High-flow Nasal Cannula Research Articles

The Management of Interstitial Lung Disease in the ICU: A Comprehensive Review

Interstitial lung disease (ILD) encompasses a diverse group of parenchymal lung diseases characterized by varying degrees of inflammation and/or fibrosis. Patients with ILD frequently require hospitalization, with many needing intensive care unit (ICU) admission, most often due to respiratory failure. The diagnosis and management of ILD in the ICU present unique challenges. Diagnosis primarily relies on chest CT imaging to identify fibrosis and inflammation. Acute exacerbations, whether in idiopathic pulmonary fibrosis (IPF) or non-IPF ILD, require careful evaluation of potential triggers and differential diagnoses. Bronchoalveolar lavage may provide valuable information, such as the identification of infections, but carries risks of complications. Biopsies, whether transbronchial or surgical, can also be informative but pose significant procedural risks. Corticosteroids are the cornerstone of treatment for acute exacerbations of IPF, with higher doses potentially benefiting non-IPF ILD. Additional immunosuppressive agents may be used in cases with evidence of inflammation. Oxygen supplementation, particularly with high-flow nasal cannula, is often employed to manage severe hypoxemia, while noninvasive ventilation can be useful for worsening hypoxemia and/or hypercapnia. When mechanical ventilation is used, it is recommended to target low tidal volumes to minimize lung injury; high PEEP may be less effective and even associated with increased mortality. Prone positioning can improve oxygenation in severely hypoxemic patients. In addition to ventilatory strategies, careful fluid management and addressing concomitant pulmonary hypertension are essential components of care. Extracorporeal membrane oxygenation is a high-risk intervention reserved for the most severe cases. Lung transplantation may be considered for end-stage ILD patients in the ICU, with outcomes dependent on the urgency of transplantation and the patient’s overall condition. Managing ILD in the ICU requires a multidisciplinary approach, and despite recent advances, mortality remains high, emphasizing the need for continued research and individualized treatment strategies.

Effect of high-flow nasal therapy on patient-centred outcomes in patients at high risk of postoperative pulmonary complications after cardiac surgery: update to the statistical analysis plan for NOTACS, a multicentre adaptive randomised controlled trial.

The NOTACS trial will assess the efficacy, safety and cost-effectiveness of high-flow nasal therapy (HFNT) compared to standard oxygen therapy (SOT) on the outcomes of patients after cardiac surgery. NOTACS is an adaptive, international, multicentre, parallel group, randomised controlled trial, with a pre-planned interim sample size re-estimation (SSR). A minimum of 850 patients will be randomised 1:1 to receive either HFNT or SOT. The primary outcome is days alive and at home in the first 90days after the planned surgery (DAH90), with a number of secondary analyses and cost-effectiveness analyses also planned. The interim SSR will take place after a minimum of 300 patients have been followed up for 90days and will allow for the sample size to increase up to a maximum of 1280 patients. This manuscript provides detailed descriptions of the design of the NOTACS trial and the analyses to be undertaken at the interim and final analyses. The main purpose of the interim analysis is to assess safety and to perform a sample size re-estimation. The main purpose of the final analysis is to examine the safety, efficacy and cost-effectiveness of HFNT compared to SOT on the outcomes of patients after cardiac surgery. This manuscript outlines the key features of the NOTACS statistical analysis plan and was submitted to the journal before the final analysis in order to preserve scientific integrity under an adaptive design framework. A previous version of this SAP was published prior to the interim analysis (Dawson, 2022). The NOTACS SAP closely follows published guidelines for the content of SAPs in clinical trials(Gamble, 2017). ISRCTN14092678 . (13 May 2020).

Risk factors affecting the development of pneumothorax in patients followed up in intensive care with a diagnosis of COVID-19

