High-flow Nasal Cannula Success Research Articles

Respiratory Support Practices for Bronchiolitis in the Pediatric Intensive Care Unit

Admissions to the pediatric intensive care unit (PICU) due to bronchiolitis are increasing. Whether this increase is associated with changes in noninvasive respiratory support practices is unknown. To assess whether the number of PICU admissions for bronchiolitis between 2013 and 2022 was associated with changes in the use of high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and invasive mechanical ventilation (IMV) and to identify factors associated with HFNC and NIV success and failure. This cross-sectional study examined encounter data from the Virtual Pediatric Systems database on annual PICU admissions for bronchiolitis and ventilation practices among patients aged younger than 2 years admitted to 27 PICUs between January 1, 2013, and December 31, 2022. Use of HFNC and NIV was defined as successful if patients were weaned to less invasive support (room air or low-flow nasal cannula for HFNC; room air, low-flow nasal cannula, or HFNC for NIV). The main outcome was the number of PICU admissions for bronchiolitis requiring the use of HFNC, NIV, or IMV. Linear regression was used to analyze the association between admission year and absolute numbers of encounters stratified by the maximum level of respiratory support required. Multivariable logistic regression was used to analyze factors associated with HFNC and NIV success and failure (defined as not meeting the criteria for success). Included in the analysis were 33 816 encounters for patients with bronchiolitis (20 186 males [59.7%]; 1910 patients [5.6%] aged ≤28 days and 31 906 patients [94.4%] aged 29 days to <2 years) treated at 27 PICUs from 2013 to 2022. A total of 7615 of 15 518 patients (49.1%) had respiratory syncytial virus infection and 1522 of 33 816 (4.5%) had preexisting cardiac disease. Admissions to the PICU increased by 350 (95% CI, 170-531) encounters annually. When data were grouped by the maximum level of respiratory support required, HFNC use increased by 242 (95% CI, 139-345) encounters per year and NIV use increased by 126 (95% CI, 64-189) encounters per year. The use of IMV did not significantly change (10 [95% CI, -11 to 31] encounters per year). In all, 22 381 patients (81.8%) were successfully weaned from HFNC to low-flow oxygen therapy or room air, 431 (1.6%) were restarted on HFNC, 3057 (11.2%) were escalated to NIV, and 1476 (5.4%) were escalated to IMV or extracorporeal membrane oxygenation (ECMO). Successful use of HFNC increased from 820 of 1027 encounters (79.8%) in 2013 to 3693 of 4399 encounters (84.0%) in 2022 (P = .002). In all, 8476 patients (81.5%) were successfully weaned from NIV, 787 (7.6%) were restarted on NIV, and 1135 (10.9%) were escalated to IMV or ECMO. Success with NIV increased from 224 of 306 encounters (73.2%) in 2013 to 1335 of 1589 encounters (84.0%) in 2022 (P < .001). In multivariable logistic regression, lower weight, higher Pediatric Risk of Mortality III score, cardiac disease, and PICU admission from outside the emergency department were associated with greater odds of HFNC and NIV failure. Findings of this cross-sectional study of patients aged younger than 2 years admitted for bronchiolitis suggest there was a 3-fold increase in PICU admissions between 2013 and 2022 associated with a 4.8-fold increase in HFNC use and a 5.8-fold increase in NIV use. Further research is needed to standardize approaches to HFNC and NIV support in bronchiolitis to reduce resource strain.

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.

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.

