Williams I M, Vohra R, Farrell A, Picton A J, Mortimer A J, McCollum C N
Department of Surgery, University Hospital of South Manchester, West Didsbury, UK.
Br J Surg. 1994 Jul;81(7):960-4. doi: 10.1002/bjs.1800810711.
Transcranial Doppler ultrasonography (TCD) of the middle cerebral artery (MCA), light-reflective cerebral oximetry and measurement of internal carotid artery stump pressure were compared as methods of monitoring cerebral perfusion during carotid surgery in 33 patients. Median cerebral oxygen saturation was 70 (range 62-85) per cent and TCD-measured mean blood velocity 42 (range 19-91) cm/s before carotid cross-clamping, falling to 68 (53-83) per cent and 16 (0-50) cm/s respectively on application of the clamps (P < 0.001). Stump pressure correlated closely with MCA blood velocity 30 s after the start of cross-clamping (rs = 0.58, P < 0.001), but not with cerebral oxygen saturation. A fall of 5 per cent or more in cerebral oxygen saturation following cross-clamp application was predicted by a decrease in mean MCA blood velocity of at least 60 per cent. Changes in cerebral oxygen saturation correlated significantly with systolic blood pressure throughout the perioperative period (rs = 0.41, P < 0.001). Significant falls in cerebral oxygenation were not predicted by low stump pressure but were associated with large reductions in the mean MCA blood velocity measured by TCD.
在33例患者的颈动脉手术中，对大脑中动脉（MCA）的经颅多普勒超声检查（TCD）、光反射式脑血氧饱和度测定和颈内动脉残端压力测量这几种监测脑灌注的方法进行了比较。颈动脉交叉阻断前，脑氧饱和度中位数为70（范围62 - 85）%，TCD测得的平均血流速度为42（范围19 - 91）cm/s，阻断后分别降至68（53 - 83）%和16（0 - 50）cm/s（P < 0.001）。交叉阻断开始30秒后，残端压力与MCA血流速度密切相关（rs = 0.58，P < 0.001），但与脑氧饱和度无关。平均MCA血流速度至少降低60%可预测交叉阻断后脑氧饱和度下降5%或更多。在整个围手术期，脑氧饱和度变化与收缩压显著相关（rs = 0.41，P < 0.001）。低残端压力不能预测脑氧合的显著下降，但与TCD测得的平均MCA血流速度大幅降低有关。
