Baker K Z, Ostapkovich N, Sisti M B, Warner D S, Young W L
Department of Anesthesiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
J Neurosurg Anesthesiol. 1997 Apr;9(2):134-40. doi: 10.1097/00008506-199704000-00005.
Remifentanil hydrochloride is a new opioid rapidly metabolized by blood and tissue esterases. The swift degradation accounts for the elimination half-life (t1/2 beta) of < 10 min. An anesthetic agent allowing more rapid postoperative assessment of the neurosurgical patient would be beneficial. This study examined the effect of remifentanil on cerebral blood flow (CBF) reactivity to changes in the arterial pressure of carbon dioxide (PaCO2). Cerebral blood flow was measured with intravenous 133-Xenon during remifentanil/ nitrous oxide (N2O) anesthesia in 10 patients undergoing craniotomy. Cerebrovascular reactivity was determined by repeating CBF measurements after the addition of carbon dioxide (CO2) to the inspired gas mixture. The CBF increased from 21 +/- 6 to 31 +/- 7 ml/100 g/min as the PaCO2 increased from 27 +/- 4 to 36 +/- 3 mm Hg. The relative CBF reactivity was 3.6 +/- 1.2%/mm Hg CO2. During the CBF determinations, the doses of remifentanil administered were not significantly different (0.38 +/- 0.18 microgram/kg/min at hypocapnia vs. 0.34 +/- 0.16 microgram/kg/min at normocapnia). Electroencephalographic monitoring showed a spectral edge frequency of 26 +/- 1 Hz before induction, 25 +/- 1 Hz during maintenance of the remifentanil/N2O anesthetic (0.32 +/- 0.15 microgram/kg/ min), 24 +/- 1 Hz during hypocapnic CBF determination, and 24 +/- 2 Hz during normocapnic CBF determination. At the completion of the procedure, the patients responded to commands within 3.6 +/- 2.5 min and were extubated 7.2 +/- 4.5 min after the remifentanil/N2O was discontinued. In conclusion, absolute CBF values during remifentanil/N2O are similar to previously reported CBF values during fentanyl/N2O and isoflurane/N2O anesthesia, and cerebrovascular reactivity to CO2 remains intact.
盐酸瑞芬太尼是一种新型阿片类药物，可被血液和组织酯酶快速代谢。其迅速降解导致消除半衰期（t1/2β）小于10分钟。一种能使神经外科患者术后评估更快的麻醉剂将是有益的。本研究考察了瑞芬太尼对脑血流量（CBF）对二氧化碳动脉压（PaCO2）变化的反应性的影响。在10例接受开颅手术的患者中，于瑞芬太尼/氧化亚氮（N2O）麻醉期间用静脉注射133-氙测量脑血流量。通过在吸入气体混合物中添加二氧化碳（CO2）后重复测量CBF来确定脑血管反应性。随着PaCO2从27±4毫米汞柱增加到36±3毫米汞柱，CBF从21±6增加到31±7毫升/100克/分钟。相对CBF反应性为3.6±1.2%/毫米汞柱CO2。在CBF测定期间，给予的瑞芬太尼剂量无显著差异（低碳酸血症时为0.38±0.18微克/千克/分钟，正常碳酸血症时为0.34±0.16微克/千克/分钟）。脑电图监测显示，诱导前频谱边缘频率为26±1赫兹，瑞芬太尼/N2O麻醉维持期间（0.32±0.15微克/千克/分钟）为25±1赫兹，低碳酸血症CBF测定期间为24±1赫兹，正常碳酸血症CBF测定期间为24±2赫兹。手术结束时，患者在3.6±2.5分钟内对指令有反应，在瑞芬太尼/N2O停用后7.2±4.5分钟拔管。总之，瑞芬太尼/N2O麻醉期间的绝对CBF值与先前报道的芬太尼/N2O和异氟烷/N2O麻醉期间的CBF值相似，并且脑血管对CO2的反应性保持完整。
