at 48 hours; (II) SF ratio <191 at 72 hours; (III) serial SF ratio at 48 or 72 hours showing no improvement over that at the time of initiation of HFNC therapy. Conclusions: Use of HFNC outside ICU setting showed benefit to patients suffering from COVID-19 related acute hypoxemic respiratory failure (AHRF). Serial SF ratio monitoring at 48 and 72 hours after therapy initiation might serve as predictors of outcome and thus guide clinical decision-making for medical resource allocation in outbreak situation.

High-flow nasal cannula oxygen therapy versus noninvasive ventilation for patients with blunt chest trauma: protocol for a randomized controlled trial.

BACKGROUND: High-flow nasal cannula oxygen therapy (HFNC) is recommended by some scholars as an optimized respiratory support method for blunt chest trauma (BCT) patients. The basis of this recommendation is limited, however, and the efficacy of HFNC or noninvasive ventilation (NIV) in BCT patients has not yet been rigorously explored. This study aims to determine if HFNC is non-inferior to NIV in reducing treatment failure in moderate to severe BCT patients with acute respiratory failure. METHODS: This will be a prospective, open-label, multicenter, non-inferiority, randomized controlled trial. Moderate to severe BCT patients with acute respiratory failure (100mmHg < PaO2/FiO2 ≦ 200mmHg) who do not need immediate intubation will be randomized to HFNC or NIV within 48 h after trauma. The primary outcome is treatment failure, defined as invasive ventilation or a switch in respiratory support modality (from HFNC to NIV or vice-versa). Secondary outcomes include arterial blood gas analysis and vital signs at 2 and 12 h after initiating HFNC or NIV treatment, as well as patients' comfort scores, dyspnea scores, daily number of nursing airway care interventions, incidence of pneumonia or pneumothorax, facial skin breakdown, duration of NIV or HFNC, 28-day mortality, and total ICU and hospital lengths of stay. Based on an α error of 5% and a ß error of 80%, with a non-inferiority limit of 9%, a sample size of 562 will be required to accomplish the trial goal, considering potential patient dropouts and nonparametric analysis. DISCUSSION: We hypothesize that HFNC will be non-inferior to NIV in reducing treatment failure in moderate to severe BCT with acute respiratory failure. The results should be useful for judging whether HFNC could be an effective alternative to NIV to treat moderate to severe BCT patients, especially for those who do not tolerate or have contraindications for NIV. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1800017313 . Registered on July 24, 2018.

Factors associated with failure of high-flow nasal cannula oxygen therapy in patients with severe COVID-19: a retrospective case series.

OBJECTIVE: To identify factors associated with high-flow nasal cannula (HFNC) therapy failure in patients with severe COVID-19. METHODS: We retrospectively examined clinical and laboratory data upon admission, treatments, and outcomes of patients with severe COVID-19. Sequential Organ Failure Assessment (SOFA) scores were also calculated. RESULTS: Of 54 patients with severe COVID-19, HFNC therapy was successful in 28 (51.9%) and unsuccessful in 26 (48.1%). HFNC therapy failure was more common in patients aged ≥60 years and in men. Compared with patients with successful HFNC therapy, patients with HFNC therapy failure had higher percentages of fatigue, anorexia, and cardiovascular disease; a longer time from symptom onset to diagnosis; higher SOFA scores; a higher body temperature, respiratory rate, and heart rate; more complications, including acute respiratory distress syndrome, septic shock, myocardial damage, and acute kidney injury; a higher C-reactive protein concentration, neutrophil count, and prothrombin time; and a lower arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2). However, male sex, a low PaO2/FiO2, and a high SOFA score were the only independent factors significantly associated with HFNC therapy failure. CONCLUSIONS: Male sex, a low PaO2/FiO2, and a high SOFA score were independently associated with HFNC therapy failure in patients with severe COVID-19.

Anesthetic management using high-flow nasal cannula therapy during cardiac catheter examination of a neonate with hypoplastic left heart syndrome.

