Hahn R G
Department of Anaesthesiology, Huddinge University Hospital, Sweden.
Acta Anaesthesiol Scand. 1989 Aug;33(6):508-12. doi: 10.1111/j.1399-6576.1989.tb02955.x.
All the theoretical relationships between blood loss and change in haematocrit used for calculating the allowable pre-transfusion blood loss assume a strictly normovolaemic situation. In this study a formula was derived in which account was taken of the variation in blood volume. The formula was based on clinical data. Measurements of the blood loss, the blood haemoglobin concentration and the haematocrit (HCT) were performed on 230 occasions in the course of 35 transurethral prostatic resections. The change in blood volume was estimated by the haemoglobin dilution method and the value so obtained was compared to both the measured haematocrit and the theoretical value that would presumably have been recorded if there had been no change in blood volume. The relationship established from these comparisons was: blood loss = preoperative blood volume x [In preop HCT - In postop HCT (1 + 0.15 x blood volume change)].
所有用于计算允许的输血前失血量的失血量与血细胞比容变化之间的理论关系均假定为严格的血容量正常情况。在本研究中，推导了一个考虑血容量变化的公式。该公式基于临床数据。在35例经尿道前列腺切除术中，对230次的失血量、血液血红蛋白浓度和血细胞比容（HCT）进行了测量。采用血红蛋白稀释法估算血容量变化，并将所得值与测量的血细胞比容以及假定血容量无变化时可能记录的理论值进行比较。通过这些比较建立的关系为：失血量=术前血容量×[ln术前HCT - ln术后HCT（1 + 0.15×血容量变化）]
