Early Initiation of Continuous Renal Replacement Therapy Improves Clinical Outcomes in Patients With Acute Respiratory Distress Syndrome

Background: The acute respiratory distress syndrome (ARDS) is a common devastating syndrome in intensive care unit in critically ill patients. Continuous renal replacement therapy (CRRT) has been shown beneficial effects on oxygenation and survival in patients with ARDS. However, it is still controversial about the timing of initiation of CRRT. Methods: Fifty-three patients with ARDS admitted to intensive care unit in Zhejiang Provincial People's Hospital, China from 2009 to 2013 were enrolled in the study. The authors compared ventilation parameter, including PaO2/FIO2, A-a gradient, positive endexpiratory pressure, plateau pressure, dynamic compliance and hemodynamic parameters, including central venous pressure, mean arterial pressure, cardiac index, extravascular lung water index, fluid balance between early initiation (within 12 hours after ARDS onset) and late initiation of CRRT (48 hours after ARDS onset) groups. The authors further investigated transforming growth factor (TGF)-beta 1 level changes in serum and bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assay during 7 days of follow-up. Results: Significant improvement of oxygenation and shorter duration of mechanical ventilation were observed in early CRRT group during 7-day follow-up. In addition, TGF-beta 1 concentrations in serum and BALF were significantly decreased in patients with early initiation of CRRT compared to those with late initiation of CRRT on day 2 and day 7. Furthermore, patients who died of ARDS had higher levels of TGF-b1 in BALF than survivors. Conclusions: Our findings showed that early initiation of CRRT is associated with favorable clinical outcomes in ARDS patients, which might be due to the reduced serum and BALF TGF-beta 1 levels through CRRT. However, large multi-center studies are needed to make further recommendations as to the optimal use of CRRT in ARDS patient populations.