BackgroundPneumothorax is a little known and reported complication of COVID-19. These patients have poorer general outcomes and greater respiratory support requirements, longer hospitalization times, and higher mortality rates. The purpose of this study was to determine which factors predict mortality in patients with tube thoracostomy diagnosed with COVID-19, admitted to the COVID-19 intensive care unit (ICU), and developing pneumothorax.MethodsThis respective, observational study was conducted in all COVID-19 ICUs at the Marmara University Pendik Training and Research Hospital, Türkiye. Patients admitted to the ICU with diagnoses of COVID-19 pneumonia and with chest tubes inserted due to pneumothorax were investigated retrospectively.ResultsOne hundred patients with tube thoracostomy were included in the study. Their median age was 68 (57–78), and 63% were men. The median follow-up time was 20 [10–29] days, and the median time from initial reverse transcriptase polymerase chain reaction (RT-PCR) results to tube thoracostomy was 17 [9–23] days. Initial RT-PCR results were positive in 90% of the patients, while 8% were negative, and 2% were unknown. Half the patients exhibited pulmonary involvement at thoracic computed tomography (CT) (n = 50), while 22 patients had COVID-19 reporting and data system (CO-RADS) scores of 5 (22%). Sixty-two patients underwent right tube thoracostomy, 24 left side placement, and 14 bilateral placement. The patients’ mean positive end expiratory pressure (PEEP) level was 10.31 (4.48) cm H2O, with a mean peak inspiratory pressure (PIP) level of 26.69 (5.95) cm H2O, a mean fraction of inspired oxygen (FiO2) level of 80.06 (21.11) %, a mean respiratory rate of 23.71 (5.62) breaths/min, and a mean high flow nasal cannula (HFNC) flow rate of 70 (8.17) L/min. Eighty-seven patients were intubated (87%), six used non-rebreathable reservoir masks, four HFNC, two non-invasive mechanical ventilation (NIV), and one a simple face mask. Comorbidity was present in 70 patients, 25 had no comorbidity, and the comorbidity status of five was unknown. Comorbidities included hypertension (38%), diabetes mellitus (23%), cardiovascular disease (12%), chronic obstructive pulmonary disease (5%), malignancy (3%), rheumatological diseases (3%), dementia (2%) and other diseases (9%). Twelve of the 100 patients survived. The median survival time was 20 (17.82–22.18) days, and the median 28-day overall survival rate was 29% (20-38%). The multivariate Cox proportional hazards model indicated that age over 68 (HR = 2.23 [95% CI: 1.39–3.56]; p = 0.001), oxygenation status other than by intubation (HR = 2.24 [95% CI: 1.11–4.52]; p = 0.024), and HCO3- below 22 compared with a normal range of 22 to 26 (HR = 1.95 [95% CI: 1.08–3.50]; p = 0.026) were risk factors associated with mortality in patients in the ICU.ConclusionsAge over 68, receipt of oxygenation other than by intubation, and HCO3- values lower than 22 in patients with COVID-19 pneumonia emerged as prognostic factors associated with mortality in terms of pneumothorax.

A novel method for positive airway pressure delivery: pulsating airflow.

The primary objective is to determine if pulsating airflow can achieve therapeutic pharyngeal pressure levels without requiring a tight-sealing mask. A pilot study included 12 nasal-breathing adults who are currently using positive airway pressure (PAP) for therapy. Patients were awake, and pharyngeal pressures were measured using a miniature pressure probe inserted through their nares. Pulsating airflow was applied via a nasal cannula with a customized valve. The inspiratory flow rate was increased until the pharyngeal pressure matched or exceeded the participant's prescribed PAP level. The expiratory flow rate was maintained at a constant low level of continuous airflow. The study demonstrated that pulsating airflow could generate pharyngeal pressures equivalent to or higher than those achieved with PAP therapy in all participants. The peak inspiratory pressures with pulsating airflow followed an oscillatory pattern matching the pulsation frequency. The mean peak pressure increased linearly with the pulsating flow rate. Compared to a high-flow nasal cannula, pulsating airflow produced significantly higher inspiratory pharyngeal pressures, reaching nearly 20 cmH2O. Pulsating airflow could be a viable method for delivering PAP therapy to patients with respiratory or sleep disorders without needing a tight-sealing mask. Further research is required to establish whether this method can improve patient compliance with PAP therapy, assess long-term safety and efficacy, and explore the impact of varying pulsation parameters on treatment outcomes.

Impact of non-invasive ventilation on microbial colonisation patterns in preterm infants: a single-centre study.

The objective of this study is to assess the relationship between non-invasive ventilation (NIV) and the colonisation of oral and nasal microbiota in preterm infants within the neonatal intensive care unit (NICU). A prospective cohort study. The NICU of Zhejiang University Children's Hospital. Patients include preterm infants with a gestational age of 28-35 weeks, enrolled within the first 24 hours of life. Infants were categorised based on respiratory support: NIV, which included nasal continuous positive airway pressure, nasal intermittent positive pressure ventilation or high-flow nasal cannula; and no respiratory support, defined as room air or low-flow nasal cannula at ≤2 L/min. The primary outcome was the colonisation of oral and nasal microbiota at 5 days post birth, measured by colony-forming units per millilitre (CFU/mL), with colonisation defined as bacterial growth >103 CFU/mL. The study included 100 preterm infants, with 50 in each group. Nasal microbial colonisation was observed in 56% (28/50) of the NIV group, significantly higher than the 28% in the no respiratory support group. No significant differences were found in oral colonisation. Adjusted binary logistic regression showed an association between NIV and increased risk of nasal colonisation (adjusted OR=2.91, 95% CI 1.12 to 7.58, p=0.028). NIV in preterm infants was linked to a higher risk of nasal microbial colonisation. This finding suggests the need for further research and consideration of infection control strategies in the NICU.

