Tateishi A, Maekawa T, Soejima Y, Sadamitsu D, Yamamoto M, Matsushita M, Nakashima K
Department of Critical Care Medicine, Yamaguchi University, School of Medicine, Japan.
Crit Care Med. 1995 Oct;23(10):1734-8. doi: 10.1097/00003246-199510000-00019.
To compare carbon dioxide-induced changes in cerebral oxy- and deoxyhemoglobin, measured by near-infrared spectroscopy, with those changes in jugular venous oxygen saturation in adult patients with acute brain disease.
A prospective study.
The medical and surgical intensive care unit of a university hospital.
Nine patients with head trauma (n = 4), cerebrovascular disease (n = 3), and meningitis (n = 2). A total of ten measurements were done, while PaCO2 was increased from hypocapnia toward normocapnia in the nine patients.
Arterial and jugular bulb catheterization, and intracranial pressure monitoring were performed as a part of the clinical intervention. An increase in PaCO2 was obtained by inhalation of CO2 and, if necessary, by reducing the ventilator rate.
In each patient, the position of the jugular bulb catheter was ascertained by skull roentgenography. Near-infrared spectroscopic values for oxy- and deoxyhemoglobin were set at zero at the beginning of the study. An increase in PaCO2 from 29 +/- 1 (SEM) torr (3.9 +/- 0.2 kPa) to 39 +/- 2 torr (5.2 +/- 0.3 kPa) was accompanied by a significant increase in jugular venous oxygen saturation from 63 +/- 3% to 76 +/- 3%; a significant increase in oxyhemoglobin of 3.5 +/- 0.9 mumol/L (of the brain tissue); and a significant decrease in deoxyhemoglobin of 1.5 +/- 0.4 mumol/L. In nine of ten measurements, the slopes of changes in oxyhemoglobin against the slopes of change in jugular venous oxygen saturation were very similar. In one patient, oxyhemoglobin changed negligibly while jugular venous oxygen saturation increased by 20%.
Jugular venous oxygen saturation consistently demonstrates cerebrovascular responsiveness to CO2. The direction and magnitude of changes in cerebral oxyhemoglobin, measured by near-infrared spectroscopy, were similar to those changes in jugular venous oxygen saturation in most of our cases. Interpretation of a negligible change in oxyhemoglobin in one patient, despite an obvious increase in jugular venous oxygen saturation, requires further study comparing near-infrared spectroscopy with standard techniques.
采用近红外光谱法比较急性脑疾病成年患者中二氧化碳诱导的脑氧合血红蛋白和脱氧血红蛋白的变化与颈静脉血氧饱和度的变化。
一项前瞻性研究。
一所大学医院的内科和外科重症监护病房。
9例患者，其中4例为头部外伤，3例为脑血管疾病，2例为脑膜炎。9例患者共进行了10次测量，同时将动脉血二氧化碳分压（PaCO2）从低碳酸血症升至正常碳酸血症。
作为临床干预的一部分，进行动脉和颈静脉球导管插入术以及颅内压监测。通过吸入二氧化碳并在必要时降低呼吸机频率来提高PaCO2。
在每位患者中，通过颅骨X线摄影确定颈静脉球导管的位置。研究开始时，将氧合血红蛋白和脱氧血红蛋白的近红外光谱值设定为零。PaCO2从29±1（标准误）托（3.9±0.2千帕）升至39±2托（5.2±0.3千帕），伴随着颈静脉血氧饱和度从63±3%显著升至76±3%；脑组织氧合血红蛋白显著增加3.5±0.9微摩尔/升；脱氧血红蛋白显著减少1.5±0.4微摩尔/升。在10次测量中的9次，氧合血红蛋白变化斜率与颈静脉血氧饱和度变化斜率非常相似。在1例患者中，氧合血红蛋白变化可忽略不计，而颈静脉血氧饱和度增加了20%。
颈静脉血氧饱和度始终显示脑血管对二氧化碳的反应性。在我们的大多数病例中，通过近红外光谱法测量的脑氧合血红蛋白变化的方向和幅度与颈静脉血氧饱和度的变化相似。对于1例患者尽管颈静脉血氧饱和度明显增加但氧合血红蛋白变化可忽略不计的情况，需要进一步研究比较近红外光谱法与标准技术。
