High-flow nasal therapy in adults with severe acute respiratory infection: a cohort study in patients with 2009 influenza A/H1N1v

Purpose: The experience with high-flow nasal cannula (HFNC) oxygen therapy in severe acute respiratory infection (SARI) is limited. The objective was to assess the effectiveness of HFNC oxygen therapy in adult patients with SARI by confirmed 2009 influenza A/H1N1v infection (by real-time reverse transcription polymerase chain reaction testing).

Material and methods: A single-center post hoc analysis of a cohort of intensive care unit patients admitted with SARI due to 2009 Influenza A/H1N1v was done. High-flow nasal cannula (Optiflow; Fisher & Paykel, Auckland, New Zealand) was indicated in the presence of acute respiratory failure when the patient was unable to maintain a pulse oxymetry more than 92% with more than 9 L/min of oxygen using a standard face mask conventional delivery systems. Nonresponders were defined by their need of subsequent mechanical ventilation.

Results: Twenty-five nonintubated adult patients were admitted for SARI (21 pneumonia). Twenty were unable to maintain pulse oxymetry more than 92% with conventional oxygen administration and required HFNC O(2) therapy, which was successful in 9 (45%). All 8 patients on vasopressors required intubation within 24 hours. After 6 hours of HFNC O(2) therapy, nonresponders presented a lower Pao(2)/fraction of inspired oxygen (median, 135 [interquartile range, 84-210] vs 73 [56-81] mm Hg P < .05) and needed higher oxygen flow rate. No secondary infections were reported in health care workers. No nosocomial pneumonia occurred during HFNC O(2) therapy.

Conclusion: High-flow nasal cannula O(2) therapy appears to be an innovative and effective modality for early treatment of adults with SARI.