Assessment of Peak Inspiratory Flow in Young Infants with Acute Viral Bronchiolitis: Physiological Basis for Initial Flow Setting in Patients Supported with High-Flow Nasal Cannula.

OBJECTIVE: To assess the inspiratory demand in young infants with acute viral bronchiolitis to provide a physiological basis for initial flow setting for patients supported with high flow nasal cannula. STUDY DESIGN: Prospective study in 44 infants up to 6 months old with acute viral bronchiolitis, admitted to a pediatric intensive care unit from November 2017 to March 2019. Airflow measurements were performed using spirometry. The primary endpoint was the inspiratory demand as measured by peak tidal inspiratory flow (PTIF). The secondary endpoints were the relationships determined between PTIF, patient weight, and disease severity. RESULTS: Median (Q25-Q75) age and weight of the patients were 37 (20-67) days and 4.3 (3.5-5.0) kg, respectively. Mean PTIF was 7.45 (95% CI 6.51-8.39, min-max: 2.40-16.00) L/minute. PTIF indexed to weight was 1.68 (95% CI 1.51-1.85, min-max: 0.67-3.00) L/kg/minute. PTIF was <2.5 L/kg/minute in 89% (95% CI 75-96) of infants. PTIF was correlated with weight (ρ= 0 .55, P < .001) but not with markers of disease severity, including modified Woods clinical asthma score, Silverman-Andersen score, respiratory rate, fraction of inspired oxygen, and PCO2. CONCLUSIONS: High flow nasal cannula therapy is used commonly to support infants with acute viral bronchiolitis. The efficiency of the device is optimal if the flow setting matches the patient's inspiratory demand. According to our results, a flow rate of <2.5 L/kg/minute would be appropriate in most situations.

Variation in Practice Related to the Use of High Flow Nasal Cannula in Critically Ill Children.

OBJECTIVES: To determine current management of critically ill children and gather views regarding high flow nasal cannula therapy and to evaluate research priorities for a large prospective randomized controlled trial of noninvasive respiratory support in children. DESIGN: Multinational cross-sectional questionnaire survey conducted in 2018. SETTING: The sample included pediatric intensive care physicians in North and South America, Asia, Europe, and Australia/New Zealand. MEASUREMENT: Questions consisted of: 1) characteristics of intensivists and hospital, 2) practice of high flow nasal cannula, 3) supportive treatment, and 4) research of high flow nasal cannula. INTERVENTIONS: None. MAIN RESULTS: We collected data from 1,031 respondents; 919 (North America, 215; Australia/New Zealand, 34; Asia, 203; South America, 186; Europe, 281) were analyzed. Sixty-nine percent of the respondents used high flow nasal cannula in non-PICU settings in their institutions. For a case of bronchiolitis/pneumonia infant, 2 L/kg/min of initial flow rate was the most commonly used. For a scenario of pneumonia with 30 kg weight, more than 60% of the respondents initiated flow based on patient body weight; while, 18% applied a fixed flow rate. Noninvasive ventilation was considered as a next step in more than 85% of respondents when the patient is failing with high flow nasal cannula. Significant practice variations were observed in clinical practice markers used, flow weaning strategy, and supportive practices. Views comparing high flow nasal cannula to continuous positive airway pressure also noticeably varied across the respondents. CONCLUSIONS: Significant practice variations including views of high flow nasal cannula compared to continuous positive airway pressure was found among pediatric intensive care physicians. To expedite establishment and standardization of high flow nasal cannula practice, research aimed at understanding the heterogeneity found in this study should be undertaken.

Tracheal opening manoeuvre (PEEP-20) in a patient with bronchopulmonary dysplasia and severe tracheobronchomalacia with neurally adjusted ventilatory assist (NAVA).

Bronchopulmonary dysplasia (BPD) is occasionally associated with tracheobronchomalacia, and it is this combination that can lead to serious outcomes. The most severe cases require tracheostomies, ventilatory support and eventually even tracheal stents or surgery. Ventilation in patients with tracheomalacia is complicated without a good patient-ventilator synchrony; the neurally adjusted ventilatory assist (NAVA) mode is potentially beneficial in these cases. This case report presents a patient affected by BPD and severe tracheobronchomalacia who was tracheostomised and ventilated 24 hours a day and who suffered from episodes of airway collapse despite using the NAVA mode. It was necessary to increase the positive end-expiratory pressure to 20 cmH2O (the PEEP-20 manoeuvre) for several minutes during an episode; this allowed the trachea to remain open and allowed us to optimise the patient's ventilation. This strategy has previously been described in a patient with tracheomalacia, reducing the frequency and need for sedation in the following episodes.