Knudsen K
Department of Anaesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg, Sweden.
Acta Anaesthesiol Scand. 2006 Jul;50(6):685-7. doi: 10.1111/j.1399-6576.2006.01046.x.
During complicated technical conditions in epidural or spinal anaesthesia, it may be difficult to safely identify the epidural space. The confirmation or exclusion of the presence of cerebrospinal fluid (CSF) during the procedure of regional anaesthesia is helpful to determine the position of the epidural needle in order to proceed with the anaesthetic block.
We have examined how CSF and different anaesthetic solutions change the colour of yellowish phenol red absorbed in cotton pads.
Sodium chloride and local anaesthetic agents do not change the colour of yellowish phenol red. However, CSF immediately changes the colour from yellow to pink or red. Letting a drop of fluid from the epidural/spinal needle fall on to the cleaning pads filled with phenol red will enable the anaesthesiologist to immediately confirm the presence or absence of CSF. The higher pH of CSF relative to that of sodium chloride and local anaesthetic agents explains the different colour reaction.
This colour reaction quickly identifies the presence of CSF and thus the intradural space during the procedure of spinal or epidural anaesthesia.
在硬膜外或脊髓麻醉的复杂技术条件下，可能难以安全地识别硬膜外间隙。在区域麻醉过程中确认或排除脑脊液（CSF）的存在有助于确定硬膜外针的位置，以便进行麻醉阻滞。
我们研究了脑脊液和不同麻醉溶液如何改变吸收在棉垫中的淡黄色酚红的颜色。
氯化钠和局部麻醉剂不会改变淡黄色酚红的颜色。然而，脑脊液会立即将颜色从黄色变为粉红色或红色。让一滴来自硬膜外/脊髓针的液体滴到装有酚红的清洁垫上，麻醉医生就能立即确认脑脊液的存在与否。脑脊液相对于氯化钠和局部麻醉剂较高的pH值解释了不同的颜色反应。
这种颜色反应能在脊髓或硬膜外麻醉过程中快速识别脑脊液的存在，从而识别硬膜内间隙。
