University of Illinois, Champaign, Illinois 61820, USA.
Prehosp Emerg Care. 2011 Apr-Jun;15(2):214-25. doi: 10.3109/10903127.2010.545474.
The primary objective of this study was to document the timeline of physiologic recovery from firefighting activities in order to inform emergency medical services (EMS) of vital sign values that might be expected during incident rehabilitation and in developing rehabilitation protocols to make decisions about when to return personnel to the fireground. Secondarily, we compared two different incident rehabilitation strategies to determine effectiveness in reducing physiologic strain following firefighting.
A repeated-measures randomized crossover design was utilized in which firefighters conducted a controlled set of firefighting activities, after which they completed incident rehabilitation in one of two conditions: 1) similar to currently used rehabilitation protocols and 2) with active cooling and nutritional intervention. Following 15 minutes of rehabilitation, each firefighter was asked to perform a simulated rescue "dummy drag" and then recover for 120 minutes in a quiet area. Core temperature and heart rate were recorded throughout the study. Blood pressures and subendocardial viability ratios were obtained before firefighting, after firefighting, and at standardized times during rehabilitation and recovery.
Heart rate and core temperature increased during firefighting, and core temperature continued to increase for 7 minutes after completion of firefighting activities. These values did not return to baseline until at least 50 minutes after firefighting activity. Systolic blood pressures were significantly reduced during rehabilitation (15.2%), and recovered 7.7% during the first 30 minutes of recovery, but remained significantly lower than before firefighting for at least 120 minutes. An index of subendocardial perfusion was also significantly depressed for up to 110 minutes after firefighters. Differences between rehabilitation protocols were minimal.
The timeline for recovery from firefighting activities is significantly longer than the typical 10-20-minute rehabilitation period that often is provided on the fireground. Modifications from the current rehabilitation protocol do not appear to improve the recovery timeline when rehabilitation is conducted in a cool room. While firefighters often are concerned about elevated blood pressures, this study suggests that firefighters and EMS personnel should also be cognizant of the potential dangers of hypotension.
本研究的主要目的是记录消防员从灭火行动中恢复的时间进程，以便为紧急医疗服务（EMS）提供在事故康复期间可能出现的生命体征值，并制定康复方案，以便决定何时让人员返回火灾现场。其次，我们比较了两种不同的事故康复策略，以确定其在减少灭火后生理紧张方面的有效性。
本研究采用重复测量随机交叉设计，消防员进行一组受控的灭火活动，然后在以下两种条件之一中完成事故康复：1）类似于当前使用的康复方案，2）采用主动冷却和营养干预。在康复 15 分钟后，每位消防员被要求进行模拟救援“假人拖曳”，然后在安静区域恢复 120 分钟。整个研究过程中记录核心体温和心率。在灭火前、灭火后以及康复和恢复期间的标准化时间点获取血压和心内膜下存活比。
心率和核心体温在灭火过程中升高，核心体温在灭火活动结束后仍持续升高 7 分钟。这些值至少在灭火后 50 分钟才恢复到基线。血压在康复期间显著降低（15.2%），在恢复的前 30 分钟内恢复了 7.7%，但至少在 120 分钟内仍显著低于灭火前。心内膜下灌注指数在消防员后也显著降低了长达 110 分钟。两种康复方案之间的差异很小。
从灭火活动中恢复的时间进程明显长于通常在火灾现场提供的 10-20 分钟的典型康复期。在凉爽的房间中进行康复时，对当前康复方案进行修改似乎并不能改善恢复时间进程。虽然消防员通常担心血压升高，但本研究表明，消防员和 EMS 人员还应意识到低血压的潜在危险。
