Outcomes Of High-flow Nasal Cannula Research Articles

Comparison of Treatment Outcomes of High-Flow Nasal Cannula and Nasal Continuous Positive Airway Pressure in Preterm Neonates with Respiratory Distress Syndrome in the NICU of Shahid Sadoughi Hospital in Yazd

Background: Neonatal respiratory distress syndrome (RDS) is a common and urgent condition in newborns, caused by a lack of surfactant production and secretion. This study aimed to compare two non-invasive methods, nasal continuous positive airway pressure (nCPAP) and highflow nasal cannula (HFNC), for managing RDS. Methods: The study was conducted in the Neonatal Intensive Care Unit (NICU) of Shahid Sadoughi Hospital between 2020 and 2021 and included 49 premature neonates (with gestation ≤34 weeks and birth weight ≤2,000 g) diagnosed with RDS. The neonates were randomly assigned to either the HFNC group (n = 24) or the nCPAP group (n = 25). Results: No significant differences in demographic features were observed between the two groups. The HFNC group had lower rates of intubation, shorter hospitalization duration, and less need for full nutritional support and oxygen therapy compared to the nCPAP group, but these differences were not statistically significant. Additionally, there were no significant differences in complications such as traumatic nasal injury, apnea, necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD), pneumothorax, pulmonary hemorrhage, and mortality between the two groups. Conclusion: The results of this study suggest that both HFNC and nCPAP are equally effective in treating premature neonates with RDS, with no significant differences in clinical outcomes. Given the cost-effectiveness of HFNC, medical staff expertise, and equipment accessibility, this approach could be considered a viable alternative to nCPAP.

Outcome of high-flow nasal cannula (HFNC) therapy in respiratory failure due to lower respiratory tract infections in PICU - a single center experience in Karachi, Pakistan.

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.

Comparison of Two Methods for Weaning from Nasal Continuous Positive Airway Pressure via the Cyclic Use of High-Flow Nasal Cannula or Room Air in Preterm Infants.

Nasal continuous positive airway pressure (NCPAP) is extensively used for preterm infants experiencing respiratory distress syndrome (RDS). Weaning from NCPAP includes direct weaning or gradually extending room air exposure. However, a high-flow nasal cannula (HFNC) is an alternative weaning method. Therefore, this study evaluated the clinical outcomes of HFNC and progressively increasing room air duration as weaning strategies. This study enrolled 46 preterm infants with RDS receiving NCPAP support who underwent the cyclic use of NCPAP and HFNC weaning protocol as the HFNC group; a retrospective analysis included 87 preterm infants weaned from NCPAP by gradually extending room air duration as the room air group. Differences in clinical conditions, complications, and short-term outcomes between the weaning methods were compared. The mean post-menstrual age at initiating NCPAP weaning was lower in the room air group than in the HFNC group (mean ± SD, 35.2 ± 2.3 weeks vs. 33.2 ± 2.5 weeks, p < 0.001). Hospital stay duration and total respiratory therapy days were longer in the HFNC group (96 ± 38 days and 80 ± 37 days, respectively) than in the room air group (78 ± 28 days and 56 ± 25 days, respectively), with p-values of 0.006 and <0.001. In conclusion, employing HFNC for weaning from NCPAP resulted in longer hospital admissions and respiratory therapy days than the room air method. However, further studies with a larger sample size are warranted for a more comprehensive evaluation, given the limited number of enrolled patients.

Can the ROX index predict high-flow nasal cannula failure in children under 2 with lower respiratory tract infection?

