Heated Humidified Oxygen Compared to Dry Oxygen Therapy in Children With Bronchiolitis

HHOT AIR Study (a Pilot Study): Heated Humidified Oxygen Therapy Compared to Standard Dry Oxygen: An Assessment in Infants With bRonchiolitis

The purpose of this study is to compare heat and humidified oxygen with cold and dry oxygen in children with bronchiolitis. The hypotheses are that heating and humidifying inspired low flow supplemental oxygen will optimize mucociliary function thereby, 1) improve oxygenation, 2) decrease work of breathing, and 3) decrease length of hospital stay.

Bronchiolitis is the leading cause of acute respiratory illness and hospitalization in infants and young children. The mainstay of treatment is supportive care, which includes frequent nasal suctioning, intravenous fluid hydration, and supplemental oxygen for hypoxemia. The airways normally heat and humidify inspired ambient air to core temperature amd 100% relative humidity at the carina. This environment, at core temperature, allows for optimal mucociliary clearance. Supplemental oxygen delivered via wall source is cold and dry, and does not reach core temperature and 100% humidity until some point distal to the carina, past the main bronchi. This presses on the lower respiratory tract to assist in heat and moisture exchange and thus decrease ciliary function. This, in combination with bronchiolitis, can impair mucociliary clearance. Specific aim 1: Determine the effect of heated and humidified oxygen therapy on clinical improvement in children with bronchiolitis, based on Respiratory Distress Assessment Instrument (RDAI) and respiratory rate (RR). Specific aim 2: Determine the effect of heated and humidified oxygen therapy on length of hospital stay and duration of supplemental oxygen requirement in children with bronchiolitis.

The RDAI is a validated clinical scoring system to assess respiratory distress and has been used in several bronchiolitis studies. The RDAI is based on two variables, wheezing and retractions, in which points are applied to each to give a score ranging from 0 to 17. The higher the total score, the worse the subject was clinically. Reported are the absolute scores at each time point, for each arm. Baseline scores are reported in the Baseline Module.

Respiratory rate was measured by counting respirations for one minute. Reported are the absolute scores at each time point, for each arm. Baseline scores are reported in the Baseline Module.

Inclusion Criteria: Ages ≤24 months of age Physician diagnosed bronchiolitis Admitted to pediatric floor Supplemental oxygen requirement, <4 L/min, for hypoxemia, oxygen saturation <92% in room air Exclusion Criteria: Prematurity, born <37 weeks gestational age Admitted to pediatric intensive care unit for medical indication Requirement of heated, humidified high flow system Chronic lung disease (such as bronchopulmonary dysplasia, cystic fibrosis, primary ciliary dyskinesia, tracheostomy status, baseline oxygen requirement) Neuromuscular disorders Chromosomal defects Metabolic disorders Immunodeficiency Unrepaired cardiac abnormalities