Effect of high-flow nasal cannula at different flow rates on diaphragmatic function in subjects recovering from an acute exacerbation of COPD: a physiological prospective pilot study.

BACKGROUND: Noninvasive ventilation (NIV) is widely employed as the initial treatment for patients with chronic acute exacerbation of obstructive pulmonary disease (AECOPD). Nevertheless, high-flow nasal cannula (HFNC) has been increasingly utilized and investigated to mitigate the issues associated with NIV. Flow rate may play a significant role in diaphragmatic function among subjects recovering from AECOPD. Based on these observations, we conducted a physiological study to assess the impact of HFNC therapy on diaphragmatic function, as measured by US, respiratory rate (RR), gas exchange, and patient comfort at various flow rates. METHODS: A prospective physiological pilot study enrolled subjects with a diagnosis of AECOPD who required NIV for more than 24 h. After stabilization, these subjects underwent a 30-min trial using NIV and HFNC at different sequential flow rates (30-60 L/min). At the end of each trial, diaphragmatic displacement (DD, cm) and diaphragmatic thickness fraction (DTF, %) were measured using ultrasound. Additionally, other physiological variables, such as RR, gas exchange, and patient comfort, were recorded. RESULTS: A total of 20 patients were included in the study. DD was no different among trials (p = 0.753). DTF (%) was significantly lower with HFNC-30 L/min compared to HFNC-50 and 60 L/min (p < 0.001 for all comparisons). No significant differences were found in arterial pH and PaCO2 at discontinuation of NIV and at the end of HFNC trials (p > 0.050). During HFNC trials, RR remained unchanged without statistically significant differences (p = 0.611). However, we observed that HFNC improved comfort compared to NIV (p < 0.001 for all comparisons). Interestingly, HFNC at 30 and 40 L/min showed greater comfort during trials. CONCLUSIONS: In subjects recovering from AECOPD and receiving HFNC, flows above 40 L/min may not offer additional benefits in terms of comfort and decreased respiratory effort. HFNC could be a suitable alternative to COT during breaks off NIV.

Noninvasive respiratory support in the perioperative setting: a narrative review.

The application of preoperative noninvasive respiratory support (NRS) has been expanding with increasing recognition of its potential role in this setting as a physiological optimization for patients with a high risk of developing atelectasis and postoperative pulmonary complications (PPC). The increased availability of high-performance anesthesia ventilator machines providing an easy way for NRS support in patients with reduced lung function should not be under-evaluated. This support can reduce hypoxia, restore lung volumes and theoretically reduce atelectasis formation after general anesthesia. Therapeutic purposes should also be considered in the perioperative setting, such as preoperative NRS to optimize treatment of patients' pre-existing diseases, e.g., sleep-disordered breathing. Finally, the recent guidelines for airway management suggest preoperative NRS application before anesthesia induction in difficult airway management to prolong the time needed to secure the airway with an orotracheal tube. This narrative review aims to revise all these aspects and to provide some practical notes to maximize the efficacy of perioperative noninvasive respiratory support.

Lung ultrasound score predicts outcomes in patients with acute respiratory failure secondary to COVID-19 treated with non-invasive respiratory support: a prospective cohort study.

BACKGROUND: Lung ultrasound has demonstrated its usefulness in several respiratory diseases management. One derived score, the Lung Ultrasound (LUS) score, is considered a good outcome predictor in patients with Acute Respiratory Failure (ARF). Nevertheless, it has not been tested in patients undergoing non-invasive respiratory support (NIRS). Taking this into account, the aim of this study is to evaluate LUS score as a predictor of 90-day mortality, ETI (Endotracheal intubation) and HFNC (High Flow Nasal Cannula) failure in patients with ARF due to COVID-19 admitted to a Respiratory Intermediate Care Unit (RICU) for NIRS management. RESULTS: One hundred one patients were admitted to the RICU during the study period. Among these 76% were males and the median age was 55 (45-64) years. Initial ARF management started with HFNC, the next step was the use of Continuous Positive Airway Pressure (CPAP) devices and the last intervention was ETI and Intensive Care Unit (ICU) admission. Of the total study population, CPAP was required in 40%, ETI in 26%, while 15% died. By means of a ROC analysis, a LUS ≥ 25 points was identified as the cut-off point for mortality(AUC 0.81, OR 1.40, 95% CI 1.14 to 1.71; p < 0.001), ETI (AUC 0.83, OR 1.43, 95% CI 1.20 to 1.70; p < 0.001) and HFNC failure (AUC 0.75, OR 1.25, 95% CI 1.12 to 1.41; p < 0.001). Kaplan-Meier survival curves also identified LUS ≥ 25 as a predictor of 90-days mortality (HR 4.16, 95% CI 1.27-13.6) and 30 days ETI as well. CONCLUSION: In our study, a ≥ 25 point cut-off of the Lung Ultrasound Score was identified as a good outcome prediction factor for 90-days mortality, ETI and HFNC failure in a COVID-19 ARF patients cohort treated in a RICU. Considering that LUS score is easy to calculate, a multicenter study to confirm our findings should be performed.

