High-flow nasal cannula therapy: An un-tapped resource?

High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy but not to non-invasive mechanical ventilation in reducing intubation rate in hypoxia and dyspnea due to acute heart failure: a systematic review and meta-analysis.

Purpose: The aim of this narrative review is to outline the mechanism of action of HFNC therapy, the clinical benefits of its use, cautions of its clinical application and limitations of previous research. Methods: A literature review was conducted using the following databases as sources: Medline, PubMed, and Google Scholar. Only publications written in English were used in this clinical review. Keywords used in the search included the following: high-flow nasal cannula, heated humidified oxygen, oxygen therapy, non-invasive ventilation, and respiratory failure. Results: The literature reveals HFNC therapy significantly decreased the use of mechanical ventilation (invasive or non-invasive) in patients experiencing respiratory failure. HFNC therapy was better tolerated by patients and decreased the patient’s work of breathing when compared to a conventional oxygen therapy (i.e., non-rebreather oxygen mask). Other clinical benefits of using HFNC when changing a patient from conventional facemask oxygen therapy to a HFNC device are significant improvements in PaO2, respiratory rate and overall comfort. Conclusions: High flow nasal cannula (HFNC) therapy serves as an alternative to conventional oxygen therapy to deliver elevated concentrations of oxygen to patients experiencing acute respiratory failure. Information detailed in this article suggests HFNC therapy is an effective therapy for improving a patient’s oxygenation status when experiencing acute respiratory failure in adults. The literature reveals, it is reasonable to initiate HFNC in adults with acute hypoxemic respiratory failure without hypercapnia, as an alternative to standard oxygen therapy or noninvasive positive pressure ventilation.

ObjectiveThe study aimed to explore the effectiveness of bedside lung ultrasound (LUS) combined with the PaO2/FiO2 (P/F) ratio in evaluating the outcomes of high-flow nasal cannula (HFNC) therapy in infants with severe pneumonia.MethodsThis retrospective study analyzed the clinical data of 150 infants diagnosed with severe pneumonia and treated with HFNC therapy at our hospital from January 2021 to December 2021. These patients were divided into two groups based on their treatment outcomes: the HFNC success group (n = 112) and the HFNC failure group (n = 38). LUS was utilized to evaluate the patients’ lung conditions, and blood gas results were recorded for both groups upon admission and after 12 h of HFNC therapy.ResultsAt admission, no significant differences were observed between the two groups in terms of age, gender, respiratory rate, partial pressure of oxygen, and partial pressure of carbon dioxide. However, the P/F ratios at admission and after 12 h of HFNC therapy were significantly lower in the HFNC failure group (193.08 ± 49.14, 228.63 ± 80.17, respectively) compared to the HFNC success group (248.51 ± 64.44, 288.93 ± 57.17, respectively) (p < 0.05). Likewise, LUS scores at admission and after 12 h were significantly higher in the failure group (18.42 ± 5.3, 18.03 ± 5.36, respectively) than in the success group (15.09 ± 4.66, 10.71 ± 3.78, respectively) (p < 0.05). Notably, in the success group, both P/F ratios and LUS scores showed significant improvement after 12 h of HFNC therapy, a trend not observed in the failure group. Multivariate regression analysis indicated that lower P/F ratios and higher LUS scores at admission and after 12 h were predictive of a greater risk of HFNC failure. ROC analysis demonstrated that an LUS score > 20.5 at admission predicted HFNC therapy failure with an AUC of 0.695, a sensitivity of 44.7%, and a specificity of 91.1%. A LUS score > 15.5 after 12 h of HFNC therapy had an AUC of 0.874, with 65.8% sensitivity and 89.3% specificity. An admission P/F ratio < 225.5 predicted HFNC therapy failure with an AUC of 0.739, 60.7% sensitivity, and 71.1% specificity, while a P/F ratio < 256.5 after 12 h of HFNC therapy had an AUC of 0.811, 74.1% sensitivity, and 73.7% specificity.ConclusionDecreased LUS scores and increased P/F ratio demonstrate a strong correlation with successful HFNC treatment outcomes in infants with severe pneumonia. These findings may provide valuable support for clinicians in managing such cases.