This study evaluates the ROX index's accuracy in predicting the success or failure of high-flow nasal cannula (HFNC) therapy in children under 2 years with acute respiratory failure (ARF) from lower respiratory tract infections. From January 2018 to 2021 we conducted this multicenter retrospective cohort study, which included patients aged 2-24 months. We aimed to assess HFNC therapy outcomes as either success or failure. The analysis covered patient demographics, diagnoses, vital signs, and ROX index values at intervals from 0 to 48 h after initiating HFNC. We used bivariate analysis, repeated measures ANOVA, multivariate logistic regression, and the area under the receiver operating characteristic (AUC-ROC) curve for statistical analysis. The study involved 529 patients from six centers, with 198 females (37%) and a median age of 9 months (IQR: 3-15 months). HFNC therapy failed in 38% of cases. We observed significant variability in failure rates across different centers and physicians (p < .001). The ROX index was significantly associated with HFNC outcomes at all time points, showing an increasing trend in success cases over time (p < .001), but not in HFNC failure cases. Its predictive ability is limited, with AUC-ROC values ranging from 0.56 at the start to 0.67 at 48 h. While the ROX index is associated with HFNC outcomes in children under 2 years, its predictive ability is modest, impacted by significant variability among patients, physicians, and centers. These findings emphasize the need for more reliable predictive tools for HFNC therapy in this patient population.

Understanding the use and outcomes of high-flow nasal cannula among infants admitted to Canadian hospitals with bronchiolitis (CanFLO): a protocol for a multicentre, retrospective cohort study

IntroductionBronchiolitis is the most common viral lower respiratory tract infection in children under 2 years of age. Respiratory support with high-flow nasal cannula (HFNC) is increasingly used in this patient...

The correlation between lung ultrasound scores and outcomes of high-flow nasal cannula therapy in infants with severe pneumonia

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.

Monitoring the Efficacy of High-Flow Nasal Cannula Oxygen Therapy in Patients with Acute Hypoxemic Respiratory Failure in the General Respiratory Ward: A Prospective Observational Study.

High-flow nasal cannula (HFNC) is widely used to treat hypoxemic respiratory failure. The effectiveness of HFNC treatment and the methods for monitoring its efficacy in the general ward remain unclear. This prospective observational study enrolled 42 patients who had acute hypoxemic respiratory failure requiring HFNC oxygen therapy in the general adult respiratory ward. The primary outcome was the all-cause in-hospital mortality. Secondary outcomes included the association between initial blood test results and HFNC outcomes. Regional ventilation distributions were monitored in 24 patients using electrical impedance tomography (EIT) after HFNC initiation. Patients with successful HFNC treatment had better in-hospital survival (94%) compared to those with failed HFNC treatment (0%, p < 0.001). Neutrophil-to-lymphocyte ratios of ≥9 were more common in patients with failed HFNC (70%) compared to those with successful HFNC (52%, p = 0.070), and these patients had shorter hospital survival rates after HFNC treatment (p = 0.046, Tarone-Ware test). Patients with successful HFNC treatment had a more central ventilation distribution compared to those with failed HFNC treatment (p < 0.05). Similarly, patients who survived HFNC treatment had a more central distribution compared to those who did not survive (p < 0.001). We concluded that HFNC in the general respiratory ward may be a potential rescue therapy for patients with respiratory failure. EIT can potentially monitor patients receiving HFNC therapy.

Comparison of ROX Index and Surfactant Protein-D with HFNC Outcome in COVID-19 Patients

