Shortened hemofilter survival time due to lipid infusion in continuous renal replacement therapy

Continuous renal replacement therapy is widely used for the treatment of critically ill patients with acute renal failure in critical care units. The survival time of the extracorporeal circuit is an important factor in providing renal replacement therapy. Despite rigorous efforts to maintain hemofilter patency, clinicians are occasionally faced with an unexplained short circuit survival time.

We present a critically ill patient undergoing continuous venovenous hemofiltration with regional citrate anticoagulation for management of acute renal failure in the context of sepsis. Once the patient was started on lipid infusion as part of total parenteral nutrition, we observed a shortened circuit survival due to premature hemofilter failure necessitating frequent changes of the hemofilter. The known potential causes for this phenomenon were ruled out.

Evaluation revealed grossly lipemic serum associated with severe hypertriglyceridemia. Discontinuation of the lipid infusion was followed by a rapid return of circuit survival time to its baseline. Evaluation of the hemofilter by electron microscopy revealed that the rapid blockage of the hollow fibers was caused by lipid microparticles and fibrin deposits.

Since total parenteral nutrition is commonly administered to malnourished and hypercatabolic critically ill patients on continuous renal replacement therapy, we suggest that intravenous lipid therapy might be a previously unreported and unappreciated remediable cause of premature hemofilter failure.