Effects of Home Nursing and Rehabilitation on Daily Life and Outgoing Activities in a Patient With Interstitial Pneumonia Supported by a High-Flow Nasal Cannula: A Case Report

Effects of Home Nursing and Rehabilitation on Daily Life and Outgoing Activities in a Patient With Interstitial Pneumonia Supported by a High-Flow Nasal Cannula: A Case Report

Nasal Continuous Positive Airway Pressure Inhibits Gastroesophageal Refluxes in the Preterm Lamb.

Gastroesophageal refluxes (GERs) are universal in newborns and may induce deleterious consequences, especially in preemies. We have previously shown that nasal continuous positive airway pressure (nCPAP) inhibits GERs in full-term lambs, complementing similar results in adult humans. The effect of high-flow nasal cannula (HFNC) on GERs, however, remains unknown. This study aimed to assess the effects of nCPAP and HFNC on GERs in our preterm lamb model. Eleven preterm lambs born 14 days before full-term (~ 34 weeks of human gestation) were studied. Esophageal pH-impedancemetry and polysomnography recordings were performed simultaneously for six hours under three randomly ordered conditions: nCPAP 6 cmH2O, HFNC 7 L/min and no respiratory support (control). The indexes (/hour) of GERs and air-containing swallows were analyzed during each condition. The states of alertness and cardiorespiratory events were also analyzed during the identified GERs. nCPAP significantly decreased the GER index compared to control and HFNC during both quiet wakefulness and non-rapid eye movement sleep, whereas HFNC did not alter the GER index. In addition, nCPAP significantly increased the air-containing swallow index compared to control and HFNC. No significant differences were observed between the tested conditions for GER-related cardiorespiratory events, which were nevertheless rarely observed. Similar to full-term lambs, nCPAP strongly inhibited GERs in the preterm lamb, despite an increase in air-containing swallows. In contrast, HFNC did not impact GERs. Our results are clinically relevant when discussing the use of CPAP in preemies with GERs.

Impact of High-Flow Nasal Cannula Oxygen Therapy on the Pressure of the Airway System in Humans.

The understanding of how pharyngeal pressure is transmitted to the trachea with high-flow nasal cannula (HFNC) implementation and the behavior of tracheal pressure in the presence of mouth leaks remains limited. This study aimed to assess the impact of HFNC administration on tracheal pressure by comparing measurements taken with open and closed mouth with varying flows. A crossover study was conducted between March 2019 and June 2023. Subjects age > 18 years, with a tracheostomy and who were in the process of decannulation were included. Tracheal and pharyngeal pressures were measured by using specific devices, with different HFNC flows and mouth conditions. Nine subjects were assessed: 77% women, with an average age of 60.5 years. Tracheal pressure was significantly higher than pharyngeal pressure only in baseline conditions (P = .03). With regard to the rest of the scenarios, there were no significant differences between both pressures. Tracheal pressure was higher than the baseline condition both with an open mouth and a closed mouth (P = .02). The tracheal pressure at 60 L/min with an open mouth was higher than at 40 L/min (P = .042). The median pharyngeal pressure with a closed mouth was higher than with an open mouth, both with 40 and 60 L/min of flow (P = .048 and P < .001, respectively). Pharyngeal pressure at 60 L/min with an open mouth was higher than both baseline condition and at 40 L/min (P = .002 and P = .043, respectively). However, pharyngeal pressure with the closed mouth was significantly higher than with the open mouth both with 40 and 60 L/min of flow (P = .031 and P = .02 respectively). The implementation of HFNC changes airway pressures with values that impact at a tracheal level as the flow used increases. Our data contribute to the difficult interpretation of the existing interrelation between the programmed flow and its effects on the respiratory system.

Predicting High-Flow Nasal Cannula Oxygen Therapy Failure in Patients With Acute Hypoxaemic Respiratory Failure Using Machine Learning: Model Development and External Validation.

