Research on Respiratory Support with HFNT

According to recent research conducted at the Department of Infectious Disease and Institute of Global Health and Innovation, Division of Medicine, Imperial College, London, UK, it has been observed that respiratory support with high-flow nasal therapy (HFNT) may show potential benefits. However, it requires further trials.

The study is published in the Intensive Care Medicine.

The World Health Organization (WHO) recommends presumptive antibiotic treatment and oxygen for those with clinically defined severe pneumonia and/or hypoxaemia (peripheral oxygen saturation (SpO2) < 90%).

The life-saving role of oxygen therapy in African children with severe pneumonia is not yet established. Therefore, K. Maitland and colleagues conducted this present Children's Oxygen Administration Strategies Trial (COAST) which simultaneously addressed two hypotheses:

• First, whether liberal oxygenation strategies in children with SpO2 ≥ 80–91% will decrease mortality (at 48 h and up to 28 days) compared with a permissive hypoxia strategy.
• Second, whether respiratory support with high-flow nasal therapy (OptiFlow™) decreases mortality (at 48 h and up to 28 days) compared with low-flow oxygen delivery (standard care).

The open-label fractional-factorial COAST trial randomised eligible Ugandan and Kenyan children aged > 28 days with severe pneumonia and severe hypoxaemia stratum (SpO2 < 80%) to high-flow nasal therapy (HFNT) or low-flow oxygen (LFO: standard care) and hypoxaemia stratum (SpO2 80–91%) to HFNT or LFO (liberal strategies) or permissive hypoxaemia (ratio 1:1:2).

Children with cyanotic heart disease, chronic lung disease or > 3 h receipt of oxygen were excluded. The primary endpoint was 48 h mortality; secondary endpoints included mortality or neurocognitive sequelae at 28 days.

Results

The following results were seen:

• The trial was stopped early after enrolling 1852/4200 children, including 388 in the severe hypoxaemia stratum (median 7 months; median SpO2 75%) randomised to HFNT (n = 194) or LFO (n = 194) and 1454 in the hypoxaemia stratum (median 9 months; median SpO2 88%) randomised to HFNT (n = 363) vs LFO (n = 364) vs permissive hypoxaemia (n = 727).
• Per-protocol 15% of patients in the permissive hypoxaemia group received oxygen (when SpO2 < 80%).
• In the severe hypoxaemia stratum, 48-h mortality was 9.3% for HFNT vs. 13.4% for LFO groups.
• In the hypoxaemia stratum, 48-h mortality was 1.1% for HFNT vs. 2.5% LFO and 1.4% for permissive hypoxaemia.
• In the hypoxaemia stratum, adjusted odds ratio for 48-h mortality in liberal vs permissive comparison was 1.16 (0.49–2.74; p = 0.73); HFNT vs LFO comparison was 0.60 (0.33–1.06; p = 0.08).
• Strata-specific 28 day mortality rates were, respectively: 18.6, 23.4 and 3.3, 4.1, 3.9%.
• Neurocognitive sequelae were rare.

Hence, the authors concluded that "respiratory support with HFNT showing potential benefit should prompt further trials."