Schoen Jessica C, Machan Jason T, Dannecker Max, Kobayashi Leo
Alpert Medical School of Brown University, Department of Emergency Medicine, Providence, Rhode Island.
Lifespan Medical Simulation Center, Providence, Rhode Island.
West J Emerg Med. 2017 Oct;18(6):1025-1034. doi: 10.5811/westjem.2017.8.34236. Epub 2017 Sep 11.
Investigators conducted a prospective experimental study to evaluate the effect of team size and recovery exercises on individual providers' compression quality and exertion. Investigators hypothesized that 1) larger teams would perform higher quality compressions with less exertion per provider when compared to smaller teams; and 2) brief stretching and breathing exercises during rest periods would sustain compressor performance and mitigate fatigue.
In Phase I, a volunteer cohort of pre-clinical medical students performed four minutes of continuous compressions on a Resusci-Anne manikin to gauge the spectrum of compressor performance in the subject population. Compression rate, depth, and chest recoil were measured. In Phase II, the highest-performing Phase I subjects were placed into 2-, 3-, and/or 4-compressor teams; 2-compressor teams were assigned either to control group (no recovery exercises) or intervention group (recovery exercises during rest). All Phase II teams participated in 20-minute simulations with compressor rotation every two minutes. Investigators recorded compression quality and real-time heart rate data, and calculated caloric expenditure from contact heart rate monitor measurements using validated physiologic formulas.
Phase I subjects delivered compressions that were 24.9% (IQR1-3: [0.5%-74.1%]) correct with a median rate of 112.0 (IQR1-3: [103.5-124.9]) compressions per minute and depth of 47.2 (IQR1-3: [35.7-55.2]) mm. In their first rotations, all Phase II subjects delivered compressions of similar quality and correctness (p=0.09). Bivariate analyses of 2-, 3-, and 4-compressor teams' subject compression characteristics by subsequent rotation did not identify significant differences within or across teams. On multivariate analyses, only subjects in 2-compressor teams exhibited significantly lower compression rates (control subjects; p<0.01), diminished chest release (intervention subjects; p=0.03), and greater exertion over successive rotations (both control [p≤0.03] and intervention [p≤0.02] subjects).
During simulated resuscitations, 2-compressor teams exhibited increased levels of exertion relative to 3- and 4-compressor teams for comparable compression delivery. Stretching and breathing exercises intended to assist with compressor recovery exhibited mixed effects on compression performance and subject exertion.
研究人员进行了一项前瞻性实验研究，以评估团队规模和恢复练习对个体施救者按压质量和体力消耗的影响。研究人员假设：1）与较小的团队相比，较大的团队在每个施救者体力消耗较少的情况下能进行更高质量的按压；2）休息期间进行简短的伸展和呼吸练习将维持按压者的表现并减轻疲劳。
在第一阶段，一组临床前医学生志愿者在复苏安妮模拟人上进行了四分钟的持续按压，以评估该受试人群中按压者表现的范围。测量了按压频率、深度和胸廓回弹。在第二阶段，第一阶段表现最佳的受试者被分成2人、3人或4人的按压团队；2人按压团队被分配到对照组（无恢复练习）或干预组（休息期间进行恢复练习）。所有第二阶段的团队都参加了20分钟的模拟，每两分钟轮换一次按压者。研究人员记录了按压质量和实时心率数据，并使用经过验证的生理公式根据接触式心率监测测量值计算热量消耗。
第一阶段的受试者按压正确比例为24.9%（四分位距1-3：[0.5%-74.1%]），每分钟按压中位数为112.0次（四分位距1-3：[103.5-124.9]），深度为47.2毫米（四分位距1-3：[35.7-55.2]）。在他们的第一次轮换中，所有第二阶段的受试者按压质量和正确性相似（p = 0.09）。对2人、3人和4人按压团队后续轮换的受试者按压特征进行双变量分析，未发现团队内部或团队之间存在显著差异。在多变量分析中，只有2人按压团队的受试者表现出显著较低的按压频率（对照组受试者；p<0.01）、胸廓回弹减少（干预组受试者；p = 0.03）以及在连续轮换中体力消耗更大（对照组[p≤0.03]和干预组[p≤0.02]受试者均如此）。
在模拟复苏过程中，对于可比的按压操作，2人按压团队相对于3人和4人按压团队表现出更高的体力消耗水平。旨在帮助按压者恢复的伸展和呼吸练习对按压表现和受试者体力消耗的影响好坏参半。
