Marshman L A, Morice A H, Thompson J S
Department of Neurosurgery, Royal Hallamshire Hospital, Sheffield, United Kingdom.
J Neurosurg Anesthesiol. 1998 Jul;10(3):171-7. doi: 10.1097/00008506-199807000-00008.
Sodium nitroprusside (SNP) is commonly used for controlled systemic hypotension during aneurysm surgery after acute subarachnoid hemorrhage (SAH). Few experimental studies have assessed cerebrovascular responsiveness to SNP acutely after a representative SAH (i.e., following arterial rupture within the subarachnoid space). Instead, most studies have focused on delayed reactivity after slow injections of unpressurized blood throughout several days. In the authors' study, SAH was created by endovascular rupture in spontaneously breathing rats under urethane anesthesia without craniotomy. After 3 hours, proximal middle cerebral arteries (MCAs) were harvested and mounted as ring preparations in vitro. After preconstriction with 30 mM prostaglandin F2a, concentration-response curves were generated to express SNP's sequential relaxation of preconstricted tone. The effective concentration of SNP for 50% relaxation was significantly lower after SAH (p < 0.001) as compared with non-operated and sham-operated controls. There was also a significantly greater maximum percentage relaxation from preconstricted tone (p < 0.001) with SNP. The results of this study suggest that SNP is a potent and efficacious dilator of MCAs in the hours immediately after acute SAH.
硝普钠（SNP）常用于急性蛛网膜下腔出血（SAH）后动脉瘤手术期间的控制性全身低血压。很少有实验研究评估在典型SAH（即蛛网膜下腔内动脉破裂后）后急性情况下脑血管对SNP的反应性。相反，大多数研究集中在数天内缓慢注射未加压血液后的延迟反应性。在作者的研究中，在没有开颅手术的情况下，通过在乌拉坦麻醉下对自主呼吸的大鼠进行血管内破裂来制造SAH。3小时后，收获大脑中动脉近端（MCAs）并在体外制成环标本。在用30 mM前列腺素F2α预收缩后，生成浓度-反应曲线以表达SNP对预收缩张力的顺序舒张作用。与未手术和假手术对照组相比，SAH后SNP使张力松弛50%的有效浓度显著降低（p < 0.001）。使用SNP时，从预收缩张力达到的最大舒张百分比也显著更高（p < 0.001）。这项研究的结果表明，在急性SAH后的数小时内，SNP是大脑中动脉的一种强效且有效的扩张剂。
