Stratton S, Niemann J T
UCLA School of Medicine, Department of Emergency Medicine, USA.
Ann Emerg Med. 1998 Apr;31(4):471-7. doi: 10.1016/s0196-0644(98)70256-2.
The concept of a "chain of survival" to improve outcome from prehospital cardiac arrest has been defined and promulgated over the last two decades. The purpose of this study was to compare outcomes of prehospital cardiac arrest in 1975 and 1995 at a single institution.
This longitudinal, before-after study compares published data collected at our municipal, tertiary care in 1974-1975 with data collected prospectively in 1995. The 1975 study group served as control subjects (n = 120). We enrolled an equal number of consecutive patients who met inclusion criteria in the 1995 cohort (consecutive patients who experienced prehospital arrest and who received prehospital Advanced Cardiac Life Support (ACLS) measures during the two study periods). Patients younger than 18 years or with posttraumatic arrest were excluded. Between 1975 and 1995 the following "links" in the "chain of survival" were added to the prehospital care system: (1) 911 access and dispatch, (2) paramedic endotracheal intubation, (3) EMT automated defibrillation, (4) standing out-of-hospital orders before hospital radiotelemetry contact, and (5) introduction of American Heart Association ACLS algorithms.
The following significant differences (chi 2) were observed between the study periods: prevalence of ventricular fibrillation or tachycardia (42% in 1975 versus 28% in 1995, P = .021), prevalence of asystole or pulseless electrical activity as the first documented rhythm (58% versus 72%, P = .021), survival to hospital discharge (22% versus 9%, P = .007), and percent of survivors of ventricular fibrillation or tachycardia (30% versus 0%, P = .004). Eighty-six percent of the 1995 cohort had advanced chronic disease and 29% experienced cardiopulmonary arrest in a nursing home.
Survival decreased dramatically during the 20-year study period. This may be because of the high incidence of chronic disease, the greater frequency of asystole and pulseless electrical activity, and the inclusion of patients with "end-of-life" arrests in which ACLS protocol was initiated in the 1995 cohort. The patient population in which ACLS is initiated is the weakest link in the "chain of survival."
在过去二十年中，已定义并推广了“生存链”的概念，以改善院外心脏骤停的结局。本研究的目的是比较1975年和1995年在同一机构的院外心脏骤停结局。
这项纵向的前后对比研究将1974 - 1975年在我们市三级医疗机构收集的已发表数据与1995年前瞻性收集的数据进行比较。1975年的研究组作为对照组（n = 120）。我们在1995年队列中纳入了数量相等的符合纳入标准的连续患者（在两个研究期间经历院外心脏骤停并接受院外高级心脏生命支持（ACLS）措施的连续患者）。排除年龄小于18岁或创伤后心脏骤停的患者。在1975年至1995年期间，“生存链”中的以下“环节”被添加到院外护理系统中：（1）拨打911接入和调度，（2）护理人员气管插管，（3）急救医疗技术员自动除颤，（4）在医院无线电遥测联系之前下达院外常备医嘱，以及（5）引入美国心脏协会ACLS算法。
在研究期间观察到以下显著差异（卡方检验）：室颤或室速的发生率（1975年为42%，1995年为28%，P = 0.021），首次记录的心律为心脏停搏或无脉电活动的发生率（58%对72%，P = 0.021），出院生存率（22%对9%，P = 0.007），以及室颤或室速幸存者的百分比（30%对0%，P = 0.004）。1995年队列中86%的患者患有晚期慢性病，29%的患者在养老院发生心肺骤停。
在20年的研究期间，生存率急剧下降。这可能是由于慢性病的高发病率、心脏停搏和无脉电活动的更频繁发生，以及1995年队列中纳入了启动ACLS方案的“临终”心脏骤停患者。启动ACLS的患者群体是“生存链”中最薄弱的环节。