Comparison of the effectiveness of different high-flow devices in neonatal care

ObjectiveTo evaluate the success rate of high-flow nasal cannula (HFNC) therapy using an adapted obsolete mechanical ventilator (MV), Optiflow™ and Vapotherm™ in newborns (NBs). MethodThis was a retrospective observational study conducted in the neonatal intensive care unit (NICU). The sample comprised NBs who underwent HFNC therapy due to ventilatory dysfunction, for weaning from non-invasive ventilation (NIV), or post-extubation. The three groups, stratified according to gestational age (GA) and birth weight, and corrected GA and weight at the beginning of HFNC use, were as follows: Optiflow ™, Vapotherm ™, and obsolete Mechanical Ventilator (MV) adapted for high flow therapy. Subsequently, the NBs were divided into a success group (SG) and a failure group (FG). HFNC success was defined as a therapy duration exceeding 72 h. ResultsA total of 209 NBs were evaluated, with 31.1 % using HFNC due to ventilatory dysfunction, 2.4 % after extubation, and 66.5 % after NIV weaning. HFNC success rate was observed in 90.9 % of the NBs, with no difference between equipment types (Vapotherm ™, Optiflow ™, and adapted VM). ConclusionDifferent types of HFNC equipment are equally effective when used in neonatology for respiratory dysfunction, as a method of weaning from NIV and post-extubation. Adapted obsolete MV can be an alternative for HFCN therapy in resource-constrained settings.

Use of non-invasive respiratory supports in high-intensity internal medicine setting during the first two waves of the COVID-19 pandemic emergency in Italy: a multicenter, real-life experience

During the first two waves of the COVID-19 emergency in Italy, internal medicine high-dependency wards (HDW) have been organized to manage patients with acute respiratory failure (ARF). There is heterogeneous evidence about the feasibility and outcomes of non-invasive respiratory supports (NIRS) in settings outside the intensive care unit (ICU), including in patients deemed not eligible for intubation (i.e., with do-not-intubate, DNI status). Few data are available about the different NIRS modalities applied to ARF patients in the newly assembled internal medicine HDW. The main aim of our study was to describe a real-life experience in this setting of cure, focusing on feasibility and outcomes. We retrospectively collected data from COVID-19 patients with ARF needing NIRS and admitted to internal medicine HDW. Patients were treated with different modalities, that is high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), or non-invasive mechanical ventilation (NIMV). Switching among different NIRS during the hospitalization and the success rate (weaning with the same NIRS) or failure (endotracheal intubation-ETI or in-hospital death) were recorded. Three hundred thirty four ARF patients (median age 74 years), of which 158 (54%) had a DNI status, were included. CPAP, NIMV, and HFNC's success rates were 54, 33, and 13%, respectively. Although DNI status was strongly associated with death (Gehan–Breslow–Wilcoxon test p < 0.001), an acceptable success rate was observed in these patients using CPAP (47%). Multivariate regression models showed older age (odds ratio—OR 4.74), chronic ischemic heart disease (OR 2.76), high respiratory rate after 24 h (OR 7.13), and suspected acute respiratory distress syndrome—ARDS (OR 21.1) as predictors of mortality risk or ETI. Our real-life experience shows that NIRS was feasible in internal medicine HDW with an acceptable success rate. Although DNI patients had a worse prognosis, the use of NIRS represented a reasonable chance of treatment.

Analysis of C-Reactive Protein, Neutrophil-to-Lymphocyte Ratio, PaO2/FiO2 Ratio on the Success of High Flow Nasal Cannula Usage in Hospitalized COVID-19 Patients