Background: In COVID-19, severe clinical deterioration can lead to respiratory distress. High Flow Nasal Cannula (HFNC) is an oxygenation treatment recommended in severe COVID-19 patients, with various studies showing decreased recovery time and intensive care needed. However, instruments to predict HNFC outcomes, specifically in COVID-19, are not yet widely studied. ROX index is a practical instrument proven effective in predicting HFNC outcome in pneumonia while showing high variabilities of optimum time of assessments and cut-off values in COVID-19. Surfactant Protein-D (SP-D) is an alveolar protein showing potential as a biomarker in acute lung injury and respiratory distress. In this study, we analyzed ROX index and SP-D potential as HFNC outcome predictors in COVID-19 patients. Methods: This prospective study recruited severe and critical COVID-19 patients treated with HFNC. Patient characteristics, laboratory values including initial serum SP-D values, and ROX index were recorded. Significant differences were analyzed using Chi-Square and Mann-Whitney tests. Receiver operating characteristic (ROC) analysis was used to determine HFNC outcome predictive abilities of ROX index and serum SP-D. Result: 31 subjects with successful HFNC outcomes in 19 subjects and failed HFNC outcomes in 12 subjects were included in this study. ROX index and SP-D value were significantly higher in subjects with successful HFNC compared to failed HFNC (p &lt; 0.05). ROX index at 6, 12, and 24 hours showed good HFNC outcome predictive ability (AUC &gt; 0.7, p &lt; 0.05). Conclusion: Successful HFNC outcome in COVID-19 was significantly related to higher ROX index and serum SP-D values. ROX index also showed good potential as an HFNC outcome predictor in COVID-19 patients.

Comparison of High-Flow Nasal Cannula with Conventional Oxygen Therapy in Patients with Hypercapnic Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis.

This study aimed to evaluate the clinical outcomes of high-flow nasal cannula (HFNC) compared with conventional oxygen therapy (COT) in patients with hypercapnic chronic obstructive pulmonary disease (COPD), including arterial partial pressure of carbon dioxide (PaCO2), arterial partial pressure of oxygen (PaO2), respiratory rate (RR), treatment failure, exacerbation rates, adverse events and comfort evaluation. PubMed, EMBASE and the Cochrane Library were retrieved from inception to September 30, 2022. Eligible trials were randomized controlled trials and crossover studies comparing HFNC and COT in hypercapnic COPD patients. Continuous variables were reported as mean and standard derivation and calculated by weighted mean differences (MD), while dichotomous variables were shown as frequency and proportion and calculated by odds ratio (OR), with the 95% confidence intervals (Cl). Statistical analysis was performed using RevMan 5.4 software. Eight studies were included, five with acute hypercapnia and three with chronic hypercapnia. In acute hypercapnic COPD, short-term HFNC reduced PaCO2 (MD -1.55, 95% CI: -2.85 to -0.25, I² = 0%, p <0.05) and treatment failure (OR 0.54, 95% CI: 0.33 to 0.88, I² = 0%, p<0.05), but there were no significant differences in PaO2 (MD -0.36, 95% CI: -2.23 to 1.52, I² = 45%, p=0.71) and RR (MD -1.07, 95% CI: -2.44 to 0.29, I² = 72%, p=0.12). In chronic hypercapnic COPD, HFNC may reduce COPD exacerbation rates, but there was no advantage in improving PaCO2 (MD -1.21, 95% CI: -3.81 to 1.39, I² = 0%, p=0.36) and PaO2 (MD 2.81, 95% CI: -1.39 to 7.02, I² = 0%, p=0.19). Compared with COT, short-term HFNC reduced PaCO2 and the need for escalating respiratory support in acute hypercapnic COPD, whereas long-term HFNC reduced COPD exacerbations rates in chronic hypercapnia. HFNC has great potential for treating hypercapnic COPD.

Comparison of ROX index (SpO2/FIO2 ratio/respiratory rate) with a modified dynamic index incorporating PaO2/FIO2 ratio and heart rate to predict high flow nasal cannula outcomes among patients with acute respiratory failure: a single centre retrospective study

