Assessment of Swallowing Function in Healthy Adults While Using High-Flow Nasal Cannula

OBJECTIVE

Despite widespread use of high flow nasal cannula (HFNC) for respiratory support, the effect of HFNC on swallowing physiology is poorly understood. Flow rates that permit safe swallowing have not been established. We aim to assess if healthy individuals have diminished swallowing function and safety at high flow rates.

STUDY DESIGN

Repeated measures with planned data collection.

SETTING

Outpatient dysphagia clinic.

METHODS

Swallowing function in a cohort of healthy individuals was assessed using Flexible Endoscopic Evaluation of Swallowing (FEES). Participants' safety of swallowing was assessed with different textures under randomized rates of HFNC (0, 30, 40, 50, and 60 LPM). Swallowing trials included quantities of thin liquids, mildly-thick liquids, and purees. Trials were scored using the Penetration-Aspiration Scale (PAS). Pearson chi-square tests were used to test for correlation between PAS result, flow rate, and consistency across each quantity of material.

RESULTS

Twenty-seven subjects were enrolled. Forty-one percent were male with mean age of 34 years (11 standard deviation). Ninety-nine percent (267/270), 97% (n = 263/270), and 99% (399/405) of 1 sip swallows, 3 sip swallows, and 5 mL swallows, respectively, were safe. There was no significant correlation between swallow safety and flow rate using Pearson Chi-Square test across all consistencies and across all quantities of materials (P > 0.05). Of note, out of all subtrials, the thin liquid, 3 sips trial at 60 LPM, had the largest percent of unsafe swallows (14%).

CONCLUSION

Our results suggest rate of aspiration is not significantly affected by high flow nasal cannula in healthy individuals.

High-flow nasal cannula during pulmonary rehabilitation for people with chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an increasingly concerning global public health issue due to its high burden of morbidity and mortality. Pulmonary rehabilitation (PR) is a comprehensive intervention to improve patients' physical and psychological conditions, commonly involving oxygen supplementation. The potential benefits of high-flow nasal cannula (HFNC) have recently sparked interest as oxygen therapy. In this context, this study aims to assess the effects of HFNC during the exercise training component of a PR program in people with COPD.

METHODS

Systematic review (CRD42022330929). We included randomised controlled trials (RCTs), including crossover RCTs with adults with stable COPD. We included trials using oxygen therapy with HFNC during the exercise training component of a PR programme.

PRIMARY OUTCOMES

disease-specific health-related quality of life (HRQoL), exercise capacity (EC) and adverse events.

SECONDARY OUTCOMES

treatment adherence, breathlessness and future exacerbations.

RESULTS

We included five studies with 300 participants with moderate to severe COPD. The certainty of the evidence was primarily low or very low for all outcomes of interest due to risk of bias, inconsistency or imprecision. HFNC has little to no difference in HRQoL (4 studies, 129 participants, MD 0.17, 95% CI -1.20 to 1.54; I2 50%). HFNC may result in little to no difference in EC (3 studies, 212 participants, mean difference 18.73, 95% CI -20.49 to 28.94; I2 56%), and we are uncertain about the effect of HFNC on breathlessness (4 studies; 244 participants, MD of -0.07, 95% CI -0.4 to 0.26; I2 63%). Only one study with 44 participants reported a participant's withdrawal because of progressive dyspnoea during lower limb exercise.

CONCLUSIONS

We are uncertain about the effect of HFNC during the exercise component of a PR programme in HRQoL, EC or dyspnoea compared to usual care or conventional supplementary oxygen. Non-domiciliary oxygen patients showed improvements in HRQoL, EC and dyspnoea.

Prognostic analysis of high-flow nasal cannula therapy and non-invasive ventilation in mild to moderate hypoxemia patients and construction of a machine learning model for 48-h intubation prediction-a retrospective analysis of the MIMIC database

Background

This study aims to investigate the clinical outcome between high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV) therapy in mild to moderate hypoxemic patients on the first ICU day and to develop a predictive model of 48-h intubation.

Methods

The study included adult patients from the MIMIC III and IV databases who first initiated HFNC or NIV therapy due to mild to moderate hypoxemia (100 < PaO2/FiO2 ≤ 300). The 48-h and 30-day intubation rates were compared using cross-sectional and survival analysis. Nine machine learning and six ensemble algorithms were deployed to construct the 48-h intubation predictive models, of which the optimal model was determined by its prediction accuracy. The top 10 risk and protective factors were identified using the Shapley interpretation algorithm.

Result

A total of 123,042 patients were screened, of which, 673 were from the MIMIC IV database for ventilation therapy comparison (HFNC n = 363, NIV n = 310) and 48-h intubation predictive model construction (training dataset n = 471, internal validation set n = 202) and 408 were from the MIMIC III database for external validation. The NIV group had a lower intubation rate (23.1% vs. 16.1%, p = 0.001), ICU 28-day mortality (18.5% vs. 11.6%, p = 0.014), and in-hospital mortality (19.6% vs. 11.9%, p = 0.007) compared to the HFNC group. Survival analysis showed that the total and 48-h intubation rates were not significantly different. The ensemble AdaBoost decision tree model (internal and external validation set AUROC 0.878, 0.726) had the best predictive accuracy performance. The model Shapley algorithm showed Sequential Organ Failure Assessment (SOFA), acute physiology scores (APSIII), the minimum and maximum lactate value as risk factors for early failure and age, the maximum PaCO2 and PH value, Glasgow Coma Scale (GCS), the minimum PaO2/FiO2 ratio, and PaO2 value as protective factors.

Conclusion

NIV was associated with lower intubation rate and ICU 28-day and in-hospital mortality. Further survival analysis reinforced that the effect of NIV on the intubation rate might partly be attributed to the other impact factors. The ensemble AdaBoost decision tree model may assist clinicians in making clinical decisions, and early organ function support to improve patients' SOFA, APSIII, GCS, PaCO2, PaO2, PH, PaO2/FiO2 ratio, and lactate values can reduce the early failure rate and improve patient prognosis.

Effectiveness of high flow nasal cannula (HFNC) versus bilevel positive airway pressure (BiPAP) in preventing tracheal reintubation in patients with high risk of extubation failure in intensive care unit - A randomised comparative trial

Background and Aims

The incidence of tracheal extubation failure in high-risk patients is higher, and non-invasive ventilation is suggested to avoid tracheal reintubation. This study compares the effectiveness of bilevel positive airway pressure (BiPAP) and high flow nasal cannula (HFNC) to reduce the rate of reintubation in intensive care unit (ICU) patients with increased risk of extubation failure.

Methods

This randomised comparative trial was conducted on 60 high-risk patients on mechanical ventilators admitted to the ICU, ready for weaning after a spontaneous breathing trial. They were randomised to Group H for HFNC and Group B for BiPAP therapy. Designated therapy was administered in these high-risk patients for up to 48 hours after tracheal extubation. Haemodynamic parameters [mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), a saturation of peripheral oxygen (SpO2), electrocardiogram (ECG)], arterial blood gas analysis (ABG) parameter [potential of hydrogen (pH), partial pressure of carbon dioxide (pCO2), partial pressure of oxygen/fraction of inspired oxygen (paO2/FiO2) ratio], the effectiveness of cough, comfort level was recorded and continuous monitoring for signs of respiratory distress and failure was done.

Results

Most of the patients were obese and had more than two risk factors for extubation failure. Several patients in Group B have significantly higher successful extubation than in Group H (P = 0.044). Most of the reintubation took place within 24 hours. The HFNC therapy was more comfortable and acceptable to patients.

Conclusion

BiPAP therapy was more efficient than HFNC in preventing tracheal reintubation among patients with a high risk of extubation failure.

Management of Acute Bronchiolitis in Spoke Hospitals in Northern Italy: Analysis and Outcome

Bronchiolitis is an acute viral infection of the lower respiratory tract that affects infants and young children. Respiratory syncytial virus (RSV) is the most common causative agent; however, other viruses can be involved in this disease. We retrospectively reviewed the clinical features of infants aged less than 12 months hospitalized for acute bronchiolitis in our Pediatric Units of Chivasso, Cirié, and Ivrea in Piedmont, Northern Italy, over two consecutive bronchiolitis seasons (September 2021-March 2022 and September 2022-March 2023). Patient-, disease-, and treatment-related variables were analyzed. The probability of therapeutic success (discharge home) was 96% for all patients (93% for RSV vs. 98% for non-RSV patients, p > 0.05). Among 192 patients, 42 infants (22%) underwent high-flow oxygen support (HFNC), and only 8 (4%) needed to be transferred to our hub referral hospital. Factors associated with hub hospital transfer were the age under 1 month and the failure of HFNC. The wide and increasing use of HFNC in pediatric inpatients improved the management of bronchiolitis in Spoke hospitals, reducing transfer to a hub hospital provided with Intensive Care Units.