To develop and validate a prediction model for high-flow nasal cannula (HFNC) failure in patients with acute hypoxaemic respiratory failure (AHRF). AHRF accounts for a major proportion of intensive care unit (ICU) admissions and is associated with high mortality. HFNC is a non-invasive respiratory support technique that can improve patient oxygenation. However, HFNC failure, defined as the need for escalation to invasive mechanical ventilation, can lead to delayed intubation, prolonged mechanical ventilation and increased risk of mortality. Timely and accurate prediction of HFNC failure has important clinical implications. Machine learning (ML) can improve clinical prediction. Multicentre observational study. This study analysed 581 patients from an academic medical centre in Boston and 180 patients from Guangzhou, China treated with HFNC for AHRF. The Boston dataset was randomly divided into a training set (90%, n = 522) and an internal validation set (10%, n = 59), and the model was externally validated using the Guangzhou dataset (n = 180). A random forest (RF)-based feature selection method was used to identify predictive factors. Nine machine learning algorithms were selected to build the predictive model. The area under the receiver operating characteristic curve (AUC) and performance evaluation parameters were used to evaluate the models. The final model included 38 features selected using the RF method, with additional input from clinical specialists. Models based on ensemble learning outperformed other models (internal validation AUC: 0.83; external validation AUC: 0.75). Important predictors of HFNC failure include Glasgow Coma Scale scores and Sequential Organ Failure Assessment scores, albumin levels measured during HFNC treatment, ROX index at ICU admission and sepsis. This study developed an interpretable ML model that accurately predicts the risk of HFNC failure in patients with AHRF. Clinicians and nurses can use ML models for early risk assessment and decision support in AHRF patients receiving HFNC. TRIPOD checklist for prediction model studies was followed in this study. Patients were involved in the sample of the study.

High-flow nasal cannula oxygen therapy versus noninvasive ventilation for elderly chronic obstructive pulmonary disease patients after extubation: a noninferior randomized controlled trial protocol

IntroductionNoninvasive ventilation (NIV) is widely used for sequential extubation in patients with chronic obstructive pulmonary disease (COPD). However, NIV may cause many adverse events such as claustrophobia, facial skin compression, air leakage, bloating, and even reflux aspiration, resulting in poor patient compliance/tolerance and high failure rate, especially for older adults who are at high risk of communication difficulties and consciousness disorder. High-flow nasal cannula (HFNC) oxygen therapy is a new alternative support to NIV, but whether it can effectively reduce the rate of re-intubation after extubation in elderly patients with COPD remains controversial. The purpose of this study is to explore the safety and efficacy of HFNC versus NIV for elderly COPD patients after extubation.Methods and analysisThis study is an investigator-initiated, single-center, prospective, non-inferior, randomized controlled trial. Elderly patients (age > 65 years) who have received invasive ventilation and was diagnosed with COPD will be randomly assigned to HFNC group or NIV group immediately after extubation with a planned enrollment of 168 patients. The primary outcomes will be reintubation rates at 72 h and 7 days after extubation. Secondary outcomes will include treatment failure, post-extubation vital signs and arterial blood gases, the scores of compliance and comfort of patients, duration of respiratory support after extubation, respiratory support related adverse events, sleep quality scores, usage of sedative and analgesic drugs after extubation, and the incidence of delirium. Additionally, clinical outcomes such as ventilator-free days at 28 days post-randomization, tracheotomy rate, duration of intensive care unit (ICU) and hospital stay, ICU and hospital mortality will be evaluated.Ethics and disseminationThis study has been approved by the Ethics Committee of West China Hospital of Sichuan University (2023–2284). Informed consent is required. It is expected that a follow-up randomized controlled trial will be conducted. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.Trial registrationThe study was retrospectively registered at ClinicalTrials.gov (ChiCTR2400087312).

High-flow nasal cannulas versus standard oxygen therapy for moderate bronchiolitis: a quasi-experimental analysis.

