Rapid stratification of the risk of cardiac arrest is essential in the assessment of patients with isolated accidental hypothermia. Traditional methods based on measurement of core temperature are unreliable in the field. Behavioural observations have been used as predictors of core temperature and thus indirect predictors of cardiac arrest. This study aims to quantify the direct relationship between observed conscious level and cardiac arrest. Retrospective case report analysis identified 114 cases of isolated accidental hypothermia meeting inclusion criteria. Level of consciousness in the acute assessment and management phase was classified using the AVPU system with an additional category of “Alert with confusion”; statistical analysis then related level of consciousness to incidence of cardiac arrest. All patients who subsequently suffered cardiac arrest showed some impairment of consciousness (p < < .0001), and the risk of arrest increased directly with the level of impairment; none of the 33 fully alert patients arrested. In the lowest impairment category, Alert confused, a quarter of the 12 patients went on to arrest, while in the highest Unresponsive category, two thirds of the 43 patients arrested. Where core temperature was available (62 cases), prediction of arrest by consciousness level was at least as good as prediction from core temperature. This study provides retrospective analytical evidence that consciousness level is a valid predictor of cardiac arrest risk in isolated accidental hypothermia; the importance of including confusion as a criterion is a new finding. This study suggests the use of consciousness alone may be at least as good as core temperature in cardiac arrest risk prediction. These results are likely to be of particular relevance to the management of accidental hypothermia in the pre-hospital and mass casualty environment, allowing for rapid and accurate triage of hypothermic patients.

中文翻译：

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意外体温过低：在对感冒患者进行急性评估时，意识作为心脏骤停风险标志的直接证据

心脏骤停风险的快速分层对于评估孤立性意外体温过低的患者至关重要。基于核心温度测量的传统方法在现场是不可靠的。行为观察已被用作核心温度的预测因子，因此是心脏骤停的间接预测因子。本研究旨在量化观察到的意识水平与心脏骤停之间的直接关系。回顾性病例报告分析确定了 114 例符合纳入标准的孤立性意外低温。使用 AVPU 系统对急性评估和管理阶段的意识水平进行分类，并增加一个“警觉混乱”类别；然后统计分析将意识水平与心脏骤停的发生率联系起来。随后发生心脏骤停的所有患者都表现出一定程度的意识障碍（p < < .0001），并且心脏骤停的风险直接随着障碍程度的增加而增加；33 名完全警觉的患者中没有一人被捕。在最低的损伤类别中，Alert 混淆了，12 名患者中有四分之一继续被捕，而在最高的无反应类别中，43 名患者中有三分之二被捕。在可获得核心温度的情况下（62 例），通过意识水平预测逮捕至少与根据核心温度预测一样好。本研究提供了回顾性分析证据，表明意识水平是孤立性意外低温中心脏骤停风险的有效预测指标；将混淆作为一项标准的重要性是一项新发现。这项研究表明，在心脏骤停风险预测中，单独使用意识可能至少与核心温度一样好。这些结果可能与院前和大规模伤亡环境中的意外体温过低管理特别相关，从而可以快速准确地对体温过低的患者进行分类。