Objectives
To determine whether continuous veno-venous hemofiltration with dialysis leads to extraction of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) from the circulation of critically ill patients with sepsis and acute renal failure and to quantitate the clearance and removal rates of these cytokines and their effect on serum cytokine concentrations.
Design
Prospective, controlled study of TNF-α and IL-1β extraction by continuous veno-venous hemofiltration with dialysis in patients with septic acute renal failure.
Setting
Intensive care unit of a tertiary institution.
Patients
Eighteen critically ill patients with sepsis and acute renal failure. Control group of six patients experiencing an acute illness while undergoing chronic hemodialysis.
Interventions
Collection of blood samples before continuous veno-venous hemofiltration with hemodialysis. Simultaneous collection of prefilter blood and ultradiafiltrate after 4 and 24 hrs of treatment.
Measurements and Main Results
TNF-α and IL-1β concentrations were measured in blood and ultradiafiltrate. Their clearances and daily extraction were calculated and compared with a control group. TNF-α was detected in 66.6% of serum samples of patients with septic acute renal failure; IL-1β was detected in 55% of patients' sera samples. Both TNF-α and IL-1β were cleared by the hemofilter during continuous veno-venous hemofiltration with dialysis. The mean clearance for TNF-α was 30.7 L/day (95% confidence interval 22.4 to 39) with a daily mean excretion of 14.1 μg (95% confidence interval 1.7 to 26.5). Mean IL-1β clearance was 36.1 L/day (95% confidence interval 25.4 to 46.8) equivalent to a mean daily IL-1β excretion of 1 μg (95% confidence interval 0.9 to 1.1). No measurable concentrations of TNF-α or IL-1β were found in the serum or ultrafiltrate specimens of control patients.
Conclusions
These findings demonstrate that continuous veno-venous hemofiltration with dialysis can remove both TNF-α and IL-1β from the circulation of septic, critically ill patients. This cytokine extraction may prove to be of benefit in attenuating the progression of multiple organ dysfunction in patients with sepsis-associated renal failure, who are receiving continuous veno-venous hemofiltration with dialysis. This potential benefit of existing hemofiltration therapies supports their preferential implementation in patients with renal failure associated with severe sepsis. These observations may stimulate the modification of filtration membrane design seeking to specifically augment the clearance from the circulation of a variety of such cytokines. (Crit Care Med 1993; 21:522–526)
