Evaluation of microparticle leakage during DALI LDL adsorption in a simulated clinical setting

The aim of the present study was to investigate microparticle (Mp) leakage during simulated LDL-hemoperfusion using 12 DALI 750 adsorbers and the original DALI hardware under conditions strictly comparable to the clinical situation. Thus, the sessions were divided into 4 sections, i.e. priming and preparation of the adsorber followed by treatment (6-7 L at a flow rate of 60 ml/min) and reinfusion. As Mp counts can be performed only in clear, cell-free media, blood was replaced by normal saline in sections 2-4 of the simulated sessions. Mp counts were analysed for ≥2, ≥5, ≥10 and ≥25 μm particle sizes in the efferent line post adsorber using a standard light blockage method. As there are no official thresholds for particle release in extracorporeal circuits, the limits for infusion of large fluid volumes of 500, 100 (80), 25 and 5 (3) Mp/ml according to the Europaische Arzneimittelbuch, the British and American Pharmacopoeias were used. Mean particle counts for the sections 3 and 4 in which the patient is connected to the efferent line were 19, 7, 2 and 0 Mp/ml and amounted to