Rea Thomas D, Eisenberg Mickey S, Becker Linda J, Murray John A, Hearne Thomas
Department of Medicine, University of Washington, Seattle, USA.
Circulation. 2003 Jun 10;107(22):2780-5. doi: 10.1161/01.CIR.0000070950.17208.2A. Epub 2003 May 19.
Little is known about temporal trends in survival and prognostic characteristics of patients with out-of-hospital cardiac arrest treated by emergency medical services (EMS). We hypothesized that an evolving combination of beneficial and adverse factors may contribute to temporal patterns of survival.
We evaluated a population-based cohort of EMS-treated adult patients with cardiac arrest (n=12 591) from 1977 to 2001 in King County, Washington. Time was grouped into an initial 5-year period and 5 successive 4-year periods. We sought to determine the potential impact of temporal changes in prognostic factors typically beyond EMS control termed "fate" factors (for example, patient age) and factors implemented by EMS termed "program" factors (programs of dispatcher-assisted cardiopulmonary resuscitation and basic life support defibrillation). Several characteristics associated with survival changed over time. Observed survival did not change over time among all patients with cardiac arrest (OR=0.98 [0.95, 1.01], trend for each successive time period) and improved over time among patients with witnessed ventricular fibrillation (OR=1.05 [1.01, 1.09]). In models that included all patients with cardiac arrest and controlled for fate factors, advancing time period was associated with an increase in survival (OR=1.08 [1.05, 1.11]). Conversely, in models that controlled for program factors, advancing time period was associated with a decrease in survival (OR=0.95 [0.93, 0.98]). Results were similar among patients with witnessed ventricular fibrillation.
The static temporal pattern of survival from cardiac arrest appeared to result from an evolving balance of prognostic factors. Programs implemented by EMS appeared to counter adverse temporal trends in prognostic factors typically beyond EMS control.
对于接受紧急医疗服务（EMS）治疗的院外心脏骤停患者的生存时间趋势和预后特征了解甚少。我们推测有益因素和不利因素的不断变化组合可能导致生存时间模式的出现。
我们评估了1977年至2001年在华盛顿州金县接受EMS治疗的成年心脏骤停患者的人群队列（n = 12591）。时间分为最初的5年时间段和随后连续的5个4年时间段。我们试图确定通常超出EMS控制范围的预后因素（称为“命运”因素，例如患者年龄）的时间变化以及EMS实施的因素（称为“程序”因素，调度员辅助心肺复苏和基本生命支持除颤程序）的潜在影响。一些与生存相关的特征随时间而变化。在所有心脏骤停患者中，观察到的生存率随时间没有变化（OR = 0.98 [0.95, 1.01]，每个连续时间段的趋势），而在目击心室颤动患者中，生存率随时间有所提高（OR = 1.05 [1.01, 1.09]）。在纳入所有心脏骤停患者并控制命运因素的模型中，时间的推进与生存率的增加相关（OR = 1.08 [1.05, 1.11]）。相反，在控制程序因素的模型中，时间的推进与生存率的降低相关（OR = 0.95 [0.93, 0.98]）。目击心室颤动患者的结果相似。
心脏骤停生存的静态时间模式似乎是由预后因素的不断变化平衡导致的。EMS实施的程序似乎抵消了通常超出EMS控制范围的预后因素的不利时间趋势。
