Abstract: Objective To investigate the factors to influence tumor necrosis factor α (TNF-α) sieving coefficient in continuous veno-venous hemofiltration (CVVH) analyzed by factorial design. Method A total of 48 patients with severe sepsis were randomly divided into 8 groups (6 patients in each group). CVVH ultrafiltration rate was set at 30ml/(kg· h) or 70ml/(kg· h), plasma flow at 100ml/min or 180ml/min, and treatment time at 6h or 12h. The patients were then divided into 8 groups according to the 2×2×2 factorial design to evaluate the impacts of the three factors on TNF-α sieving coefficient. Results Ultrafiltration rate and treatment time had interacted effect on TNF-α sieving coefficient (P=0.001). TNF-α sieving coefficient was the highest in the group with ultrafiltration rate of 30ml/h and treatment time of 6h (0.162±0.002). TNF-α sieving coefficient increased in ultrafiltration rate of 30ml/kg.h as compared to that of 70ml/(kg· h), and in treatment time of 6h as compared to that of 12h (P＜0.001). TNF-α sieving coefficient decreased in plasma flow of 100ml/min as compared to that of 180ml/min (P 0.001). Conclusion Ultrafiltration rate and treatment time have interacted effect on TNF-α sieving coefficient. TNF-α sieving coefficient becomes decreased when ultrafiltration rate increases and treatment time is prolonged. TNF-α sieving coefficient becomes increased when plasma flow rises.

Key words: Hemofiltration, Factorial design, TNF-a sieving coefficient