中度急性高容量血液稀释联合控制性降压对颅内动脉瘤手术病人血流动力学和脑血流的影响

Effects of moderate acute hypervolemic hemodilution combined with controlled hypotension on hemodynamics and regional cerebral blood flow

目的 观察中度急性高容量血液稀释 (AHH)联合应用控制性降压对颅内动脉瘤夹闭术病人血液动力学和局部脑血流 (rCBF)的影响。方法 19例颅内动脉瘤病人随机分为异氟醚组 (A组 ,n =10 )和尼莫地平组 (B组 ,n =9)。诱导后两组均进行中度AHH(Hct=2 5 %～ 30 % ) ,监测血流动力学、颅内压 (ICP)及动脉瘤跨壁压 (TMP)的变化。降压期间 ,A组提高异氟醚吸入浓度至 1 4～1 6MAC ;B组尼莫地平 5～ 8μg·kg-1静注 ,继以 10～ 10 0 μg·kg-1·h-1的速率持续泵入 ,两组均维持MAP在 8 0～ 8 7kPa。用激光多普勒血流仪 (LDF)连续监测降压前 (T0 )、降压中 (包括动脉瘤夹闭前T1、夹闭后T2 )和升压后 (T3 )rCBF的变化。结果 与AHH前比较 ,两组在AHH后Hb、Hct和CaO2均显著降低 (P <0 0 1) ,MAP、CVP、HR、ICP及TMP均无显著性变化 (P >0 0 5 ) ;两组在T0 ～T3 期间rCBF和CaO2 均无明显变化 (P >0 0 5 ) ;T3 时A组的HR快于B组 (P <0 0 5 )。结论 在颅内动脉瘤夹闭术中 ,实施中度AHH能保持血流动力学和TMP稳定 ,联合应用异氟醚或尼莫地平控制性降压 ,不影响rCBF。

Objective To assess the effecs of moderate acute hypervolemic hemodilution (AHH)combined with controlled hypotension on hemodynamics and regional cerebral blood flow (rCBF) in intracranial aneurysm surgery Methods Nineteen ASA Ⅰ Ⅱ patients with intracranial aneurysm scheduled for intracranial aneurysm surgery were randomly divided into isoflurane group (A, n=10) and nimodipine group (B, n=9) The patients′ Hb was more than 11g/dl and Hct more than 35% The patients were premedicated intravenous atropine 0 5mg and midazolam 3 5mg An intrathecal catheter was inserted at L 3 5 for monitoring of intracrenal pressure (ICP) Anesthesia was induced with fentanyl 3 4μg/kg, propofol 2mg/kg and vevuronium 0 1mg/kg After tracheal intubation the patients were mechanically ventilated PaCO 2 was maintained at 3 7 4 0kPa Radial artery was cannulated for direct blood pressure monitor and internal jugular vein was cannulated for CVP monitoring In both groups anesthesia was maintained with 1 0 1 1 MAC isoflurane inhalation and intermittent intravenous boluses of fentanyl and muscle relaxant until Hct was reduced to 25% 30% AHH was carried out by intravenous infusion of gelofusine at 15 20ml·kg 1 ·h 1 Blood routine was checked every 30 min MAP, HR, CVP intracranial pressure (ICP) were continuously monitored and blood gas checked before and after AHH Oxygen content of arterial blood (CaO 2) and TMP(TMP=MAP-ICP) were calculated Controlled hypotension was performed after opening of dura and during isolation and clipping of aneurysm and induced by either inhalation of higher concentration of isoflurane (1 4 1 6MAC) or by intravenous bolus of nimodipine 5 8μg/kg followed by continuous IV infusion (10 100μg·kg 1 ·h 1 ) MAP was maintained at 8 0 8 7kPa rCBF, MAP, HR, CVP were monitored before (T 1),during (T 2) hypotension and after MAP returned to normal(T 3) rCBF was continuously measured by laser Doppler flowmetry(LDF) Results Hb, Hct and CaO 2 decreased significantly after AHH in both groups as compared with those before AHH There was no significant change in MAP, HR, CVP, ICP and TMP(P>0 05) During T 1 3 rCBF did not change significantly in both groups (P>0 05) HR in group A was faster than that in group B at T 3 (P<0 05).Conclusions In intracranial aneurysm surgery during moderate AHH hemodynamics and TMP can be fairly well maintained rCBF does not change when AHH is combined with controlled hypotension (MAP=8 0 8 7kPa) induced by inhalation of high concentration isoflurane or intravenous nimodipine