Objective: Hemodialysis (HD) and continuous venovenous hemodiafiltration (CVVHDF) have been adopted as forms of renal replacement therapy (RRT) in patients with acute renal failure (ARF). Although CVVHDF has many advantages, previous studies reported no definite improvement in survival rate compared to HD.
Material and methods: In this retrospective study, 148 intensive care unit patients underwent HD (70 males, 25 females; mean age 45 +/- 17 years) or CVVHDF (42 males, 11 females; mean age 52 +/- 18 years). The severity of illness was estimated at the initiation of RRT and on the third day of RRT and presented using the APACHE III scoring system. The number of organ failures was checked at the initiation of RRT.
Results: The survival rate was 46% in the HD group and 21% in the CVVHDF group (p = 0.002). CVVHDF was applied to the more severely ill patients, who had longer periods using a ventilator (p = 0.002) and/or vasopressor (p < 0.001), higher numbers of organ failures (p < 0.001) and higher initial APACHE III scores (p < 0.001). Among patients with APACHE III scores > 103, the survival rate was 13% in the CVVHDF group and 0% in the HD group. In patients with kidney failure and failure of two other organs, the survival rate was 9% in the HD group and 36% in the CVVHDF group (p = 0.035).
Conclusion: The mortality rate in the CVVHDF group was higher than that in the HD group, which may have been because CVVHDF was applied to the more severely ill patients. In contrast, CVVHDF may give a chance of survival to patients with APACHE III scores > 103 and may be more useful than HD in patients with failure of three or more organs.