Mineshima M, Agishi T, Hasuo Y, Era K, Suzuki T, Teraoka S, Ota K
Tokyo Women's Medical College, Japan.
Artif Organs. 1992 Oct;16(5):510-3. doi: 10.1111/j.1525-1594.1992.tb00333.x.
Until recently, the albumin concentration of supplementation fluid for double filtration plasmapheresis (DFPP) has been empirically determined. Inadequate albumin infusion often leads to hypoproteinemic symptoms such as edema. In the current study, an aimed condensation coefficient (CCaimed) was introduced in an attempt to estimate the appropriate plasma albumin level for each patient. This coefficient is theoretically derived from a one-compartment model for the patient's plasma albumin: CCaimed = CS/CD = 1 - (1 - CR)/[1 - exp(- CC.VR)] where CD and CS are albumin concentrations in discarded plasma and supplementation fluid. CR is the change ratio of albumin concentration in the patient's plasma during a DFPP treatment, and VR(= VS/VP) is the ratio of supplementation fluid volume (VS) to the patient's total plasma volume (VP). And CC denotes the albumin condensation coefficient in a DFPP line, which depends on the filtration fraction of the plasma fractionator (FFPF) and the sieving coefficients of both the plasma separator (SCPS) and the plasma fractionator (SCPF): CC = CD/CP = SCPS.(1 - FFPF.SCPF)/(1 - FFPF) where CP is the albumin concentration of the patient's plasma. From the above relations, CS can be determined as follows: CS = CC.CCaimed.CP Because many kinds of proteins are removed during a single DFPP treatment, a slightly higher albumin concentration in the supplementation fluid is needed to maintain an appropriate plasma level. Therefore, the CR value should be more than unity. For a patient with hematocrit (HCT) of 30%, body weight (BW) of 50 kg, and CP of 3.0 g/dl, who is receiving a DFPP treatment using AP-05H (SCPS of 0.970) and Evaflux 2A (SCPF of 0.526) under FFPF of 0.8 with VS of 500 ml, VP = BW(1- HCT/100)/13 = 50 x (1 - 30/100)/13 = 2.69 L, VR = 500/(2.69 x 1,000) = 0.186, CC = 2.81, and CCaimed = 1.25 assuming 1.1 for CR. Therefore, CS = 2.81 x 1.25 x 3.0 = 10.5 g/dl using the above equations.
直到最近，双重滤过血浆置换（DFPP）补充液中的白蛋白浓度一直是凭经验确定的。白蛋白输注不足往往会导致诸如水肿等低蛋白血症症状。在当前研究中，引入了目标浓缩系数（CCaimed），试图估算每位患者合适的血浆白蛋白水平。该系数理论上源自患者血浆白蛋白的单室模型：CCaimed = CS/CD = 1 - (1 - CR)/[1 - exp(- CC.VR)]，其中CD和CS分别是废弃血浆和补充液中的白蛋白浓度。CR是DFPP治疗期间患者血浆中白蛋白浓度的变化率，VR(= VS/VP)是补充液体积（VS）与患者总血浆体积（VP）的比值。并且CC表示DFPP管路中的白蛋白浓缩系数，它取决于血浆成分分离器的滤过分数（FFPF）以及血浆分离器（SCPS）和血浆成分分离器（SCPF）的筛系数：CC = CD/CP = SCPS.(1 - FFPF.SCPF)/(1 - FFPF)，其中CP是患者血浆中的白蛋白浓度。根据上述关系，CS可按如下方式确定：CS = CC.CCaimed.CP 由于在单次DFPP治疗过程中会去除多种蛋白质，因此需要补充液中白蛋白浓度略高一些以维持合适的血浆水平。所以，CR值应大于1。对于一位血细胞比容（HCT）为30%、体重（BW）为50 kg且CP为3.0 g/dl的患者，其接受使用AP - 05H（SCPS为0.970）和Evaflux 2A（SCPF为0.526）在FFPF为0.8且VS为500 ml的条件下进行的DFPP治疗，VP = BW(1 - HCT/100)/13 = 50 x (1 - 30/100)/13 = 2.69 L，VR = 500/(2.69 x 1,000) = 0.186，CC = 2.81，假设CR为1.1时CCaimed = 1.25。因此，使用上述公式可得CS = 2.81 x 1.25 x 3.0 = 10.5 g/dl。
