The Benefits of Early Continuous Renal Replacement Therapy in Critically Ill Patients with Acute Kidney Injury at High-Altitude Areas: A Retrospective Multi-center Cohort Study

Severe hypoxia would aggravate the acute kidney injure (AKI) in high-altitude areas and continuous renal replacement therapy (CRRT) has been used to treat critically ill patients with AKI. However, the characteristics and outcomes of CRRT of critically ill patients with AKI in high altitude and the optimal timing of CRRT initiation are still unclear. 1,124 patients were diagnosed with AKI and treated with CRRT in ICU, involving high-altitude group (n = 648) and low-altitude group (n = 476). Compared with low-altitude group, patients with AKI in high altitude showed longer CRRT (4.8 vs. 3.7, P  = 0.036) and more rapid progression of AKI stages ( P   0.05). Referring to the analysis of survival and kidney recovery curves, a higher mortality but a lower possibility of renal recovery was observed in high-altitude group ( P  < 0.001). However, in the high-altitude group, the survival rate of early CRRT initiation was significantly higher than that of delayed CRRT initiation ( P  < 0.001). The findings showed poorer clinical outcomes of patients undergoing CRRT for AKI in high altitude. CRRT at high altitude was unlikely to increase the adverse events. Moreover, early CRRT initiation might reduce the mortality and promote renal recovery in high-altitude patients.