TNF-α depuration is a predictor of mortality in critically ill patients under continuous veno-venous hemodiafiltration treatment.

INTRODUCTION: Critically ill patients with acute kidney injury (AKI) present high mortality rates. The magnitude of inflammatory response could determine the prognosis of such patients. Continuous renal replacement therapy (CRRT) may play an important role in removing inflammatory mediators in patients with AKI. AIM: To investigate whether the magnitude of inflammatory mediator's removal is associated with mortality among critically ill patients on CVVHDF, a CRRT modality. METHODS: This study consisted of 64 critically ill patients requiring CVVHDF. Plasma levels of C3a, TNF-α, IL-10, IL-6, IL-1ß, sTNFRI and sTNFRII were determined by enzyme-linked immunosorbent assay (ELISA) at the beginning of CVVHDF and after 24h (outlet). Clearance of cytokines during the first 24h of CVVHDF was calculated. Clinical and laboratory data were acquired from patient's records data. RESULTS: Mean age of patients requiring CVVHDF was 63years, 67.2% were men and 87.3% were Caucasian. Thirty-five (35) patients (54.7%) died. Comparing non-survivors with the group of survivors we observed higher incidence of sepsis (68.6 versus 37.9%, p<0.05), higher APACHE II score (34.8±7.6 versus 29.2±7.1, p<0.05) and higher lactate levels (23.2±17.6 versus 16.4±6.6, p<0.05). According to the inter-tertile range of TNF-α clearance (ITR1 (<0.54); ITR2 (0.54-2.93); ITR3 (>2.93)) we found that those patients with higher TNF-α removal by RRT (ITR3) had a better survival. Multivariable analysis showed that lower clearance of TNF-α remained independently associated with high mortality after adjustment for sex, age, use of vasoactive drugs, APACHE II score sepsis, creatinine and lactate before CVVHDF (HR: 0.179, 95% IC: 0.049-0.661, p<0.01). CONCLUSION: The attenuation of inflammatory response may be related to the lower mortality observed on those patients with higher TNF-α removal by CVVHDF.

The use of regional citrate anticoagulation for continuous venovenous hemodiafiltration in acute kidney injury.

OBJECTIVE: Continuous renal replacement therapy is commonly used in the treatment of acute kidney injury. Although the optimal anticoagulation system is not well defined, citrate has emerged as the most promising method. We evaluated the data of 143 patients with acute kidney injury subjected to citrate-based continuous venovenous hemodiafiltration. DESIGN: Retrospective cohort study. SETTING: Intensive care unit of tertiary care private hospital. PATIENTS: Patients with acute kidney injury treated from February 2004 to July 2006. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main cause of acute kidney injury was sepsis (58%). The mean dialysis dose was 36.6 mL/kg/hr allowing for excellent metabolic control (last tests: creatinine, 1.1 mg/dL; urea, 46 mg/dL). No significant bleeding, severe electrolyte, or calcium disorders were observed. Of the 418 filters used, almost 28,000 hrs of treatment, hemofilter patency was 68% at 72 hrs. Hospital mortality was 59%, and 22% of survivors were dialysis-dependent at the time of discharge. Within our sample, we identified 21 patients with liver failure (mean prothrombin time index, 21% vs. 67%, p < 0.001). This group presented with a lesser median systemic ionized calcium level (1.06 vs. 1.12 mmol/L, p < 0.001) and similar mean total calcium level (8.5 vs. 8.6 mg/dL, not significant), compared with patients without liver failure. These subjects also showed acidemia (median pH, 7.31 vs. 7.40, p < 0.001); however, they exhibited higher levels of lactate (median 29 vs. 16 mg/dL, p < 0.001), chloride (mean 109 vs. 107 mEq/L, p = 0.045) and had a trend to higher mortality rate (76% vs. 56%). CONCLUSIONS: Besides a trend toward higher mortality rate observed in the group with liver failure, we found that citrate-based continuous venovenous hemodiafiltration allowed an effective dialysis dose and reasonable filter patency.