In the last decades none of the medical therapies investigated have shown clear efficacy in the treatment of bronchiolitis, and literature agrees on a general de-implementation of pharmacological therapies, recognizing an effective role only to nutritional support and oxygen therapy. High-flow nasal cannulas (HFNC) has become increasingly popular in the last decade, despite its lack of clear efficacy. Recent randomized controlled trials (RCT) comparing standard oxygen therapy (SOT) and HFNC did not demonstrate significant benefit of HFNC. To acquire more clinical data on HFNC efficacy we performed a retrospective, quasi-experimental analysis of patients admitted for bronchiolitis in the epidemic seasons 2021-2022 and 2022-2023. To assess the efficacy of SOT and HFNC we used a pragmatic approach, a fuzzy regression discontinuity design, which is a quasi-experimental test. Unlike RCTs, this process is not a true randomization, but may be interpreted as quasi-randomization in an observational setting. HFNC did not reduce length of oxygen therapy (LOO) nor length of hospitalization (LOS) (respectively, p: 0.383 and p: 0.454). Treatment failure was not significantly different in the treatment groups (p: 0.354). It is crucial to perform additional RCTs with uniform protocols to determine the efficacy of HFNC more accurately in the treatment of bronchiolitis. HFNC does not reduce LOO, suggesting that early use of HFNC does not change the course of disease in moderate bronchiolitis. In view of the greater complexity and higher cost, HFNC should not be routinely used as first-line treatment in children with moderate respiratory distress and mild hypoxemia.

Impact of low dose inhaled nitric oxide treatment in spontaneously breathing and intubated COVID-19 patients: a retrospective propensity-matched study

BackgroundThe benefit of Inhaled nitric oxide (iNO) therapy in the setting of COVID-19-related ARDS is obscure. We performed a multicenter retrospective study to evaluate the impact of iNO on patients with COVID-19 who require respiratory support.MethodsThis retrospective multicenter study included COVID-19 patients enrolled in the SCCM VIRUS COVID-19 registry who were admitted to different Mayo Clinic sites between March 2020 and June 2022 and required high-flow nasal cannula (HFNC), non-invasive ventilation (NIV), or invasive mechanical ventilation (IMV). Patients were included in the ‘spontaneously breathing’ group if they remained non-intubated or were initiated on an HFNC (± NIV) before intubation. Patients who got intubated without prior use of an HFNC (± NIV) were included in the ‘intubated group.’ They were further divided into categories based on their iNO usage. Propensity score matching (PSM) and inverse propensity of treatment weighting (IPTW) were performed to examine outcomes.ResultsAmong 2767 patients included in our analysis, 1879 belonged to spontaneously breathing (153 received iNO), and 888 belonged to the intubated group (193 received iNO). There was a consistent improvement in FiO2 requirement, P/F ratio, and respiratory rate within 48 h of iNO use among both spontaneously breathing and intubated groups. However, there was no significant difference in intubation risk with iNO use among spontaneously breathing patients (PSM OR 1.08, CI 0.71–1.65; IPTW OR 1.10, CI 0.90–1.33). In a time-to-event analysis using Cox proportional hazard model, spontaneously breathing patients initiated on iNO had a lower hazard ratio of in-hospital mortality (PSM HR 0.49, CI 0.32–0.75, IPTW HR 0.40, 95% CI 0.26–0.62) but intubated patients did not (PSM HR: 0.90; CI 0.66–1.24, IPTW HR 0.98, 95% CI 0.73–1.31). iNO use was associated with longer in-hospital stays, ICU stays, ventilation duration, and a higher incidence of creatinine rise.ConclusionsThis retrospective propensity-score matched study showed that spontaneously breathing COVID-19 patients on HFNC/ NIV support had a decreased in-hospital mortality risk with iNO use in a time-to-event analysis. Both intubated and spontaneously breathing patients had improvement in oxygenation parameters with iNO therapy but were associated with longer in-hospital stays, ICU stays, ventilation duration, and higher incidence of creatinine rise.

Factors associated with the effectiveness of high-flow therapy in patients with acute hypoxemic respiratory failure: An observational study

BackwardThe COVID-19 pandemic has severely tested global health systems. Non-invasive respiratory support, especially combining high-flow nasal cannula (HFNC) and continuous positive airway pressure, has effectively treated COVID-19 induced Acute Hypoxemic Respiratory Failure and reduced mortality. However, HFNC alone is more comfortable, better tolerated, and less costly than non-invasive ventilation. Understanding which patients benefit from HFNC monotherapy versus combined therapies is essential. MethodsThis observational study included patients admitted to the intermediate respiratory care unit of a COVID-19 hospital between December 2020 and September 2021. All patients treated with HFNC were included (n = 1301). HFNC failure was defined as the need for escalated therapy (non-invasive ventilation, intubation) or death. Epidemiological, clinical, non-invasive respiratory support parameters, and laboratory data were collected, and a multivariable analysis identified key determinants. ResultsHFNC was successful in 39.9 % of patients. (n = 511) Risk factors for HFNC failure included increased age, male gender, obesity, obstructive sleep apnea, higher respiratory rate, initial SpO2/FiO2 ≤ 148, and initial PaO2/FiO2 ≤ 100. An increase in the ROX Index at 24 h and slower disease progression were associated with successful treatment. These findings led to the developmet of an index to identify patients who benefit most from HFNC monotherapy. ConclusionsHFNC monotherapy can be effective for a specific profile of patients with Acute Hypoxemic Respiratory Failure due to COVID-19. This tool may help manage these patients more appropriately. Further studies are needed to determine if these findings can be applied to Acute Hypoxemic Respiratory Failure caused by other pathologies. Implications for Clinical PracticeThis study underscores the importance of early identification and management of patients at risk of HFNC failure in intermediate respiratory care units. By recognizing factors such as age, comorbidities, and respiratory indices, healthcare providers can implement targeted strategies to enhance HFNC success. These strategies may include more stringent monitoring, tailored respiratory support, and timely escalation to more intensive therapies if needed. Our findings highlight the need for a comprehensive approach to managing severe respiratory failure in critical care settings, ultimately improving patient outcomes and reducing the burden on healthcare systems.

