Hagioka Shingo, Takeda Yoshimasa, Takata Ken, Morita Kiyoshi
Department of Anesthesiology and Resuscitology, Okayama Medical School, Japan.
Crit Care Med. 2003 Oct;31(10):2502-8. doi: 10.1097/01.CCM.0000084845.76762.F4.
To determine the effectiveness of nasopharyngeal cooling for selective brain cooling and neuroprotection from ischemia.
Prospective animal study.
Experimental laboratory in a university hospital.
Male Wistar rats (n = 28).
In study 1, hippocampal temperature was decreased to 31 degrees C under spontaneous circulation. In the nasopharyngeal cooling group, physiologic saline (5 degrees C) was infused to the bilateral nasal cavities at the rate of 100 mL.min-1.kg weight-1. In the whole body cooling group, a fan and a water blanket (5 degrees C) were used. In study 2, ischemia and resuscitation were performed in normothermic and nasopharyngeal cooling (initiated with resuscitation after 5 mins of ischemia and continued for 20 mins) groups.
The hippocampal temperature was decreased to 31 degrees C in 7 +/- 2 mins without any change in the rectal temperature in the nasopharyngeal cooling group, whereas a decrease in hippocampal temperature to 31 degrees C took 33 +/- 1 mins in the whole body cooling group. Although skull base region was cooled by nasopharyngeal cooling, the epidural temperature of the parietal region was lower than the hippocampal temperature, indicating that brain temperature was hematogenously lowered. There was no difference between changes in cerebral blood flow or between the ratios of oxygen extraction from arterial blood in the head region in the nasopharyngeal cooling and whole body cooling groups. In the second study, all animals were successfully resuscitated, and the times required for recovery of mean arterial blood pressure (60 mm Hg) after resuscitation in the nasopharyngeal cooling and normothermic groups were the same. The histologic damage was significantly attenuated in the nasopharyngeal cooling group (33 +/- 21% cell death in the hippocampus) compared with that in the normothermic group (73 +/- 11%).
Nasopharyngeal cooling enables rapid and selective reductions in cortical and subcortical temperatures without disturbing the recovery of systemic circulation after resuscitation.
确定鼻咽部降温用于选择性脑降温及对缺血进行神经保护的有效性。
前瞻性动物研究。
大学医院的实验实验室。
雄性Wistar大鼠（n = 28）。
在研究1中，在自主循环状态下将海马温度降至31℃。在鼻咽部降温组，以100 mL·min⁻¹·kg体重⁻¹的速率向双侧鼻腔注入生理盐水（5℃）。在全身降温组，使用风扇和水毯（5℃）。在研究2中，在正常体温组和鼻咽部降温组（缺血5分钟后复苏开始并持续20分钟）进行缺血及复苏操作。
在鼻咽部降温组，海马温度在7±2分钟内降至31℃，直肠温度无任何变化；而在全身降温组，海马温度降至31℃需要33±1分钟。尽管鼻咽部降温使颅底区域温度降低，但顶叶区域的硬膜外温度低于海马温度，表明脑温是通过血液途径降低的。鼻咽部降温组和全身降温组在脑血流量变化或头部区域动脉血氧摄取率方面无差异。在第二项研究中，所有动物均成功复苏，鼻咽部降温组和正常体温组复苏后恢复至平均动脉血压（60 mmHg）所需时间相同。与正常体温组（73±11%）相比，鼻咽部降温组的组织学损伤明显减轻（海马区细胞死亡33±21%）。
鼻咽部降温能够快速、选择性地降低皮质和皮质下温度，且不影响复苏后全身循环的恢复。
