SKIN SURFACE WARMING EFFECTS/ADRENERGIC METABOLIC RESPONSE TO CORE HYPOTHERMIA

低体温通常发生在手术期间，并且与 术后早期心肌缺血发生率增加 期 冷诱导心肌缺血的机制是 不清楚，但两个主要的体温调节反应（血管收缩 可能还牵涉到流口水血管收缩是肾上腺素能的 介导和行动，以保存热量，而流口水产生热量， 提高新陈代谢率。 这些肾上腺素和代谢反应 可能会对心血管系统产生不利影响，因此， 重要的是要了解是什么触发了这些生理变化， 它们是如何被调制的。 在拟议的研究中，主要的具体目标是确定如何 皮肤表面温度调节对核心体温过低的反应。 我们将通过测量血浆中 儿茶酚胺、血管收缩和血液动力学变化。 的 通过寒战和全身氧含量评估代谢反应 消费 年龄相关差异的确定 对冷应激的反应将提供对 冷诱导的心肌缺血。 确定相对 核心和皮肤表面温度的贡献 体温调节反应将提供对寒冷程度的了解- 诱导的生理变化可以在发展成 围手术期体温过低

Hypothermia occurs commonly during surgery, and is associated with an increased incidence of myocardial ischemia in the early post-operative period. The mechanisms for cold induced myocardial ischemia are unclear, but two primary thermoregulatory responses (vasoconstriction and slavering may be implicated. Vasoconstriction is adrenergically mediated and acts to conserve heat, while slavering produces heat by increasing metabolic rate. These adrenergic and metabolic responses could adversely affect the cardiovascular system, and it is therefore important to understand what triggers these physiologic changes, and how they are modulated. In the proposed study, the primary specific aim is to determine how skin-surface temperature modulates the response to core hypothermia. We will assess the adrenergic response by measuring plasma catecholamines, vasoconstriction, and hemodynamic changes. The metabolic response will be assessed by shivering and total body oxygen consumption. The determination of age-related differences in the response to cold stress will provide insight into the medianisms of cold-induced myocardial ischemia. Determination of the relative contribution of core and skin-surface temperatures to the thermoregulatory response will provide an understanding of how cold- induced physiologic changes can be modulated in patients who develop perioperative hypothermia.