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S68 The Hi-flo Study: A Prospective Open Randomised Controlled Trial Of High Flow Nasal Cannula Oxygen Therapy Against Standard Care In Bronchiolitis
  1. C Hathorn,
  2. G Ernst,
  3. S Hasan,
  4. D Wong,
  5. M Seear
  1. British Columbia Children’s Hospital, Vancouver, Canada


Introduction High flow nasal cannula (HFNC) oxygen therapy is increasingly used as a form of respiratory support with limited evidence to support its use. Data from retrospective studies suggest that HFNC reduces rates of intubation and respiratory parameters in infants with bronchiolitis. It is well-tolerated, easy to use, and has very few adverse effects.

Objective To determine if HFNC therapy reduces work of breathing, oxygen requirement and time to resolution of respiratory distress more quickly than standard care in bronchiolitis.

Methods We conducted a prospective open randomised controlled trial to compare HFNC oxygen therapy with standard care for children with bronchiolitis in ward environments in a tertiary referral children’s hospital over a two-year study period. Patients under 18 months of age with a clinical diagnosis of bronchiolitis were eligible. Subjects were randomised to standard supportive care with low flow oxygen (up to 2 litres/minute) or HFNC oxygen at 8 litres/minute. Fractional inspired concentration of oxygen was titrated to maintain saturations >92%. A validated composite clinical score (modified Tal) was measured every 3 h. 1

Results 72 patients were recruited, 36 in each treatment arm. The mean age of subjects was 4 months, range 0.5–12.9 months. 42% were male, and all but two were born at term. 79% were RSV positive. 3 patients in the control group, and 4 in the intervention group required admission to intensive care. There was no improvement in time to resolution of respiratory distress or oxygen requirement in patients receiving HFNC oxygen therapy. There was a trend towards lower clinical scores in the first 3 h following initiation of treatment in the intervention group. There were no adverse effects from HFNC therapy, and it was found to be safe in a ward environment.

Conclusion HFNC oxygen therapy may improve clinical parameters during the first hours of treatment, but it did not significantly reduce time to resolution of respiratory distress or oxygen requirement.


  1. McCallum G, et al. Severity scoring systems: are they internally valid, reliable and predictive of oxygen use in children with acute bronchiolitis? Pediatric Pulmonology 2013;48(8):797–803

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