Efficacy and safety of early prone positioning combined with HFNC or NIV in moderate to severe ARDS: A multi-center prospective cohort study

Abstract

Background: Previous studies suggest that prone positioning (PP) can increase PaO2/FiO2 and reduce mortality in moderate to severe acute respiratory distress syndrome (ARDS). The aim of our study was to determine whether the early use of PP combined with non-invasive ventilation (NIV) or high-flow nasal cannula (HFNC) can avoid the need for intubation in moderate to severe ARDS patients. Methods: This prospective observational cohort study was performed in two teaching hospitals. Non-intubated moderate to severe ARDS patients were included and were placed in PP with NIV or with HFNC. The efficacy in improving oxygenation with four support methods - HFNC, HFNC+PP, NIV, NIV+PP - were evaluated by blood gas analysis. The primary outcome was the rate of intubation. Results: Between January 2018 and April 2019, 20 ARDS patients were enrolled. The main causes of ARDS were pneumonia due to influenza (9 cases, 45%) and other viruses (2 cases, 10%). Ten cases were moderate ARDS and 10 cases were severe. Eleven patients avoided intubation (success group), and 9 patients were intubated (failure group). All 7 patients with a PaO2/FiO2 < 100 mmHg on NIV required intubation. PaO2/FiO2 in HFNC+PP were significantly higher in the success group than in the failure group (125 ± 41 mmHg vs 119 ± 19 mmHg, P = 0.043). PaO2/FiO2 demonstrated an upward trend in patients with all four support strategies: HFNC < HFNC+PP ≤ NIV < NIV+PP. The average duration for PP was 2 h twice daily. Conclusions: Early application of PP with HFNC, especially in patients with moderate ARDS and baseline SpO2 > 95%, may help avoid intubation. The PP was well tolerated, and the efficacy on PaO2/FiO2 of the four support strategies was HFNC < HFNC+PP ≤ NIV