Obstructive sleep apnea (OSA) is associated with increasing risk of recurrent stroke and mortality. Nasogastric tubes used by dysphagic stroke patients may interfere with nasal continuous positive airway pressure (CPAP) due to air leakage. This study was evaluated the effects and short-term tolerability of high-flow nasal cannula (HFNC) therapy for OSA in stroke patients with nasogastric intubation. The HFNC titration study was performed in post-acute ischemic stroke patients with nasogastric intubation and OSA. Then, participants were treated with HFNC therapy in the ward for one week. Eleven participants (eight males) who were all elderly with a median age of 72 (IQR 67–82) years and a body mass index of 23.5 (IQR 22.0–26.6) completed the titration study. The HFNC therapy at a flow rate up to 50~60 L/min significantly decreased the apnea-hypopnea index from 52.0 events/h (IQR 29.9–61.9) to 26.5 events/h (IQR 3.3–34.6) and the total arousal index from 34.6 (IQR 18.6–42.3) to 15.0 (IQR 10.3–25.4). The oxygen desaturation index was also significantly decreased from 53.0 events/h (IQR 37.0–72.8) to 16.2 events/h (IQR 0.8–20.1), accompanied by a significant improvement in the minimum SpO2 level. Finally, only three participants tolerated flow rates of 50~60 L/minute in one-week treatment period. Conclusively, HFNC therapy at therapeutic flow rate is effective at reducing the OSA severity in post-acute ischemic stroke patients with nasogastric intubation. Owing to the suboptimal acceptance, HFNC might be a temporary treatment option, and CPAP therapy is suggested after the nasogastric tube is removed.

Purpose:The aim of this study is to determine the clinical efficacy of high-flow nasal cannula (HFNC) therapy compared with conventional oxygen therapy in children presented with respiratory distress.Study Design:This was a randomized controlled study.Materials and Methods:Infants and children aged between 1 month to 5 years who were admitted to our tertiary referral center for respiratory distress (July 1, 2014 to March 31, 2015) and met the inclusion criteria were recruited.Interventions:Infants and children hospitalized with respiratory distress were randomized into two groups of interventions. All clinical data, for example, respiratory score, pulse rate, and respiratory rate were recorded. The results were subsequently analyzed.Results:A total of 98 respiratory distress children were enrolled during the study period. Only 4 children (8.2%) failed in HFNC therapy, compared with 10 children (20.4%) in conventional oxygen therapy group (P = 0.09). After adjusted for body weight, underlying diseases, and respiratory distress score, there was an 85% reduction in the odds of treatment failure in HFNC therapy group (adjusted odds ratio 0.15, 95% confidence interval 0.03–0.66, P = 0.01). Most children in HFNC therapy group had significant improvement in clinical respiratory score, heart rate, and respiratory rate at 240, 360, and 120 min compared with conventional oxygen therapy (P = 0.03, 0.04, and 0.03).Conclusion:HFNC therapy revealed a potential clinical advantage in management children hospitalized with respiratory distress compared with conventional respiratory therapy. The early use of HFNC in children with moderate-to-severe respiratory distress may prevent endotracheal tube intubation.Trial Register:TCTR 20170222007.

Objective: To evaluate the outcome of high-flow nasal cannula (HFNC) therapy by ROX index in critically ill children with acute respiratory failure due to lower respiratory tract infections in pediatric intensive care unit (PICU). Study Design: Analytical, Observational, Cross-sectional study. Setting: The PICU of the Indus Hospital, Karachi, Pakistan. Period: November 2022 to October 2023. Methods: We enrolled children of either gender, aged above 1 month up to 16 years and presenting with acute respiratory insufficiency due to lower respiratory tract infections. The use of HFNC was monitored for 72-hours. HFNC failure was characterized by requiring either noninvasive mechanical ventilation or invasive mechanical ventilation due to an unstable state. Results: In a total of 62 children, 39 (62.9%) were male. The mean age was 27.01±30.96 months. The most common diagnosis at the time of admission were pneumonia, and bronchiolitis noted in 25 (40.3%), and 33 (53.2%) children, respectively. Gradual improvement in ROX index was observed among children with HFNC success while a declining ROX index predicted HFNC failure. Outcome of HFNC was successful in 45 (72.6%) children. Mortality was observed in 12 (19.4%) children. Presence of comorbidity was significantly associated with unsuccessful HFNC outcomes. Conclusion: ROX index was found to be a good predictor of HFNC outcome. Overall, HFNC therapy in PICU demonstrated 72.6% success rate. HFNC outcomes are hampered particularly in cases involving comorbidities highlighting the need for tailored interventions.

