Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, 751 85, Uppsala, Sweden,
Intensive Care Med. 2011 Aug;37(8):1277-84. doi: 10.1007/s00134-011-2264-7. Epub 2011 Jun 7.
Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods.
Intranasal balloons catheters circulated with saline at 20°C were applied for 60 min in ten awake volunteers. No sedation was used. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects' personal experience were completed after the experiment.
Brain temperature decrease measured by MRSI was -1.7 ± 0.8°C and by phase-mapping -1.8 ± 0.9°C (n = 9) at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 ± 0.3°C (n = 5). The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent in the MMSE test. Postcooling nasal examination detected increased nasal secretion in nine of the ten volunteers. Volunteers' acceptance of the method was good.
Both MR techniques revealed brain temperature reductions after 60 min of intranasal cooling with balloons circulated with saline at 20°C in awake, unsedated volunteers.
经鼻冷却可用于启动治疗性低温。然而，脑温度的直接测量较为困难，且冷却时脑内温度分布尚不清楚。本研究旨在使用非侵入性磁共振（MR）方法测量接受经鼻冷却的人类志愿者的脑温。
在 10 名清醒志愿者中，使用经鼻球囊导管将 20°C 的生理盐水循环 60 分钟。未使用镇静剂。使用磁共振波谱成像（MRSI）和相位映射技术测量并绘制脑温变化。整个实验过程中监测心率和血压。冷却前后测量直肠温度。冷却前后进行简易精神状态检查（MMSE）和鼻检查。实验结束后，完成有关受试者个人体验的问卷调查。
MRSI 测量的脑温下降值为-1.7±0.8°C，相位映射为-1.8±0.9°C（n=9），冷却结束时。温度变化的空间分布相对均匀。直肠温度下降了-0.5±0.3°C（n=5）。生理参数稳定，无寒战报告。志愿者在冷却过程中保持清醒，MMSE 测试中无认知功能障碍。冷却后鼻检查发现 10 名志愿者中有 9 名的鼻腔分泌物增加。志愿者对该方法的接受程度良好。
在清醒、未镇静的志愿者中，使用经鼻球囊导管将 20°C 的生理盐水循环 60 分钟，两种 MR 技术均显示脑温降低。