High-Flow Nasal Cannula Therapy as an Adjuvant Therapy for Respiratory Support during Endoscopic Techniques: A Narrative Review

High-flow nasal cannula (HFNC) is a respiratory support technique that delivers a controlled concentration of oxygen with high flow, heat, and humidity via the nasal pathway. As it has many physiological effects, its use has increased for a variety of clinical indications; however, there is limited guidance on using HFNC as a respiratory support tool during endoscopic procedures. We conducted a narrative review to evaluate the effect of HFNC as an adjuvant tool during fiberoptic bronchoscopy (FOB), upper gastrointestinal tract endoscopy, and surgical procedures in adults. A search of the PubMed and Cochrane databases were performed. Approximately 384 publications were retrieved, and 99 were selected (93 original works and 6 case reports with a literature review). In patients who underwent FOB, HFNC appears to be superior to conventional oxygen therapy (COT) in preventing hypoxaemia. In contrast, for gastrointestinal endoscopy, the current evidence is insufficient to recommend HFNC over COT in a cost-effective manner. Finally, in surgical procedures such as laryngeal microsurgery or thoracic surgery, HFNC has been shown to be a safe and effective alternative to orotracheal intubation. As the results are heterogeneous, we advocate for the need for more quality studies to understand the effectiveness of HFNC during endoscopic procedures.

Associations With Severe Desaturation Events Among Children Receiving Noninvasive Respiratory Support at Time of Intubation

BACKGROUND

Endotracheal intubation is a common procedure associated with adverse events, including severe desaturation. Many patients receive noninvasive respiratory support to reduce the need for intubation. There are minimal data about the association between noninvasive respiratory support and the risk of a severe desaturation event during intubation. We aim to differentiate patients based on the level of noninvasive respiratory support, analyze the severe desaturation event by groups, and identify modifiable risk factors.

METHODS

Oral intubations, excluding tube exchanges or re-intubation after unplanned extubation, from October 2018 through July 2020, at the study site were reviewed. A severe desaturation event was defined as [Formula: see text] < 70% or a >15% decrease from baseline in cyanotic heart disease. We analyzed outcomes by 4 groups: room air/nasal cannula (≤0.5 L/kg/min), high-flow nasal cannula (HFNC) (0.5-2 L/kg/min), high HFNC (≥2 L/kg/min), and noninvasive ventilation (NIV).

RESULTS

Of 243 subjects who were intubated, 31% were receiving room air/nasal cannula, 25% were receiving HFNC, 18% were receiving high HFNC, and 26% were receiving NIV. Twelve percent of all the subjects had a severe desaturation event. In a univariate analysis, the incidence of a severe desaturation event was similar among all levels of respiratory support (P = .14). A severe desaturation event was more likely in those subjects who were receiving [Formula: see text] ≥ 0.6 at the time of the decision to intubate (19.6%) versus [Formula: see text] < 0.6 (8.1%) (P = .02). The duration of noninvasive respiratory support was longer (5 vs 1 h; P = .02) among those with a severe desaturation event. In a regression analysis, when adjusting for ≥2 intubation attempts pre-intubation, NIV use was independently associated with increased odds of severe desaturation events (odds ratio 3.14, CI 1.08-10.5).

CONCLUSIONS

Results of our study suggest that [Formula: see text] > 0.60, the duration of noninvasive respiratory support, and exposure to NIV before an intubation are risk factors of severe desaturation events during intubation.

Outcomes of a respiratory therapist driven high flow nasal cannula management protocol for pediatric critical asthma patients

INTRODUCTION

This study aimed to determine if a respiratory therapist (RT)-driven high flow nasal cannula (HFNC) protocol could decrease duration of HFNC use, pediatric intensive care unit (PICU) and hospital length of stay (LOS), and duration of continuous albuterol use in pediatric patients with critical asthma.

METHODS

This was a quality improvement project performed at a quaternary academic PICU. Patients admitted to the PICU between 2 and 18 years of age with a diagnosis of asthma requiring continuous albuterol and HFNC were included. Implementation of an RT-driven HFNC protocol [Plan-Do-Study-Act (PDSA) 1] occurred in October 2017. Additional interventions included weaning continuous albuterol and HFNC simultaneously (PDSA 2; March 2019), adjusting HFNC wean rate (PDSA 3; July 2020), and a HFNC holiday (PDSA 4; October 2021). HFNC duration was the primary outcome. Secondary outcomes included LOS data and continuous albuterol duration. Noninvasive ventilation (NIV), invasive mechanical ventilation (IMV), and 7-day PICU and hospital readmission rates were used as balancing measures.

RESULTS

A total of 410 patients were included. Patient demographics and adjunct therapy use did not differ among the groups. After PDSA 2, mean HFNC duration decreased (26.8-18.1 h). Mean PICU LOS decreased (41-31.8 h). Mean hospital LOS also decreased (86.5-68 h). These outcomes remained stable during PDSA 3 and 4. Continuous albuterol duration and NIV use were unchanged, while IMV use decreased.

CONCLUSIONS

An RT-driven HFNC protocol led to decreased length of HFNC and PICU and hospital LOS for pediatric patients with critical asthma without an increase in adverse events.

The role of dexmedetomidine in ARDS: an approach to non-intensive care sedation

Introduction

Severe COVID-19 is a life-threatening condition characterized by complications such as interstitial pneumonia, hypoxic respiratory failure, and acute respiratory distress syndrome (ARDS). Non-pharmacological intervention with mechanical ventilation plays a key role in treating COVID-19-related ARDS but is influenced by a high risk of failure in more severe patients. Dexmedetomidine is a new generation highly selective α2-adrenergic receptor (α2-AR) agonist that provides sedative effects with preservation of respiratory function. The aim of this study is to assess how dexmedetomidine influences gas exchange during non-invasive ventilation (NIV) and high-flow nasal cannula (HFNC) in moderate to severe ARDS caused by COVID-19 in a non-intensive care setting.

Methods

This is a single center retrospective cohort study. We included patients who showed moderate to severe respiratory distress. All included subjects had indication to NIV and were suitable for a non-intensive setting of care. A total of 170 patients were included, divided in a control group (n = 71) and a treatment group (DEX group, n = 99).

Results

A total of 170 patients were hospitalized for moderate to severe ARDS and COVID-19. The median age was 71 years, 29% females. The median Charlson comorbidity index (CCI) was 2.5. Obesity affected 21% of the study population. The median pO2/FiO2 was 82 mmHg before treatment. After treatment, the increase of pO2/FiO2 ratio was clinically and statistically significant in the DEX group compared to the controls (125 mmHg [97-152] versus 94 mmHg [75-122]; ***p < 0.0001). A significative reduction of NIV duration was observed in DEX group (10 [7-16] days vs. 13 [10-17] days; *p < 0.02). Twenty four patients required IMV in control group (n = 71) and 16 patients in DEX group (n = 99) with a reduction of endotracheal intubation of 62% (OR 0.38; **p < 0.008). A higher incidence of sinus bradycardia was observed in the DEX group.

Conclusion

Dexmedetomidine provides a "calm and arousal" status which allows spontaneous ventilation in awake patients treated with NIV and HFNC. The adjunctive therapy with dexmedetomidine is associated with a higher pO2/FiO2, lower duration of NIV, and a lower risk of NIV failure. A higher incidence of sinus bradycardia needs to be considered.

Medical Treatment of Obstructive Sleep Apnea in Children

Obstructive sleep apnea (OSA) is characterized by recurrent complete or partial obstruction of the upper airway. The prevalence is 1-4% in children aged between 2 and 8 years and rising due to the increase in obesity rates in children. Although persistent OSA following adenotonsillectomy is usually associated with obesity and underlying complex disorders, it can also affect otherwise healthy children. Medical treatment strategies are frequently required when adenotonsillectomy is not indicated in children with OSA or if OSA is persistent following adenotonsillectomy. Positive airway pressure treatment is a very effective modality for persistent OSA in childhood; however, adherence rates are low. The aim of this review article is to summarize medical treatment options for OSA in children.

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

OBJECTIVES

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.

METHODS

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 12 hours 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.

RESULTS

In total, 41 patients were analyzed, 25 succeeded and 16 failed HFNC therapy. At 12 hours, 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%.

CONCLUSIONS

Diaphragmatic contraction speed by ultrasound emerges as a diagnostic complement to clinical tools to predict HFNC success. Future studies should confirm these results.

Association of Non-Invasive Respiratory Support with Extubation Outcomes in Brain-Injured Patients Receiving Mechanical Ventilation: A Secondary Analysis of ENIO

RATIONALE

Non-invasive respiratory support using high flow nasal cannula (HFNC) or non-invasive positive pressure ventilation (NIPPV) can decrease the risk of reintubation in patients being liberated from mechanical ventilation, but effects in patients with acute brain injury are unknown.