BACKGROUND: Sedation during cardiac catheter examination in neonates with complex congenital heart disease is challenging, as even the slightest change in the circulatory or respiratory status can lead to hemodynamic collapse. Here, we report a case wherein we achieved adequate sedation with a high-flow nasal cannula (HFNC) for catheter examination in a neonate with a congenital cardiac anomaly. CASE PRESENTATION: An 11-day-old boy with hypoplastic left heart syndrome was scheduled for a cardiac catheter examination prior to the Norwood procedure. He underwent bilateral pulmonary artery banding (PAB) on day 1 and was receiving dobutamine, milrinone, alprostadil, and dexmedetomidine in addition to air and nitrogen insufflation via HFNC, which was applied following extubation on day 3 and nitrogen therapy on day 6 owing to persistent pulmonary overcirculation symptoms (tachypnea and low arterial blood pressure) despite bilateral PAB. A catheter examination was performed on day 11 with careful monitoring of expired carbon dioxide and observation of chest wall motion. Adequate sedation was provided with supplemental midazolam and fentanyl along with HFNC without tracheal intubation. CONCLUSIONS: The findings from this case suggest that HFNC is a safe and effective tool for oxygenation during cardiac catheter examination under sedation in neonates.

Physiological responses and perceived comfort to high-flow nasal cannula therapy in awake adults: effects of flow magnitude and temperature.

Clinical use of heated, high-flow nasal cannula (HFNC) for noninvasive respiratory support is increasing and may have a therapeutic role in stabilizing the upper airway in obstructive sleep apnea (OSA). However, physiological mechanisms by which HFNC therapy may improve upper airway function and effects of different temperature modes are unclear. Accordingly, this study aimed to determine effects of incremental flows and temperature modes (heated and nonheated) of HFNC on upper airway muscle activity (genioglossus), pharyngeal airway pressure, breathing parameters, and perceived comfort. Six participants (2 females, aged 35 ± 14 yr) were studied during wakefulness in the supine position and received HFNC at variable flows (0-60 L/min) during heated (37°C) and nonheated (21°C) modes. Breathing parameters via calibrated Respitrace inductance bands (chest and abdomen), upper airway pressures via airway transducers, and genioglossus muscle activity via intramuscular bipolar fine wire electrodes were measured. Comfort levels during HFNC were quantified using a visual analog scale. Increasing HFNC flows did not increase genioglossus muscle activation despite increased negative epiglottic pressure swings (P = 0.009). HFNC provided ∼7 cmH2O positive airway pressure at 60 L/min in nonheated and heated modes. In addition, increasing the magnitude of HFNC flow reduced breathing frequency (P = 0.045), increased expiratory time (P = 0.040), increased peak inspiratory flow (P = 0.002), and increased discomfort (P = 0.004). Greater discomfort occurred at higher flows in the nonheated versus the heated mode (P = 0.034). These findings provide novel insight into key physiological changes that occur with HFNC for respiratory support and indicate that the primary mechanism for improved upper airway stability is positive airway pressure, not increased pharyngeal muscle activity.NEW & NOTEWORTHY This study evaluated upper airway muscle function, breathing, and comfort across different HFNC flows and temperatures. There were no increases in genioglossus muscle activity at higher flows despite greater negative epiglottic pressure swings. Increasing negative pressure swings was associated with increasing discomfort in the nonheated mode. HFNC was associated with ∼7 cmH2O increase in positive airway pressure, which may be the primary mechanism for upper airway stability with HFNC rather than increases in pharyngeal muscle activity.

High Flow Nasal Cannula Decreased Pulmonary Complications in Neurologically Critically Ill Patients.

Objective: Pulmonary complications could badly affect the recovery of neurological function and neurological prognosis of neurological critically ill patients. This study evaluated the effect of high-flow nasal cannula (HFNC) therapy on decreasing pulmonary complications in neurologically critically ill patients. Patients and Methods: The patients admitted to the intensive care unit (ICU) with serious neurological disease and receiving oxygen therapy were retrospectively reviewed (Ethical No. IRB2021-YX-001). Patients were divided into the HFNC group and the conventional oxygen therapy (COT) group. We analyzed the data within these two groups, including patients' baseline data, short-term outcomes of respiratory complications, general outcomes including hospital stay, ICU stay and mortality, and neurological functions. To analyze the relevant factors, we performed multivariable logistic regression analysis. Results: A total of 283 patients met the criteria, including 164 cases in the HFNC group and 119 cases in the COT group. The HFNC group had remarkably less mechanical ventilation requirement with lower phlegm viscosity. Even more, ICU stay and total hospital stay were significantly shortened in the HNFC group. Conclusion: HFNC decreased pulmonary complications in neurologically critically ill patients and improved recovery of neurological function and neurological prognosis.

Course of illness and outcomes in older COVID-19 patients treated with HFNC: a retrospective analysis.

