Abstract
BACKGROUND: Since the 2009 pandemic influenza, we have nationally established a committee of the extracorporeal membrane oxygenation (ECMO) project. This project involves adequate respiratory management for severe respiratory failure using ECMO. This study aimed to investigate the correlations between changes in respiratory management using ECMO in Japan and outcomes of patients with influenza-associated acute respiratory failure between 2009 and 2016. METHODS: We investigated the incidence, severity, characteristics, and prognosis of influenza-associated acute respiratory failure in 2016 by web-based surveillance. The correlations between clinical characteristics, ventilator settings, ECMO settings, and prognosis were evaluated. RESULTS: A total of 14 patients were managed with ECMO in 2016. There were no significant differences in age, sex, and the acute physiology and chronic health evaluation II score between 2009 and 2016. The maximum sequential organ failure assessment score and highest positive end-expiratory pressure were lower in 2016 than in 2009 (p = 0.03 and p = 0.015, respectively). Baseline and lowest partial pressure of arterial oxygen (PaO(2))/fraction of inspiratory oxygen (F(I)O(2)) ratios were higher in 2016 than in 2009 (p = 0.009 and p = 0.002, respectively). The types of consoles, circuits, oxygenators, centrifugal pumps, and cannulas were significantly changed between 2016 and 2009 (p = 0.006, p = 0.003, p = 0.004, p < 0.001, respectively). Duration of the use of each circuit was significantly longer in 2016 than in 2009 (8.5 vs. 4.0 days; p = 0.0001). Multivariate analysis showed that the use of ECMO in 2016 was an independent predictor of better overall survival in patients with influenza-associated acute respiratory failure (hazard ratio, 7.25; 95% confidence interval, 1.35-33.3; p = 0.021). CONCLUSIONS: Respiratory management for influenza-associated acute respiratory failure using ECMO was significantly changed in 2016 compared with 2009 in Japan. The outcome of ECMO use had improved in 2016 compared with the outcome in 2009 in patients with influenza-associated acute respiratory failure.