Jaiyesimi F
Ann Trop Paediatr. 1986 Mar;6(1):51-7. doi: 10.1080/02724936.1986.11748411.
Using a hypothetical formula to calculate exchange volumes, erythropheresis was performed on 47 occasions in 20 children with secondary polycythaemia. Following this procedure the mean haematocrit in the patients was reduced from 69.0 to 58.0% (P less than 0.001), and the individual haematocrit to 61% or below. In 39 (83%) of the 47 exchanges the reduction coefficient, i.e., the volume of exchange which effected a unit reduction in the haematocrit, ranged from 1.0 to 3.0 ml/kg bodyweight. The derivation of these coefficients facilitated the formulation of an equation which expresses the volume of blood (V) that needs to be exchanged in a patient in terms of his weight, observed haematocrit (Hct1) desired haematocrit (Hct2) and the reduction coefficient (RC): V = Bodyweight (kg) X (Hct1 - Hct2) X RC. Haematocrit rebound occurred after 83% 50% and 14% of 30-min, 60-min and 90-min exchanges, respectively, indicating that the optimal duration of the procedure should be between 60 and 90 min. Hypercyanotic spells complicated two of the 47 exchanges and one patient suffered a fatal micturition-related cardiovascular collapse shortly after erythropheresis.
使用一个假设公式计算置换量，对20例继发性红细胞增多症患儿进行了47次红细胞单采术。该操作后，患者的平均血细胞比容从69.0%降至58.0%（P<0.001），个体血细胞比容降至61%或更低。在47次置换中的39次（83%）中，降低系数，即导致血细胞比容单位降低的置换量，范围为1.0至3.0 ml/kg体重。这些系数的推导有助于制定一个方程，该方程根据患者的体重、观察到的血细胞比容（Hct1）、期望的血细胞比容（Hct2）和降低系数（RC）来表示患者需要置换的血液量（V）：V =体重（kg）×（Hct1 - Hct2）×RC。分别在30分钟、60分钟和90分钟置换后的83%、50%和14%出现了血细胞比容反弹，表明该操作的最佳持续时间应在60至90分钟之间。47次置换中有2次出现了重度发绀发作，1例患者在红细胞单采术后不久因排尿相关的致命性心血管衰竭死亡。