OBJECTIVES

To evaluate the association between post-extubation non-invasive respiratory support and reintubation in patients with acute brain injury being liberated from mechanical ventilation.

METHODS

This was a secondary analysis of a prospective, observational study of mechanically ventilated patients with acute brain injury (NCT03400904). The primary endpoint was reintubation during ICU admission. We used mixed effects logistic regression models with patient-level covariates and random intercepts for hospital and country to evaluate the association between prophylactic (i.e, planned) HFNC or NIPPV and reintubation.

MEASUREMENTS AND MAIN RESULTS

1,115 patients were included from 62 hospitals and 19 countries, of whom 267 received HFNC or NIPPV following extubation (23.9%). Compared to conventional oxygen therapy, neither prophylactic HFNC nor NIPPV was associated with decreased risk of reintubation (respectively, odds ratio (OR), 0.97; 95% confidence interval (CI), 0.54-1.73; OR, 0.63; 95%CI, 0.30-1.32). Findings remained consistent in sensitivity analyses accounting for alternate adjustment procedures, missing data, shorter timeframes of extubation failure, and competing risks precluding reintubation. In a Bayesian analysis using skeptical and data-driven priors, the probability of reduced reintubation ranged from 17-34% for HFNC and 46-74% for NIPPV.

CONCLUSIONS

In a large cohort of brain-injured patients undergoing liberation from mechanical ventilation, prophylactic use of HFNC and NIPPV were not associated with reintubation. Prospective trials are needed to explore treatment effects in this population.

Impact of the publication of the Italian guidelines for bronchiolitis on the management of hospitalized children in Pisa, Italy

Bronchiolitis represents one of the major causes of hospitalization and mortality in children younger than 1 year, but its management continues to be heterogenous both in those who are hospitalized and in those who are not. To assess the impact of the publication of the Italian guidelines on bronchiolitis in October 2014, we analyzed data from children aged ≤12 months admitted for bronchiolitis at the University Hospital of Pisa from January 2010 to December 2019, dividing them into two groups based on whether admission was either preceding (Group 1) or following (Group 2) the publication of the guidelines. 346 patients (mean age 4.1 ± 2.8 months, 55% males) were admitted in the study period; 43.3%, 49.4%, and 7.3% of patients had mild, moderate or severe bronchiolitis, respectively. The mean length of hospital stay was 6.7 ± 2.9 days; 90.5% of the patients underwent nasal swab and 200 patients tested positive for RSV (in mono or coinfection with other viruses). We found no difference in RSV prevalence and severity distribution between the two groups, while we observed a significant reduction in the use of both chest X-rays (66.9% vs. 34.8%, p < 0.001), blood testing (93.4% vs. 58.2%, p < 0.001) and inhaled or systemic corticosteroids (93.1% vs. 47.8%, p < 0.001) in Group 2. No significant reduction in the use of antibiotics and of inhaled β2 agonists was found. Our data suggest that the publication of the Italian guidelines for bronchiolitis has contributed to improving the management of patients admitted for bronchiolitis in our Unit.

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

BACKGROUND

COVID-19 infection caused by the SARS-Cov-2 virus may result in severe acute respiratory failure and require respiratory support in the ICU.

OBJECTIVE

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.

MATERIALS AND METHODS

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.

RESULTS

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 sixth and 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).

CONCLUSION

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.

High Flow Nasal Cannula in Patients With Cancer at the End of Life

CONTEXT

High flow nasal cannula (HFNC) is frequently used to manage dyspnea in patients with cancer near the end of life. Because HFNC is restricted to the in-patient setting, patients on HFNC need to be liberated from it to be discharged from the hospital.

OBJECTIVES

The purpose of this study is to assess the rate of successful liberation from HFNC in a palliative and supportive care unit (PSCU).

METHODS

The study is a retrospective chart review of all 374 adult patients with cancer on HFNC admitted to a palliative and supportive care unit at a tertiary medical center from January 1, 2018 to December 31, 2020. We determined the proportion of patients who were liberated from HFNC (by day three and overall) and the proportion of patients discharged alive.

RESULTS

The mean age of the patients was 64, 54% were male and 73% were white. Only 16% (95% CI: 13-20) of the patients were discharged alive. Liberation from HFNC by day three and overall was accomplished in 23% and 25% of the patients respectively. Comparing the patients who could be liberated from HFNC vs. those who could not by day three, 38% vs. 9% were discharged alive respectively; and overall, 62% vs. 1% respectively (P < 0.001 in both cases).

CONCLUSION

Only a minority of patients with cancer at the end of life can be liberated from HFNC, and only a minority are discharged alive. This information is important when discussing goals of care with patients and their families before initiating HFNC.

High flow nasal cannula therapy in the pediatric home setting

BACKGROUND

High-flow nasal cannula (HFNC) therapy may be better tolerated than traditional noninvasive ventilation (NIV) and is rapidly gaining acceptance in pediatric acute care. In Israel, HFNC is approved for domestic use. We aim to describe its indications, efficacy, parental satisfaction, and safety.

METHODS

Retrospective study of children treated with home HFNC therapy in three pediatric centers. Data included demographic parameters, indication of use, weight and days of hospitalization before and after initiation. Safety, tolerability, and parental satisfaction were assessed via standardized telephone questionnaire.

RESULTS

Median (interquartile range [IQR]) age of initiating home HFNC in 75 children was 8.3 (2.2, 29.6) months. Indications were obstructive sleep apnea (33; 44%), airway malacia (19; 25%), chronic lung disease (15; 20%), neuromuscular disease (4; 5%), and postextubation support (4; 5%). Weight standard deviation score rose from -2.3 pre-HFNC to -1.7 at 6.7 months post-HFNC initiation, p < 0.001. Hospital admission days during the 2 months pre- versus post-HFNC initiation were 22 (5.5, 60) and 5 (0, 14.7) respectively, p < 0.008. Median (IQR) parental satisfaction score was 5/5 (4, 5). Fifty of 60 (83%) respondents would recommend home HFNC to other families in a similar situation. There were no serious adverse events.

CONCLUSION

In our population, domestic HFNC appeared safe and well tolerated for a variety of indications. Its introduction was associated with improved weight gain, fewer hospitalization days and high parental satisfaction. Further work is required to characterize groups of children most likely to benefit from HFNC, as opposed to traditional modes of NIV.

Comparison of High-Flow Nasal Cannula Versus Conventional Oxygen Therapy After Extubation in Children Undergoing Cardiac Surgery: A Meta-analysis

This meta-analysis aims to compare high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) post-extubation in pediatric cardiac surgical patients. The present meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two authors independently searched three electronic databases including PubMed, Embase, and the Cochrane Library to identify relevant articles published in English from inception to February 2023. Searching was conducted using keywords and medical subject headings (MeSH), which included "conventional oxygen therapy," "high-flow nasal cannula," "extubation," "pediatrics," and "cardiac surgery." Our primary outcome was extubation failure defined as the need for reintubation within 24 to 72 hours after planned extubation. Secondary outcomes assessed in this meta-analysis included partial pressure of arterial oxygen (PaO2), partial pressure of arterial carbon dioxide (PaCO2), and the ratio of PaO2 and FiO2 (fraction of inspired oxygen). A total of three studies were included in the meta-analysis, with a total of 227 patients.  No significant difference was found between the two groups (the HFNC group and the COT group) in terms of reintubation (RR: 0.88, 95% CI: 0.34, 2.30, p-value: 0.80). Pooled meta-analysis showed that PaO2 was significantly greater in patients receiving HFNC at six hours (MD: 33.73, 95% CI: 18.33, 49.14, p-value<0.001), at 12 hours (MD: 44.90, 95% CI: 28.59, 61.22, p-value<0.001) and at 24 hours (MD: 43.53, 95% CI: 29.16, 57.91, p-value<0.001) of extubation. PaCO2 was significantly lower in patients receiving HFNC at six hours (MD: -5.40, 95% CI: -7.94, -2.85, p-value<0.001) and at 12 hours (MD: -5.93, 95% CI: -9.78, -2.09, p-value<0.001) of extubation. However, no significant difference was reported between the two groups after 24 hours of extubation (MD: -0.84, 95% CI: -9.04, 7.37, p-value: 0.84) and PaO2/FiO2 was significantly greater in patients receiving HFNC at six hours (MD: 64.14, 95% CI: 36.10, 92.17, p-value<0.001), at 12 hours (MD: 70.73, 95% CI: 20.46, 121.01, p-value<0.001) and at 24 hours (MD: 82.18, 95% CI: 50.03, 114.32, p-value<0.001) of intubation. In conclusion, the meta-analysis revealed that compared with COT, HFNC significantly increased PaO2 and the ratio of PaO2 to FiO2, and decreased PaCO2. No significant differences were observed in the rate of reintubation between the two groups. This is the first meta-analysis comparing HFNC and COT in pediatric cardiac surgical patients.