Effect of high-flow nasal cannula oxygen versus standard oxygen on mortality in patients with acute hypoxaemic respiratory failure: protocol for a multicentre, randomised controlled trial (SOHO)

IntroductionFirst-line oxygenation strategy in patients with acute hypoxaemic respiratory failure consists in standard oxygen or high-flow nasal oxygen therapy. Clinical practice guidelines suggest the use of high-flow nasal oxygen rather...

High-Flow Nasal Oxygen in Patients with Acute Hypercapnic Respiratory Failure: A Narrative Review of the Physiological Rationale and Clinical Evidence

Acute hypercapnic respiratory failure is a life-threatening condition caused by alveolar hypoventilation. It is mostly caused by an acute exacerbation of chronic obstructive pulmonary disease or conditions yielding muscle dysfunction. Noninvasive ventilation through a facemask is the cornerstone first-line strategy to support hypercapnic patients with acidemia, and current guidelines strongly recommend this intervention to improve survival and long-term clinical outcomes. Because of its benefits related to carbon dioxide washout from the upper airways and the enhanced comfort, high-flow nasal oxygen has been proposed as a respiratory support strategy in patients with hypercapnic respiratory failure, both as an alternative to and in combination with noninvasive ventilation. When compared to noninvasive ventilation as a first-line intervention, high-flow nasal oxygen shows a higher rate of failure. Hence, if not contraindicated, the use of noninvasive ventilation should be preferred. After the resolution of acidemia with noninvasive ventilation, high-flow nasal oxygen showed promising physiological effects compared to conventional oxygen. During weaning from mechanical ventilation in patients with or at risk of developing hypercapnia, high-flow nasal oxygen showed encouraging results, especially when applied alternating with sessions of noninvasive ventilation. Optimal settings of high-flow nasal oxygen in hypercapnic patients include the use of a smaller-size cannula, flows ranging between 30 and 40 L/min, and FiO2 adjusted to obtain SpO2 between 88% and 92%. Specific interfaces, such as asymmetric cannulas, may further enhance the benefits of a high flow in terms of carbon dioxide clearance. In this narrative review, we provide an updated overview of the physiological rationale and clinical evidence concerning the use of high-flow nasal oxygen in patients with acute hypercapnic respiratory failure.

55 Post-pandemic paediatric asthma admissions: Clinical characteristics and outcomes of children hospitalized with asthma in 2022: The READAPT-Kids study cohort

