Rieger A, Menzel M, Rainov N G, Sanchin L, Rot S, Furka I, Görömbey Z, Burkert W
Department of Neurosurgery, Martin-Luther-University, Halle, Germany.
Neurosurgery. 1997 Aug;41(2):462-7; discussion 467-8. doi: 10.1097/00006123-199708000-00027.
Clinical oxygen monitoring in the injured brain is somewhat difficult. However, ischemia is one of the major factors responsible for secondary tissue damage after head injury or subarachnoid hemorrhage. Therefore, the aim of the present study was to investigate the value of continuously monitoring the partial pressure of oxygen in cerebral venous blood (PcvO2) during changes in intracranial pressure (ICP).
In eight domestic pigs with Clark type probes placed in the posterior third of the superior sagittal sinus, PcvO2 was continuously registered while ICP was stepwise elevated by an inflatable balloon placed below the tentorium. Arterial blood pressure was continuously monitored, cerebral perfusion pressure (CPP) was calculated, and arterial partial carbon dioxide pressure and partial pressure of oxygen were registered intermittently.
The mean intraparenchymal ICP before the start of balloon inflation was 5 +/- 1 mm Hg, the mean CPP was 80 +/- 15 mm Hg, and the mean PcvO2 was 36 +/- 3 mm Hg. At maximum ICP elevation, CPP decreased to 20 +/- 12 mm Hg, PcvO2 decreased to 10 +/- 6 mm Hg, and ICP increased to 90 +/- 10 mm Hg. Strong linear correlations between ICP and PcvO2 and between CPP and PcvO2 were revealed, and mean correlation coefficients of 0.89 for ICP/PcvO2 and 0.73 for CPP/PcvO2 were calculated.
The present study demonstrates that polarographic PcvO2 monitoring in the superior sagittal sinus is a reliable method for the early detection of reduced CPP during ICP elevation. This technique is capable of registering the global oxygen supply and oxygen consumption of the brain. It seems superior to jugular venous oxymetry and is better suited for clinical use because of a somewhat low artifact susceptibility.
对受伤大脑进行临床氧监测存在一定困难。然而，缺血是颅脑损伤或蛛网膜下腔出血后导致继发性组织损伤的主要因素之一。因此，本研究的目的是探讨在颅内压（ICP）变化期间连续监测脑静脉血氧分压（PcvO2）的价值。
在八只将Clark型探头置于上矢状窦后三分之一处的家猪中，当通过置于小脑幕下方的可充气气球使ICP逐步升高时，连续记录PcvO2。持续监测动脉血压，计算脑灌注压（CPP），并间歇性记录动脉血二氧化碳分压和血氧分压。
在气球充气开始前，平均脑实质内ICP为5±1 mmHg，平均CPP为80±15 mmHg，平均PcvO2为36±3 mmHg。在ICP升高至最大值时，CPP降至20±12 mmHg，PcvO2降至10±6 mmHg，ICP升至90±10 mmHg。揭示了ICP与PcvO2之间以及CPP与PcvO2之间存在强线性相关性，计算得出ICP/PcvO2的平均相关系数为0.89，CPP/PcvO2的平均相关系数为0.73。
本研究表明，对上矢状窦进行极谱法PcvO2监测是在ICP升高期间早期检测CPP降低的可靠方法。该技术能够记录大脑的整体氧供应和氧消耗。它似乎优于颈静脉血氧测定法，并且由于伪影敏感性较低而更适合临床应用。