BackgroundEarly identification of patients with acute hypoxemic respiratory failure (AHRF) who are at risk of failing high-flow nasal cannula (HFNC) therapy could facilitate closer monitoring, and timely adjustment/escalation of treatment. We aimed to establish whether machine learning (ML) models could predict HFNC outcome, early in the course of treatment, with greater accuracy than currently used clinical indices.MethodsWe developed ML models trained using measurements made within the first 2 h of treatment from 184 AHRF patients (37% HFNC failures) treated at the respiratory ICU of the University Hospital of Modena between 2018 and 2023. For external validation, we used a dataset on 567 AHRF patients (22% failures) comprising 510 patients from the recent RENOVATE trial in Brazil and 57 from the MIMIC-IV and eICU databases in the US. Predictive performance of the ML models was benchmarked against optimized thresholds of the following clinical indices: respiratory rate oxygenation index (ROX) and variants, heart rate to saturation of pulse oxygen (SpO2) ratio, SpO2/FiO2 ratio, PaO2/FiO2 ratio, sequential organ failure assessment and heart rate, acidosis, consciousness, oxygenation and respiratory rate scores.ResultsInternal and external predictive performance of a Support Vector Machine (SVM) ML model was superior to all clinical indices across all scenarios tested. In external validation on the 567-patient dataset, a SVM model trained on non-invasive measurements had an accuracy of 73%, sensitivity of 73%, specificity of 73%, and AUC of 0.79. The ROX index had an accuracy of 64%, sensitivity of 79%, specificity of 60%, and AUC of 0.74. When arterial blood gasses (ABG’s) were also used for model training, the SVM model had an accuracy of 83%, sensitivity of 84%, specificity of 82%, and AUC of 0.82 in external validation on the MIMIC-IV/eICU dataset. The modified ROX index, which requires PaO2, achieved 70% accuracy, 63% sensitivity, 74% specificity, and AUC of 0.65.ConclusionsDecision support tools based on SVM models could provide clinicians with more accurate early predictions of HFNC outcome than currently available clinical indices. If available, ABG measurements could improve the capability to accurately identify patients at risk of failing HFNC therapy.

Delivering aerosols to the lungs through the nasal route has a number of advantages, but its use has been limited by high depositional loss in the extrathoracic airways. The objective of this study was to evaluate the nose-to-lung (N2L) delivery of excipient enhanced growth (EEG) formulation aerosols generated with a new inline dry powder inhaler (DPI). The device was also adapted to enable aerosol delivery to a patient simultaneously receiving respiratory support from high flow nasal cannula (HFNC) therapy. The inhaler delivered the antibiotic ciprofloxacin, which was formulated as submicrometer combination particles containing a hygroscopic excipient prepared by spray-drying. Nose-to-lung delivery was assessed using in vitro and computational fluid dynamics (CFD) methods in an airway model that continued through the upper tracheobronchial region. The best performing device contained a 2.3 mm flow control orifice and a 3D rod array with a 3-4-3 rod pattern. Based on in vitro experiments, the emitted dose from the streamlined nasal cannula had a fine particle fraction <5 μm of 95.9% and mass median aerodynamic diameter of 1.4 μm, which was considered ideal for nose-to-lung EEG delivery. With the 2.3-343 device, condensational growth in the airways increased the aerosol size to 2.5-2.7 μm and extrathoracic deposition was <10%. CFD results closely matched the in vitro experiments and predicted that nasal deposition was <2%. The developed DPI produced high efficiency aerosolization with significant size increase of the aerosol within the airways that can be used to enable nose-to-lung delivery and aerosol administration during HFNC therapy.

Contaminated aerosols and micro droplets are easily generated by infected hosts through sneezing, coughing, speaking and breathing1–3 and harm humans’ health and the global economy. While most of the efforts are usually targeted towards protecting individuals from getting infected,4 eliminating transmissions from infection sources is also important to prevent disease transmission. Supportive therapies for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) pneumonia such as oxygen supplementation, nebulizers and non-invasive mechanical ventilation all carry an increased risk for viral transmission via aerosol to healthcare workers.5–9 In this work, we study the efficacy of five methods for self-containing aerosols emitted from infected subjects undergoing nebulization therapies with a diverse spectrum on oxygen delivery therapies. The work includes five study cases: Case I: Use of a Full-Face Mask with biofilter in bilevel positive airway pressure device (BPAP) therapy, Case II: Use of surgical mask in High Flow Nasal Cannula (HFNC) therapy, Case III: Use of a modified silicone disposable mask in a HFNC therapy, Case IV: Use of a modified silicone disposable mask with a regular nebulizer and normal breathing, Case V: Use of a mitigation box with biofilter in a Non-Invasive Positive Pressure Ventilator (NIPPV). We demonstrate that while cases I, III and IV showed efficacies of 98–100%; cases II and V, which are the most commonly used, resulted with significantly lower efficacies of 10–24% to mitigate the dispersion of nebulization aerosols. Therefore, implementing cases I, III and IV in health care facilities may help battle the contaminations and infections via aerosol transmission during a pandemic.

