Madsen J B, Cold G E, Hansen E S, Bardrum B, Kruse-Larsen C
Department of Anaesthesia, Hvidovre Hospital, Denmark.
Br J Anaesth. 1987 Oct;59(10):1204-7. doi: 10.1093/bja/59.10.1204.
Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification of the classical Kety-Schmidt technique using xenon-133 i.v. Anaesthesia was maintained with an inspired isoflurane concentration of 0.75% (plus 67% nitrous oxide in oxygen), during which CBF and CMRO2 were 34.3 +/- 2.1 ml/100 g min-1 and 2.32 +/- 0.16 ml/100 g min-1 at PaCO2 4.1 +/- 0.1 kPa (mean +/- SEM). Controlled hypotension to an average MAP of 50-55 mm Hg was induced by increasing the dose of isoflurane, and maintained at an inspired concentration of 2.2 +/- 0.2%. This resulted in a significant decrease in CMRO2 (to 1.73 +/- 0.16 ml/100 g min-1), while CBF was unchanged. After the clipping of the aneurysm the isoflurane concentration was reduced to 0.75%. There was a significant increase in CBF, although CMRO2 was unchanged, compared with pre-hypotensive values. These changes might offer protection to brain tissue during periods of induced hypotension.
对10例因脑动脉瘤夹闭术而接受开颅手术的患者，在异氟烷诱导的低血压期间测量脑血流量和脑氧代谢率。在蛛网膜下腔出血后5 - 13天，采用改良的经典凯蒂 - 施密特技术，经静脉注射氙 - 133来测量血流量和代谢率。吸入异氟烷浓度维持在0.75%（加67%氧化亚氮和氧气），在此期间，当动脉二氧化碳分压为4.1±0.1千帕（均值±标准误）时，脑血流量和脑氧代谢率分别为34.3±2.1毫升/100克·分钟和2.32±0.16毫升/100克·分钟。通过增加异氟烷剂量诱导控制性低血压至平均动脉压50 - 55毫米汞柱，并维持吸入浓度为2.2±0.2%。这导致脑氧代谢率显著降低（降至1.73±0.16毫升/100克·分钟），而脑血流量未改变。动脉瘤夹闭后，异氟烷浓度降至0.75%。与低血压前值相比，脑血流量显著增加，尽管脑氧代谢率未改变。这些变化可能在诱导低血压期间为脑组织提供保护。