Utilización de soportes respiratorios no invasivos post extubación en pacientes adultos críticos: revisión narrativa SRNI post extubación en adultos críticos / Use of Non-Invasive Respiratory Support in Critically Ill Patients Post-Extubation: a Narrative Review NIRS Post-Extubation in Critically Ill Adults

La tasa de reintubación orotraqueal luego de la extubación se registra entre un 10 a 20%. La aplicación de soportes respiratorios no-invasivos (SRNI) posterior a la extuba-ción como cánula nasal de alto-flujo, ventilación no invasiva (dos niveles de presión) y presión positiva continua en la vía aérea demostraron ser seguras y efectivas post ex-tubación. El período pre-destete representa un momento crucial en el manejo de los pa-cientes críticos ya que el fracaso de la extubación, definido como la necesidad de reintu-bación dentro de los 2 a 7 días, demostró peores resultados al aumentar la mortalidad entre un 25-50%. Esta situación conlleva al requerimiento de ventilación mecánica prolongada, neumonía asociada a la ventilación mecánica y estancias prolongadas de internación. Por lo tanto, es esencial identificar a los pacientes que se beneficiarán utilizando SRNI post extubación.

The rate of re-intubation after extubation is recorded at 10-20%. The use of non-invasive respiratory support (NIRS) post-extubation such as high-flow nasal cannula, non-invasive ventilation (bilevel pressure) and continuous positive airway pressure (CPAP) have been shown to be safe and effective post-extubation. The pre-weaning period represents a crucial time in the management of critically ill patients, as extubation failure, defined as the need for reintubation within 2-7 days, showed worse outcomes with mortality increasing by 25-50%. This situation leads to the requirement for prolonged mechanical ventilation, ventilator-associated pneumonia and long lengths of hospital stay. Therefore, it is essential to identify patients who will benefit from NIRS post extubation.

Terapia nasal de alto flujo durante la exacerbación del asma en sujetos adultos / 18 Terapia nasal de alto flujo durante la exacerbación del asma en sujetos adultos High-flow nasal therapy during asthma exacerbation in adult subjects

El asma es una enfermedad respiratoria crónica frecuente que afecta al 1-18% de la población en diferentes países y secaracteriza por síntomas variables como sibilancias, disnea, opresión torácica, tos y además presentar limitación variable alflujo aéreo espiratorio. Las exacerbaciones moderadas-graves de asma se diagnostican clínicamente por la presencia dedisnea persistente y la obstrucción de las vías respiratorias. En la actualidad, la terapia de oxigenoterapia convencional seutiliza principalmente en entornos clínicos, pero no puede garantizar un soporte respiratorio suficiente, lo que aumenta laprobabilidad de requerir ventilación mecánica no invasiva o en casos donde esté en riesgo la vida del paciente ventilaciónmecánica invasiva. La terapia nasal de alto flujo (TNAF) se introdujo en la práctica clínica y su papel está adquiriendo cadavez más importancia. Sin embargo no se ha descrito su uso en pacientes adultos con exacerbación del asma. Esta revisiónse diseñó para analizar los potenciales fisiológicos de la TNAF y su eficacia en pacientes adultos que cursan exacerbacióndel asma en entornos clínicos.(AU)