Background: Several studies had shown High Flow Nasal Cannula (HFNC) is effective in treating hypoxemic COVID-19 patients. The C-Reactive Protein and Neutrophil-to-Lymphocyte Ratio is an inflammatory marker that could predict the severity of COVID-19, where the P/F ratio infers oxygenation status. Since COVID-19-related ARDS is closely related to a hyper-inflammatory state and HFNC becomes widely utilized for hypoxemic patients, it has become important to discover reliable inflammatory biomarkers related to therapeutic HFNC success. This study aims to assess the factors that influence the success of HNFC therapy, in terms of demographic and laboratory profiles of CRP, NLR, and P/F ratio. Method: A retrospective, single-center cohort study was conducted in a tertiary care hospital in Malang, East Java from January to March 2022. Subjects of 31 PCR-confirmed, hospitalized COVID-19 patients who were treated with HFNC were included. Results: This study involved 2 groups comprised of 19 subjects with successful HFNC and 12 patients who failed. Significant demographic factors affecting successful HFNC were female gender (OR=1.46 95% CI=1.08-1.99; P=0.037) and occupation type (P=0.023). Whereas, biomarkers of CRP (8.90±6.8 mg/L vs 12.39±11.7 mg/L; P=0.656), NLR (7.24±4.66 vs 12.85±12.9; P=0.243) and P/F ratio (171.40±54 vs 148.00±40; P=0.219) were found to be non-significant between successful and failed HFNC cohorts, respectively. Conclusion: HFNC could provide a specific positive end-expiratory pressure in COVID-19 patients with contributing factors of successful HFNC being female and occupational type. However, CRP, NLR, and P/F did not contribute significantly to HFNC's success.

The Use of the "Respiratory Rate Oxygenation (ROX) Index" in the Assessment of Respiratory Support and Observation of Its Outcome in COVID-19 Patients With Acute Respiratory Failure.

COVID-19 infection caused by the SARS-Cov-2 virus may result in severe acute respiratory failure and require respiratory support in the ICU. The present study was designed to evaluate the role of the respiratory rate oxygenation (ROX) index in the assessment of the adequacy of non-invasive respiratory support the COVID-19 patients with acute respiratory failure and observe its outcome. This cross-sectional, observational study was conducted between October 2020 and September 2021 in the Department of Anaesthesia, Analgesia, and Intensive Care Medicine of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. A total of 44 patients with a confirmed diagnosis of COVID-19 with acute respiratory failure were enrolled in this study based on inclusion and exclusion criteria. Informed written consent was taken from the patient/patient's guardian. Each patient underwent detailed history taking through physical examination and relevant investigations.All necessary information were recorded in a separate case record form. All the patients receiving high-flow nasal cannula (HFNC) were assessed at two hours, six hours, and 12 hours for variables of the ROX Index. The team of respective physicians was applied responsibly for determining HFNC failure to discontinue or deescalate respiratory support as a part of continuous positive airway pressure (CPAP) ventilation success. Each selected patient was observed for the duration of different types of respiratory support. CPAP failure or success, progression to mechanical ventilation, and data were collected from individual medical records. The patients who were successfully weaned from CPAP were recorded. The diagnostic accuracy of the ROX index was determined. The mean age of the patients was 65±8.80 years with a majority in the age group 61-70 years (36.4%). A male predominance was observed with 79.5% male and 20.5% female. Of all, HFNC failure was observed in 29.5% of patients. Oxygen saturation (SpO2), respiratory rate (RR), and ROX index were statistically worse at the sixthand 12th hour of initiation of HFNC (P<0.05). At a cut-off value of 3.90, the ROC curve showed 90.3% sensitivity and 76.9% specificity in predicting HFNC success (the area under the curve (AUC) was 0.909). Similarly, 46.2% of patients had CPAP failure. SpO2, RR, and ROX index were found statistically worse among those patients at the sixth and 12th hour of CPAP therapy (P<0.05). The ROC curve showed 85.7% sensitivity and 83.3% specificity at a cut-off value of 2.64 in predicting CPAP success (the AUC was 0.881). The ROX index's clinical score form, which does not require lab findings or sophisticated computation techniques, is its key benefit. The study findings recommend the use of the ROX index to predict the outcome of respiratory support in acute respiratory failure in COVID-19 patients.

Predictive Accuracy of the ROX Index for Re-Intubation in Mechanically Ventilated Patients With COVID-19.

