Shear Torin, Tobias Joseph D
School of Medicine, University of Missouri, Columbia, MO 65212, USA.
Paediatr Anaesth. 2005 Jun;15(6):504-8. doi: 10.1111/j.1460-9592.2005.01495.x.
Controlled hypotension (CH) is used to limit intraoperative blood loss and decrease the need for homologous transfusions. Despite the efficacy of the technique, hypotension has the potential to affect cerebral perfusion and oxygen delivery. There are no data providing a direct measurement of cerebral oxygenation during this technique.
The current study prospectively evaluated cerebral oxygenation during CH using near infrared spectroscopy. Nineteen patients ranging in age from 6 to 18 years were enrolled in the study. CH was provided using a combination of intravenous opioids and sevoflurane supplemented with labetolol as necessary.
There were a total of 268 readings obtained from the cerebral oximeter. The baseline cerebral oximeter reading was 81+/-8% on the right and 82+/-7% on the left. During CH (mean arterial pressure of 65-69, 60-64, 55-59, and <54 mmHg), the right cerebral oximeter values were 80+/-9, 78+/-8, 78+/-10, and 84+/-9%, respectively while the left cerebral oximeter values were 79+/-7, 80+/-7, 78+/-8, and 78+/-8%, respectively. Of the 268 readings, there were 11 points (4%) at which either the left or right cerebral oximeter was 10-19 less than the baseline value and no points at which the reading was 20 or more from the baseline value.
Our preliminary data with a measurement of cerebral oxygenation demonstrates the safety of CH within the accepted mean blood pressure recommendations of 55-65 mmHg.
控制性低血压（CH）用于限制术中失血并减少异体输血的需求。尽管该技术有效，但低血压有可能影响脑灌注和氧输送。目前尚无数据能直接测量该技术过程中的脑氧合情况。
本研究采用近红外光谱法对控制性低血压期间的脑氧合情况进行前瞻性评估。19例年龄在6至18岁之间的患者纳入本研究。控制性低血压通过静脉注射阿片类药物和七氟醚联合应用，并根据需要补充拉贝洛尔来实现。
总共从脑血氧饱和度仪获得268次读数。脑血氧饱和度仪的基线读数右侧为81±8%，左侧为82±7%。在控制性低血压期间（平均动脉压分别为65 - 69、60 - 64、55 - 59和<54 mmHg），右侧脑血氧饱和度仪的值分别为80±9%、78±8%、78±10%和84±9%，而左侧脑血氧饱和度仪的值分别为79±7%、80±7%、78±8%和78±8%。在268次读数中，有11个点（4%）左侧或右侧脑血氧饱和度仪读数比基线值低10 - 19，没有读数比基线值低20或更多的点。
我们测量脑氧合的初步数据表明，在公认的平均血压建议范围55 - 65 mmHg内，控制性低血压是安全的。
