Continuous renal replacement therapy combined with ulinastatin in acute respiratory distress syndrome: A systematic review and meta-analysis

Acute respiratory distress syndrome (ARDS) is a severe clinical condition with high mortality, and effective adjunctive therapies remain limited. In recent years, continuous renal replacement therapy (CRRT) and ulinastatin have both been applied in ARDS management, but the clinical value of their combined use is still unclear. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy of CRRT combined with ulinastatin compared with CRRT alone in patients with ARDS. A comprehensive search of 11 English and Chinese databases was performed from inception to August 29, 2025. Randomized controlled trials enrolling adult patients with ARDS and comparing CRRT plus ulinastatin versus CRRT alone were included. Mortality was the primary outcome, and secondary outcomes included intensive care unit (ICU) length of stay, mechanical ventilation time (MVT), Acute Physiology and Chronic Health Evaluation II (APACHE II) score at 7 days, oxygenation index (OI) at 7 days, and partial pressure of oxygen (PaO₂) at 7 days. Five studies involving 384 patients met the inclusion criteria. Pooled analysis showed that combination therapy significantly reduced mortality (risk ratio [RR] = 0.37, 95% confidence interval [CI] 0.23-0.60), ICU length of stay, MVT, and APACHE II scores at 7 days, and significantly improved OI and PaO₂ at 7 days compared with CRRT alone. Overall, current evidence of limited quality suggests that CRRT combined with ulinastatin may improve short-term clinical outcomes in patients with ARDS. Future rigorous, large-scale, multicenter randomized controlled trials are essential to verify these findings.