Several studies have suggested that high-flow nasal cannula (HFNC) is useful for respiratory support after extubation in subjects with COVID-19 pneumonia, whereas 18% subsequently needed to undergo re-intubation. This study aimed to evaluate whether the breathing frequency (f)-ratio of oxygen saturation (ROX) index, which has been shown to be useful for predicting future intubation, is also useful for re-intubation in subjects with COVID-19. We retrospectively analyzed mechanically ventilated subjects with COVID-19 who underwent HFNC therapy after extubation at 4 participating hospitals between January 2020-May 2022. We evaluated the predictive accuracy of ROX at 0, 1, and 2 h for re-intubation until ICU discharge and compared the area under the receiver operating characteristic (ROC) curve of the ROX index with those of f and SpO2 /FIO2 . Among the 248 subjects with COVID-19 pneumonia, 44 who underwent HFNC therapy after extubation were included. A total of 32 subjects without re-intubation were classified into the HFNC success group, and 12 with re-intubation were classified into the failure group. The overall trend that the area under the ROC curve of the ROX index was greater than that of the f and SaO2 /FIO2 was observed, although there was no statistical significance at any time point. The ROX index at 0 h, at the cutoff point of < 7.44, showed a sensitivity and specificity of 0.42 and 0.97, respectively. A trend of positive correlation between the time until re-intubation and ROX index at each time point was observed. The ROX index in the early phase of HFNC therapy after extubation was useful for predicting re-intubation with high accuracy in mechanically ventilated subjects with COVID-19. Close observation for patients with < 7.44 ROX index just after extubation may be warranted because of their high risk for re-intubation.

High-flow nasal cannula for severe COVID-19 patients in a Japanese single-center, retrospective, observational study: 1 year of clinical experience.

High-flow nasal cannula (HFNC) can be effective in treating type 1 respiratory failure by reducing the severity of coronavirus disease 2019 (COVID-19). The purpose of this study was to assess the reduction of disease severity and safety of HFNC treatment in patients with severe COVID-19. We retrospectively observed 513 consecutive patients with COVID-19 admitted to our hospital from January 2020 to January 2021. We included patients with severe COVID-19 who received HFNC for their deteriorating respiratory status. HFNC success was defined as improvement in respiratory status after HFNC and transfer to conventional oxygen therapy, while HFNC failure was defined as transfer to non-invasive positive pressure ventilation or ventilator, or death after HFNC. Predictive factors associated with failure to prevent severe disease were identified. Thirty-eight patients received HFNC. Twenty-five (65.8%) patients were classified in the HFNC success group. In the univariate analysis, age, history of chronic kidney disease (CKD), non-respiratory sequential organ failure assessment (SOFA) ≥ 1, oxygen saturation to fraction of inspired oxygen ratio (SpO2/FiO2) before HFNC ≤ 169.2, were significant predictors of HFNC failure. Multivariate analysis revealed that SpO2/FiO2 value before HFNC ≤ 169.2 was an independent predictor of HFNC failure. No apparent nosocomial infection occurred during the study period. Appropriate use of HFNC for acute respiratory failure caused by COVID-19 can reduce the severity of severe disease without causing nosocomial infection. Age, history of CKD, non-respiratory SOFA before HFNC ≤ 1, and SpO2/FiO2 before HFNC ≤ 169.2 were associated with HFNC failure.

Evaluating the use of the respiratory-rate oxygenation index as a predictor of high-flow nasal cannula oxygen failure in COVID-19.

