Is the F180 (Fresenius 180) dialysis filter effective in removing myoglobin from the blood?

F180 Dialysis Filter for Myoglobin Removal

The F180 (Fresenius 180) dialysis filter is not specifically effective for myoglobin removal, and high-permeability or high cut-off membranes are superior for this purpose.

Evidence for Myoglobin Removal with Different Membrane Types

The available evidence does not specifically address the F180 filter, but provides clear guidance on membrane characteristics needed for effective myoglobin removal:

High-Permeability Membranes Show Superior Performance

• High-permeability polysulfone dialyzers (allowing elimination of substances up to 30 kDa molecular weight) achieved myoglobin clearances of 90.5 mL/min (range 52.4-126.3 mL/min), surpassing all previously reported dialysis techniques 1
• These high-permeability membranes removed a median of 0.54 g myoglobin per treatment hour (range 0.15-2.21 g) 1

Standard High-Flux Membranes Have Limited Efficacy

• Continuous venovenous hemofiltration (CVVH) using standard AN69 polyacrylonitrile membranes achieved myoglobin clearance of only 22 ml/min initially, declining to 14 ml/min over time 2
• The sieving coefficient for myoglobin with standard membranes decreased from 0.28 at 2 hours to 0.11 at 24 hours, likely due to protein coating and membrane fouling 3
• Mean myoglobin clearance with standard CVVH was 14.3 ml/min at 2 hours, declining to 5.6 ml/min by 24 hours 3

Why the F180 Filter Is Inadequate

The F180 is a standard high-flux dialyzer, not a high cut-off or high-permeability membrane:

• Myoglobin has a molecular weight of 17,000 Da, which exceeds the clearance capacity of standard high-flux membranes 2
• Standard membranes are designed primarily for small molecule clearance (urea, creatinine) rather than middle molecules like myoglobin 4
• The consensus guidelines indicate that filter choice requires special consideration for removal of larger molecular weight substances, recommending filters with higher water permeability for such applications 4

Recommended Approach for Myoglobin Removal

First-Line: High Cut-Off or High-Permeability Membranes

• Use dialyzers specifically designed for molecules up to 30 kDa molecular weight, which provide 4-6 times better myoglobin clearance than standard membranes 1
• High cut-off membranes in continuous venovenous hemodialysis (CVVHD) with high blood and dialysate flows are effective 5

Alternative: Hemoadsorption Technology

• CytoSorb® hemoadsorber added to CVVHD achieved significantly faster myoglobin elimination (AUC 42% vs 63% at 24 hours, p=0.029) compared to high cut-off filters alone 5
• CytoSorb showed much better efficacy than high cut-off hemofilters during the first 8 hours, though saturation occurs after 8-12 hours requiring exchange 5
• This technology successfully reduced myoglobin levels even when high-dose CRRT with EMiC-2 filter failed 6

Clinical Pitfalls to Avoid

• Do not rely on standard high-flux membranes like the F180 for myoglobin removal in rhabdomyolysis with acute kidney injury 2, 1
• Membrane performance declines over time due to protein coating; plan for filter exchanges every 8-12 hours when using hemoadsorbers 5
• The sieving coefficient for myoglobin decreases substantially over time with all membrane types, while small molecule clearance (urea, creatinine) remains stable 2, 3
• Monitor for hypophosphatemia during intensive myoglobin removal, which occurred in 46.7% of patients but typically resolves after cessation of treatment 3