SKIN SURFACE WARMING EFFECTS/ADRENERGIC METABOLIC RESPONSE TO CORE HYPOTHERMIA

体温过低通常发生在手术中，并与 术后早期心肌缺血发生率增加 句号。冷诱导心肌缺血的机制是 不清楚，但有两种主要的体温调节反应(血管收缩 和颤抖)可能有牵连。血管收缩是肾上腺素引起的 作为媒介并起到保温的作用，而颤抖通过 提高代谢率。这些肾上腺素能和代谢反应 可能会对心血管系统产生不利影响，因此 了解是什么触发了这些生理变化，以及 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低温的反应。 我们将通过测量血浆来评估肾上腺素能反应 儿茶酚胺、血管收缩和血液动力学改变。新陈代谢 反应将通过颤抖和全身氧气来评估 消费。年龄相关差异的测定 对冷应激的反应将为深入了解 冷诱导心肌缺血。亲属关系的确定 地心和皮肤表面温度对温度的贡献 体温调节反应将提供对温度有多低的理解- 诱发的生理变化可以在发生 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 postoperative period. The mechanisms for cold induced myocardial ischemia are unclear, but two primary thermoregulatory responses (vasoconstriction and shivering) may be implicated. Vasoconstriction is adrenergically mediated and acts to conserve heat, while shivering 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 catecholaniines, vasoconstriction, and hemodymic 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 mechanisms 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.