Acute blood purification aiming at myoglobin removal

Possibility of adsorption method

Abstract

Blood purification is based on the principles of dialysis, filtration, and adsorption. The molecular weight of myoglobin (Mgb) is 17800 Da, making it a medium-sized molecular compound ; thus, it cannot be separated using the principles of dialysis. With a focus on the principles of filtration, methods using a high cut-off membrane have been developed for Mgb removal; however, albumin loss is a problem with this method. The principle of adsorption is based on the interaction between the membrane material and solute ; thus, if the membrane adsorption characteristics match Mgb, Mgb removal may be possible with this method. However, no study has focused on the principle of adsorption for Mgb removal. In this study, we performed continuous hemofiltration using an AN69ST membrane (AN-CHF) and sustained high-efficiency daily diafiltration using a mediator-adsorbing membrane (SHEDD-fA) with a polymethylmethacrylate (PMMA) membrane for a patient with high blood Mgb levels and calculated the Mgb clearance. The Mgb level was 197328ng/ml, indicating a marked increase. AN-CHF (QB: 150ml/min, QF: 1000ml/h) was started, and then the method was switched to SHEDD-fA (QB : 150ml/min, QD : 300ml/min, QF : 1250ml/h). The AN-CHF blood clearance was 9.1ml/min, while SHEDD-fA was 37.9 ml/min. The theoretical filtration clearance limit of SHEDD-fA was 20.8ml/min, and the blood clearance of SHEDD-fA is extremely high, even for substances with a sieving coefficient of 1.0. The involvement of the principle of adsorption was considered in view of the molecular weight of Mgb.