The aim of this prospective randomized crossover study was to compare the short-term effects of high-flow nasal cannula (HFNC) therapy and a 45° head-up tilt to the short-term effects of conventional oxygen (O2) therapy in post-abdominal surgery patients. A total of 18 subjects who were successfully weaned from ventilator support after abdominal surgery were included in the study. The subjects were randomly assigned to 2 groups: conventional O2 was applied in group A for 15 min, and HFNC (60 L/min) was applied in group B for 15 min. A 15-min washout period with conventional O2 was performed before the interventions were switched in both groups. Heart rate, blood pressure, breathing frequency, ratio of arterial partial pressure of oxygen to the fraction of inspired oxygen (PaO2 /FIO2 ), and subject-reported comfort scores were recorded. Changes in end-expiratory lung impedance (EELI) were calculated with electrical impedance tomography. Results are presented as the percent change in lung volume compared to baseline during volume-controlled continuous mandatory ventilation before extubation. HFNC improved EELI in both the ventral (conventional O2 vs HFNC, -48.2% ± 41.0 vs -30.0% ± 40.3, P < .001) and the dorsal (conventional O2 vs HFNC, -37.0% ± 75.9 vs -26.5% ± 68.4, P = .02) regions of the lungs. Subjective subject-reported scores indicated that HFNC was more comfortable than conventional O2 (conventional O2 vs HFNC, 5.8 ± 1.5 vs 6.9 ± 1.9, P = .02). No differences were found in the other examined parameters. A head-up tilt position with conventional O2 improved EELI in the dorsal regions (55.9% ± 100.1, P < .001) but not in the ventral regions (-37.9% ± 43.1%, P = .38) of the lungs compared to HFNC or conventional O2 alone. In post-abdominal surgery subjects who had been extubated, HFNC improved lung volume and patient comfort. A head-up tilt position introduced a heterogeneous increase in EELI in the dorsal regions of the lungs. HFNC therapy may be beneficial in this patient group. (ChiCTR1900020886, http://chictr.org.cn).

Interstitial lung disease (ILD) is characterized by dyspnoea on exertion and exercise-induced hypoxaemia. High-flow nasal cannula (HFNC) therapy reduces the respiratory workload through higher gas flow and oxygen supplementation, which may affect exercise tolerance. This study aimed to examine the effects of oxygen and gas flow rates through HFNC therapy on exercise tolerance in ILD patients. We conducted three-treatment crossover study. All ILD patients performed the exercises on room air (ROOM AIR setting: flow, 0 L/min; fraction of inspired oxygen [FiO2], 0.21), HFNC (FLOW setting: flow 40 L/min, FiO2 0.21), and HFNC with oxygen supplementation (FLOW + OXYGEN setting: flow 40 L/min, FiO2 0.6). The primary endpoint was the endurance time, measured using constant-load cycle ergometry exercise testing at a peak work rate of 80%. Twenty-five participants (10 men, 71.2 ± 6.7 years) were enrolled. The increase in exercise duration between the ROOM AIR and FLOW was 46.3 s (95% CI, -6.1 to 98.7; p = 0.083), and the FLOW and FLOW + OXYGEN was 91.5 s (39.1-143.9; p < 0.001). The percutaneous oxygen saturation (SpO2) at rest was significantly higher with the FLOW + OXYGEN setting than with the ROOM AIR and FLOW settings, and the difference persisted during exercise. At equivalent time points during exercise, the SpO2 with the FLOW setting was significantly higher than that with the ROOM AIR setting. Oxygen supplementation in HFNC therapy improved exercise tolerance and SpO2. We found that gas flow alone did not improve exercise tolerance, but improved SpO2 during exercise.

