Development of a Novel Cooling Vest to Prevent Heat-Induced Thermoregulatory Dysfunction in Persons with Spinal Cord Injury

患有脊髓损伤（SCI）的人，特别是那些T6以上（Hi-SCI）的人，无法有效地 由于运动、感觉和交感神经通路的中断而调节核心体温（Tcore）。 交感神经通路的中断限制了血管舒张和出汗增加热量的中枢调节 减少热量损失和血管收缩。因此，当暴露于环境热时， 皮肤血管舒张和出汗损害维持恒定Tcore的能力。Hi-SCI患者经常 在社交、宗教或工作活动中长时间处于炎热的环境中， 在温暖的季节或在炎热的气候区。他们报告说，迅速进展到感觉“过热”， 即使在身体健全的人认为是温和炎热的条件下， (AB)对照在此期间，它们的Tcore急剧上升可达到高温（≥38°C），如果允许， 进展，可导致中暑，引起癫痫发作，意识丧失，并可能死亡。干预措施 解决SCI患者热相关疾病风险增加的方法有限。因此，继续 开发我们的反馈控制“智能”冷却背心，并测试其安全性和有效性， 散发身体热量以补偿体温调节失调，对于将不良影响降至最低至关重要 大多数高SCI退伍军人在暴露于温暖的温度下时所经历的健康和生活质量。 这项初步研究的目标是：1）进一步开发和测试自我调节的安全性和耐受性。 冷却背心在AB参与者，和2）确定冷却背心的功效，以提供保护， 在高温暴露期间，高SCI退伍军人的Tcore和热不适过度上升。五AB 将招募10名受试者和10名Hi-SCI受试者（C4-T2，AIS A-B）进行研究。AB参与者将 观察以确保背心的安全性，这将通过评估皮肤温度和 在2小时的温暖暴露（35°C）期间，背心下的主观热感觉。在参与者中， SCI在2小时的温暖暴露（35°C），重复测量实验设计[两个条件（湿 背心，不穿背心）]，以证明冷却背心在减弱预期上升方面的功效 和热不适。 主要目的（安全性）：在温暖的热室（35°C）中，AB参与者将穿着湿冷却背心 在最大设置2小时，在坐姿，以确定：（1）最低皮肤温度下的 湿式冷却背心，和（2）湿式冷却背心的主观舒适性（安全测试）。 主要假设：AB参与者将证明（1）背心下方的所有皮肤温度将≥20°C。 (2)所有参与者将报告热感觉（TS）≥“凉爽”（非“寒冷”或“非常寒冷”）（Zhang 9点热 感觉量表）。 次要目的（SCI疗效）：在两个不同的日子里，Hi-SCI受试者将穿着湿 冷却背心[或无背心]（随机顺序）在温暖的热室中以坐姿长达2小时 (35°C）以确定：（1）Tcore的变化，和（2）热舒适性的变化（功效测试）。 次要假设：Hi-SCI参与者在温暖环境中穿着湿冷却背心 将有以下发现：1）65%的患者将显示Tcore升高显著降低（≤0.3°C） 比[无背心条件]下的预期平均升高（0.6±0.3°C），以及2） SCI参与者将报告热和热不适的感觉降低（Zhang 6点热 舒适度量表）比预期的“热或非常热”和“不舒服”的感觉， （没有条件）。

Persons with spinal cord injury (SCI), particularly those with injuries above T6 (Hi-SCI), are unable to effectively regulate core body temperature (Tcore) due to interruption of motor, sensory, and sympathetic pathways. Interruption of sympathetic pathways limits central regulation of vasodilation and sweating for increasing heat loss and vasoconstriction for decreasing heat loss. Thus, when exposed to ambient heat, limited control of cutaneous vasodilation and sweating impairs the ability to maintain a constant Tcore. Persons with Hi-SCI often find themselves in hot environments for prolonged periods during social, religious, or work functions, especially during warmer seasons or when in hot climate zones. They report rapidly progressing to feeling “overheated,” uncomfortable, and fatigued during even limited exposure to conditions considered as mildly hot by able-bodied (AB) controls. During these times, their dramatic rise in Tcore can reach hyperthermia (≥38°C) and, if allowed to progress, can lead to heat stroke, causing seizures, loss of consciousness, and potentially death. Interventions that address the increased risk for heat-related illness in persons with SCI are limited. Therefore, continuing development of our feedback-controlled ”smart” cooling vest and testing its safety and efficacy to sufficiently dissipate body heat to compensate for thermodysregulation, is absolutely vital to minimize the adverse effects on health and quality of life that most Veterans with Hi-SCI experience during exposure to warm temperatures. The goals of this pilot study are to: 1) further develop and test the safety and tolerability of a self-regulating cooling vest in AB participants, and 2) determine the efficacy of the cooling vest to provide protection from an excessive rise in Tcore and thermal discomfort during warm exposure in Veterans with Hi-SCI. Five AB participants and ten participants with Hi-SCI (C4-T2, AIS A-B) will be recruited for study. AB participants will be observed to ensure the safety of the vest, which will be determined by assessing skin temperatures and subjective thermal sensation beneath the vest during 2 hours of warm exposure (35°C). In participants with Hi- SCI during 2 hours of warm exposure (35°C), a repeated measures experimental design for [two-conditions (wet vest, no vest)] is being proposed to demonstrate the efficacy of the cooling vest to attenuate the expected rise in Tcore and thermal discomfort. Primary Objective (Safety): In a warm thermal chamber (35°C), AB participants will wear the wet cooling vest at maximal setting for 2 hours in the seated position to determine: (1) minimum skin temperatures beneath the wet cooling vest, and (2) subjective comfort of the wet cooling vest (safety testing). Primary Hypotheses: AB participants will demonstrate (1) All skin temperatures beneath the vest will be ≥20°C. (2) All participants will report a thermal sensation (TS) ≥ “cool” (not “cold” or “very cold”) (Zhang 9-point Thermal Sensation scale). Secondary Objective (Efficacy in SCI): On 2 separate days, participants with Hi-SCI will wear either the wet cooling vest [or no vest] (in random order) for up to 2 hours in the seated position in a warm thermal chamber (35°C) to determine: (1) change in Tcore, and (2) change in thermal comfort (efficacy testing). Secondary Hypotheses: Participants with Hi-SCI wearing the wet cooling vest when in the warm environment will have the following findings: 1) 65% will demonstrate a significantly reduced elevation in Tcore (≤0.3°C) than the expected mean increase (0.6±0.3°C) in the [no vest condition], and 2) a greater percentage of participants with SCI will report a decreased perception of heat and thermal discomfort (Zhang 6-point Thermal Comfort scale) than the expected perceptions of “hot or very hot” and “uncomfortable” that will be reported in the [no vest condition].