Sullivan H G, Keenan R L, Isrow L, Feria A W
J Neurosurg. 1980 Mar;52(3):426-30. doi: 10.3171/jns.1980.52.3.0426.
In a patient undergoing craniotomy for clipping of an anterior communicating artery aneurysm, sodium nitroprusside was used to lower systemic arterial blood pressure to 80/35 mm Hg (mean arterial blood pressure (MABP) = 50 mm Hg), at which time the electroencephalogram (EEG) changed abruptly from normal to a burst suppression pattern. At the onset of burst suppression, PaCO2 was 18 mm Hg. After PaCO2 had been increased to 28 mm Hg, the patient tolerated a blood pressure of 45/25 mm Hg (MABP = 32 mm Hg) during aneurysm clipping without EEG change. The observations reported here support the conclusion that, with moderate hypotension, hypocarbia may cause brain ischemia and that the level of PaCO2 may influence the degree of hypotension that may be safely used during aneurysm surgery. The importance of repeated arterial blood gas measurements when induced hypotension is employed for berry aneurysm surgery is stressed. Intraoperative EEG monitoring may be employed to help judge safe levels of intraoperative hypotension during intracranial aneurysm surgery.
在一名因夹闭前交通动脉瘤而接受开颅手术的患者中，使用硝普钠将体循环动脉血压降至80/35 mmHg（平均动脉压（MABP）=50 mmHg），此时脑电图（EEG）突然从正常变为爆发抑制模式。在爆发抑制开始时，动脉血二氧化碳分压（PaCO2）为18 mmHg。将PaCO2提高到28 mmHg后，患者在动脉瘤夹闭期间耐受45/25 mmHg的血压（MABP = 32 mmHg），脑电图无变化。此处报告的观察结果支持以下结论：在中度低血压情况下，低碳酸血症可能导致脑缺血，且PaCO2水平可能影响动脉瘤手术期间可安全使用的低血压程度。强调了在进行浆果状动脉瘤手术采用诱导性低血压时重复进行动脉血气测量的重要性。术中脑电图监测可用于帮助判断颅内动脉瘤手术期间术中低血压的安全水平。
