Molnár C, Settakis G, Sárkány P, Kálmán S, Szabó S, Fülesdi B
Department of Anesthesiology and Intensive Care, Health and Medical Science Centre, University of Debrecen, Nagyerdei krt. 98, H-4012 Debrecen, Hungary.
Eur J Anaesthesiol. 2007 Feb;24(2):179-84. doi: 10.1017/S0265021506001335. Epub 2006 Sep 14.
It is widely accepted that sevoflurane affects cerebral circulation, but there are uncertainities regarding the magnitude of its effect. The aim of the present work was to assess the effect of sevoflurane on the cerebral circulation at surgical levels of anaesthesia.
Twenty patients undergoing elective lumbar discectomies were investigated. Anaesthesia was induced with propofol and maintained with sevoflurane. The level of surgical anaesthesia was determined by bispectral index, the target level was 45-55. Transcranial Doppler (TCD) measurement was performed before induction and after reaching the surgical level of anaesthesia. Besides routine parameters (middle cerebral artery mean blood flow velocity (MCAV) and pulsatility index (PI)) derived parameters (estimated cerebral perfusion pressure (eCPP), cerebral blood flow index (CBFI) and resistance area product (RAP)) were calculated by taking changes of mean arterial pressure also into account.
MCAV decreased from 54.1 +/- 13.3 to 43.7 +/- 18.5 cm s-1, P < 0.01 and PI increased from 0.79 +/- 0.2 to 0.92 +/- 0.2, P < 0.01 after reaching the surgical level of anaesthesia. As a result eCPP decreased by 18.2%, CBFI by 25.5% and RAP increased by 15% respectively.
Our data indicate a vasodilatory effect of sevoflurane at surgical level of anaesthesia on large cerebral vessels or a vasoconstriction of the resistance arterioles likely caused by decreased brain metabolism.
七氟醚影响脑循环已被广泛认可，但其影响程度仍存在不确定性。本研究旨在评估手术麻醉水平下七氟醚对脑循环的影响。
对20例行择期腰椎间盘切除术的患者进行研究。麻醉诱导采用丙泊酚，维持采用七氟醚。手术麻醉深度由脑电双频指数（BIS）确定，目标值为45 - 55。分别于麻醉诱导前及达到手术麻醉深度后进行经颅多普勒（TCD）测量。除常规参数（大脑中动脉平均血流速度（MCAV）和搏动指数（PI））外，还通过考虑平均动脉压的变化计算得出派生参数（估计脑灌注压（eCPP）、脑血流指数（CBFI）和阻力面积乘积（RAP））。
达到手术麻醉深度后，MCAV从54.1±13.3降至43.7±18.5 cm/s，P<0.01；PI从0.79±0.2升至0.92±0.2，P<0.01。结果eCPP分别下降18.2%，CBFI下降25.5%，RAP升高15%。
我们的数据表明，在手术麻醉水平下，七氟醚对大脑大血管有舒张作用，或可能是由于脑代谢降低导致阻力小动脉收缩。