Asthma is a common chronic respiratory disease that affects 1-18% of the population in different countries and is characte-rized by variable symptoms such as wheezing, dyspnea, chest tightness, cough, and variable expiratory airflow limitation.Moderate-severe exacerbations of asthma are clinically diagnosed by the presence of persistent dyspnea and airway obs-truction. Currently, conventional oxygen-therapy is mainly used in clinical settings, but it cannot guarantee sufficient respiratorysupport, increasing the likelihood of requiring non-invasive ventilation or in cases where invasive mechanical ventilation islife-threatening. High-flow nasal therapy (HFNT) was introduced into clinical practice and its role is becoming increasinglyimportant. However, its use in adult patients with asthma exacerbation has not been reported. This review aimed to discussthe physiological potentials of HFNT and effectiveness in adult patients with asthma exacerbation in clinical settings.(AU)

Delivery of Aerosolized Bronchodilators by High-Flow Nasal Cannula During COPD Exacerbation.

BACKGROUND: Bronchodilator delivery via a high-flow nasal cannula (HFNC) has generated interest in recent years. The efficacy of in-line vibrating mesh nebulizers with an HFNC during COPD exacerbation is limited. The aim of this study was to evaluate the clinical response of subjects with COPD exacerbation who require bronchodilator therapy (anticholinergic and ß-agonist) by using a vibrating mesh nebulizer in line with an HFNC. METHODS: This was a prospective single-center study performed in a respiratory intermediate care unit that enrolled patients with a diagnosis of COPD exacerbation who required noninvasive ventilation on admission. All the subjects underwent noninvasive ventilation breaks with an HFNC. After clinical stability, pulmonary function tests were performed to assess changes in FEV1 and clinical parameters before and after bronchodilation by using a vibrating mesh nebulizer in line with an HFNC. RESULTS: Forty-six patients with COPD exacerbation were admitted. Five patients who did not use noninvasive ventilation and 10 patients who did not receive bronchodilator treatment with a vibrating mesh nebulizer were excluded. Thirty-one were selected, but 1 subject was secondarily excluded due to loss of data. Finally, 30 subjects were included. The primary outcome was spirometric changes in FEV1. The mean ± SD FEV1 before receiving bronchodilator treatment by using a vibrating mesh nebulizer in line with an HFNC was 0.74 ± 0.10 L, and, after receiving treatment, the mean ± SD FEV1 changed to 0.88 ± 0.12 L (P < .001). Similarly, the mean ± SD FVC increased from 1.75 ± 0.54 L to 2.13 ± 0.63 L (P < .001). Considerable differences were observed in breathing frequency and heart rate after receiving bronchodilator treatment. No relevant changes were observed in the Borg scale or Sp O2 after treatment. The mean clinical stability recorded was 4 d. CONCLUSIONS: In subjects with COPD exacerbation, bronchodilator treatment by using a vibrating mesh nebulizer in line with an HFNC showed a mild but significant improvement in FEV1 and FVC. In addition, a decrease in breathing frequency was observed, suggesting a reduction in dynamic hyperinflation.

Combined Noninvasive Respiratory Support Therapies to Treat COVID-19.

BACKGROUND: The roles of high-flow nasal cannula (HFNC) and CPAP in coronavirus disease 2019 (COVID-19) are controversial. The objective of the study was to evaluate the impact of the application of a noninvasive respiratory support algorithm on clinical outcomes in subjects with COVID-19 and with acute respiratory failure. METHODS: We performed a single-center prospective observational study of subjects with respiratory failure from COVID-19 managed with HFNC and with CPAP plus HFNC (combined therapy). The main outcome was the intubation rate, which defined failure of therapy. We also analyzed the role of the ROX index ([[Formula: see text]/[Formula: see text]]/breathing frequency) to predict the need for intubation. RESULTS: From June to December 2020, 113 subjects with COVID-19 respiratory failure were admitted to our respiratory intermediate care unit. HFNC was applied in 65 subjects (57.52%) and combined therapy in 48 subjects (42.47%). A total of 83 subjects (73.45%) were successfully treated with noninvasive respiratory support. The intubation rate was 26.54%, and the overall mortality rate was 14.15%. The mortality rate in subjects who were intubated was 55.2%. An ROX index of 6.28 at 12 h predicted noninvasive respiratory support failure, with 97.6% sensitivity and 51.8% specificity. CONCLUSIONS: Data from our cohort managed in a respiratory intermediate care unit showed that combined noninvasive respiratory support was feasible, with favorable outcomes. Further prospective studies are required.