Helium-oxygen Gas Mixtures Delivered by a High Flow Nasal Cannula in Bronchiolitis

The aim of this prospective pilot study is to determine the effect of heliox delivered via a proprietary calibrated heated and humidified high flow nasal cannula (HFNC) system (Vapotherm Precision Flow Heliox) in children ages 0-24 months with severe bronchiolitis.

Respiratory syncytial virus associated bronchiolitis is a leading cause of global infant morbidity and mortality [1], yet care remains largely supportive. Several recent studies show that a helium-oxygen gas mixture (heliox) improves outcomes in children with moderate to severe bronchiolitis [2-5, 7]. Heliox is a safe, inert gas with no biological effects and very low density [6]. By improving laminar flow, heliox improves gas exchange in conditions where airway resistance is increased, such as asthma, croup and bronchiolitis [6]. Recent data shows that infants with moderate to severe bronchiolitis have a reduced length of hospital stay when heliox is delivered via facemask or CPAP, as compared to heliox via nasal cannula [2]. Limitations to this study include the small number of patients (84/319 [26%]) who tolerated the facemask therapy and the fact that nasal cannula heliox was delivered at low flows (3 LPM). Oxygen is increasingly being delivered with a heated, humidified, high flow nasal cannula (HFNC) system to infants with moderate to severe bronchiolitis in our PICU. To date, there are no definitive randomized controlled trials that show the HFNC system is an effective treatment in bronchiolitis. However, there are several retrospective, prospective and pilot interventional studies showing clinical improvement in this patient population treated with the HFNC system [8-11]. We hypothesize that delivering heliox via a heated, humidified, high flow nasal cannula will be well tolerated, safe and effective. Specific Aim #1: The aim of this prospective pilot study is to determine the effect of heliox delivered via a proprietary calibrated heated and humidified high flow nasal cannula (HFNC) system (Vapotherm Precision Flow Heliox) in children ages 0-24 months with severe bronchiolitis. Hypothesis #1: Clinical and physiologic markers of respiratory distress will be improved in patients receiving heliox via HFNC compared to standard therapy following separation from mechanical ventilation.

Following separation from mechanical ventilation, patient is placed on heliox (70% oxygen-30% helium) delivered with Vapotherm, a proprietary heated, humidified, high-flow nasal cannula delivery system.

Following separation from mechanical ventilation, patient is placed on heliox (70% oxygen-30% helium) delivered with Vapotherm, a proprietary heated, humidified, high-flow nasal cannula delivery system.

Change in the respiratory assessment score from baseline (within 15 minutes of extubation) to 48 hours after extubation. The score ranges from 0 to 12, with higher scores indicating worsening respiratory distress.

Inclusion Criteria: Children 0-24 months Admission to the Pediatric Intensive Care Unit Diagnosis of bronchiolitis, with respiratory syncytial virus infection confirmed by laboratory testing Mechanical ventilation Exclusion Criteria: Inclusion in another clinical trial Significant cardiac disease Anatomically abnormal airway Neurologic disease Immunodeficiency History of chronic lung disease Craniofacial anomaly Chromosomal anomalies Known or suspected dysphagia

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