Diquat (1,1'-ethylene-2,2'-bipyridinium) is a bipyridine herbicide that shares a similar physicochemical structure and redox cycling mechanism with paraquat. Upon ingestion, it is rapidly absorbed and distributed to the gastrointestinal tract, kidneys, liver, skeletal muscle, lungs, myocardium, and central nervous system. Patients with severe diquat poisoning often develop toxic encephalopathy, circulatory collapse, and multi-organ dysfunction. Extracorporeal treatments, including hemoperfusion, hemodialysis, and continuous kidney replacement therapy (CKRT), are widely employed to manage diquat poisoning. Continuous veno-venous hemodiafiltration (CVVHDF), the most frequently used CKRT modality, is primarily indicated for acute kidney injury (AKI). AKI occurs in up to 73.3% of patients with acute diquat poisoning, and nearly all patients with severe acute diquat poisoning are at risk of developing AKI. In clinical practice, patients with severe acute diquat poisoning are typically defined as those with a plasma diquat concentration of ≥1000 ng/mL measured at the time of presentation to the emergency department (ED). However, the Extracorporeal Treatments in Poisoning (EXTRIP) workgroup has not issued any definitive recommendations on initiating extracorporeal treatments for diquat poisoning, and the optimal timing for starting CVVHDF has yet to be evaluated in clinical trials. Currently, the standard practice delays initiation of CVVHDF until AKI has developed. Accordingly, this study proposes a pragmatic cluster-randomized controlled trial (RCT) to determine whether, in severe acute diquat poisoning patients, accelerated initiation of CVVHDF following hemoperfusion is preferred compared to a standard approach in which CVVHDF is initiated only in the presence of AKI or at the discretion of the treating clinician.