It can be challenging for clinicians to predict which patients with respiratory failure secondary to coronavirus disease 2019 (COVID-19) will fail on high-flow nasal cannula (HFNC) oxygen and require escalation of therapy. This study set out to evaluate the association between the respiratory rate-oxygenation index (ROX) and HFNC failure in such patients and to assess whether ROX trajectory correlates with treatment failure. This was a single-centre, retrospective, observational study of patients with COVID-19 requiring HFNC, conducted over a 3-month period. ROX was calculated as "pulse-oximetry oxygen saturation (SpO2) over the fractional inspired oxygen concentration (FiO2)/respiratory rate" for each patient at 2, 4, and 12 hours from starting HFNC. HFNC failure was defined as escalation to continuous positive airway pressure ventilation or invasive mechanical ventilation (IMV). Time-to-event analyses were performed to account for the longitudinal data set and time-dependent variables. We included 146 patients. Ninety-three (63.7%) experienced HFNC failure, with 53 (36.3%) requiring IMV. Higher ROX values were associated with a lower subhazard of HFNC failure on time-to-HFNC failure analysis (subhazard ratio, 0.29; 95% confidence interval [CI], 0.18-0.46; P<0.001). This remained true after controlling for informative censoring. Median ROX values changed differentially over time, increasing in the HFNC success group (0.06 per hour; 95% CI, 0.05-0.08; P<0.001) but not in the HFNC failure group (0.004 per hour; 95% CI, -0.05 to 0.08; P=0.890). A higher ROX is associated with a lower risk of HFNC failure. Monitoring ROX trajectory over time may help identify patients at risk of treatment failure. This has potential clinical applications; however, future prospective studies are required.

Diaphragmatic Ultrasound Predictors of High-Flow Nasal Cannula Therapeutic Failure in Critically Ill Patients With SARS-CoV-2 Pneumonia.

High flow nasal cannula (HFNC) is frequently used in patients with acute respiratory failure, but there is limited evidence regarding predictors of therapeutic failure. The objective of this study was to assess diaphragmatic ultrasound criteria as predictors of failure to HFNC, defined as the need for orotracheal intubation or death. Prospective cohort study including adult patients consecutively admitted to the critical care unit, from July 24 to October 20, 2020, with respiratory failure secondary to SARS-CoV-2 pneumonia who required HFNC. After 12hours of HFNC initiation we measured ROX index (ratio of SpO2 /FiO2 to respiratory rate), excursion and diaphragmatic contraction speed (diaphragmatic excursion/inspiratory time) by ultrasound, both in supine and prone position. In total, 41 patients were analyzed, 25 succeeded and 16 failed HFNC therapy. At 12hours, patients who succeeded HFNC therapy presented higher ROX index in supine position (9.8 [9.1-15.6] versus 5.4 [3.9-6.8], P < .01), and higher PaO2 /FiO2 ratio (186 [135-236] versus 117 [103-162] mmHg, P=.03). To predict therapeutic failure, the supine diaphragmatic contraction speed presented sensitivity of 89% and a specificity of 57%, while the ROX index presented a sensitivity of 92.8% and a specificity of 75%. Diaphragmatic contraction speed by ultrasound emerges as a diagnostic complement to clinical tools to predict HFNC success. Future studies should confirm these results.

Analysis of risk factors for the failure of respiratory support with high-flow nasal cannula oxygen therapy in children with acute respiratory dysfunction: A case-control study.

