Polymyxin B-Haemoperfusion In Severe Interstitial Lung Disease: Safety And Efficacy Of Low Dose Heparin

Background: Rapidly progressive interstitial lung disease (ILD) in anti-MDA-5 dermatomyositis carries high mortality despite timely and intensive immunosuppressive therapy. Case reports suggest possible benefit with polymyxin B-haemoperfusion (PMX-HPF). However, its use and that of heparin anticoagulation during PMX-HPF is uncertain.

Methods: A middle-aged Chinese female patient who had failed to respond to multiple immunsuppressive drugs and who developed opportunistic infections was treated with PMX-HPF at our centre. Polymyxin B immobilized column (PMX-20R, Toray Industries, Tokyo, Japan) was used. PMX-HPF was performed using the Infomed HF440 CRRT platform (Infomed SA, Geneve, Switzerland) via a central venous dialysis catheter. The patient was treated with four consecutive 4 h, daily sessions of PMX-HPF. There was no ultrafiltration. Pumped blood flow (Q_B) was 150 mL/min. Low dose heparin anticoagulation was used. Serial serum ferritin, lactate dehydrogenase (LDH) and P/F ratio (partial pressure of oxygen PaO2/fractional inspired oxygen FiO2) were measured.

Results: Circuit arterial, venous, pre-filter and trans-cartridge pressures were within recommended ranges pre- vs. post-treatment. No significant bleeding or clotting occurred. The patient tolerated the four treatments but showed no definite respiratory improvement and ultimately succumbed.

Conclusion: Based on this case, low dose heparin anticoagulation is safe and effective in intermittent, daily PMX-HPF. Survival benefit was not demonstrated in this single patient with “rescue” PMX-HPF. Co-initiation of PMX-HPF with immunosuppressive treatment may be synergistic and thus more effective. Further studies are thus needed.