BackgroundHigh flow nasal cannula (HFNC) is increasingly being used to support patients with acute respiratory failure (ARF) and to avoid need for intubation. However, almost one third of the patients do not respond and require escalation of respiratory support. Previously, ROX index (SpO2/FIO2 [SF] ratio/respiratory rate) has been validated among pneumonia patients to facilitate early recognition of patients likely to fail HFNC and therefore, benefit from timely interventions. However, it has been postulated that incorporation of PaO2/FIO2 (PF) ratio from arterial blood gas (ABG) analysis may better predict the outcome of HFNC compared to indices that utilizes SF ratio. Similarly, heart rate increase after HFNC therapy initiation has been found to be associated with HFNC failure. Therefore, we aimed to compare ROX index with a new modified index to predict HFNC outcomes among ARF patients.Materials and methodsThis single centre 2-year retrospective study included ARF patients of varying etiologies treated with HFNC. The modified index incorporated heart rate and substituted PF ratio for SF ratio in addition to respiratory rate. We named the index POX-HR and calculated Delta POX-HR index as the difference pre- and post-HFNC initiation POX-HR. We also recorded ROX index at the time when post-HFNC initiation ABG was done (‘post-HFNC initiation ROX’) and calculated Delta ROX. HFNC success was defined as no need of escalation of respiratory support or discharged to ward within 48 h of HFNC initiation, or successful wean off HFNC for at least 12 h. Evaluation was performed using area under the receiver operating characteristic curve (AUROC) and cut-offs assessed for prediction of HFNC outcomes.ResultsOne hundred eleven patients were initiated on HFNC for ARF, of whom 72 patients (64.9%) had HFNC success. Patients with HFNC failure had significantly lower values for all the indices. At median of 3.33 h (IQR 1.48–7.24 h), Delta POX-HR demonstrated the best prediction accuracy (AUROC 0.813, 95% CI 0.726–0.900). A Delta POX-HR > 0.1 was significantly associated with a lower risk of HFNC failure.ConclusionsOur proposed modified dynamic index (Delta POX-HR) may facilitate early and accurate prediction of HFNC outcomes compared to ROX index among ARF patients of varied etiologies.

Predicting High-Flow Nasal Cannula Therapy Outcomes Using the ROX-HR Index in the Pediatric ICU.

High-flow nasal cannula (HFNC) use is increasing in pediatric patients. Objective measures that predict HFNC outcomes are lacking. The respiratory rate-oxygenation (ROX) and ROX heart rate (ROX-HR) indices are validated to predict HFNC therapy failure in adults. This study examined the performance of both indices in predicting HFNC therapy failure in children admitted to the pediatric ICU (PICU). This retrospective, longitudinal, observational cohort study was completed in a 24-bed PICU in a quaternary care children's hospital. All subjects ≤ 24 months of age initiated on HFNC in the PICU from January 1, 2018-August 31, 2020, were included. The ROX and ROX-HR indices were collected at standardized time points during HFNC therapy. Performance in predicting HFNC failure was evaluated using area under the receiver operating characteristic curve (AUROC) and Kaplan-Meier survival analysis. Failure was defined as escalation of respiratory support to either noninvasive ventilation or endotracheal intubation. Among 446 subject encounters, 111 (24.9%) failed HFNC therapy. HFNC failure was associated with lower ROX and ROX-HR indices at termination compared to HFNC liberation (P < .001). A ROX-HR index < 3 was significantly associated with a higher risk of HFNC failure at 1 (AUROC 0.76, P = .01) and 6 (AUROC 0.81, P = .02) h. ROX-HR may be a useful tool for early identification of patients ≤ 24 months at risk for HFNC failure and allow for earlier intervention. Larger prospective studies are necessary to validate the utility of the ROX-HR index in pediatric patients.

Prediction of high-flow nasal cannula outcomes at the early phase using the modified respiratory rate oxygenation index

BackgroundThis study was designed to explore the early predictive value of the respiratory rate oxygenation (ROX) index modified by PaO2 (mROX) in high-flow nasal cannula (HFNC) therapy in patients with acute hypoxemia respiratory failure (AHRF).MethodSeventy-five patients with AHRF treated with HFNC were retrospectively reviewed. Respiratory parameters at baseline and 2 h after HFNC initiation were analyzed. The predictive value of the ROX (ratio of pulse oximetry/FIO2 to respiratory rate) and mROX (ratio of arterial oxygen /FIO2 to respiratory rate) indices with two variations by adding heart rate to each index (ROX-HR and mROX-HR) was evaluated.ResultsHFNC therapy failed in 24 patients, who had significantly higher intensive care unit (ICU) mortality and longer ICU stay. Both the ROX and mROX indices at 2 h after HFNC initiation can predict the risk of intubation after HFNC. Two hours after HFNC initiation, the mROX index had a higher area under the receiver operating characteristic curve (AUROC) for predicting HFNC success than the ROX index. Besides, baseline mROX index of greater than 7.1 showed a specificity of 100% for HFNC success.ConclusionThe mROX index may be a suitable predictor of HFNC therapy outcomes at the early phase in patients with AHRF.

