Exercise in Burn Survivors

描述(申请人提供)：在美国，每年有40,000-70,000人因烧伤而住院，其中16%(6,400至11,200人)的严重烧伤覆盖了至少20%的总体表面积(BSA)。20年前，覆盖50%BSA的烧伤是致命的，而现在90%的BSA烧伤的患者还活着。医疗保健的这些改进的结果是，数十万人承受烧伤的长期后果。例如，烧伤后数年的疲劳几乎是一种普遍的抱怨，因为它是阻止这些人重返工作岗位和进行日常生活活动的主要障碍。我们发现，大约76%的愈合良好的烧伤受试者(受伤后多年)具有有氧适应/能力，以最大摄氧量(V？O2max)衡量，与年龄和性别相关的最低20%与正常值47相符。根据大量关于有氧能力与死亡率、心血管风险和生活质量的研究，~76%的严重烧伤患者的死亡风险将增加3-5倍，一般健康状况较差，并且更有可能在2、15、16、86、100、116岁时需要依赖护理。鉴于这些发现，拟议的工作将解决以下问题，这些问题的答案对康复的烧伤患者的健康和全面康复至关重要：1)严重烧伤患者在受伤多年后有氧适应能力低下的机制是什么？2)以前遭受过严重烧伤的个人能否提高他们的有氧能力？如果是，通过什么机制？为了解决这些问题和相关假设，受试者在评估前至少2年经历了覆盖其BSA的20%-35%、40%-55%和60%的严重烧伤，将参加6个月的运动训练方案。在训练方案之前和之后，将评估受试者的有氧能力(V？O2max)、影响VO2max的中心和外周心血管变量(即稳态和最大心输出量、每搏输出量、心率和动静脉血氧差)，以及提高氧化能力的肌肉生化和组织学标志。受试者还将接受左心室收缩/舒张期功能、生活质量、身体成分和日常生活活动的量化评估。这些程序将解决总体假设，即运动训练对愈合良好的烧伤患者的最大摄氧量(VO2max)(及相关机制)的增加受烧伤程度的影响。获得的信息将确定烧伤幸存者在认识到体力活动的好处方面的潜力和局限性，TAT对心血管健康、减少对衰老的依赖以及生活质量的改善2、15、16、100很重要，同时作为实施基于运动的康复计划的基础，以改善严重烧伤患者在受伤多年后的健康。

DESCRIPTION (provided by applicant): Each year 40,000 - 70,000 individuals in the US are hospitalized for burn-related injuries, with 16% (6,400 to 11,200) having severe burns covering at least 20% of their total body surface area (BSA). Twenty years ago burns covering 50% BSA were fatal, while presently patients with 90% BSA burned are surviving. The outcome of these improvements in medical care is that hundreds of thousands of individuals endure the long- term consequences of burn injuries. For example, years following the burn injury fatigue is an "almost universal complaint" as a major barrier preventing such individuals from returning to work and performing activities of daily living 60, 65. We identified that ~76% of well-healed burned subjects (many years post-injury) have an aerobic fitness/capacity, measured by maximal oxygen uptake (V¿ O2max), in the lowest 20th percentile relative to age and sex matched normative values 47. Based upon numerous studies relating aerobic capacity with mortality, cardiovascular risk, and quality of life, ~76% of severely burned individuals will have 3 to 5 fold greater mortality risk, have poorer general health, and will be more likely to require dependent care as they age 2, 15, 16, 86, 100, 116. Given these findings, the proposed work will address the following questions, the answers to which are vital to the health and full rehabilitation of the recovered burned patient: 1) What are the mechanisms resulting in low aerobic fitness in severely burned individuals years after the injury? 2) Can individuals who previously suffered significant burn injuries improve their aerobic capacity and if so by what mechanisms? To address these questions and related hypotheses, subjects who experienced severe burn injuries covering 20- 35%, 40-55%, and >60% of their BSA a minimum of 2 years prior to assessment will participate in a 6 month exercise training protocol. Prior to and followin the training protocol, subjects will be evaluated for aerobic capacity (V¿ O2max), central and peripheral cardiovascular variables that influence VO2max (i.e., steady-state and ¿ maximum cardiac output, stroke volume, heart rate, and arteriovenous oxygen differences), and muscle biochemical and histological markers of improved oxidative capacity. Subjects will also be evaluated for left ventricular systolic/diastolic function, quality of life, body composition, and quantification of activities of daily living. These procedures will address the overall hypothesis that increases in VO2max (and related mechanisms) with exercise training in well-healed burned individuals are influenced by the extent of the burn injury. The obtained information will identify burn survivors' potential and limitations in realizing the benefits of physical activity tat are important for cardiovascular health, reduced dependency with aging, and improvements in quality of life 2, 15, 16, 100, while serving as the foundation by which exercise-based rehabilitation programs can be implemented to improve the health of severely burned individuals years following the injury.