Winslow E H, Clark A P, White K M, Tyler D O
School of Nursing, University of Texas, Arlington 76019.
Heart Lung. 1990 Sep;19(5 Pt 2):557-61.
The purpose of this study was to determine the effects of a lateral turn on mixed venous oxygen saturation (SvO2) and heart rate in 183 critically ill adults. Mean SvO2 decreased from a baseline of 67% to 61% saturation (p less than 0.0001) immediately after turning and gradually returned to 66% saturation (p less than 0.002) within 4 minutes. Mean heart rate increased slightly from a baseline of 99 beats/min to 102 beats/min (p less than 0.0001) immediately after turning and decreased slightly to 101 beats/min (p less than 0.0004) within 4 minutes. These statistically significant changes in SvO2 and heart rate were not clinically significant for most patients. However, physiologic responses to turning were highly variable. SvO2 reductions of 25% or more from baseline, heart rate increases and decreases of 10 beats/min or more, and signs of activity intolerance occurred in some patients. Nurses should expect critically ill patients to have a decrease in SvO2 of approximately 9% of baseline and small changes in heart rate after turning. These changes should be transient, with SvO2 and heart rate gradually returning toward baseline levels during the next 4 minutes. If turning triggers large or prolonged changes in SvO2 or heart rate, prompt repositioning and evaluation are needed to prevent adverse effects.
本研究的目的是确定在183例危重症成人患者中，向一侧翻身对混合静脉血氧饱和度（SvO2）和心率的影响。翻身刚结束时，平均SvO2从基线饱和度67%降至61%（p<0.0001），并在4分钟内逐渐回升至66%饱和度（p<0.002）。平均心率在翻身刚结束时从基线的99次/分钟略有增加至102次/分钟（p<0.0001），并在4分钟内略有下降至101次/分钟（p<0.0004）。这些SvO2和心率的统计学显著变化对大多数患者而言并无临床意义。然而，对翻身的生理反应差异很大。一些患者出现SvO2较基线降低25%或更多、心率增减10次/分钟或更多以及活动不耐受的体征。护士应预期危重症患者翻身之后SvO2会较基线降低约9%，心率会有小幅度变化。这些变化应是短暂的，SvO2和心率会在接下来的4分钟内逐渐恢复至基线水平。如果翻身引发SvO2或心率出现大幅或持续变化，则需要迅速重新调整体位并进行评估，以防止出现不良影响。
