Ward K R, Menegazzi J J, Zelenak R R, Sullivan R J, McSwain N E
University of Pittsburgh Affiliated Residency in Emergency Medicine.
Ann Emerg Med. 1993 Apr;22(4):669-74. doi: 10.1016/s0196-0644(05)81845-1.
To compare the use of mechanical and manual chest compressions during cardiac arrest based on continuous monitoring of end-tidal PCO2 (PETCO2).
Prospective, randomized, crossover design.
Fifteen consecutive adults ranging in age from 33 to 78 years who presented in nontraumatic cardiac arrest to the emergency department of a large teaching hospital.
Study protocols were begun late in the resuscitation after initial resuscitation attempts were unsuccessful. Patients received four alternating five-minute trials (two manual and two mechanical), being randomized to begin with either technique. Mechanical compressions were performed by a mechanical device at a compression depth of 2 in. Both mechanical and manual compressions were delivered at a rate of 80 with a ventilation delivered after every fifth compression. Persons performing manual CPR were experienced American Heart Association basic life support providers, and no person performed manual CPR more than once during the study period. No resuscitative drugs were administered during the study period. PETCO2 was monitored continuously; those performing manual CPR were blinded to the PETCO2 monitor. Data were analyzed with repeated-measures analysis of variance and Scheffé multiple comparisons with the alpha error rate set of .05.
Mean PETCO2 during mechanical CPR was 13.6 +/- 4.14 mm Hg compared with 6.9 +/- 2.42 mm Hg during manually performed CPR (P < .001), a difference of 97%. Average mechanical CPR PETCO2 was higher in all cases. No patient was resuscitated successfully. Capnography also indicated that most CPR providers were inconsistent in their chest compressions.
This study suggests that cardiac output produced with mechanical chest compressions is greater than that produced with manual compressions as demonstrated by the significantly higher PETCO2 levels during mechanical CPR. Reasons for this are unclear. In addition, monitoring of PETCO2 may help optimize chest compressions during CPR.
基于对呼气末二氧化碳分压（PETCO2）的持续监测，比较心脏骤停期间机械胸外按压与徒手胸外按压的使用情况。
前瞻性、随机、交叉设计。
15名年龄在33至78岁之间的连续成年患者，他们因非创伤性心脏骤停被送至一家大型教学医院的急诊科。
在初始复苏尝试未成功后，于复苏后期开始研究方案。患者接受四次交替的五分钟试验（两次徒手按压和两次机械按压），随机从两种技术中的任何一种开始。机械按压由机械装置以2英寸的按压深度进行。机械按压和徒手按压均以每分钟80次的速率进行，每五次按压后进行一次通气。进行徒手心肺复苏的人员是经验丰富的美国心脏协会基础生命支持提供者，且在研究期间无人进行超过一次的徒手心肺复苏。研究期间未使用复苏药物。持续监测PETCO2；进行徒手心肺复苏的人员对PETCO2监测器不知情。数据采用重复测量方差分析和Scheffé多重比较进行分析，α错误率设定为0.05。
机械心肺复苏期间的平均PETCO2为13.6±4.14毫米汞柱，而徒手进行心肺复苏期间为6.9±2.42毫米汞柱（P<0.001），差异为97%。在所有情况下，平均机械心肺复苏PETCO2均较高。无患者成功复苏。二氧化碳波形图还表明，大多数心肺复苏提供者的胸外按压不一致。
本研究表明，机械胸外按压产生的心输出量大于徒手按压，机械心肺复苏期间显著更高的PETCO2水平证明了这一点。其原因尚不清楚。此外，监测PETCO2可能有助于优化心肺复苏期间的胸外按压。