Variation in Use of High-Flow Nasal Cannula and Noninvasive Ventilation Among Patients With COVID-19.

The use of high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) for hypoxemic respiratory failure secondary to COVID-19 are recommended by critical-care guidelines; however, apprehension about viral particle aerosolization and patient self-inflicted lung injury may have limited use. We aimed to describe hospital variation in the use and clinical outcomes of HFNC and NIV for the management of COVID-19. This was a retrospective observational study of adults hospitalized with COVID-19 who received supplemental oxygen between February 15, 2020, and April 12, 2021, across 102 international and United States hospitals by using the COVID-19 Registry. Associations of HFNC and NIV use with clinical outcomes were evaluated by using multivariable adjusted hierarchical random-effects logistic regression models. Hospital variation was characterized by using intraclass correlation and the median odds ratio. Among 13,454 adults with COVID-19 who received supplemental oxygen, 8,143 (60%) received nasal cannula/face mask only, 2,859 (21%) received HFNC, 878 (7%) received NIV, 1,574 (12%) received both HFNC and NIV, with 3,640 subjects (27%) progressing to invasive ventilation. The hospital of admission contributed to 24% of the risk-adjusted variation in HFNC and 30% of the risk-adjusted variation in NIV. The median odds ratio for hospital variation of HFNC was 2.6 (95% CI 1.4-4.9) and of NIV was 3.1 (95% CI 1.2-8.1). Among 5,311 subjects who received HFNC and/or NIV, 2,772 (52%) did not receive invasive ventilation and survived to hospital discharge. Hospital-level use of HFNC or NIV were not associated with the rates of invasive ventilation or mortality. Hospital variation in the use of HFNC and NIV for acute respiratory failure secondary to COVID-19 was great but was not associated with intubation or mortality. The wide variation and relatively low use of HFNC/NIV observed within our study signaled that implementation of increased HFNC/NIV use in patients with COVID-19 will require changes to current care delivery practices. (ClinicalTrials.gov registration NCT04323787.).

First Attempt at Using Electrical Impedance Tomography to Predict High Flow Nasal Cannula Therapy Outcomes at an Early Phase.

Objective: Spatial and temporal ventilation distributions in patients with acute respiratory failure during high flow nasal cannula (HFNC) therapy were previously studied with electrical impedance tomography (EIT). The aim of the study was to explore the possibility of predicting HFNC failure based on various EIT-derived parameters.Methods: High flow nasal cannula failure was defined reintubation within 48 h after HFNC. EIT was performed with the patients spontaneously breathing in the supine position at the start of HFNC. EIT-based indices (comprising the global inhomogeneity index, center of ventilation, ventilation delay, rapid shallow breathing index, minute volume, and inspiration to expiration time) were explored and evaluated at three time points (prior to HFNC, T1; 30 min after HFNC started, T2; and 1 h after, T3).Results: A total of 46 subjects were included in the final analysis. Eleven subjects had failed HFNC. The time to failure was 27.8 ± 12.4 h. The ROX index (defined as SpO2/FiO2/respiratory rate) for HFNC success patients was 8.3 ± 2.7 and for HFNC failure patients, 6.2 ± 1.8 (p = 0.23). None of the investigated EIT-based parameters showed significant differences between subjects with HFNC failure and success. Further subgroup analysis indicated that a significant difference in ventilation inhomogeneity was found between ARDS and non-ARDS [0.54 (0.37) vs. 0.46 (0.28) as evaluated with GI, p < 0.01]. Ventilation homogeneity significantly improved in ARDS after 60-min HFNC treatment [0.59 (0.20) vs 0.57 (0.19), T1 vs. T3, p < 0.05].Conclusion: Spatial and temporal ventilation distributions were slightly but insignificantly different between the HFNC success and failure groups. HFNC failure could not be predicted by changes in EIT temporal and spatial indexes of ventilation distribution within the first hour. Further studies are required to predict the outcomes of HFNC.