Objective To evaluate the effects of high flow nasal cannula therapy (HFNC) as sequential treatment on patients after extubation. Methods The clinical data of 61 post-extubation patients who were treated in the First People’s Hospital of Changde from January 2016 to December 2017 were retrospectively analyzed, of which 29 cases underwent HFNC treatment (HFNC group) and 32 cases underwent noninvasive positive pressure ventilation (NPPV) treatment (NPPV group). The general condition prior to extubation and clinical indexes after extubation were compared between the two groups. Results There was no significant difference in clinical indexes such as age, gender, time of ventilation, acute physiology and chronic health evaluation (APACHEⅡ) score, heart rate, respiratory rate, average arterial pressure, oxygenation index, partial pressure of oxygen (PaO2) and partial pressure of carbon dioxide (PaCO2) between the two groups (P all>0.05). There was no significant difference in oxygenation index and PaCO2 at 1 hour, 24 hours and 48 hours after extubation, as well as in reintubation ratio between the two groups (P>0.05). The incidences of pressure ulcer and aspiration in HFNC group were lower than those in NPPV group, but the difference was not significant (P>0.05). The tolerance score and intensive care unit (ICU) retention time in HFNC group was lower than that in NPPV group (P<0.05). Conclusions HFNC is effective and safe in the treatment of post-extubation patients, which is worthy of clinical promotion. Key words: High flow nasal cannula therapy; Noninvasive positive pressure ventilation; Extubation

ObjectiveThis study aimed to extract incident and accident reports associated with high-flow nasal cannula (HFNC) therapy from the publicly available database maintained by the Japan Council for Quality Health Care (JCQHC) and to identify contributing factors using the P-mSHEL model (Patient-management-Software-Hardware-Environment-Liveware), with the goal of providing insights for improving HFNC safety.MethodsAmong 94,069 incident reports (defined as cases without patient harm) and 56,783 accident reports (cases with patient harm) submitted between 2010 and 2023, a total of 170 HFNC-related cases (131 incidents and 39 accidents) were identified. Quantitative variables included the time of occurrence, patient demographics, and involvement of healthcare professionals. Qualitative data were classified into six categories (P, m, S, H, E, L) using the P-mSHEL model. For accident cases, the presence or absence of sequelae was analyzed using logistic regression.ResultsIn accident cases, the Patient (P) factor (odds ratio = 2.65, p = 0.006) and the Management (m) factor (odds ratio = 2.46, p = 0.033) were significantly associated with the occurrence of sequelae. In incident cases, the Liveware (L) factor (i.e., human error) was involved in 80.2% of reports, and the Hardware (H) factor (i.e., medical devices) in 52.7%, highlighting the critical roles of human and device-related factors.ConclusionTo ensure the safe use of HFNC, it is essential to implement risk mitigation strategies targeting the Patient and Management factors, such as comprehensive patient screening and strengthened organizational systems. Furthermore, given the high involvement of the Liveware and Hardware factors, structured educational programs and practical interventions for medical device operation are warranted.

INTRODUCTION High-flow nasal cannula (HFNC) therapy has emerged as a valuable therapy for adult patients with acute respiratory failure(,) or to prevent postextubation respiratory failure.(,) Currently, HFNC therapy is recommended in guidelines on the management of patients with coronavirus 2019 disease (COVID-19).() HFNC therapy delivers humidified and heated gas at a high flow that can […]

IntroductionApproximately 30% of otherwise healthy children will have residual obstructive sleep apnoea (OSA) after first line therapy with adenotonsillectomy (AT) with lower success rates in children with risk factors. Continuous positive airway pressure (CPAP) is often the next treatment option and, whilst highly effective therapy, can be challenging to sustain in children. A pilot study is underway at our centre to evaluate the efficacy of heated humidified high flow nasal cannula therapy (HFNC) compared to CPAP in children with residual OSA. A secondary aim of this study is to determine which therapy (HFNC versus CPAP) the patients prefer. This abstract will report preliminary findings.MethodsChildren under 18 years old identified as requiring a CPAP trial for residual OSA management were invited to undergo an additional polysomnography, where they underwent a trial of HFNC overnight, which was undertaken in a similar manner to the CPAP trial. Participants and caregivers completed a questionnaire regarding comfort level following both the HFNC and CPAP titration nights.Results11 participants (4 males) between 4 months and 15 years old have completed the study to date. Using an 11-point Likert scale, the average reported comfort level grading for HFNC was 1.5 points higher than CPAP.DiscussionThis preliminary data suggests that on average caregivers and participants found HFNC more comfortable than CPAP. Alternative therapies such as HFNC may be effective in managing OSA and may be better tolerated in children non-adherent to CPAP.