What is the evidence for the use of high flow nasal cannula oxygen in adult patients admitted to critical care units? A systematic review

Background: Humidified high flow nasal cannula oxygen therapy is increasingly available in Australian adult intensive care units. Its use in paediatric populations has been extensively studied and has shown positive effects however its clinical effectiveness in adults has not been established. Purpose: A systematic review of the literature was conducted to critique current evidence, inform nursing practice and make recommendations for nursing research. Methods: An extensive search strategy identified clinical studies comparing standard oxygen therapy with high flow therapy in critical care units. Two reviewers independently assessed articles for eligibility, methodological quality and inclusion. Outcomes of interest included oxygenation, ventilation, work of breathing, positive airway pressure, patient comfort and long term effect. A narrative synthesis was conducted to describe the emerging evidence. Findings: Eight studies were included for review. All were abstracts or poster presentations from scientific meetings therefore the quality of data available for analysis was poor. Findings indicated there was preliminary evidence to support the use of high flow therapy to optimise oxygenation in adults. This therapy may reduce the effort of breathing and provide augmented airway pressures. Patients described the therapy as comfortable. No definitive evidence supported the claim that ventilation is improved or conclusively demonstrated a long-term effect. Conclusion: Humidified high flow nasal cannula may be used as an intermediate therapy to improve oxygenation in adult critical care patients. Further research is required to determine the duration of effect of the therapy, identify the patient population for whom it is most beneficial and evaluate long-term outcomes; to enable definitive recommendations for practice to be made.Jodie Kernick, Judy Magare