Theoretically optimal duty cycles for chest and abdominal compression during external cardiopulmonary resuscitation.
Theoretically optimal duty cycles for chest and abdominal compression during external cardiopulmonary resuscitation.
复制标题
理论上体外心肺复苏期间胸部和腹部按压的最佳工作周期。
DOI：
10.1111/j.1553-2712.1995.tb03621.x
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Thelander,K
中科院分区：
文献类型：
--
作者：
Babbs,CF;Thelander,K
目的：利用人体循环电子模型比较体外心肺复苏过程中不同时间胸部按压对血液动力学的影响，包括有和没有腹部按压（IAC）。方法：利用SPICE通用电路仿真程序，在数字计算机工作站建立人体循环的电模拟模型。在该模型中，心脏和血管被表示为电阻-电容网络，压力被表示为电压，血流被表示为电流，血液惯性被表示为电感，心脏和静脉瓣膜被表示为二极管。心脏和大血管的外部加压，就像在IAC - CPR中发生的那样，通过阻尼矩形电压脉冲的交替应用来模拟，首先在胸内血管电容和地之间，然后在腹内血管电容和地之间。在这个模型中，压缩频率分别为60、80和100 cycles/min，占空比范围为10%到90%，并对有无IAC进行了比较。结果：总按压频率在60 ~ 100 cycles/min范围内，血流动力学变化不大，但占空比的影响较大。在标准CPR和IAC - CPR中，当胸腔按压时间等于循环时间的30%时，总流量和冠状动脉流量最大。与没有腹部压迫的标准CPR相比，介入腹部压迫在所有占空比下显著改善了模拟全身血流量和灌注压。占空比30%的IAC压缩可产生平均动脉压> 75 mm Hg，人工心输出量>2.0 L/min。在30%胸压（即高脉冲胸压技术）下，模型中的冠状动脉灌注明显优化。结论：在电模拟人体循环模型中，联合高脉冲胸外按压和IACs可使心肺复苏术中的血流量最大化。
Objective:To use an electronic model of human circulation to compare the hemodynamic effects of different durations of chest compression during external CPR, both with and without interposed abdominal compression (IAC).Methods:An electrical analog model of human circulation was studied on digital computer workstations using SPICE, a general‐purpose circuit simulation program. In the model the heart and blood vessels were represented as resistive‐capacitive networks, pressures as voltages, blood flow as electric current, blood inertia as inductance, and cardiac and venous valves as diodes. External pressurization of the heart and great vessels, as would occur in IAC‐CPR, was simulated by the alternate application of damped rectangular voltage pulses, first between intrathoracic vascular capacitances and ground, and then between intra‐abdominal vascular capacitances and ground. With this model compression frequencies of 60, 80, and 100 cycles/min and duty cycles ranging from 10% to 90%, both with and without IAC, were compared.Results:There was little difference in hemodynamics when the overall compression frequency was varied between 60 and 100 cycles/min, but the effects of duty cycle were substantial. During both standard CPR and IAC‐CPR, total flow and coronary flow were greatest at chest compression durations equal to 30% of cycle time. Interposed abdominal compression substantially improved simulated systemic blood flow and perfusion pressure at all duty cycles, compared with standard CPR without abdominal compression. Mean arterial pressure > 75 mm Hg and artificial cardiac output > 2.0 L/min could be generated by 30% duty cycle compression with IAC. Coronary perfusion in the model is clearly optimized at 30% chest compression (i.e., high‐impulse chest compression technique).Conclusion:Combined high‐impulse chest compressions and IACs maximize blood flow during CPR in the electrical analog model of human circulation.