Kern K B, Sanders A B, Janas W, Nelson J R, Badylak S F, Babbs C F, Tacker W A, Ewy G A
Department of Internal Medicine, University of Arizona College of Medicine, Tucson 85724.
Ann Emerg Med. 1991 Jul;20(7):761-7. doi: 10.1016/s0196-0644(05)80838-8.
Open-chest cardiac massage is an effective method of resuscitation if instituted within 15 minutes of normothermic cardiac arrest that has failed to respond to ongoing closed-chest CPR efforts. The usefulness of invasive forms of CPR after various periods of untreated cardiac arrest is less certain. This study was performed to determine the effectiveness of open-chest resuscitation after prolonged periods of untreated cardiac arrest.
Prospective, controlled laboratory investigation using an animal model of cardiac arrest. Open-chest cardiac massage initially was compared to standard closed-chest compression CPR. The efficacy of open-chest CPR then was evaluated after ten and 40 minutes of untreated ventricular fibrillation.
Twenty mongrel dogs (24 +/- 1 kg).
After 20 minutes of untreated ventricular fibrillation, open-chest resuscitation was significantly better than closed-chest efforts for the production of coronary perfusion pressure (58 +/- 14 vs 2 +/- 1 mm Hg; P less than .05) and initial resuscitation success (five of five vs one of five; P less than .03). Open-chest cardiac massage was equally effective for initial resuscitation if begun after ten or 20 minutes of untreated ventricular fibrillation (five of five vs five of five), but if untreated ventricular fibrillation continued for 40 minutes prior to instituting open-chest massage, no resuscitation benefit was found (none of five; P less than .005). There were marked differences in 24-hour survival depending on the length of time untreated cardiac arrest continued prior to instituting open-chest resuscitation efforts. After 20 minutes of ventricular fibrillation, initial resuscitation was successful with open-chest massage, but long-term survival was poor.
Open-chest cardiac massage did not produce long-term survival if untreated cardiac arrest persisted for 20 or more minutes prior to invasive resuscitation efforts.
如果在常温心脏骤停且持续胸外心脏按压复苏无效后的15分钟内实施开胸心脏按压，它是一种有效的复苏方法。而在心脏骤停未经处理的不同时间段后采用侵入性心肺复苏（CPR）的有效性尚不确定。本研究旨在确定在长时间未经处理的心脏骤停后开胸复苏的有效性。
使用心脏骤停动物模型进行前瞻性对照实验室研究。最初将开胸心脏按压与标准胸外按压CPR进行比较。然后在心室颤动未经处理10分钟和40分钟后评估开胸CPR的疗效。
20只杂种狗（体重24±1千克）。
在心室颤动未经处理20分钟后，开胸复苏在产生冠状动脉灌注压方面显著优于胸外按压（58±14 vs 2±1毫米汞柱；P<0.05），且初始复苏成功率更高（5只中有5只成功 vs 5只中有1只成功；P<0.03）。如果在心室颤动未经处理10分钟或20分钟后开始进行开胸心脏按压，其初始复苏效果相同（5只中有5只成功 vs 5只中有5只成功），但如果在进行开胸按压前心室颤动持续了40分钟，则未发现复苏益处（5只中无一成功；P<0.005）。根据在开始开胸复苏前未经处理的心脏骤停持续时间不同，24小时生存率存在显著差异。心室颤动20分钟后，开胸按压初始复苏成功，但长期生存率较差。
如果在侵入性复苏措施前未经处理的心脏骤停持续20分钟或更长时间，开胸心脏按压不能带来长期生存。