High-Flow Nasal Cannula for Patients with Acute Respiratory Failure Treated in a General Medical Ward: A Prospective Cohort Study

Background: Hypoxemia and the need for oxygen administration are frequent causes of hospital admission. High-flow nasal cannula (HFNC) delivers heated humidified high-flow gas at an adjustable inspired oxygen fraction via a large-bore nasal cannula and provide specific physiological benefits. The efficacy of HFNC has been investigated in the intensive care unit but data in other care settings are scarce, especially in low- and middle-income countries. Objective: To describe the safety and associated clinical outcomes of HFNC used in patients admitted to general medical wards. Materials and Methods: The present study was a prospective cohort study that enrolled adult patients with acute respiratory failure and no other major organ failures admitted to the general medical wards at Siriraj Hospital in Bangkok and treated with HFNC. Enrolled subjects were managed by a multidisciplinary care team trained in HFNC usage. The primary outcome was to determine the rate of HFNC failure, defined as the subsequent need for endotracheal intubation, non-invasive ventilation (NIV), reintubation, or death within 48 hours. Secondary outcomes included determining the in-hospital mortality, 28-day mortality, and the factors associated with HFNC failure. Results: Seventy-one subjects were enrolled. In these patients, acute de novo hypoxemic respiratory failure was the most common indication for HFNC (42.3%), followed by prophylaxis after extubation (38.0%), and cardiogenic pulmonary edema (19.7%). The overall rate of HFNC failure was 25.4%. The overall in-hospital and 28-day mortality rates were 14.1% and 21.1%, respectively. The only factor associated with HFNC failure was the respiratory rate at day 1. Conclusion: The use of HFNC in general medical wards is feasible, but a 25% rate of failure within 48 hours can be expected. A higher respiratory rate at day 1 is associated with the failure of HFNC. Keywords: Acute respiratory failure; General medical ward; High-flow oxygen therapy; Outcomes; Safety

SpO2/FiO2 as a predictor of high flow nasal cannula outcomes in children with acute hypoxemic respiratory failure

The high-flow nasal cannula (HFNC) is a useful treatment modality for acute hypoxemic respiratory failure (AHRF) in children. We compared the ability of the oxygen saturation to fraction of inspired oxygen ratio (S/F) and arterial oxygen partial pressure to fraction of inspired oxygen ratio (P/F) to predict HFNC outcomes in children with AHRF. This study included children treated with HFNC due to AHRF from April 2013 to March 2019 at the Severance Children’s Hospital. HFNC failure was defined as the need for mechanical ventilation. Trends of S/F and P/F during HFNC were analyzed. To predict HFNC outcomes, a nomogram was constructed based on predictive factors. A total of 139 patients with arterial blood gas data were included in the S/F and P/F analyses. S/F < 230 at initiation showed high prediction accuracy for HFNC failure (area under the receiver operating characteristic curve: 0.751). Univariate analyses identified S/F < 230 at HFNC initiation and < 200 at 2 h (odds ratio [OR] 12.83, 95% CI 5.06–35.84), and hemato-oncologic disease (OR 3.79, 95% CI 1.12–12.78) as significant predictive factors of HFNC failure. The constructed nomogram had a highly predictive performance, with a concordance index of 0.765 and 0.831 for the exploratory and validation groups, respectively. S/F may be used as a predictor of HFNC outcomes. Our nomogram with S/F for HFNC failure within 2 h may prevent delayed intubation in children with AHRF.

