Myoglobin clearance and removal during continuous venovenous hemofiltration

Area of Science:

• Nephrology
• Intensive Care Medicine
• Biomedical Engineering

Background:

• Myoglobin, a protein with high molecular weight, is poorly cleared by traditional dialysis.
• Myoglobinuric acute renal failure can result from conditions causing muscle breakdown and elevated creatine kinase levels.
• Convective therapies like continuous venovenous hemofiltration (CVVH) offer potential for enhanced solute removal.

Observation:

• A single case of myoglobin-induced renal failure was treated with CVVH.
• The treatment utilized a 0.9 m(2) polyacrylonitrile (AN69) membrane hemofilter with an ultrafiltration rate of 2-3 l/h.
• Serum myoglobin levels decreased significantly during CVVH therapy.

Findings:

• CVVH demonstrated effective removal of myoglobin, with serum concentrations dropping from 92,000 to 28,600 microg/l within 18 hours.
• The mean sieving coefficient for myoglobin was 0.6, decreasing to 0.4 over time, indicating reduced efficiency possibly due to filter fouling.
• Mean myoglobin clearance was 22 ml/min, decreasing to 14 ml/min, while urea, creatinine, and phosphorus clearance remained high (sieving coefficient of 1.0).

Implications:

• CVVH can remove substantial amounts of myoglobin, suggesting its utility in managing myoglobinuric renal failure.
• The decrease in the sieving coefficient over time highlights potential challenges like filter clotting or protein adsorption.
• Further research is needed to determine if early CVVH intervention can alter the course or duration of myoglobinuric acute renal failure.