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.

In Vitro Evaluation of Nebulized Pharmaceutical Aerosol Delivery to the Lungs Using a New Heated Dryer System (HDS)

The objective of this study was to develop a new heated dryer system (HDS) for high efficiency lung delivery of nebulized aerosol and demonstrate performance with realistic in vitro testing for trans-nasal aerosol administration simultaneously with high-flow nasal cannula (HFNC) therapy and separately for direct oral inhalation (OI) of the aerosol. With the HDS-HFNC and HDS-OI platforms, new active synchronization control routines were developed to sense subject inhalation and coordinate drug aerosol delivery. In vitro experiments were conducted to predict regional drug loss and lung delivery efficiency in systems that included the HDS with various patient interfaces, realistic airway models, and simulated breathing waveforms. For the HDS-HFNC platform and a repeating breathing waveform, total system loss was < 10%, extrathoracic deposition was approximately 6%, and best-case lung delivery efficiency was 75-78% of nebulized dose. Inclusion of randomized breathing with the HFNC system decreased lung delivery efficiency by ~ 10% and had no impact on nasal depositional loss. For the HDS-OI platform and best-case mouthpiece, total system loss was < 8%, extrathoracic deposition was < 1%, and lung delivery efficiency was > 90% of nebulized dose. Normal vs. deep randomized oral inhalation had little impact on performance of the HDS-OI platform and environmental aerosol loss was negligible. In conclusion, both platforms demonstrated the potential for high efficiency lung delivery of the aerosol with the HDS-OI platform having the added advantages of nearly eliminating extrathoracic deposition, being insensitive to breathing waveform, and preventing environmental aerosol loss.

Factors associated with failure of using high flow nasal cannula in children

INTRODUCTION

High flow nasal cannula (HFNC) has significantly success in treating acute respiratory distress while HFNC failure dramatically increases mortality and morbidity.

OBJECTIVE

To describe factors associated with failure of HFNC use in children.

METHODS

We performed a retrospective observational study using demographic and laboratory findings. We compared clinical and laboratory variables in both successful and failed HFNC groups. The correlations between factors and HFNC failure were constructed by binary logistic regression analysis.

RESULTS

Between August 2016 and May 2018, 250 children receiving HFNC (median age 16 months; range 1-228 months, male 50.8%) were enrolled. Pneumonia was the most common cause of respiratory distress, and the median length of stay (LOS) in hospital was 11 days. HFNC failure was found 16.4% while HFNC complication was 4.8% including epistaxis, pressure sore, and gastric distension. Based on multivariable logistic regression analysis, factors associated with HFNC failure were children with congenital heart disease comorbidity (p = 0.005), HFNC use with maximum FiO₂  > 0.6 (p = 0.021), lobar infiltration on chest X-ray (p = 0.012), the reduction of heart rate, and respiratory rate <20% after 1 h of HFNC use (p = 0.001 and p = 0.001, respectively).

CONCLUSION

HFNC is feasible to use for children with respiratory distress; however, patients with congenital heart disease, using HFNC with FiO₂  > 0.6, lobar infiltration on chest X-ray should be closely monitored. Heart rate and respiratory rate are important parameters in addition to clinical assessment for evaluating HFNC failure in children.

Clinical outcomes of high-flow nasal cannula oxygen therapy in acute heart failure patients with hypoxemia: A retrospective cohort study

Acute heart failure (AHF) is life-threatening medical condition requiring hospital admission and appropriate oxygen therapy. High flow nasal cannula oxygen therapy (HFNC) has gained its popularity in treatment of AHF, however, there were less studies have demonstrated the physiological efficacy of HFNC. Purpose of this study was to evaluated the physiological responses and clinical outcomes of HFNC by comparing with noninvasive positive pressure ventilation (NPPV) therapy. A retrospective cohort investigation was conducted at emergency intensive care unit (EICU) and cardiovascular center of our hospital from June 2019 to March 2022, AHF patients with hypoxemia were reviewed. According to the received oxygen therapy model, patients were divided into HFNC and NPPV groups. Demographic data, arterial blood gas (ABG) parameter, echocardiography findings, complications and other related variables were extracted and collected from the electronic medical records (EMRs) by well-trained investigators. Physiological responses and clinical outcomes within and between 2 groups were analyzed. Finally, 156 patients with a mean age of 69.3 ± 7.1 years were reviewed, there were 82 (52.6%) male and 74 (47.4%) female patients in the sample and 70 (44.9%) and 86 (55.1%) patients classified III and IV score were included in this study, 80 patients received HFNC and 76 underwent NPPV oxygen therapy. There were no significant differences of baseline characteristics for the 2 groups patients. Changes of left ventricular function parameters, ABG and clinical outcomes were all improved satisfactorily after 24 h medical interventions in both group, what's more, patients underwent HFNC therapy could acquire a better amelioration when compared with NPPV groups (P < .05). HFNC may be an ideal model for patients with AHF, particularly those with hypoxemia. HFNC therapy could significantly improve several objective parameters of physiological responses and clinical outcomes.

Recent advances in the use of high flow nasal oxygen therapies

High flow nasal oxygen is a relatively new option for treating patients with respiratory failure, which decreases work of breathing, improves tidal volume, and modestly increases positive end expiratory pressure. Despite well-described physiologic benefits, the clinical impact of high flow nasal oxygen is still under investigation. In this article, we review the most recent findings on the clinical efficacy of high flow nasal oxygen in Type I, II, III, and IV respiratory failure within adult and pediatric patients. Additionally, we discuss studies across clinical settings, including emergency departments, intensive care units, outpatient, and procedural settings.

Predictors of successful trial off continuous positive airway pressure and high flow nasal cannula in preterm infants <30 weeks' gestation: A retrospective study

OBJECTIVES

To identify the predictors of successful first trial off nasal continuous positive airway pressure (nCPAP).

METHODS

A retrospective cohort study of infants ≤29 weeks' gestation who required nCPAP for >24 h was conducted. Logistic regression was used to detect predictors for successful trial off nCPAP. Statistical analysis was performed using the SAS software.

RESULTS

A total of 727 infants were included in the analysis. Infants who were successful in their first trial off nCPAP (n = 313) were of higher gestational age (GA) and birth weight (BW), as well as a higher proportion of female infants, compared with those who were not successful (p < 0.01). When stratified by GA, a negative correlation was noted between GA and postmenstrual age at successful trial off nCPAP or high flow nasal cannula (HFNC) (r = 0.45, p < 0.01). Logistic regression analysis showed that GA (odds ratio [OR] 1.13, 95% confidence interval [CI] [1.03-1.24], p = 0.01) and percentage of time spent with an oxygen saturation over 89% in the 24 h preceding the trial off nCPAP (OR 1.08, 95% CI [1.05-1.11], p = 0.00) were independent predictors for successful trial off nCPAP.

CONCLUSION

Successful trial off nCPAP or HFNC in preterm infants is significantly associated with higher GA, BW, female gender, and the specific oxygen saturation histogram in the preceding 24-h period.

High Flow Nasal Cannula in the Pediatric Intensive Care Unit

INTRODUCTION

The use of high flow nasal cannula (HFNC) has become widely used in pediatric intensive care units (PICUs) throughout the world. The rapid adoption has outpaced the number of studies evaluating the safety and efficacy in a variety of pediatric diseases/conditions.

AREAS COVERED

This scoping review begins with the definition and mechanisms of action of HFNC and then follows with a review of the literature focused on studies performed on critically ill children cared for in the PICU. The Pubmed database was searched with a pediatric filter from the time period 2000 to 2021.

EXPERT OPINION

The rapid adoption of HFNC in PICUs has largely been driven by changes in institutional practices and small observational studies. There is a lack of adequately powered studies evaluating patient-centered outcomes, such as intubation rates, mortality, PICU and hospital length of stay. Given the wide variability in flow rates and clinical indications, more research is needed to better define effective flow rates for different disease states as well as markers of treatment success and failure. One particular entity that is poorly studied is the use of HFNC in those at risk for developing pediatric acute respiratory distress syndrome (PARDS).

