Eftestøl Trygve, Sunde Kjetil, Steen Petter Andreas
Stavanger University College, Department of Electrical and Computer Engineering, Stavanger, Norway.
Circulation. 2002 May 14;105(19):2270-3. doi: 10.1161/01.cir.0000016362.42586.fe.
Cardiopulmonary resuscitation (CPR) creates artifacts on the ECG and, with automated defibrillators, a pause in CPR is mandatory during rhythm analysis. The rate of return of spontaneous circulation (ROSC) is reduced with increased duration of this hands-off interval in rats. We analyzed whether similar hands-off intervals in humans with ventricular fibrillation causes changes in the ECG predicting a lower probability of ROSC.
The probability of ROSC after a shock was continually determined from ECG signal characteristics for up to 20 seconds of 634 such hands-off intervals in patients with ventricular fibrillation. In hands-off intervals with an initially high (40% to 100%) or median (25% to 40%) probability for ROSC, the probability was gradually reduced with time to a median of 8% to 11% after 20 seconds (P<0.001). In episodes with a low initial probability (0% to 25%; median, 5%), there was no further reduction with time.
The interval between discontinuation of chest compressions and delivery of a shock should be kept as short as possible.
心肺复苏（CPR）会在心电图上产生伪迹，并且对于自动除颤器而言，在进行心律分析时必须暂停CPR。在大鼠中，随着这种无按压间隔时间的延长，自主循环恢复（ROSC）率会降低。我们分析了在心室颤动患者中类似的无按压间隔是否会导致心电图发生变化，从而预示ROSC的可能性降低。
根据心电图信号特征，持续测定634例心室颤动患者电击后长达20秒的无按压间隔期间的ROSC概率。在最初ROSC概率较高（40%至100%）或中等（25%至40%）的无按压间隔中，该概率随时间逐渐降低，至20秒时中位数降至8%至11%（P<0.001）。在初始概率较低（0%至25%；中位数为5%）的发作中，概率随时间没有进一步降低。
胸外按压中断与电击之间的间隔应尽可能缩短。
