Is cytokine removal by continuous hemofiltration feasible?

Area of Science:

• Critical care medicine
• Nephrology
• Immunology

Background:

• Critically ill patients with acute renal failure and sepsis face high mortality.
• Systemic inflammatory response syndrome (SIRS) contributes to mortality.
• Continuous renal replacement therapy (CRRT) is explored for removing inflammatory mediators.

Purpose of the Study:

• To evaluate the effectiveness of CRRT in removing inflammatory mediators in critically ill patients.
• To assess the potential of CRRT in managing SIRS.

Main Methods:

• Analysis of inflammatory mediator removal by CRRT.
• Investigation of mass removal using high-permeability membranes and high filtrate volumes.
• Evaluation of cytokine removal via membrane adsorption and filter changes.

Main Results:

• CRRT removes only insubstantial numbers of inflammatory mediators compared to endogenous clearance.
• Effective mass removal requires highly permeable membranes, filtrate volume > 2 L/hr, and substance half-life > 60 min.
• Membrane adsorption shows transient reduction in tumor necrosis factor-alpha (TNF) levels, necessitating frequent filter changes.

Conclusions:

• CRRT's beneficial effect on SIRS requires confirmation through controlled clinical trials.
• Current CRRT protocols may not be sufficient for significant inflammatory mediator clearance.
• Further research is needed to optimize CRRT strategies for critically ill patients.