Emissary venous flow and selective brain cooling in hyperthermic human subjects.

我们测量了男性志愿者在全身热疗时的皮肤血流量和头部出汗率，角状眼球和乳突发出静脉的血流量，食道，鼓室和平均皮肤温度。1.当眼角血流受阻8-10分钟时，当眼心温度仍在升高时，鼓室温度的上升速度较术前增加，而食道温度的上升速度不变。当皮肤压迫面部静脉以增加眼角血流量时，鼓室温度的上升速度比以前降低，但食道温度没有变化。2.无论是被动体温还是运动，眼角静脉流量急剧增加的鼓室温度是相同的。3.重度化妆的受试者食道和鼓室温差[TES-TTY]小于不化妆的受试者。4.当体位由仰卧位改为30ﾟ仰卧位时，随着鼓室温度上升速度的降低，眼角静脉和乳突发出静脉的血流量增加。当受试者保持仰卧状态时，[TES-TTY]在整个全身热疗期间保持较小的水平。5.体温升高时，平均皮肤温度可达37-38ﾟC，皮肤血流量和出汗率在核心温度仍在升高的情况下仍达平台期。我们认为，只要大脑温度在热损失反应处于最大水平的温度范围内，选择性脑冷却导致的大脑温度下降就不会抑制热损失反应。从这些结果中，我们得出结论，选择性大脑降温对人类是可能的，也是重要的。选择性脑降温是通过静脉血液流入头皮和面部，通过汗水蒸发，通过使者静脉和眼静脉进入脑内实现的。

We measured skin blood flow and sweating rate of the head, blood flow in the angular oculi and mastoid emissary veins, esophageal, tympanic, and mean skin temperatures during whole body hyperthermia in male volunteers. 1. When angular oculi flow was obstructed for 8-10 min while core temperatures were still rising, the rate of rise in tympanic temperature increased than before but that in esophageal temperature did not change. When angular oculi flow was increased by skin compression over the facial veins at an alinasl level, the rate of rise in tympanic temperature decreased than before but esophageal temperature did not change. 2. Tympanic temperature at which a sharp increase of flow occurred in angular oculi veins was the same in either passive body warming or exercise. 3. Temperature difference between the esophagus and the tympanum [Tes-Tty] became less in the subjects with heavy make-up than in those without. 4. When body posture was changed from supine to a 30ﾟ head-up position, blood flows in angular oculi and mastoid emissary veins were increased with a fall in the rate of rise in tympanic temperature. When the subjects remained supine, [Tes-Tty] remained small for the entire period of whole body hyperthermia. 5. During body warming, mean skin temperature reached 37-38ﾟC and skin blood flow and sweating rate of the face reached a plateau even when core temperatures were still rising. We suggest that the fall in brain temperature by selective brain cooling would not suppress the heat loss responses as far as brain temperature is within the range of temperature at which the heat loss responsesare at their maximum level. From these results, we conclude that selective brain cooling is possible and important in humans. Selective brain cooling is achieved by inflow of venous blood, cooled on the scalp and face by evaporation of sweat, through the emissary and ophtahalmic veins into the intracranium.