Abstract Background Asthma exacerbations triggered by acute respiratory infections (ARIs) are a major cause of hospitalizations in children. There were large reductions in asthma admission during the SARS-CoV2 pandemic. Following the relaxation of public health interventions, there was a resurgence in admissions for ARIs. The effect of this rebound in ARIs on asthma management practices and outcomes is not well understood. Objectives To describe sociodemographic characteristics, etiology, management, and clinical outcomes of children and youth under the age of 18 years admitted to a tertiary care paediatric hospital with an acute asthma exacerbation from July 1, 2022 to Dec 31, 2022. Design/Methods An observational cohort study of children and youth less than 18 years, hospitalized with an acute asthma exacerbation from July 1, 2022 to Dec 31, 2022 at a single large Canadian children’s hospital. This was a subgroup analysis of the READAPT-Kids study cohort (Clinical chaRacteristics and outcomEs of hospitAlized children with Acute resPiratory infecTions.) Cases were identified using ICD-10-CA codes, then manually screened for inclusion. Detailed clinical and demographic information was extracted. Results Among 551 patients hospitalized with an ARI, 29.2% (n=161) were diagnosed with an asthma exacerbation. 99 were male (61.5%) with a median age of 3.8 years (IQR 2.2-6.3). 41.3% (n=64) had a previously documented asthma history, and of those, only 16.9% were taking any form of asthma therapy at admission. In hospital, 91.4% were given systemic corticosteroids, 86.5% had at least 1 viral pathogen identified, 72.2% had a chest x ray, 42.1% received antibiotics, and 23.7% had high flow nasal cannula oxygen outside of the paediatric intensive care (PICU). 22.4% (n=36), were admitted to the PICU, and 3.7% required invasive mechanical ventilation, there were no patient deaths. Median length of stay was 2.6 days (IQR 1.7–4.6 days). At discharge, 79.5% were prescribed regular inhaled corticosteroid therapy. Conclusion Asthma admissions accounted for a significant proportion of children hospitalized with ARIs in the post-pandemic era, with one fifth requiring transfer to PICU. CXR and antibiotic usage were high. Over 80% of those with a previous diagnosis of asthma were not taking inhaled corticosteroids at the time of admission.

High-Flow Nasal Aerosol Therapy; Regional Aerosol Deposition and Airway Responsiveness.

Introduction: In normal subjects, during tidal breathing, aerosols deposit by settling in small airways. With obstructive lung disease (OLD), collapse of airways during expiration causes turbulence and increased deposition in central airways. High-flow nasal cannula (HFNC) therapy, washing out dead space, may affect deposition mechanisms and drug delivery. This study compared aerosol deposition and airway responsiveness in OLD after traditional and HFNC nebulization therapy. Methods: Twelve subjects with moderate to severe OLD participated in a two-day study. Spirometry was measured pre- and post-aerosol inhalation. On Day 1 (D1) subjects tidally inhaled radiolabeled albuterol (99mTc DTPA) by mouth via AeroTech II, (Biodex. Shirley, NY). Day 2 (D2) inhalation was via HFNC using i-AIRE (InspiRx, Inc. Somerset, NJ). The HFNC system (60 L/m) was infused by syringe pump at 50 mL/h. D2 lung deposition was monitored in real time by gamma camera to match D1. Pre and post heart rate, O2 sat, and nasopharyngeal deposition (NP) were measured. Mechanistic contributions were modeled using multiple linear regression (MLR) of deposition rate (DR µg/m) as a function of breathing frequency, airway geometry (FEV1), and parenchymal integrity (DLCO). Results: Albuterol lung depositions were matched (p = 0.13) with D1 central/peripheral (sC/P) ratios 1.99 ± 0.98. Following HFNC, peripheral deposition increased (31% ± 33%, sC/P = 1.51 ± 0.43, p = 0.01). D2/D1% change FVC increased by 16.1 ± 16.7% (p = 0.003). NP deposition averaged 333% of lung. Heart rate and O2 sat were unaffected (p = 0.31, p = 0.63 respectively). DR analysis was markedly different between D1 (R2 = 0.82) and D2 (R2 = 0.12). Conclusion: In subjects with OLD, HFNC nebulization at 60 L/min was well tolerated and increased peripheral drug delivery. Spirometry significantly improved. Systemic effects were undetected indicating limited nasal absorption. MLR demonstrated that different mechanisms of deposition govern traditional vs HFNC aerosol delivery. Breath-enhanced nebulization via HFNC may provide controllable and effective aerosol therapy in OLD.

Treatment of OSA beyond adenotonsillectomy.

Pediatric obstructive sleep apnea (OSA) is a common syndrome in children. While an adenotonsillectomy is effective for most, it may not be the treatment of choice for all, and possible alternative treatment options are briefly discussed herein. In obese children, in whom OSA is more prevalent, and has high rates of persistence after surgery, weight loss interventions may be recommended. Anti-inflammatory therapies, such as nasal steroids and montelukast, reduce the size of the adenoids and tonsils and are considered part of the stepwise treatment approach. Functional orthodontic therapies may improve OSA as well as orthopedic interventions in children in whom orthodontic indications exist. Positive airway pressure and high flow nasal cannula, stent the airway open and alleviate the obstruction, but adherence may be challenging. Tongue surgery, as well as several additional interventions are further discussed. In conclusion, multiple therapeutic options are available for pediatric OSA. Further studies are required to better identify the children most likely to benefit from these therapies.

Long-Term Disabilities in ICU Survivors of COVID-19.