Comparison of High-Flow Nasal Cannula and Conventional Oxygen Therapy Following Extubation After Pediatric Cardiac Surgery: A Retrospective Study

Introduction: Infants and children with congenital heart disease may develop respiratory failure in association with cardiac surgery or as a result of heart disease. In fact, the postextubation period in this group of patients can be complex and the use of continuous positive airway pressure or non-invasive ventilation may be necessary if conventional oxygen therapy is not sufficient. The aim of our study was to compare efficiency and outcomes of high-flow nasal cannula or conventional oxygen therapy post-extubation after pediatric cardiac surgery. Patients and Methods: A single centre retrospective study was conducted between January and December 2020 in our 12 beds pediatric cardiac intensive care unit. Patients were divided into two groups. In one group 45 patients (Group I), those who received high-flow nasal cannula after extubation, and in the other group 45 patients (Group II), those who received oxygen therapy with a mask after extubation. The aim of the study was to evaluate the rela- tive efficacy of high flow nasal cannula and conventional oxygen therapy on PaCO2, PaO2 and PaO2/FiO2. Results: PaO2 values at 1, 6, 12, 24 and 48 hour post-extubation were significantly higher in high-flow nasal cannula group (p&lt; 0.05). PaCO2 values were significantly lower in the high-flow nasal cannula group at 1, 6, 12, 24 and 48 hour post-extubation (p= 0.01). PaO2/FiO2 values in high-flow nasal cannula group at all-time points post-extubation were significantly higher than in conventional oxygen therapy group (p= 0.01). Conclusion: High-flow nasal cannula is useful in decreasing PaCO2 and improving PaO2 in children follow- ing extubation after cardiac surgery. In addition, the simplicity of and tolerability to high-flow nasal cannula is also important. Although more expensive, the use of high-flow nasal cannula can be considered as a safe and effective alternative to conventional oxygen therapy following pediatric cardiac surgery.

Application of high-flow nasal cannula in hypoxemic patients with COVID-19: a retrospective cohort study

BackgroundIt had been shown that High-flow nasal cannula (HFNC) is an effective initial support strategy for patients with acute respiratory failure. However, the efficacy of HFNC for patients with COVID-19 has not been established. This study was performed to assess the efficacy of HFNC for patients with COVID-19 and describe early predictors of HFNC treatment success in order to develop a prediction tool that accurately identifies the need for upgrade respiratory support therapy.MethodsWe retrospectively reviewed the medical records of patients with COVID-19 treated by HFNC in respiratory wards of 2 hospitals in Wuhan between 1 January and 1 March 2020. Overall clinical outcomes, the success rate of HFNC strategy and related respiratory variables were evaluated.ResultsA total of 105 patients were analyzed. Of these, 65 patients (61.9%) showed improved oxygenation and were successfully withdrawn from HFNC. The PaO2/FiO2 ratio, SpO2/FiO2 ratio and ROX index (SpO2/FiO2*RR) at 6h, 12h and 24h of HFNC initiation were closely related to the prognosis. The ROX index after 6h of HFNC initiation (AUROC, 0.798) had good predictive capacity for outcomes of HFNC. In the multivariate logistic regression analysis, young age, gender of female, and lower SOFA score all have predictive value, while a ROX index greater than 5.55 at 6 h after initiation was significantly associated with HFNC success (OR, 17.821; 95% CI, 3.741-84.903 p<0.001).ConclusionsOur study indicated that HFNC was an effective way of respiratory support in the treatment of COVID-19 patients. The ROX index after 6h after initiating HFNC had good predictive capacity for HFNC outcomes.

Clinical outcomes of high-flow nasal cannula in COVID-19 associated postextubation respiratory failure. Asingle-centre case series.

