A pilot study of high-adsorption hemofiltration in human septic shock

Background: To compare the hemodynamic and biological effects of high-adsorption continuous veno-venous hemofiltration (CVVH) with standard CVVH in septic shock. Methods: In a randomized cross-over clinical trial twelve patients with septic shock and multiple organ failure were enrolled at a tertiary intensive care unit. Patients were allocated to either 9 hours of high-adsorption hemofiltration (CVVH with 3 hourly filter change using AN69 hemofilters-3F-CVVH) or 9 hours of standard hemofiltration (CVVH without filter change-1F-CVVH). Results: Changes in hemodynamic variables, dose of noradrenaline required to maintain a mean arterial pressure greater than 75 mmHg and plasma concentrations of cytokines (IL-6, IL-8, IL-10 and IL-18) were measured. A 9-hour period of 3F-CVVH was associated with greater reduction in noradrenaline dose than a similar period of 1F-CVVH (median reduction: 16 vs. 3.5 mu g/min, p=0.036, median percentage reduction: 48.1% vs. 17.5%, p=0.028). Unlike 1F-CVVH, 3F-CVVH was associated with a reduction in the plasma concentration of IL-6, IL-10 and IL-18 at 9 hours and a significant decrease 30 minutes after additional filter changes (IL-6: p < 0.01, p < 0.01; IL-10: p=0.03, p=0.016 and IL-18: p=0.016, p < 0.01, respectively). Both, 3F-CVVH and 1F-CVVH were associated with decreased plasma concentrations of IL-8 at 9 hours (p < 0.01, p < 0.01, respectively). In a confirmatory ex-vivo experiment IL-6 concentrations substantially decreased during 3F-CVVH (at baseline 511pg/mL and at end: 21pg/mL) whereas IL-6 concentrations increased in control blood (at baseline 511pg/mL and at end: 932pg/mL). Conclusions: High-adsorption CVVH appears more effective than standard CVVH in decreasing noradrenaline requirements and plasma concentrations of cytokines in septic shock patients.