Predicting Flow Rate Escalation for Pediatric Patients on High Flow Nasal Cannula Using Machine Learning

Background: High flow nasal cannula (HFNC) is commonly used as non-invasive respiratory support in critically ill children. There are limited data to inform consensus on optimal device parameters, determinants of successful patient response, and indications for escalation of support. Clinical scores, such as the respiratory rate-oxygenation (ROX) index, have been described as a means to predict HFNC non-response, but are limited to evaluating for escalations to invasive mechanical ventilation (MV). In the presence of apparent HFNC non-response, a clinician may choose to increase the HFNC flow rate to hypothetically prevent further respiratory deterioration, transition to an alternative non-invasive interface, or intubation for MV. To date, no models have been assessed to predict subsequent escalations of HFNC flow rates after HFNC initiation. Objective: To evaluate the abilities of tree-based machine learning algorithms to predict HFNC flow rate escalations. Methods: We performed a retrospective, cohort study assessing children admitted for acute respiratory failure under 24 months of age placed on HFNC in the Johns Hopkins Children's Center pediatric intensive care unit from January 2019 through January 2020. We excluded encounters with gaps in recorded clinical data, encounters in which MV treatment occurred prior to HFNC, and cases electively intubated in the operating room. The primary study outcome was discriminatory capacity of generated machine learning algorithms to predict HFNC flow rate escalations as compared to each other and ROX indices using area under the receiver operating characteristic (AUROC) analyses. In an exploratory fashion, model feature importance rankings were assessed by comparing Shapley values. Results: Our gradient boosting model with a time window of 8 h and lead time of 1 h before HFNC flow rate escalation achieved an AUROC with a 95% confidence interval of 0.810 ± 0.003. In comparison, the ROX index achieved an AUROC of 0.525 ± 0.000. Conclusion: In this single-center, retrospective cohort study assessing children under 24 months of age receiving HFNC for acute respiratory failure, tree-based machine learning models outperformed the ROX index in predicting subsequent flow rate escalations. Further validation studies are needed to ensure generalizability for bedside application.

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.

Indications and Safety of High Flow Nasal Cannula in Pediatric Intensive Care Unit: Retrospective Single Center Experience in Saudi Arabia

Background

High flow nasal cannula (HFNC) is a new device for respiratory support. Its use continues to increase in pediatrics as its system is easily set up and well tolerated by patients. We aimed in this study to explore indications and safety of HFNC use and predictors of HFNC failure.

Methods

Hospital records of 92 children with acute respiratory distress admitted to the pediatric intensive care unit (PICU) in Abha Maternity and Children Hospital from January 2018 until March 2020 and received HFNC therapy were studied. A data collection sheet was used that included patients’ age, gender, the indication of HFNC, associated chronic diseases, previous admission to PICU, vital signs (initially, 8 hours and 48 hours after using HFNC), outcome after using HFNC, and reasons for HFNC failure.

Results

After receiving HFNC, children’s respiratory rate, heart rate, systolic blood pressure, and oxygen saturation improved significantly (p < 0.001, p < 0.001, p < 0.001, p = 0.005, and p < 0.001, respectively). Regarding laboratory findings, pH and serum bicarbonate improved significantly (p < 0.001 for both), while PaCO2 improved but not significantly. The failure rate of HFNC was 23.0%. HFNC failure rates were significantly higher among children with chronic diseases than those with no chronic disease (33.3% and 14.9%, respectively, p = 0.038) and among children with the air-leak syndrome (p < 0.001). After 48 hours of HFNC use, children who experienced HFNC failure had significantly higher respiratory and heart rates (p < 0.001 and p = 0.018, respectively), lower diastolic blood pressure (p = 0.011), and higher PaCO2 (p < 0.001).

Conclusion

After HFNC use, significant improvements occur in all clinical parameters and laboratory values of children with respiratory distress, but about one-fourth of cases may experience HFNC failure. Predictors for HFNC failure include underlying chronic disease, low diastolic blood pressure, high respiratory rate, high heart rate, high initial PaCO2.

Impact of Body Mass Index and Initial Respiratory Support on Pediatric Subjects in Acute Respiratory Failure

BACKGROUND

It is unknown how the initial choice of respiratory support by pediatric ICU providers contributes to outcomes of nonintubated obese children with respiratory failure. We hypothesized that body mass index and the type of initial respiratory support applied are associated with poor clinical outcomes in patients who carry respiratory failure-associated diagnoses.

METHODS

This is a retrospective analysis of de-identified patient data obtained from the Virtual PICU System database (2009-2018). We included subjects 2-18 y old who received bi-level positive airway pressure/CPAP or high-flow nasal cannula as the initial respiratory support and were assigned respiratory failure-associated diagnoses (ie, acute hypoxic respiratory failure). The study population was divided into 2 body mass index percentile groups, underweight/healthy weight (< 85th percentile) and overweight/obese (≥ 85th percentile), and subjects were evaluated for the following outcomes: endotracheal intubation requirement, medical and physical PICU length of stay, and mortality scores.

RESULTS

A total of 1,721 subjects were included: 1,091 (63.4%) underweight/healthy weight and 630 (36.6%) overweight/obese. Body mass index percentile was not associated with the initial respiratory support utilized (odds ratio 0.961 [95% CI 0.79-1.17], P = .73). Multivariable logistic regression analysis demonstrated that the odds of requiring endotracheal intubation (odds ratio 1.60 [95% CI 1.10-2.35], P = .02) were significantly higher in overweight/obese subjects initially placed on high-flow nasal cannula. Body mass index and bi-level positive airway pressure/CPAP therapy were both positively associated with medical and physical PICU length of stay, Pediatric Risk of Mortality Score 3 (PRISM3) scores, and Pediatric Index of Mortality 2 (PIM2) scores when separate multivariable models were fit for these 4 response variables.

CONCLUSIONS

The selection of respiratory support may place overweight/obese pediatric patients at higher risk for endotracheal intubation. Due to methodological limitations, we were unable to draw conclusions about the initial approach to the respiratory management of overweight/obese pediatric patients. Further investigation may be warranted.

Failure of High-Flow Nasal Cannula Therapy in Pneumonia and Non-Pneumonia Sepsis Patients: A Prospective Cohort Study

Despite the increasing use of high-flow nasal cannulas (HFNCs) to treat critically ill patients, data on their effectiveness for sepsis patients remains very limited. We studied a prospective cohort of sepsis patients from the Korean Sepsis Registry (18 intensive care units (ICUs)). Patients started on HFNC therapy for hypoxemia within the first three ICU days were enrolled. HFNC failure was defined as intubation or ICU death, and the primary outcome was early HFNC failure occurring within 72 h of HFNC initiation. Of 901 patients with sepsis admitted to the ICU, 206 who received HFNC therapy were finally included (117 with pneumonia vs. 89 with non-pneumonia sepsis; median age, 71.0 (63.0–78.0) years; P_aO₂/F_iO₂ ratio, 160.2 (107.9–228.2) mm Hg; septic shock, n = 81 (39.3%)). During HFNC therapy, 72 (35.0%) patients were intubated and 51 (24.8%) died. HFNC failure developed in 95 (46.1%) patients, and among them, early failure rate was 85.3% (81/95). On multivariate analysis, an immunocompromised state (odds ratio (OR) = 2.730), use of a combination of antibiotics (OR = 0.219), and the P_aO₂/F_iO₂ ratio (OR = 0.308) were significantly associated with early HFNC failure in pneumonia sepsis patients. However, in non-pneumonia sepsis patients, lactate levels (OR = 1.532) were significantly associated with early HFNC failure. In conclusion, a high proportion of sepsis patients experience HFNC failure, usually within 72 h after therapy initiation, which emphasizes the importance of close monitoring. Furthermore, unlike in pneumonia sepsis, organ failure (i.e., lactate) might serve as a prognostic marker in non-pneumonia sepsis (i.e., type IV respiratory failure).

An Integrated Model including the ROX Index to Predict the Success of High-Flow Nasal Cannula Use after Planned Extubation: A Retrospective Observational Cohort Study

High-flow nasal cannula (HFNC) therapy is commonly used to prevent reintubation after planned extubation. In clinical practice, there are no appropriate tools to evaluate whether HFNC therapy was successful or failed after planned extubation. In this retrospective observational study, we investigated whether the use of the ROX index was appropriate to differentiate between HFNC success and failure within 72 h after extubation and to develop an integrated model including the ROX index to improve the prediction of HFNC success in patients receiving HFNC therapy after planned extubation. Of 276 patients, 50 patients (18.1%) were reintubated within 72 h of extubation. ROX index values of >8.7 at 2 h, >8.7 at 6 h, and >10.4 at 12 h after HFNC therapy were all meaningful predictors of HFNC success in extubated patients. In addition, the integrated model including the ROX index had a better predictive capability for HFNC success than the ROX index alone. In conclusion, the ROX index at 2, 6, and 12 h could be applied to extubated patients to predict HFNC success after planned extubation. To improve its predictive power, we should also consider an integrated model consisting of the ROX index, sex, body mass index, and the total duration of ventilator care.

