Aufderheide Tom P, Sigurdsson Gardar, Pirrallo Ronald G, Yannopoulos Demetris, McKnite Scott, von Briesen Chris, Sparks Christopher W, Conrad Craig J, Provo Terry A, Lurie Keith G
Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, USA.
Circulation. 2004 Apr 27;109(16):1960-5. doi: 10.1161/01.CIR.0000126594.79136.61. Epub 2004 Apr 5.
A clinical observational study revealed that rescuers consistently hyperventilated patients during out-of-hospital cardiopulmonary resuscitation (CPR). The objective of this study was to quantify the degree of excessive ventilation in humans and determine if comparable excessive ventilation rates during CPR in animals significantly decrease coronary perfusion pressure and survival.
In humans, ventilation rate and duration during CPR was electronically recorded by professional rescuers. In 13 consecutive adults (average age, 63+/-5.8 years) receiving CPR (7 men), average ventilation rate was 30+/-3.2 per minute (range, 15 to 49). Average duration per breath was 1.0+/-0.07 per second. No patient survived. Hemodynamics were studied in 9 pigs in cardiac arrest ventilated in random order with 12, 20, or 30 breaths per minute. Survival rates were then studied in 3 groups of 7 pigs in cardiac arrest that were ventilated at 12 breaths per minute (100% O2), 30 breaths per minute (100% O2), or 30 breaths per minute (5% CO2/95% O2). In animals treated with 12, 20, and 30 breaths per minute, the mean intrathoracic pressure (mm Hg/min) and coronary perfusion pressure (mm Hg) were 7.1+/-0.7, 11.6+/-0.7, 17.5+/-1.0 (P<0.0001), and 23.4+/-1.0, 19.5+/-1.8, and 16.9+/-1.8 (P=0.03), respectively. Survival rates were 6/7, 1/7, and 1/7 with 12, 30, and 30+ CO2 breaths per minute, respectively (P=0.006).
Professional rescuers were observed to excessively ventilate patients during out-of-hospital CPR. Subsequent animal studies demonstrated that similar excessive ventilation rates resulted in significantly increased intrathoracic pressure and markedly decreased coronary perfusion pressures and survival rates.
一项临床观察性研究显示，在院外心肺复苏（CPR）期间，救援人员持续对患者进行过度通气。本研究的目的是量化人类过度通气的程度，并确定动物CPR期间类似的过度通气率是否会显著降低冠状动脉灌注压和生存率。
在人类中，专业救援人员通过电子记录CPR期间的通气率和持续时间。在连续接受CPR的13名成年人（平均年龄63±5.8岁，7名男性）中，平均通气率为每分钟30±3.2次（范围为15至49次）。每次呼吸的平均持续时间为每秒1.0±0.07秒。无患者存活。对9只心脏骤停的猪进行血流动力学研究，随机按每分钟12、20或30次呼吸进行通气。然后对3组每组7只心脏骤停的猪进行生存率研究，分别以每分钟12次呼吸（100%氧气）、30次呼吸（100%氧气）或30次呼吸（5%二氧化碳/95%氧气）进行通气。在分别以每分钟12、20和30次呼吸治疗的动物中，平均胸内压（毫米汞柱/分钟）和冠状动脉灌注压（毫米汞柱）分别为7.1±0.7、11.6±0.7、17.5±1.0（P<0.0001）和23.4±1.0、19.5±1.8、16.9±1.8（P=0.03）。每分钟12次、30次和30次加二氧化碳呼吸的生存率分别为6/7、1/7和1/7（P=0.006）。
观察到专业救援人员在院外CPR期间对患者进行过度通气。随后的动物研究表明，类似的过度通气率会导致胸内压显著升高，冠状动脉灌注压和生存率明显降低。
