AKI and RRT Acute renal injury (AKI) is a common group of clinical syndromes. The pathophysiological mechanisms and the rate of progression of AKI vary depending on the etiology, and the treatment and outcome vary widely. There is a wide range of treatments for AKI, but the main treatment modality remains supportive therapy based on renal replacement therapy (RRT). Although several modalities of RRT have been used in the clinic, such as intermittent hemodialysis (IHD), continuous hemofiltration and more recently continuous low efficiency dialysis (SLED), the morbidity and mortality associated with AKI has not been significantly improved. However, AKI-related morbidity and mortality have not improved significantly and exceed 50% in critically ill patients. Therefore, in addition to early treatment, it is important to select the most appropriate treatment for AKI patients according to their etiology and pathophysiological mechanisms. In the past decade or so, the use of continuous renal replacement therapies (CRRTs), mainly continuous veno-venous hemodiafiltration (CVVH), has been promoted in clinical practice, with the main advantages of high dialysis efficacy and low hemodynamic impact. Therefore, they play an important role in the rescue of severe AKI, and their efficacy is remarkable. However, it is worth pointing out that these CRRT techniques not only require special equipment, but are also very expensive to use, with CVVH costing about RMB 200-300 per hour and the total cost of treatment reaching tens of thousands of RMB or more, according to the average tertiary care hospital. This treatment is a huge financial burden for the country, families and individuals. In fact, only a very small percentage of AKIs are clinically manifested as multi-organ failure (MOF). In terms of AKI treatment, the majority of AKIs in China can be treated locally with simpler and less expensive treatment measures than CRRT. Peritoneal dialysis (PD) uses the peritoneum as a natural dialysis membrane to remove toxic substances from the body. The peritoneum not only has a larger area, but also has less volume fluctuations during dialysis, so it is similar to CVVH in terms of metabolite removal and maintaining blood stability, but its cost is less than one-tenth that of CVVH, so PD is extremely valuable in the treatment of AKI. Therefore, PD has a very wide application in the treatment of AKI. The next issue will focus on the rational use of PD in the treatment of AKI syndrome.