A high-flow nasal cannula (HFNC) is an alternative device for oxygena-tion, which improves gas exchange and reduces the work of breathing. Postextubation respiratory failure causes increased morbidity and mortality. HFNC has been widely employed during the COVID-19 pandemic. The purpose of this paper is to report a single-centre experience on the effectiveness and safety of HFNC in weaning COVID-19 patients. Nine patients showed severe acute respiratory failure and interstitial pneumonia due to SARS-CoV-2. After mechanical ventilation (5 Helmet CPAP, 4 invasive mechanical ventilation), they were de-escalated to HFNC. Settings were: 34-37°C, flow from 50 to 60 L min-1. FiO2 was set to achieve appropriate SpO2. Nine patients (4 females; age 63 ± 13.27 years; BMI 27.2 ± 4.27) showed a baseline PaO2/FiO2 of 109 ± 45 mm Hg. After a long course of ventilation all patients improved (PaO2/FiO2 336 ± 72 mm Hg). Immediately after initiation of HFNC (2 hours), PaO2/FiO2 was 254 ± 69.3 mm Hg. Mean ROX index at two hours was 11.17 (range: 7.38-14.4). It was consistent with low risk of HFNC failure. No difference was observed on lactate. After 48 hours of HFNC oxygen therapy (day 3), mean PaO2/FiO2 increased to 396 ± 83.5 mm Hg. All patients recovered from respiratory failure after 7 ± 4.1 days. HFNC might be helpful in weaning COVID-19 respiratory failure. Effectiveness and comfort should be assessed between 2 and 48 hours. Clinical outcomes, oxygenation, and ROX index should be considered, to rule out the need for intubation. Further evidence is required for firm conclusions.

High-flow nasal cannula therapy: clinical practice in intensive care units

BackgroundDespite the extensive use of high-flow nasal cannula (HFNC) therapy in intensive care units (ICU) for acute respiratory failure (ARF), its daily clinical practice has not been assessed. We designed a regional survey in ICUs in North-west France to evaluate ICU physicians’ clinical practice with HFNC.Materials and methodsWe sent an observational survey to ICU physicians from 34 French ICUs over a 6-month period in 2016–2017. The survey included questions regarding the indications and expected efficiency of HFNC, practical aspects of use (initiation, weaning) and satisfaction. Comparisons between junior and senior ICU physicians were performed using a Fischer exact test.ResultsAmong the 235 ICU physicians contacted, 137 responded (58.3%) all of whom regularly used HFNC. Hypoxemic ARF was considered a good indication for HFNC by all 137, but only 30% expected HFNC success (i.e., avoiding intubation in at least 60% of cases). Among hypoxemic indications, 30% of juniors considered acute pulmonary edema a good indication versus 74% of seniors (p < 0.0001). Hypercapnic ARF was considered a good indication by 33% with only 2% expecting HFNC success. A need for conventional oxygen therapy ≥ 6 L/min justified HFNC therapy for 40% and ≥ 9 L/min for 39% of responders. 58% of ICU physicians started HFNC therapy with a FiO2 ≥ 50% and 28% with a gas flow ≥ 50 L/min. Practices for HFNC weaning were heterogeneous: 48% considered a FiO2 ≤ 30%; whereas, 30% considered a FiO2 ≤ 30% with a high flow ≤ 20 L/min. Criteria for HFNC failure (i.e., need for intubation) were ventilatory pauses or arrest (97%), persistent hypoxemia (95%), respiratory acidosis (81%), worsening of breathing (95%, 100% of seniors and 86% of juniors, p = 0.003), bronchial congestion (75%) and circulatory failure (61%, 72% of seniors and 44% of juniors, p = 0.007).ConclusionHFNC is used by ICU physicians in many situations of ARF, despite their relatively low expectations of success, especially in cases of hypercapnia. Clinical practices appear somewhat heterogeneous. Despite the physiological benefit of HFNC, further prospective observational studies are still required on HFNC outcomes and daily practices.