Zhang Yang, Davis Jon-Kyle, Casa Douglas J, Bishop Phillip A
1Chinese Badminton Association, Zhejiang Jiaxing Badminton Association, Zhejiang Province, CHINA; 2Gatorade Sports Science Institute, Barrington, IL; 3Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT; and 4Department of Kinesiology, University of Alabama, Tuscaloosa, AL.
Med Sci Sports Exerc. 2015 Nov;47(11):2464-72. doi: 10.1249/MSS.0000000000000693.
Cold water immersion (CWI) provides rapid cooling in events of exertional heat stroke. Optimal procedures for CWI in the field are not well established. This meta-analysis aimed to provide structured analysis of the effectiveness of CWI on the cooling rate in healthy adults subjected to exercise-induced hyperthermia.
An electronic search (December 2014) was conducted using the PubMed and Web of Science. The mean difference of the cooling rate between CWI and passive recovery was calculated. Pooled analyses were based on a random-effects model. Sources of heterogeneity were identified through a mixed-effects model Q statistic. Inferential statistics aggregated the CWI cooling rate for extrapolation.
Nineteen studies qualified for inclusion. Results demonstrate CWI elicited a significant effect: mean difference, 0.03°C·min(-1); 95% confidence interval, 0.03-0.04°C·min(-1). A conservative, observed estimate of the CWI cooling rate was 0.08°C·min(-1) across various conditions. CWI cooled individuals twice as fast as passive recovery. Subgroup analyses revealed that cooling was more effective (Q test P < 0.10) when preimmersion core temperature ≥38.6°C, immersion water temperature ≤10°C, ambient temperature ≥20°C, immersion duration ≤10 min, and using torso plus limbs immersion. There is insufficient evidence of effect using forearms/hands CWI for rapid cooling: mean difference, 0.01°C·min(-1); 95% confidence interval, -0.01°C·min(-1) to 0.04°C·min(-1). A combined data summary, pertaining to 607 subjects from 29 relevant studies, was presented for referencing the weighted cooling rate and recovery time, aiming for practitioners to better plan emergency procedures.
An optimal procedure for yielding high cooling rates is proposed. Using prompt vigorous CWI should be encouraged for treating exercise-induced hyperthermia whenever possible, using cold water temperature (approximately 10°C) and maximizing body surface contact (whole-body immersion).
冷水浸泡（CWI）可在劳力性热射病发生时迅速降温。目前野外CWI的最佳操作流程尚未完全确立。本荟萃分析旨在对CWI对运动诱发体温过高的健康成年人降温速率的有效性进行结构化分析。
于2014年12月通过PubMed和科学网进行电子检索。计算CWI与被动恢复之间降温速率的平均差值。采用随机效应模型进行汇总分析。通过混合效应模型Q统计量确定异质性来源。推断性统计汇总CWI降温速率以进行外推。
19项研究符合纳入标准。结果表明CWI产生了显著效果：平均差值为0.03°C·min⁻¹；95%置信区间为0.03 - 0.04°C·min⁻¹。在各种条件下，CWI降温速率的保守观察估计值为0.08°C·min⁻¹。CWI使个体降温的速度是被动恢复的两倍。亚组分析显示，当浸泡前核心体温≥38.6°C、浸泡水温≤10°C、环境温度≥20°C、浸泡持续时间≤10分钟以及采用躯干加四肢浸泡时，降温效果更佳（Q检验P < 0.10）。尚无足够证据表明使用前臂/手部CWI进行快速降温有效：平均差值为0.01°C·min⁻¹；95%置信区间为 - 0.01°C·min⁻¹至0.04°C·min⁻¹。呈现了来自29项相关研究的607名受试者的综合数据汇总，用于参考加权降温速率和恢复时间，旨在帮助从业者更好地规划应急程序。
提出了实现高降温速率的最佳操作流程。应鼓励尽可能使用快速有力的CWI来治疗运动诱发的体温过高，采用冷水温度（约10°C）并最大化体表接触（全身浸泡）。