Coronavirus disease-2019 (COVID-19) has rapidly spread worldwide and causes high mortality of elderly patients. High-flow nasal cannula therapy (HFNC) is an oxygen delivery method for severely ill patients. We retrospectively analyzed the course of illness and outcomes in 110 elderly COVID-19 patients (≥65 years) treated with HFNC from 6 hospitals. 38 patients received HFNC (200 mmHg < PaO2/FiO2 ≤ 300 mmHg, early HFNC group), and 72 patients received HFNC (100 mmHg < PaO2/FiO2 ≤ 200 mmHg, late HFNC group). There were no significant differences of sequential organ failure assessment (SOFA) scores and APECH II scores between early and late HFNC group on admission. Compared with the late HFNC group, patients in the early HFNC group had a lower likelihood of developing severe acute respiratory distress syndrome (ARDS), longer time from illness onset to severe ARDS and shorter duration of viral shedding after illness onset, as well as shorter lengths of ICU and hospital stay. 24 patients died during hospitalization, of whom 22 deaths (30.6%) were in the late HFNC group and 2 (5.3%) in the early HFNC group. The present study suggested that the outcomes were better in severely ill elderly patients with COVID-19 receiving early compared to late HFNC.

Effects of different high-flow nasal cannula flow rates on swallowing function.

BACKGROUND: High-flow nasal cannula therapy is used as a noninvasive treatment for people with acute respiratory disease. The aim of this study was to assess the impact of high-flow nasal cannula different flow rates on different characteristics of swallowing in healthy volunteers. METHODS: A prospective cohort study where healthy adult volunteers were subject to high-flow nasal cannula at different flow rates (0, 10, 20, 30, 40, and 50 L/min, in random order). The 30-mL water swallow test, repetitive saliva swallowing test, and 0-100 mm visual analog scale assessed aspiration, swallow frequency and effort, respectively. FINDINGS: Thirty subjects (mean age 30 years) were enrolled. Nine subjects (30.0%) choked at 10, 40 and 50 L/min during the 30-mL water swallow test (p < 0.05). Swallowing effort was increased during flow rates ≥20 compared to 10 L/min (p < 0.05). Flow rates ≥20 L/min resulted in lower number of swallows during the repetitive saliva swallowing test compared to 0 and 10 L/min (p < 0.05). INTERPRETATION: High-flow nasal cannula flow rates above 40 L/min associated with choking (increased risk of aspiration), and was associated with decreased swallowing function in healthy volunteers. It may be important to assess swallowing function in patients with various clinical conditions and treated with high-flow nasal cannula, especially those at risk of aspiration pneumonia.

High-Flow Nasal Cannula Therapy With Early Extubation for Subjects Undergoing Off-Pump Coronary Artery Bypass Graft Surgery.

BACKGROUND: The effects of high-flow nasal cannula (HFNC) therapy on postoperative atelectasis and duration of oxygen therapy after off-pump coronary artery bypass graft are unknown. The purpose of this study was to compare the effects of HFNC therapy for subjects who underwent off-pump coronary artery bypass graft with the effects of standard oxygen therapy in terms of oxygen requirement and atelectasis. METHODS: This prospective single-blinded randomized, controlled trial included 148 subjects who underwent off-pump coronary artery bypass graft between 2010 and 2015 with HFNC (n = 72) or without HFNC (standard O2, n = 76). The primary end point was the percentage difference in loss of lung volume between subjects with or without HFNC therapy. Secondary end points included the total amount of oxygen administered and duration of oxygen therapy with and without HFNC therapy. RESULTS: There were significant between-group differences in the percentage loss of lung volume (P < .001), total amount of oxygen administered (P < .001), duration of oxygen therapy (P < .001), and the need for postoperative diuretic therapy (P = .037). The amount (ρ = 0.569, P < .001) and duration (ρ = 0.678, P < .001) of oxygen administered were correlated with atelectasis volume. CONCLUSIONS: Using HFNC therapy after off-pump coronary artery bypass graft shortened the duration of oxygen therapy and reduced the percentage loss of lung volume and total amount of oxygen administered when compared with standard oxygen therapy.

Noninvasive Respiratory Support at the End of Life.

Noninvasive respiratory support at the end of life is controversial, although it is becoming increasingly common. Supplemental oxygen is widely prescribed for palliative care and may help with hypoxemic respiratory failure. Noninvasive ventilation has a well-established evidence-based role in the management of respiratory failure due to exacerbations of COPD and cardiogenic pulmonary edema. However, its role during palliative care is unclear, and evidence of support is limited. High-flow nasal cannula oxygen therapy is a new strategy for which there is evidence to support its use for hypoxemic respiratory failure. However, any benefit of the use of high-flow nasal cannula oxygen therapy in the palliative setting is unknown at this time. This review examined evidence relating to the use of noninvasive respiratory support at the end of life.