Houri P K, Frank L R, Menegazzi J J, Taylor R
Department of Emergency Medicine, University of Pittsburgh, PA 15213, USA.
Prehosp Emerg Care. 1997 Apr-Jun;1(2):65-7. doi: 10.1080/10903129708958789.
The American Heart Association (AHA) currently recommends two-finger (TF) chest compression for infants. A previous study demonstrated that two-thumb (TT) with lateral chest wall compression provided significantly higher arterial pressures than did the TF method. Limitations of that study included the lack of an asphyxial model and non-standardized compression forces.
To test the hypothesis that TT chest compression generates higher arterial pressures than does the TF method, using an asphyxial model. Also, by standardizing sternal compression force (SCF), the authors sought to show that the increased pressures are the result of thoracic compression.
The study was a randomized, crossover trial in immature swine weighing 10 kg. Each swine was sedated, anesthetized, paralyzed, intubated, and mechanically ventilated on room air. A femoral arterial catheter was placed. Cardiac arrest was induced by asphyxiation and verified by ECG and pressure tracings. Eleven AHA-certified basic rescuers each randomly performed four 1-minute trials of external chest compressions. Each of the two CPR techniques was performed, with and without feedback of SCF. Compression forces were measured using the Uniforce Sensor System (Force Imaging Technology, Inc., Chicago, IL). During the feedback mode, the rescuers were instructed to maintain sternal pressures at 20-25 psi. During the nonfeedback mode, the rescuers were blinded to the force transducer. All compressions were analyzed for systolic blood pressure (SBP), diastolic blood pressure (DBP), and SCF. Data were analyzed using repeated-measures analysis of variance (RMANOVA) and Tukey multiple comparisons (alpha = 0.05).
A total of 2,297 compressions were analyzed. The TT method produced significantly higher SBPs both with (25% increase) and without (57% increase) feedback when compared with the TF. The DBPs were not significantly different. The SCFs were also significantly higher in the two groups with feedback. The SCFs in the TF groups did not reach the standardized value of 20 psi, whereas in the TT groups, both were in the range of 20-25 psi.
The TT method produced significantly higher SBPs. The authors were unable to demonstrate that the increased SBPs were secondary to the thoracic compression component because the rescuers did not reach the predetermined SCF in the TF groups. In this swine model of infant CPR, TT chest compression is an easier and more effective method.
美国心脏协会（AHA）目前推荐对婴儿进行双指（TF）胸外按压。此前一项研究表明，双拇指（TT）加胸壁外侧按压所产生的动脉压显著高于TF法。该研究的局限性包括缺乏窒息模型以及按压力量未标准化。
使用窒息模型检验TT胸外按压比TF法产生更高动脉压的假设。此外，通过标准化胸骨按压力量（SCF），作者试图证明压力升高是胸廓按压的结果。
该研究是一项针对体重10 kg的未成熟猪的随机交叉试验。每头猪均接受镇静、麻醉、肌肉松弛、插管，并在室内空气中进行机械通气。置入股动脉导管。通过窒息诱导心脏骤停，并通过心电图和压力描记图进行验证。11名获得AHA认证基础生命支持的急救人员每人随机进行4次1分钟的胸外按压试验。两种心肺复苏技术均在有和没有SCF反馈的情况下进行。使用Uniforce传感器系统（Force Imaging Technology公司，伊利诺伊州芝加哥）测量按压力量。在反馈模式下，指导急救人员将胸骨压力维持在20 - 25磅力/平方英寸。在无反馈模式下，急救人员对力传感器不知情。对所有按压进行收缩压（SBP）、舒张压（DBP）和SCF分析。使用重复测量方差分析（RMANOVA）和Tukey多重比较（α = 0.05）对数据进行分析。
共分析了2297次按压。与TF法相比，TT法在有反馈（升高25%）和无反馈（升高57%）时均产生显著更高的SBP。DBP无显著差异。在有反馈的两组中，SCF也显著更高。TF组的SCF未达到20磅力/平方英寸的标准化值，而TT组的SCF均在20 - 25磅力/平方英寸范围内。
TT法产生显著更高的SBP。作者无法证明SBP升高是胸廓按压部分的继发结果，因为TF组的急救人员未达到预定的SCF。在这个婴儿心肺复苏的猪模型中，TT胸外按压是一种更简便且更有效的方法。