BackgroundEvidence-based clinical practice guidelines regarding high-flow nasal cannula (HFNC) use for respiratory support in critically ill children are lacking. Therefore, we aimed to determine the risk factors for early HFNC failure to reduce the failure rate and prevent adverse consequences of HFNC failure in children with acute respiratory dysfunction.MethodsDemographic and laboratory data were compared among patients, admitted to the pediatric intensive care unit between January 2017 and December 2018, who were included in a retrospective cohort study. Univariate and multivariate analyses were performed to determine risk factors for eventual entry into the predictive model for early HFNC failure and to perform an external validation study in a prospective observational cohort study from January to February 2019. Further, the association of clinical indices and trends pre- and post-treatment with HFNC treatment success or failure in these patients was dynamically observed.ResultsIn total, 348 pediatric patients were included, of these 282 (81.0%) were included in the retrospective cohort study; HFNC success was observed in 182 patients (64.5%), HFNC 0–24 h failure in 74 patients (26.2%), and HFNC 24–48 h failure in 26 patients (9.2%). HFNC 24 h failure was significantly associated with the pediatric risk of mortality (PRISM) III score [odds ratio, 1.391; 95% confidence interval (CI): 1.249–1.550], arterial partial pressure of carbon dioxide-to-arterial partial pressure of oxygen (PaCO2/PaO2) ratio (odds ratio, 38.397; 95% CI: 6.410–230.013), and respiratory rate-oxygenation (ROX) index (odds ratio, 0.751; 95% CI: 0.616–0.915). The discriminating cutoff point for the new scoring system based on the three risk factors for HFNC 24 h failure was ≥ 2.0 points, with an area under the receiver operating characteristic curve of 0.794 (95% CI, 0.729–0.859, P < 0.001), sensitivity of 68%, and specificity of 79%; similar values were noted on applying the model to the prospective observational cohort comprising 66 patients (AUC = 0.717, 95% CI, 0.675–0.758, sensitivity 83%, specificity 44%, P = 0.009). In this prospective cohort, 11 patients with HFNC failure had an upward trend in PaCO2/PaO2 ratio and downward trends in respiratory failure index (P/F ratio) and ROX index; however, opposite directions of change were observed in 55 patients with HFNC success. Furthermore, the fractional changes (FCs) in PaCO2/PaO2 ratio, P/F ratio, percutaneous oxygen saturation-to-fraction of inspired oxygen (S/F) ratio, and ROX index at 2 h post-HFNC therapy onset were statistically significant between the two groups (all, P < 0.05).ConclusionIn the pediatric patients with acute respiratory insufficiency, pre-treatment PRISM III score, PaCO2/PaO2 ratio, and ROX index were risk factors for HFNC 24 h failure, and the direction and magnitude of changes in the PaCO2/PaO2 ratio, P/F ratio, and ROX index before and 2 h after HFNC treatment were warning indicators for HFNC 24 h failure. Further close monitoring should be considered for patients with these conditions.

Expert consensus on the diagnosis and treatment of severe and critical coronavirus disease 2019.

Expert consensus on the diagnosis and treatment of severe and critical coronavirus disease 2019.

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.

The ROX index as a predictor of high-flow nasal cannula outcome in pneumonia patients with acute hypoxemic respiratory failure: a systematic review and meta-analysis.

BackgroundThe respiratory rate-oxygenation (ROX) index has been increasingly applied to predict the outcome of high-flow nasal cannula (HFNC) in pneumonia patients with acute hypoxemic respiratory failure (AHRF). However, its diagnostic accuracy for the HFNC outcome has not yet been systematically assessed. This meta-analysis sought to evaluate the predictive performance of the ROC index for the successful weaning from HFNC in pneumonia patients with AHRF.MethodsA literature search was conducted on electronic databases through February 12, 2022, to retrieve studies that investigated the diagnostic accuracy of the ROC index for the outcome of HFNC application in pneumonia patients with AHRF. The area under the hierarchical summary receiver operating characteristic curve (AUHSROC) was estimated as the primary measure of diagnostic accuracy due to the varied cutoff values of the index. We observed the distribution of the cutoff values and estimated the optimal threshold with corresponding 95% confidential interval (CI).ResultsThirteen observational studies comprising 1751 patients were included, of whom 1003 (57.3%) successfully weaned from HFNC. The ROC index exhibits good performance for predicting the successful weaning from HFNC in pneumonia patients with AHRF, with an AUHSROC of 0.81 (95% CI 0.77–0.84), a pooled sensitivity of 0.71 (95% CI 0.64–0.78), and a pooled specificity of 0.78 (95% CI 0.70–0.84). The cutoff values of the ROX index were nearly conically symmetrically distributed; most data were centered between 4.5 and 6.0, and the mean and median values were 4.8 (95% CI 4.2–5.4) and 5.3 (95% CI 4.2–5.5), respectively. Moreover, the AUHSROC in the subgroup of measurement within 6 h after commencing HFNC was comparable to that in the subgroup of measurement during 6–12 h. The stratified analyses also suggested that the ROC index was a reliable predictor of HFNC success in pneumonia patients with coronavirus disease 2019.ConclusionsIn pneumonia patients with AHRF, the ROX index measured within 12 h after HFNC initiation is a good predictor of successful weaning from HFNC. The range of 4.2–5.4 may represent the optimal confidence interval for the prediction of HFNC outcome.

