The purpose of this single center, randomized, control, open-labeled study is to evaluate the effect and safety of RCA versus no anticoagulation for CRRT in hyperlactatemia patients with increased bleeding risk.

For continuous renal replacement therapy (CRRT) patients with shock and muscle hypoperfusion, which characterised by tissue hypoxia and hyperlactatemia, the Kidney Disease Improving Global Outcomes (KIDIGO) guideline recommended no use of regional citrate anticoagulation (RCA) considering the potential increased citrate accumulation (CA) risk. In the condition of increased bleeding, no-anticoagulation was recommended for these patients. However, CRRT processed without anticoagulation was proved to be associated with shorter filter lifespan. Therefore, the purpose of this single center, randomized, control, open-labeled study is to evaluate the safety and efficacy of RCA versus no-anticoagulation for CRRT in hyperlactatemia patients with increased bleeding risk.

Inclusion Criteria:

• Age≥16 years
• Hyperlactatemia (Lactic acid or serum lactate level > 2 mmol/L)
• Required CRRT
• Increased bleeding risk: PLT < 40 x 109, aPTT > 60 s, INR > 1.5, bleeding or active bleeding within 7 days, recent trauma or surgery (especially head trauma and neurosurgery), recent stroke, intracranial venous malformation or aneurysm, retinal hemorrhage, uncontrolled hypertension, and epidural catheter implantation.

Exclusion Criteria:

• Drugs (biguanide, linezolid, cyanide, etc.) and congenital metabolic disorders (glucose-6 phosphatase and 1,6 phosphofructosase deficiency) and mitochondrial damage caused hyperlactatemia.
• Receiving systemic anticoagulant treatment (heparin/lmol/warfarin/aspirin, etc.) within 24 hours.
• Critical patients with lactic acid ≥15mmol\L (with a mortality of 100%) were excluded
• Patients with APTT > 100S were excluded (retrospective data suggested that this type of patients received CRRT treatment should last for more than 24 hours)
• Patients who are pregnant or during lactation
• Severe liver failure: child-pugh score >10 (chronic severe liver failure), MELD score > 30 (acute severe liver failure), total bilirubin >51 mol/L
• Patients with internal fistula were treated with CRRT
• Unable to cooperate with treatment due to mental problems (such as depression and mental illness)
• CRRT with arteriovenous fistula, or the prescribed treatment time < 12 hours