PROGNOSTIC INDEXES AND MORTALITY IN CRITICALLY ILL PATIENTS WITH ACUTE-RENAL-FAILURE TREATED WITH DIFFERENT DIALYTIC TECHNIQUES

The objective of this study was to compare the evolution of patients w ith acute renal failure (ARF) treated conservatively or with different dialytic techniques in an intensive care unit (ICU). From June 1992 t o November 1994, 1087 consecutive patients were admitted in our ICU. T wo hundred and twenty of these presented with ARE and were divided int o three groups: group I (control group): 156 patients with ARF who did not receive substitutive techniques; group II: 21 patients under inte rmittent hemodialysis (IHD) or peritoneal dialysis (PD); group III: 43 patients under continuous hemodiafiltration (CHDF). The studied varia bles were age, etiology of renal failure, requirement of dialysis, typ e of dialysis, length of ICU and hospital stay, and renal function out come. APACHE II and SAPS scores were recorded on admission and analyze d for hospital mortality. Chi-square test and the analysis of variance were used for the statistical analysis. Results are presented as mean +/- SD. A p value below 0.05 was considered statistically significant . Although etiology of ARF was multifactorial, we found a high frequen cy of ARF due to sepsis (56.8%), hypoperfusion (58.7%), and acute tubu lar necrosis (62.5%). Sepsis and heart failure were clinical condition s associated to a greater mortality. We did not find any statistical d ifference between the two dialyzed groups for all the studied variable s, nor between the three groups regarding APACHE II and hospital stay. Significant differences were found between dialyzed and non-dialyzed patients respect to age, group I: 64.1 +/- 13.6 group II: 56.4 +/- 19. 7, and group III: 56.0 +/- 14.1 (p < 0.001), creatinine peak serum lev els, group I: 260 +/- 130, group II: 494 +/- 209, and group II: 441 +/ - 170 mu mol/L (p < 0.0001), and mortality group I: 46.9%, group II: 6 6.7%, and group III: 76.2% (p < 0.002). SAPS score showed differences between the control group and the CHDF group 13.9 +/- 4.8 and 16.4 +/- 5.4 (p < 0.007), respectively. The use of dialytic techniques in crit ically ill ARF patients is associated with greater mortality. Prognost ic indexes on admission did not correctly classify our patients with A RF. Continuous hemodiafiltration does not involve greater mortality or length of stay as compared to conventional dialysis.