The role of ROX index in predicting intubation in COVID-19 pneumonia receiving high flow nasal cannula: A systematic review

Introduction: One of the important COVID-19 management considerations was to prevent delayed intubation. There is a lack of objective criteria to decide the time of intubation. Previously, respiratory parameters were the only tools used to determine the success of high flow nasal cannula (HFNC) therapy, but several studies have reported on the role of respiratory rate oxygenation (ROX) index which combined respiratory rate (RR) and oxygen saturation/fraction of inspired oxygen (SpO2/FiO2) in predicting intubation after receiving high flow nasal cannula (HFNC). The primary objective of this study was to evaluate the validity of the ROX index in predicting intubation in COVID-19 pneumonia receiving HFNC. Methods: This study is a systematic review that used online databases (PubMed, Science Direct, Google Scholar, and CENTRAL) in obtaining eligible journals. The sources of data were from published observational studies and preprints. The outcomes of this study were ROX index validity, intubation predictors, and factors associated with the ROX index. Results: Seven journals were yielded during the search. ROX index was significantly lower in the HFNC failure group at any time interval with high sensitivity and specificity in predicting intubation (p ≤ 0.001). ROX index can be used to predict intubation starting at 4 hours after HFNC initiation and calculated repeatedly. Conclusion: ROX index was a good parameter in predicting intubation in COVID-19 pneumonia patients who receive HFNC. The higher value of the ROX index was associated with a higher chance of HFNC success and a lower risk of mortality.

A Retrospective Study on Experience of High-flow Nasal Cannula Oxygen in Critically Ill COVID-19 Adult Patients Admitted to Intensive Care Unit.

BackgroundThe use of high-flow nasal cannula (HFNC) in coronavirus disease-2019 (COVID-19) patients is debated due to its uncertain benefits and risks of aerosol dispersion. This retrospective study was aimed to assess the outcome of treatment with HFNC therapy in adult COVID-19 patients with acute hypoxemic respiratory failure (AHRF) admitted in intensive care units (ICU) and to assess the factors affecting outcome.Material and methodsWe retrieved electronic medical records of all COVID-19 patients who received HFNC for respiratory support after failure to maintain adequate oxygenation with conventional oxygen devices, between June 1 and August 31, 2020. The data retrieved were statistically analyzed.ResultsA total number of 558 COVID-19 patients were admitted to ICUs, out of which 139 patients were identified to be on HFNC and 85 met the inclusion criteria for the study. The success rate of 48.2% with HFNC was observed in these patients. The patients recorded to experience HFNC success were of young age and having higher baseline oxygen saturation compared to those who had its failure. The ROX indices post-initiation were observed to be significantly higher in the success group (p ≤0.001). Awake-prone positioning while receiving HFNC was followed by around more patients in the success group (p <0.001). On multivariate logistic regression analysis, baseline oxygen saturation, awake-prone positioning, and number of days on HFNC were found to be independently affected outcome with HFNC.ConclusionAlmost half of the cases of moderate-to-severe COVID-19 pneumonia can be managed successfully with HFNC, without the need of mechanical ventilation.How to cite this articleKerai S, Singh R, Saxena KN, Desai SD, Bhalotra AR. A Retrospective Study on Experience of High-flow Nasal Cannula Oxygen in Critically Ill COVID-19 Adult Patients Admitted to Intensive Care Unit. Indian J Crit Care Med 2022;26(1):62–66.

Effectiveness of the use of a high-flow nasal cannula to treat COVID-19 patients and risk factors for failure: a meta-analysis.

