Effectiveness of High Flow Nasal Oxygen in the Prevention of Intubation/Mechanical Ventilation in Adult Patients with Respiratory Failure: Using A Systematic Review and Meta-Analysis.

Abstract

Aims and Objectives: This systematic review is a study that evaluates the effectiveness of High Flow Nasal Oxygen (HFNO) in reducing the need for intubation and invasive mechanical ventilation in patients with acute respiratory failure (ARF). These findings are also compared with standardised oxygen therapy and non-invasive ventilation (NIV). The study also aims to analyse the effect of HFNO on clinical outcomes and patient mortality. Gaps in literature are also addressed and evidence-based suggestions are provided for the improvement of future research and clinical implementations. Methodology: MesH words were extracted and search strategy was formulated on the basis of these MesH words and alternative keywords on three databases: MedLine, Cochrane and Embase. A systematic review was conducted according to the PRISMA guidelines with primary and secondary screening, which revealed ten studies to be included. The Cochrane RoB tool was employed to undertake a risk of bias (RoB) analysis for randomized controlled trials (RCTs), whereas the quality of observational research was assessed using the Newcastle Ottawa Scale (NOS). Results: Ten studies were included in this systematic review, conducted in seven countries and four continents, with six of the included studies taking place in Europe. Six of the ten studies involved ARF secondary to COVID-19, while the rest included patients with heterogeneous secondary pathologies. The main intervention throughout the studies was the use of HFNO; however, the intervention structure varied. The primary outcomes included the rate of intubation and mortality rate, while secondary outcomes included the in-hospital length of stay, time to intubation, ventilator free days, and PaO2:FiO2 ratio. The adverse effects associated with HFNO use were also reported. A consistent improvement in the rates of intubation with a significant decline in comparison with standard oxygen therapy was also reported. The patient mortality showed a varying pattern, with some studies reporting a decreased mortality rate, some finding no significant difference and some with an increase in mortality. The studies also reported a reduction in the length of stay in the intensive care unit (ICU), but not in the emergency department. The number of ventilator-free days also declined with this intervention. The use of HFNO thus appears to be associated with an improvement in SaO2, PaO2:FiO2 ratio, and respiratory rate. Overall, the adverse events did not show a significant difference from standard therapy. Conclusion: HFNO has been associated with an improvement in both physiological and clinical parameters in patients with ARF, especially when considering the need for intubation. These changes reduce ventilator-associated complications. This study also addresses the gaps in literature and provides evidence-based suggestions for future research.