Background: In the haemodynamically unstable patient the method of treatment of acute renal failure is still largely controversial. The purpose of our study was to compare slow extended dialysis with continuous
haemodiafiltration in the critical patient with indication for renal replacement therapy and haemodynamic
instability. Patients and Methods: This is a cohort study comparing in 63 ventilated critical patients a 12 month
period when only continuous haemodiafiltration was used (n=25) with an equal period of slow extended
dialysis (n=38). Our primary objective was to evaluate the impact of the dialytic procedure on cardiovascular
stability in those patients. As secondary aims we considered system coagulation/thrombosis and predictors
of mortality. In the two groups we analysed the first session performed, the second session performed and
the average of all the sessions performed in each patient. Results: In these patients, mortality in the
intensive care unit was high (68% in the continuous haemodiafiltration group and 63% in the slow extended
dialysis group). We did not find any association between the dialytic technique used and death; only
the APACHE score was a predictor of death. Slow extended dialysis was a predictor of haemodynamic
stability, a negative predictor of sessions that had to be interrupted for haemodynamic instability, and a
predictor of achieving the volume removal initially sought. Slow extended dialysis was also associated
with less coagulation of the system. Conclusions: Our data suggested that slow extended dialysis use was
not inferior to continuous haemodiafiltration use in terms of cardiovascular tolerability