Background:Coronavirus disease 2019 (COVID-19) has spread globally, and many patients with severe cases have received oxygen therapy through a high-flow nasal cannula (HFNC).Objectives:We assessed the efficacy of HFNC for treating patients with COVID-19 and risk factors for HFNC failure.Methods:We searched PubMed, Embase, and the Cochrane Central Register of randomized controlled trials (RCTs) and observational studies of HFNC in patients with COVID-19 published in English from January 1st, 2020 to August 15th, 2021. The primary aim was to assess intubation, mortality, and failure rates in COVID-19 patients supported by HFNC. Secondary aims were to compare HFNC success and failure groups and to describe the risk factors for HFNC failure.Results:A total of 25 studies fulfilled selection criteria and included 2851 patients. The intubation, mortality, and failure rates were 0.44 (95% confidence interval (CI): 0.38–0.51, I2 = 84%), 0.23 (95% CI: 0.19–0.29, I2 = 88%), and 0.47 (95% CI: 0.42–0.51, I2 = 56%), respectively. Compared to the success group, age, body mass index (BMI), Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score, D-dimer, lactate, heart rate, and respiratory rate were higher and PaO2, PaO2/FiO2, ROX index (the ratio of SpO2/FiO2 to respiratory rate), ROX index after the initiation of HFNC, and duration of HFNC were lower in the failure group (all Ps < 0.05). There were also more smokers and more comorbidities in the failure group (all Ps < 0.05). Pooled odds ratios (ORs) revealed that older age (OR: 1.04, 95% CI: 1.01–1.07, P = 0.02, I2 = 88%), a higher white blood cell (WBC) count (OR: 1.06, 95% CI: 1.01–1.12, P = 0.02, I2 = 0%), a higher heart rate (OR: 1.42, 95% CI: 1.15–1.76, P < 0.01, I2 = 0%), and a lower ROX index(OR: 0.61, 95% CI: 0.39–0.95, P = 0.03, I2 = 93%) after the initiation of HFNC were all significant risk factors for HFNC failure.Conclusions:HFNC is an effective way of providing respiratory support in the treatment of COVID-19 patients. Older age, a higher WBC count, a higher heart rate, and a lower ROX index after the initiation of HFNC are associated with an increased risk of HFNC failure.

High-flow nasal cannula oxygen therapy in hypoxic patients with COVID-19 pneumonia: A retrospective cohort study confirming the utility of respiratory rate index.

BackgroundAlthough high-flow nasal cannula (HFNC) oxygen treatment has been frequently used in coronavirus disease 2019 (COVID-19) patients with acute respiratory failure after the 3rd wave of the pandemic in Japan, the usefulness of the indicators of ventilator avoidance, including respiratory rate-oxygenation (ROX) index and other parameters, namely oxygen saturation/fraction of inspired oxygen ratio and respiratory rate (RR), remain unclear.MethodsBetween January and May 2021, our institution treated 189 COVID-19 patients with respiratory failure requiring oxygen, among which 39 patients requiring HFNC treatment were retrospectively analyzed. The group that switched from HFNC treatment to conventional oxygen therapy (COT) was defined as the HFNC success group, and the group that switched from HFNC treatment to a ventilator was defined as the HFNC failure group. We followed the patients’ oxygenation parameters for a maximum of 30 days.ResultsHFNC treatment success occurred in 24 of 39 patients (62%) treated with HFNC therapy. Compared with the HFNC failure group, the HFNC success group had a significantly higher degree of RR improvement in the univariate analysis. Logistic regression analysis of HFNC treatment success adjusting for age, respiratory improvement, and a ROX index ≥5.55 demonstrated that an improved RR was associated with HFNC treatment success. The total COT duration was significantly shorter in the HFNC success group than in the HFNC failure group.ConclusionsHFNC treatment can be useful for ventilator avoidance and allow the quick withdrawal of oxygen administration. RR improvement may be a convenient, useful, and simple indicator of HFNC treatment success.

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.