Filter coagulation related risk factors associated with continuous renal replacement therapy in critically ill patients with hematologic disorders: A retrospective cohort study

Abstract Background: For hematological critical illness with acute kidney injury, citrate anticoagulation and Continuous Venous-venous Hemodialysis (CVVHD)/ Continuous Venous-venous Hemodiafiltration (CVVHDF) modality significantly prolongs continuous renal replacement therapy (CRRT) filter lifespan, but coagulation in the extracorporeal circulation of the filter remains an influencing factor for CRRT treatment interruption. We aimed to assess the factors influencing the risk of filter coagulation for hematologic critical illnesses. Methods: We included critically ill patients with hematologic disorders who received CRRT at hematologic ICU from November 1, 2023 to August 31, 2024. Univariate and multivariate logistic analyses were used to identify independent predictors for filter coagulation. Results: In this cohort of 90 critically-ill patients with hematologic disorders who received CRRT(CVVHD or CVVHDF)，67(68.89%) patients with filter coagulation and 23(31.11%) without filter coagulation. Univariate analysis revealed significant differences between groups in citrate infusion rate (2.1 vs 3.8 mmol/L, P=0.017), ultrafiltration rate (160 vs 125 mL/h, P=0.014), pH (7.25 vs 7.38, P=0.032), lactate (3.1 vs 4.6 mmol/L, P=0.010), post-filter ionized calcium (0.41 vs 0.28 mmol/L, P<0.001), platelet count (85 vs 42×10⁹/L, P=0.036), activated partial thromboplastin time (APTT: 48 vs 36 s, P=0.011), and fibrinogen concentration (2.1 vs 3.8 g/L, P=0.004).Multivariable logistic regression identified citrate infusion rate <2.5 mmol/L (OR 0.017, 95% CI 0.002–0.529, P = 0.017), higher volume ultrafiltration (>35 mL/kg/h OR 0.985, 95% CI 0.973–0.997, P = 0.014), post-filter ionized calcium>0.35 mmol/L (OR 3.339, 95% CI 1.007–6.357, P = 0.030), hypolactatemia (<2 mmol/L OR 0.721, 95% CI 0.562–0.926, P = 0.010), thrombocytosis (PLT>100×10⁹/L OR 1.961, 95% CI 1.921–2.940, P = 0.036), and coagulopathy (APTT >40 s OR 1.243, 95% CI 1.052–1.470, P = 0.011) were the risk factors of filter coagulation. Conclusion: In CRRT therapy, applying citrate anticoagulation, closely monitoring ultrafiltration volume and post-filtration ionized calcium concentration, improving hypolactatemia, and adjusting platelet and coagulation function contributed to prolong filter lifespan, reduce the interruption risk of CRRT therapy, and improve therapeutic efficacy.