A randomized cross-over comparison of the hemodynamic response to intermittent hemodialysis and continuous hemofiltration in ICU patients with acute renal failure

Objective: To compare the hemodynamic response of ICU patients with acute renal failure of a 24-h continuous arteriovenous hemofiltration (CAVH) and that of patients with a 4-h intermittent hemodialysis (HD). Design: Cross-over randomized clinical trial. The two periods to be compared were a 24-h CAVH and the 24-h encompassing a 4-h HD. These two periods were separated by a 24-h wash-out period. Setting: Ten bed medicosurgical ICU of a tertiary care center in Paris, France. Patients: Inclusion criterion was the requirement of replacement therapy for acute renal failure in patients already submitted to mechanical ventilation. Interventions: CAVH was performed with Ringers' lactate used for restitution and infused before the hemofilter. The ultrafiltrate output was maintained at around 15 ml/min, HD was performed with a bicarbonate-buffered dialysate. Mean outcome measures: Mean arterial pressure (MAP), use of adrenergic drugs, and change in body weight during each period. Results: Twenty-seven consecutive patients were included, 15 CAVH-HD and 12HD-CAVH. CAVH and HD allowed the same metabolic efficacy. No hemodynamic parameter (MAP, amount of adrenergic drugs, change in body weight) differed between the two methods. Conclusions: CAVH is equivalent to HD in terms of MAP and the use of vasopressive drugs and fluids. Establishing the superiority of CAVH would require carefully controlled studies assessing either outcome or changes in tissue oxygenation.