Wang Huan, Olivero William, Lanzino Giuseppe, Elkins William, Rose Jean, Honings Debra, Rodde Mary, Burnham Jan, Wang David
Illinois Neurological Institute, St. Francis Medical Center, University of Illinois College of Medicine at Peoria, Illinois 61656, USA.
J Neurosurg. 2004 Feb;100(2):272-7. doi: 10.3171/jns.2004.100.2.0272.
Hypothermia is by far the most potent neuroprotectant. Nevertheless, timely and safe delivery of hypothermia remains a clinical challenge. To maximize neuroprotection yet minimize systemic complications, ultra-early delivery of selective cerebral hypothermia by Emergency Medical Service (EMS) personnel in the field would be advantageous. The authors (W.E. and H.W.) have developed a cooling helmet by using National Aeronautics and Space Administration spinoff technology. In this study its effectiveness in lowering brain temperature in patients with severe stroke or head injury is examined.
Patients were randomly assigned to groups receiving either the cooling helmet or no cooling, and brain temperatures (0.8 cm below the cortical surface) were continuously monitored for a mean of 48 to 72 hours with a Neurotrend sensor and then compared with the patients' core temperatures. There were eight patients in the study group and six in the control group. The mean change in temperature (brain-body temperature) calculated from 277 data hours in the study group was -1.6 degrees C compared with a mean change in temperature of +0.22 degrees C calculated from 309 data hours in the control group. This was statistically significant (p < 0.0001). On average, 1.84 degrees C of brain temperature reduction (range 0.9-2.4 degrees C) was observed within 1 hour of helmet application. It took a mean of 3.4 hours (range 2-6 hours) to achieve a brain temperature lower than 34 degrees C and 6.67 hours (range 1-12 hours) before systemic hypothermia (< 36 degrees C) occurred. Use of the helmet resulted in no significant complications. There was, however, one episode of asymptomatic bradycardia (heart rate < 40) that responded to a 0.5 degrees C body temperature increase.
This helmet delivers initial rapid and selective brain cooling and maintains a significant temperature gradient between the core and brain temperatures throughout the hypothermic period to provide sufficient regional hypothermia yet minimize systemic complications. It results in delayed systemic hypothermia, creating a safe window for possible ultra-early delivery of regional hypothermia by EMS personnel in the field.
低温是目前最有效的神经保护剂。然而，及时、安全地实施低温治疗仍是一项临床挑战。为了在最大化神经保护作用的同时最小化全身并发症，由紧急医疗服务（EMS）人员在现场超早期实施选择性脑低温治疗将具有优势。作者（W.E.和H.W.）利用美国国家航空航天局的衍生技术开发了一种冷却头盔。在本研究中，对其降低重症中风或头部损伤患者脑温的有效性进行了检验。
将患者随机分为接受冷却头盔治疗组和未接受冷却治疗组，使用Neurotrend传感器连续监测脑温（皮层表面以下0.8厘米处）平均48至72小时，然后与患者的核心体温进行比较。研究组有8例患者，对照组有6例患者。研究组277个数据小时计算得出的温度平均变化（脑温 - 体温）为 -1.6℃，而对照组309个数据小时计算得出的温度平均变化为 +0.22℃。这具有统计学显著性（p < 0.0001）。在佩戴头盔后1小时内，平均观察到脑温降低1.84℃（范围为0.9 - 2.4℃）。平均需要3.4小时（范围为2 - 6小时）使脑温低于34℃，在全身低温（< 36℃）出现之前平均需要6.67小时（范围为1 - 12小时）。使用头盔未导致明显并发症。然而，有1例无症状心动过缓（心率 < 40），在体温升高0.5℃后得到缓解。
这种头盔能实现最初快速且选择性的脑冷却，并在整个低温治疗期间维持核心体温与脑温之间显著的温度梯度，以提供足够的局部低温，同时最小化全身并发症。它导致全身低温延迟出现，为EMS人员在现场可能超早期实施局部低温治疗创造了一个安全窗口。
