Resolution of organ functional scores to predict the outcome in adult acute respiratory distress syndrome patients receiving high-frequency oscillatory ventilation

Background: High-frequency oscillatory ventilation (HFOV) may be used as a rescue therapy for adults with acute respiratory distress syndrome who have failed conventional ventilation (CV). We undertook a prospective study to investigate the determinants of mortality and the sequential evolution of organ failures in HFOV-treated adult acute respiratory distress syndrome patients. Methods: The indication for HFOV was severe oxygenation failure (Pao ₂/Fio ₂ <120 mm Hg) while receiving aggressive CV support (defined by either Pao2 ≤65 mm Hg with Fio ₂ ≥0.6 when positive end-expiratory pressures >10 cmH ₂O or plateau airway pressure ≥35 cm H ₂O). Demographic, clinical, and physiologic data were collected prospectively (May 2007-July 2009). Organ System Failure (OSF), Sequential Organ Failure Assessment (SOFA), and Multiple Organ Dysfunction (MOD) scores were recorded during and after HFOV application. Additional outcome measures included HFOV successful weaning rate, cause of failure, complications, survival rate, and cause of death. Results: The intensive care unit mortality rate was 62% (21 of 34). Survivors had a significantly shorter CV time before HFOV than nonsurvivors (32.8 hours ± 16.7 hours vs. 47.9 hours ± 26.2 hours, p = 0.049). Survivors had significantly lower baseline lung injury scores, OSF, SOFA, and MOD scores than nonsurvivors. After HFOV, the OSF, SOFA, and MOD scores were significantly decreased for survivors, particularly from day 3 onward. CONCLUSIONS: Survivors had early improvements in OSF scores after HFOV application. Organ failure system scoring may be used for deciding on HFOV initiation and for evaluating the effects of HFOV.