van Iterson M, van der Waart F J, Erdmann W, Trouwborst A
Department of Anaesthesiology, Academic Medical Centre, University of Amsterdam, Netherlands.
Lancet. 1995 Oct 28;346(8983):1127-9. doi: 10.1016/s0140-6736(95)91800-0.
Transfusion of homologous blood should be avoided when possible, and one technique that diminishes perioperative requirement for donor blood is haemodilution. In children its effects on systemic haemodynamics and systemic oxygenation have not been reported. Six children aged 4-12 yr were anaesthetised for major surgery and blood was withdrawn to reduce packed cell volume to 25%. Cardiac index increased from 3.1 (SD 0.5) L min-1 m-2 at baseline to 4.4 (0.5) L min-1 m-2 at the end of surgery, when packed cell volume was 16 (1)%; this change, compensating for the decline in oxygen carrying capacity, was associated with a fall in systemic vascular resistance and a rise in stroke volume. Oxygen extraction from haemoglobin rose from 0.22 (0.05) to 0.33 (0.06). Perioperative blood loss was 40% of circulating blood volume; however, owing to reinfusion of autologous blood (and use of a cell saver in three patients), the haemoglobin one day after operation was only 19% lower than preoperatively (9.9 [1.5] vs 12.5 [2.5] g/dL). In this study, children seemed at least as able as adults to compensate for the effects of haemodilution, which allowed major surgery without transfusion of homologous blood.
应尽可能避免输注同源血，一种减少围手术期供血需求的技术是血液稀释。关于其对儿童全身血流动力学和全身氧合的影响尚未见报道。6名4至12岁的儿童接受大手术麻醉，抽取血液使血细胞比容降至25%。手术结束时血细胞比容为16（1）%，心脏指数从基线时的3.1（标准差0.5）L·min⁻¹·m⁻²增至4.4（0.5）L·min⁻¹·m⁻²；这一变化补偿了氧携带能力的下降，与全身血管阻力降低和每搏量增加有关。血红蛋白的氧摄取率从0.22（0.05）升至0.33（0.06）。围手术期失血量为循环血量的40%；然而，由于自体血回输（3例患者使用了血液回收机），术后一天的血红蛋白仅比术前低19%（9.9 [1.5] 对12.5 [2.5] g/dL）。在本研究中，儿童似乎至少与成人一样能够代偿血液稀释的影响，从而在不输注同源血的情况下进行大手术。