Characteristics and outcomes of patients receiving high flow nasal cannula therapy prior to mechanical ventilation in COVID-19 respiratory failure: A prospective observational study

Background

Treatment strategies for acute hypoxic respiratory failure secondary to coronavirus 2019 disease (COVID-19) had significant variation early in the pandemic. We sought to determine if patients treated with high flow nasal cannula (HFNC) prior to mechanical ventilation had differing outcomes compared to those treated only with conventional oxygen.

Methods

This was a prospective, observational study of patients with COVID-19 admitted to a tertiary care medical center with a diagnosis of acute hypoxic respiratory failure. Adult patients with a positive polymerase chain reaction test for COVID-19 who required mechanical ventilation were included.

Results

A total of 91 patients met the inclusion criteria for our study. The mean age was 68.4 years (standard deviation [SD] ± 12) and 58% were male. The mean initial partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) ratio was 152 (SD ± 65) and was not significantly different between the HFNC group and the conventional oxygen strategy group (P = 0.95). The observed mortality rate was 30% in the HFNC group versus 52% in the conventional oxygen strategy group (P = 0.05). The multivariate odds ratio of mortality for patients on HFNC was 0.375 compared to a conventional oxygen strategy (95% confidence interval 0.122-1.151, P = 0.09).

Conclusions

While HFNC appears to be safe as the initial treatment strategy for COVID-19 associated respiratory failure, HFNC did not result in a statistically significant difference in mortality compared to a conventional oxygen strategy. Further studies are needed to confirm these findings.

Role of Non-Invasive Respiratory Supports in COVID-19 Acute Respiratory Failure Patients with Do Not Intubate Orders

The current gold-standard treatment for COVID-19-related hypoxemic respiratory failure is invasive mechanical ventilation. However, do not intubate orders (DNI), prevent the use of this treatment in some cases. The aim of this study was to evaluate if non-invasive ventilatory supports can provide a good therapeutic alternative to invasive ventilation in patients with severe COVID-19 infection and a DNI. Data were collected from four centres in three European countries. Patients with severe COVID-19 infection were included. We emulated a hypothetical target trial in which outcomes were compared in patients with a DNI order treated exclusively by non-invasive respiratory support with patients who could be intubated if necessary. We set up a propensity score and an inverse probability of treatment weighting to remove confounding by indication. Four-hundred patients were included: 270 were eligible for intubation and 130 had a DNI order. The adjusted risk ratio for death among patients eligible for intubation was 0.81 (95% CI 0.46 to 1.42). The median length of stay in acute care for survivors was similar between groups (18 (10-31) vs. (19 (13-23.5); p = 0.76). The use of non-invasive respiratory support is a good compromise for patients with severe COVID-19 and a do not intubate order.

Combined high flow nasal cannula and negative pressure ventilation as a novel respiratory approach in a patient with acute respiratory failure and limb-girdle muscular dystrophy

We describe the case of a 56-year-old-man with limb-girdle muscular dystrophy affected by acute hypercapnic failure secondary to pneumonia treated with high flow nasal cannula, intermittent abdominal ventilation, and negative pressure ventilation. The patient did not tolerate noninvasive positive pressure ventilation and refused invasive ventilation and tracheostomy. We successfully experienced a novel approach combining high flow nasal cannula with cycles of intermittent abdominal pressure ventilation and negative pressure ventilation.

Acute Responses to Oxygen Delivery via High Flow Nasal Cannula in Patients with Severe Chronic Obstructive Pulmonary Disease-HFNC and Severe COPD

Differences in oxygen delivery methods to treat hypoxemia have the potential to worsen CO₂ retention in chronic obstructive lung disease (COPD). Oxygen administration using high flow nasal cannula (HFNC) has multiple physiological benefits in treating respiratory failure including reductions in PaCO₂ in a flow-dependent manner. We hypothesized that patients with COPD would develop worsening hypercapnia if oxygen fraction was increased without increasing flow rate. We evaluated the acute response to HFNC in subjects with severe COPD when flow remained constant and inspired oxygen was increased. In total, 11 subjects with severe COPD (FEV1 < 50%) on supplemental oxygen with baseline normocapnia (PaCO₂ < 45 mm Hg; n = 5) and hypercapnia (PaCO₂ ≥ 45 mm Hg; n = 6) were studied. Arterial blood gas responses were studied at three timepoints: Baseline, HFNC at a flow rate of 30 L/min at resting oxygen supplementation for 1 h, and FiO₂ 30% above baseline with the same flow rate for the next hour. The primary endpoint was the change in PaCO₂ from baseline. No significant changes in PaCO₂ were noted in response to HFNC applied at baseline FiO₂ in the normocapnic and hypercapnic group. At HFNC with FiO₂ 30% above baseline, the normocapnic group did not show a change in PaCO₂ (baseline: 38.9 ± 1.8 mm Hg; HFNC at higher FiO₂: 38.8 ± 3.1 mm Hg; p = 0.93), but the hypercapnic group demonstrated significant increase in PaCO₂ (baseline: 58.2 ± 9.3 mm Hg; HFNC at higher FiO₂: 63.3 ± 10.9 mm Hg; p = 0.025). We observed worsening hypercapnia in severe COPD patients and baseline hypercapnia who received increased oxygen fraction when flow remained constant. These data show the need for careful titration of oxygen therapy in COPD patients, particularly those with baseline hypercapnia when flow rate is unchanged.

Pleth variability index may predict preload responsiveness in patients treated with nasal high flow: a physiological study

The purpose of this study was to determine whether the plethysmographic variability index ("PVi") can predict preload responsiveness in patients with nasal high flow (NHF) (≥30 L/min) with any sign of hypoperfusion. "Preload responsiveness" was defined as a ≥10% increase in stroke volume (SV), measured by transthoracic echocardiography, after passive leg raising. SV and PVi were reassessed in preload responders after receiving a 250-mL fluid challenge. Twenty patients were included and 12 patients (60%) were preload responders. Responders showed higher baseline mean PVi (24% vs. 13%; P = 0.001) and higher mean PVi variation (ΔPVi) after passive leg raising (6.8% vs. -1.7%; P < 0.001). No differences between mean ΔPVi after passive leg raising and mean ΔPVi after fluid challenge were observed (6.8% vs. 7.4%; P = 0.24); and both values were strongly correlated (r = 0.84; P < 0.001). Baseline PVi and ΔPVi after passive leg raising showed excellent diagnostic accuracy identifying preload responders (AUROC 0.92 and 1.00, respectively). Baseline PVi ≥ 16% had a sensitivity of 91.7% and a specificity of 87.5% for detecting preload responders. Similarly, ΔPVi after passive leg raising ≥2% had a 100% of both sensitivity and specificity. Thus, PVi might predict "preload responsiveness" in patients treated with NHF, suggesting that it may guide fluid administration in these patients.NEW & NOTEWORTHY This is the first study that analyzes the use of noninvasive plethysmographic variability index (PVi) for preload assessment in patients treated with nasal high flow (NHF). Its results showed that PVi might identify preload responders. Therefore, PVi may be used in the day-to-day clinical decision-making process in critically ill patients treated with NHF, helping to provide adequate resuscitation volume.

A path to successful patient outcomes through aerosol drug delivery to children: a narrative review

Although using aerosolized medications is a mainstay of treatment in children with asthma and other respiratory diseases, there are many issues in terms of device and interface selection, delivery technique and dosing, as well as patient and parental education that have not changed for half a century. Also, due to many aerosol devices and interfaces available on the market and the broad range of patient characteristics and requirements, providing effective aerosol therapy to children becomes a challenge. While aerosol delivery devices are equally effective, if they are age-appropriate and used correctly, the majority of aerosol devices require multiple steps to be used efficiently. Unfortunately, many children with pulmonary diseases have problems with the correct delivery technique and do not gain therapeutic benefits from therapy that result in poor disease management and increased healthcare costs. Therefore, the purpose of this paper is to review the current knowledge on aerosol delivery devices used in children and guide clinicians on the optimum device- and interface-selection, delivery technique, and dosing in this patient population. Strategies on how to deliver aerosolized medications in crying and distressed children and how to educate parents on aerosol therapy and promote patient adherence to prescribed medications are also provided. Future directions of aerosol therapy in children should focus on these issues and implement policies and clinical practices that highlight the potential solutions to these problems.

