Ketko Itay, Eliyahu Uri, Epstein Yoram, Heled Yuval
The Warrior Health Research Institute; Israel Defense Forces; Medical Corps; Tel Hashomer, Israel; Heller Institute of Medical Research; Sheba Medical Center; Tel Hashomer, Israel.
The Warrior Health Research Institute; Israel Defense Forces; Medical Corps; Tel Hashomer, Israel.
Temperature (Austin). 2014 Jul 2;1(2):101-6. doi: 10.4161/temp.29752. eCollection 2014 Jul-Sep.
Introduction The common practice in the Israel Defense Force is that all exertional heat related injuries victims undergo a heat tolerance test (HTT) as a part of the "return to duty" process. The purpose of this study was to develop a quantitative, supportive physiological index for the assessment of the HTT based on the understanding that heat strain level should combine the thermal and cardiovascular strains. Materials and methods The HTT results of 104 individuals with a history of heat injuries were retrospectively analyzed after randomly divided into two groups (an analysis group and a validation group). Rectal temperature and heart rate were monitored continuously during the test. Using the ratio between those two variables we constructed the TCR (Thermal-Circulatory Ratio) index and defined thresholds for determining heat tolerance based on the HTT. Results Using a TCR value of 0.279 [°C/bpm] or less after completing the 120 min HTT can be used as a significant measure to distinguish between heat tolerance and heat intolerance individuals with sensitivity and specificity of 100% of 89%, respectively. In addition, a TCR value of 0.320 [°C/bpm] or less calculated after 60 min was found as a significant measure to determine heat tolerance with 100% sensitivity and 69% specificity. The latter threshold may assist in significantly shortening the HTT for those individuals whose TCR value matches this criterion. Discussion and conclusion A new index (TCR) that combines the thermal and cardiovascular responses to exercise-heat stress was found to be a valid measure, with high sensitivity and specificity, to support the distinguishing between heat tolerance and heat intolerance individuals following a HTT. Furthermore, the suggested index may enable to shorten the HTT, which will make the test more efficient.
引言 在以色列国防军的常规做法是，所有与运动性热损伤相关的受害者都要接受耐热性测试（HTT），作为“重返岗位”流程的一部分。本研究的目的是基于热应激水平应结合热应激和心血管应激的认识，开发一种用于评估HTT的定量、辅助性生理指标。材料与方法 将104名有热损伤史的个体随机分为两组（分析组和验证组）后，对其HTT结果进行回顾性分析。在测试过程中持续监测直肠温度和心率。利用这两个变量之间的比值构建了TCR（热循环比值）指数，并根据HTT确定了耐热性的判定阈值。结果 在完成120分钟的HTT后，使用0.279[°C/次/分钟]或更低的TCR值可作为区分耐热和不耐热个体的重要指标，其敏感性和特异性分别为100%和89%。此外，发现60分钟后计算得出的0.320[°C/次/分钟]或更低的TCR值是判定耐热性的重要指标，敏感性为100%，特异性为69%。后一个阈值可能有助于显著缩短那些TCR值符合该标准的个体的HTT时间。讨论与结论 一种结合了对运动热应激的热应激和心血管反应的新指标（TCR）被发现是一种有效的测量方法，具有高敏感性和特异性，可辅助区分HTT后的耐热和不耐热个体。此外，建议的指标可能能够缩短HTT时间，这将使测试更高效。