COVID-19 is associated with prolonged disability, particularly after critical illness. This study aimed to assess and compare disability post-hospital discharge of subjects who were invasively ventilated versus those who were not, following ICU admission due to COVID-19. This study also explored variables associated with long-term disability. In this prospective cohort study, subjects with COVID-19 who received invasive ventilation, noninvasive ventilation, or high-flow nasal cannula during ICU stay were assessed with the World Health Organization Disability Assessment Schedule (WHODAS) 2.0 at 3 and 6 months post-hospital discharge. Data were analyzed collectively and stratified as subjects with and without invasive mechanical ventilation. Analysis of variance and multiple regression analyses were applied. The subjects (N = 43) were mainly male, middle age, and overweight. Subjects who were invasively ventilated (n = 21) had decreased physical function compared to those who were not during hospital assessments. From 3-6 months after discharge, all WHODAS domains and the overall score decreased in both groups (P < .001), indicating disability recovery. The participation domain, which assesses joining in society, was the only domain that remained worse in the ventilation group compared to the no ventilation group (P = .01). No interaction was found between time and the study groups, suggesting that the recovery trajectory was similar. At 6 months, considering the entire cohort, 70% and 56% had no disability in self-care and getting along domains, respectively, while 42% exhibited moderate to severe disability in the participation domain. According to the overall WHODAS score, 86% of subjects still had some level of disability at 6 months. In multivariate analyses, the overall WHODAS score along with the household and participation domains showed significant positive correlations, indicating higher disability, with corticosteroid use. Disability persisted at 6 month post-hospital discharge for ICU survivors of COVID-19, regardless of the need for invasive mechanical ventilation. Participation was the only domain that showed higher disability among those who received invasive ventilation.

Efficacy of High Flow Nasal Cannula in the Treatment of Patients with COVID-19 with Acute Respiratory Distress Syndrome: Results of Single Centre Study in Vietnam.

Most hospitalized patients required invasive or non-invasive ventilation and High Flow Nasal Cannula (HFNC). Therefore, this study was conducted to describe the characteristics of patients with severe Coronavirus Disease-2019 (COVID-19) treated by HFNC and its effectiveness for reducing the rate of intubated-mechanical ventilation in the Intensive Care Unit (ICU) of Phu Chanh COVID-19 Department-Binh Duong General Hospital. It was a cross-sectional and descriptive study. All severe patients with COVID-19 with acute respiratory failure eligible for the study were included. Patient characteristics, clinical symptoms, laboratory results, and treatment methods were collected for analysis; parameters and data related to HFNC treatment and follow-up were analysed. 80 patients, aged of 49.7 ± 16.6years, were treated with HFNC at admission in ICU. 14 patients had type 2 diabetes (17.5%), 3 patients had chronic respiratory disease (3.8%), 19 patients had high blood pressure (23.8%), and 5 patients with other comorbidities (7.4%). The majority of patients with severe COVID-19 had typical symptoms of COVID-19 such as shortness of breath (97.5%), intensive tired (81.3%), cough (73.7%), anosmia (48.3%), ageusia (41.3%), and fever (26.3%). The results of arterial blood gases demonstrated severe hypoxia under optimal conventional oxygen therapy (PaO2 = 52.5 ± 17.4mmHg). Respiratory rate, SpO2, PaO2 were significantly improved after using HFNC at 1st day, 3rd day and 7th day (P < 0.05; P < 0.05; P < 0.01; respectively). Receiver operating characteristics (ROC) index was significantly increased after treating with HFNC vs before HFNC treatment (4.79 ± 1.86, 5.53 ± 2.39, and 7.41 ± 4.24 vs 2.97 ± 0.39; P < 0.05, P < 0.05 and P < 0.01, respectively). 54 (67.5%) patients were success with HFNC treatment and 26 (32.5%) patients with HFNC failure needed to treat with Continuous Positive Airway Pressure (CPAP) (13 patients; 50%) or intubated ventilation (13 patients; 50%). HFNC therapy could be considered as a useful and effective alternative treatment for patients with acute respiratory failure. HFNC might help to delay the intubated ventilation for patients with respiratory failure and to minimise the risk of invasive ventilation complications and mortality. However, it is crucial to closely monitor the evolution of patient's respiratory status and responsiveness of HFNC treatment to avoid unintended delay of intubation-mechanical ventilation. An independent ethics committee approved the study (The Ethics Committee of Binh Duong General Hospital; No. HDDD-BVDK BINH DUONG 9.2021), which was performed in accordance with the Declaration of Helsinki, Guidelines for Good Clinical Practice.