Mechanical-Ventilation Supply and Options for the COVID-19 Pandemic. Leveraging All Available Resources for a Limited Resource in a Crisis

The novel coronavirus disease (COVID-19) has exposed critical supply shortages both in the United States and worldwide, including those in intensive care unit (ICU) and hospital bed supply, hospital staff, and mechanical ventilators. Many of those who are critically ill have required days to weeks of supportive invasive mechanical ventilation (IMV) as part of their treatment. Previous estimates set the U.S. availability of mechanical ventilators at approximately 62,000 full-featured ventilators, with 98,000 non–full-featured devices (including noninvasive devices). Given the limited availability of this resource both in the United States and in low- and middle-income countries, we provide a framework to approach the shortage of IMV resources. Here we discuss evidence and possibilities to reduce overall IMV needs, discuss strategies to maximize the availability of IMV devices designed for invasive ventilation, discuss the underlying methods in the literature to create and fashion new sources of potential ventilation that are available to hospitals and front-line providers, and discuss the staffing needs necessary to support IMV efforts. The pandemic has already pushed cities like New York and Boston well beyond previous ICU capacity in its first wave. As hot spots continue to develop around the country and the globe, it is evident that issues may arise ahead regarding the efficient and equitable use of resources. This unique challenge may continue to stretch resources and require care beyond previously set capacities and boundaries. The approaches presented here provide a review of the known evidence and strategies for those at the front line who are facing this challenge.

How to deliver aerosolized medications through high flow nasal cannula safely and effectively in the era of COVID-19 and beyond: A narrative review

Background

The treatments of COVID-19 involve some degree of uncertainty. Current evidence also shows mixed findings with regards to bioaerosol dispersion and airborne transmission of COVID-19 during high flow nasal cannula (HFNC) therapy. While coping with this global pandemic created hot debates on the use of HFNC, it is important to bring detached opinions and current evidence to the attention of health care professionals (HCPs) who may need to use HFNC in patients with COVID-19.

Aim

The purpose of this paper is to provide a framework on the selection, placement, and use of nebulizers as well as HFNC prongs, gas flow, and delivery technique via HFNC to help clinicians deliver aerosolized medications through HFNC safely and effectively in the era of COVID-19 and beyond.

Methods

We searched PubMed, Medline, CINAHL, and Science Direct to identify studies on aerosol drug delivery through HFNC using the following keywords: (“aerosols,” OR “nebulizers”) AND (“high flow nasal cannula” OR “high flow oxygen therapy” OR “HFNC”) AND (“COVID-19,” OR “SARS-CoV-2”). Twenty-eight articles including in vitro studies, randomized clinical trials, scintigraphy studies, review articles, prospective and retrospective research were included in this review.

Discussion and results

It is not clear if the findings of the previous studies on bacterial contamination could be applied to viral transmission because they do not provide data that could be extrapolated to the risk of SARS-CoV-2 transmission. In the face of the unknown risk with the transmission of COVID-19 during HFNC therapy, the benefits of HFNC must be weighed against the risk of infection to HCPs and other patients. Due to the limited number of ventilators available in hospitals and the confirmed effectiveness of HFNC in treating hypoxemic respiratory failure, HFNC may prevent early intubation, and prolonged intensive care unit stays in patients with COVID-19.

Conclusion

Clinicians should review the magnitude of this risk based on current evidence and use the suggested strategies of this paper for safe and effective delivery of aerosolized medications through HFNC in the era of COVID-19 and beyond.

Non-Invasive Ventilatory Strategies to Decrease Bronchopulmonary Dysplasia-Where Are We in 2021?

Recent advances in neonatology have led to the increased survival of extremely low-birth weight infants. However, the incidence of bronchopulmonary dysplasia (BPD) has not improved proportionally, partly due to increased survival of extremely premature infants born at the late-canalicular stage of lung development. Due to minimal surfactant production at this stage, these infants are at risk for severe respiratory distress syndrome, needing prolonged ventilation. While the etiology of BPD is multifactorial with antenatal, postnatal, and genetic factors playing a role, ventilator-induced lung injury is a major, potentially modifiable, risk factor implicated in its causation. Infants with BPD are at a higher risk of developing complications including sepsis, pulmonary arterial hypertension, respiratory failure, and death. Long-term problems include increased risk of hospital readmissions, respiratory infections, and asthma-like symptoms during infancy and childhood. Survivors who have BPD are also at increased risk of poor neurodevelopmental outcomes. While the ultimate solution for avoiding BPD lies in the prevention of preterm births, strategies to decrease its incidence are the need of the hour. It is time to focus on gentler modes of ventilation and the use of less invasive surfactant administration techniques to mitigate lung injury, thereby potentially decreasing the burden of BPD. In this article, we discuss the use of non-invasive ventilation in premature infants, with an emphasis on studies showing an effect on BPD with different modes of non-invasive ventilation. Practical considerations in the use of nasal intermittent positive pressure ventilation are also discussed, considering the significant heterogeneity in clinical practices and management strategies in its use.

Flexible Bronchoscopy in a Patient With Pneumomediastinum and Hypoxemic Respiratory Failure: High-Flow Nasal Cannula to the Rescue

Flexible bronchoscopy with bronchoalveolar lavage carries a significant risk of hypoxia in patients with acute hypoxemic respiratory failure. Noninvasive positive pressure ventilation and high-flow nasal cannula are the most commonly used modalities for reducing procedure-related hypoxemia in such patients. There is no guideline on how to safely perform a bronchoscopy in patients with spontaneous pneumomediastinum and hypoxemic respiratory failure. Here we describe a case of bilateral necrotizing pneumonia, spontaneous pneumomediastinum, and moderate acute respiratory distress syndrome who required diagnostic flexible bronchoscopy.

Feasibility of Pediatric Non-Invasive Respiratory Support in Low- and Middle-Income Countries

Non-Invasive respiratory support can be viewed as mechanical respiratory support without endotracheal intubation and it includes continuous positive airway pressure, bi-level positive airway pressure, high flow nasal cannula, and non-invasive positive pressure ventilation. Over past few years, non-invasive respiratory support is getting more popular across pediatric intensive care units for acute respiratory failure as well as for long-term ventilation support at home. It reduces the need for invasive mechanical ventilation, decreases the risk of nosocomial pneumonia as well as mortality in selected pediatric and adult population. Unfortunately, majority of available studies on non-invasive respiratory support have been conducted in high-income countries, which are different from low- and middle-income countries (LMICs) in terms of resources, manpower, and the disease profile. Hence, we need to consider disease profile, severity at hospital presentation, availability of age-appropriate equipment, ability of healthcare professionals to manage patients on non-invasive respiratory support, and cost-benefit ratio. In view of the relatively high cost of equipment, there is a need to innovate to develop indigenous kits/ devices with available resources in LMICs to reduce the cost and potentially benefit health system. In this review, we highlight the role of non-invasive respiratory support in different clinical conditions, practical problems encountered in LMICs setting, and few indigenous techniques to provide non-invasive respiratory support.

The Mechanisms of Benefit of High-Flow Nasal Therapy in Stable COPD

High-flow nasal therapy (HFNT) is a unique system that delivers humidified, heated oxygen-enriched air via nasal cannula at high flow rates. It is a promising therapy for chronic obstructive pulmonary disease (COPD) patients. Several studies have examined the physiologic effects of this therapy in the patient population and have revealed that it improves mucociliary clearance, reduces nasopharyngeal dead space, and subsequently increases CO₂ washout. It also improves alveolar recruitment and gas exchange. These mechanisms may explain the promising results observed in recently published studies that examined the role of HFNT in stable COPD patients.

Use of bilevel positive pressure ventilation in patients with bronchiolitis

RATIONAL

This study aims at describing the use of bilevel positive airway pressure (BiPAP) in infants with severe bronchiolitis.

WORKING HYPOTHESIS

The use of BiPAP in infants with bronchiolitis may be associated with a worst outcome.

STUDY DESIGN

A single-center retrospective study performed from October 2013 to April 2016.

METHODOLOGY

All infants from 1 day to 6 months of age admitted in the pediatric intensive care unit (PICU) were included if they had a clinical diagnosis of bronchiolitis and if they required any type of noninvasive ventilation (NIV), including high flow nasal cannula, continuous positive airway pressure and BiPAP at admission in PICU. There was no local written protocol regarding the ventilator management during the study.

RESULTS

Overall, 252 infants (median age 45 (26-72) days) were included in the study and 110 infants (44%) were supported by BiPAP at admission. More infants were born preterm in the group of patients supported by BiPAP at admission. No complication related to NIV occurred. Patients in the BiPAP group had a longer duration of noninvasive support as well as a longer PICU length of stay. However, hospital length of stay did not differ according to the type of respiratory support at admission.

CONCLUSION

The use of BiPAP was not associated with endotracheal intubation, however it was associated with increased PICU length of stay and increased duration of NIV.

Quantifying continuous nebulization via high flow nasal cannula and large volume nebulizer in a pediatric model

BACKGROUND

Use of high flow nasal cannula (HFNC) to deliver aerosolized medications to children has gained considerable interest. However, data on continuous albuterol delivery (CAD) via HFNC are lacking. This study quantified CAD via HFNC/vibrating mesh nebulizer (VMN) and large-volume jet nebulizer (LVN) with face mask (FM) in a pediatric model. Aerosol delivery with two HFNC cannula designs were also compared.

