Hirai O, Handa H, Ishikawa M
No To Shinkei. 1982 Nov;34(11):1059-65.
Epidural pulse waveform is important as an indicator of intracranial pressure (ICP) dynamics. In this study, the origin of epidural pulse and the clinical implication of its waveform were investigated, using anesthetized artificially ventilated dogs. For this purpose, a cortical artery and a vein were cannulated, and the pressures were recorded simultaneously with epidural pressure (EDP), epidural pulse waveform (EDP-WF), systemic arterial pressure measured in a carotid artery (SAP), central venous pressure (CVP) and electrocardiogram. EDP-WF is composed of several initial peaks and a small delayed peak on the descending limb. The former peaks were slightly delayed from the SAP pulse and were synchronous with the cortical arterial pulse. The latter peak was synchronous with the atrial "a" wave on CVP, but not with the cortical venous pulse. Moreover, the cortical venous pulse was quite similar to EDP-WF. These findings indicate that the pulsation of the brain may be generated by the pulsatile arterial blood flow into the brain, which also affected the pulsation of the cortical vein. The latter peak which was considered to be of venous origin may reflect the dynamics of venules in the brain, not of the cortical vein. Increase of ICP by constant inflation of the epidural balloon or inhalation of CO2 cause EDP-WF monotonous. It is possible that the transmission of arterial pulse into the brain was augmented because of the tightness of the brain or decrease of cerebral vascular tone, although the cortical arterial pressure was not significantly changed or was even slightly decreased. Using a bolus injection technique, the change of EDP-WF in cats was compared with volume-pressure response (VPR) and pulse pressure (PP) which are reported to be good indicators for ICP dynamics. At about 30mmHg, EDP-WF became monotonous while VPR or PP showed only linear relationships with EDP up to 50 to 60 mmHg. Therefore EDP-WF may provide useful information about ICP dynamics in a relatively lower pressure range which could not be detected by VPR or PP study.
硬膜外脉搏波形作为颅内压（ICP）动态变化的指标很重要。在本研究中，使用麻醉后人工通气的犬，研究了硬膜外脉搏的起源及其波形的临床意义。为此，将一根皮质动脉和一根静脉插管，并与硬膜外压力（EDP）、硬膜外脉搏波形（EDP-WF）、在颈动脉测量的体动脉压（SAP）、中心静脉压（CVP）和心电图同时记录压力。EDP-WF由几个初始峰和降支上的一个小延迟峰组成。前者的峰比SAP脉搏略延迟，与皮质动脉脉搏同步。后者的峰与CVP上的心房“a”波同步，但与皮质静脉脉搏不同步。此外，皮质静脉脉搏与EDP-WF非常相似。这些发现表明，脑的搏动可能由流入脑内的搏动性动脉血流产生，这也影响了皮质静脉的搏动。被认为是静脉起源的后者的峰可能反映了脑内小静脉的动态变化，而不是皮质静脉的动态变化。通过持续向硬膜外气囊充气或吸入二氧化碳使ICP升高会导致EDP-WF单调变化。尽管皮质动脉压没有显著变化甚至略有下降，但由于脑的紧绷或脑血管张力的降低，动脉脉搏向脑内的传导可能增强。使用推注注射技术，将猫的EDP-WF变化与据报道是ICP动态变化良好指标的容量-压力反应（VPR）和脉压（PP）进行了比较。在约30mmHg时，EDP-WF变得单调，而VPR或PP在高达50至60mmHg时仅与EDP呈线性关系。因此，EDP-WF可能在相对较低的压力范围内提供有关ICP动态变化的有用信息，而这是VPR或PP研究无法检测到的。