METHODS

A pediatric manikin was connected to a lung simulator (Vt = 150 mL, RR = 28 breaths/minute, I:E 1:2.4) via collecting filter at the carina. XL Pediatric and SML Adult HFNC designs were tested to determine optimal cannula design for CAD. VMN was placed Before humidifier (37°C), albuterol (5 mg/mL) was nebulized at 3, 6, and 12 L/minute (n = 3). To compare HFNC/VMN with LVN and FM, albuterol (15 mg/hour) was aerosolized for 3 hours/device (n = 3). LVN was connected to FM and filled with 9 mL of albuterol (5 mg/mL) and 66 mL of normal saline to deliver 25 mL/hour at 13 L/minute. VMN was connected to the infusion pump to deliver 7.5 mL/hr of albuterol (2 mg/mL). Drug eluted from filters was assayed with UV spectrophotometry (276 nm).

RESULTS

Optimal aerosol delivery occurred at 3 L/minute (12.6% ± 0.5%) with SML Adult HFNC (P = .04). When used for CAD, inhaled drug delivery with HFNC/VMN (2.2 mg/hr ± 0.1, 14.8% ± 0.7%) was significantly greater than LVN and FM (0.48 ± 0.09 mg/hour, 3.2% ± 0.6%) (P = .001).

CONCLUSIONS

Administration of CAD via HFNC/VMN led to a greater than fourfold increase in drug delivery compared to LVN with FM. Optimal aerosol delivery occurred at 3 L/minute with SML Adult HFNC.

High flow nasal cannula treatment for obstructive sleep apnea in infants and young children

BACKGROUND

Continuous positive airway pressure (CPAP) is the nonsurgical treatment of choice for children with obstructive sleep apnea (OSA). However, CPAP limitations include difficulty with adherence and midface hypoplasia risk. We, therefore, sought to assess the effect of warm humidified air delivered via open nasal cannula (HFNC) on OSA in children in the sleep laboratory and at home.

METHODS

A retrospective review was performed among children recommended treatment of OSA with HFNC. Reasons for HFNC recommendation included poor surgical candidacy, residual OSA following surgery, and CPAP intolerance. Children underwent both diagnostic and HFNC titration sleep studies and were prescribed HFNC for home use. Standard sleep architecture, arousals, and apnea-hypopnea indices (AHI) were assessed with the evaluation of reported adherence and complications over 12 months of treatment.

RESULTS

Twenty-two children (average 12.8 months, 95% confidence interval [95% CI: 7.0, 18.6]) with OSA (obstructive AHI [OAHI] range: 4.8-89.2 events/h) underwent HFNC titration with significant reduction in OAHI (28.9 events/h [17.6, 40.2] vs 2.6 [1.1, 4.0]; P < .001) (mean [95% CI]). Nineteen patients received home HFNC treatment. By 12 months, four patients were lost to follow-up and OSA resolved in three patients (16%). Of 12 remaining patients, 7 (58%) continued therapy while 5 (42%) discontinued due to intolerance. The most common treatment complication was cannula dislodgement. Additional complications included skin irritation, dry mucus membranes, restlessness, oxygen desaturation, and increased central apneas.

CONCLUSION

HFNC offers a treatment alternative to CPAP in infants and young children with OSA and was well tolerated at home in our study.

CFD Guided Optimization of Nose-to-Lung Aerosol Delivery in Adults: Effects of Inhalation Waveforms and Synchronized Aerosol Delivery

PURPOSE

The objective of this study was to optimize nose-to-lung aerosol delivery in an adult upper airway model using computational fluid dynamics (CFD) simulations in order to guide subsequent human subject aerosol delivery experiments.

METHODS

A CFD model was developed that included a new high-flow nasal cannula (HFNC) and pharmaceutical aerosol delivery unit, nasal cannula interface, and adult upper airway geometry. Aerosol deposition predictions in the system were validated with existing and new experimental results. The validated CFD model was then used to explore aerosol delivery parameters related to synchronizing aerosol generation with inhalation and inhalation flow rate.

RESULTS

The low volume of the new HFNC unit minimized aerosol transit time (0.2 s) and aerosol bolus spread (0.1 s) enabling effective synchronization of aerosol generation with inhalation. For aerosol delivery correctly synchronized with inhalation, a small particle excipient-enhanced growth delivery strategy reduced nasal cannula and nasal depositional losses each by an order of magnitude and enabled ~80% of the nebulized dose to reach the lungs. Surprisingly, nasal deposition was not sensitive to inhalation flow rate due to use of a nasal cannula interface with co-flow inhaled air and the small initial particle size.

CONCLUSIONS

The combination of correct aerosol synchronization and small particle size enabled high efficiency nose-to-lung aerosol delivery in adults, which was not sensitive to inhalation flow rate.

Impact of High-Flow Nasal Cannula on Arterial Blood Gas Parameters in the Emergency Department

Background: High-flow nasal cannula (HFNC) oxygen is becoming an integral part of respiratory failure management. Effects of HFNC on arterial blood gas (ABG) parameters especially partial carbon dioxide (PaCO2) require further investigation to provide insight into the efficacy and safety of the treatment.

Methods: Acute respiratory failure patients with sequential ABG parameters before and after initiating HFNC between June 2015 and June 2017 were analyzed in a tertiary academic center. Patients' baseline characteristics were evaluated and sequential ABG changes were compared and subgrouped as chronic obstructive pulmonary disease (COPD), respiratory acidosis, hypercapnia, and high lactate.

Results: A total of 120 patients were enrolled in the study. There was a significant difference between the mean partial pressure of oxygen in arterial blood (PaO2), lactate, and peripheral oxygen saturation (SpO2) values between sequential ABGs after HFNC (P <0.001). In the COPD group (n=32), there was a significant difference between initial ABG means of PaO2, lactate, and SpO2 values and sequential ABG means (p<0.001). Hypercapnic patients PaCO2 levels were significantly lower after HFNC (p<0.001), while in the COPD group there was no significant change in PaCO2 values (p=0.068).

Conclusions: Treatment with HFNC produced improvement of blood gas parameters in subjects with acute respiratory failure in the emergency department (ED). These results suggest that HFNC can be used in hypercapnic patients as well as hypoxemic patients. Further randomized controlled studies required to establish the impact of HFNC in the ED.

Use of Dexmedetomidine in Early Prone Positioning Combined With High-Flow Nasal Cannula and Non-Invasive Positive Pressure Ventilation in a COVID-19 Positive Patient

As the COVID-19 pandemic continues to manifest in our society, we still lack evidence-based treatment guidelines. Current treatment for COVID-19 pneumonia has been modeled from currently established guidelines such as that of acute respiratory distress syndrome (ARDS). COVID-19 pneumonia, also known as SARS-CoV-2, is characterized by severe hypoxia and near-normal respiratory system compliance with a time-related presentation. Dexmedetomidine is a centrally acting alpha-2 receptor agonist that promotes sedative and anxiolytic effects without the risk of respiratory depression and can provide cooperative or semi-rousable sedation. Patients who are developing ARDS secondary to COVID-19 pneumonia have been treated with self-proning intervals in combination with supplementation of oxygenation via high-flow nasal cannula (HFNC) or non-invasive positive pressure ventilation (NIPPV); however, a few patients have poor tolerance to the devices, leading to poor compliance and eventual worsening respiratory symptoms leading to intubation. In the current case report, we detail how a patient was able to successfully be self-proned with proper tolerance to HFNC and NIPPV while using dexmedetomidine, leading to discharge without the need for further oxygen supplementation at home.

A Rationale for Use of High Flow Nasal Cannula for Select Patients With Suspected or Confirmed Severe Acute Respiratory Syndrome Coronavirus-2 Infection

Infection with the novel 2019 coronavirus (SARS-CoV-2) is associated with the development of a viral pneumonia with severe hypoxemia and respiratory failure. In many cases these patients will require mechanical ventilation; but in others the severity of disease is significantly less and may not need invasive support. High flow nasal cannula (HFNC) is a widely used modality of delivering high concentrations of oxygen and airflow to patients with hypoxemic respiratory failure, but its use in patients with SARS-CoV-2 is poorly described. Concerns with use of HFNC have arisen including aerosolization of viral particles to healthcare workers (HCW) to delaying intubation and potentially worsening of outcomes. However, use of HFNC in other coronavirus pandemics and previous experimental evidence suggest HFNC is low risk and may be effective in select patients infected with SARS-CoV-2. With the significant increase in resource utilization in care of patients with SARS-CoV-2, identification of those that may benefit from HFNC allowing allocation of ventilators to those more critically ill is of significant importance. In this manuscript, we review pertinent literature regarding the use of HFNC in the current SARS-CoV-2 pandemic and address many concerns regarding its use.