Shortening of cardiopulmonary resuscitation time before the defibrillation worsens the outcome in out-of-hospital VF patients

Objective

The purpose of the study is to investigate the influence of cardiopulmonary resuscitation (CPR) time before the first defibrillation.

Methods

The present study retrospectively analyzed the Utstein template records from April 1, 2002, to June 30, 2005. Patients who had out-of-hospital–witnessed cardiac arrest caused by cardiac disease and who presented with ventricular fibrillation (VF) as the initial cardiac rhythm were included in the study. Before April 1, 2003, the emergency medical technician (EMT) needed to obtain telephone permission before attempting defibrillation, and CPR was continued until permission was received (CPR first). On and after April 1, 2003, the EMT was immediately able to attempt a defibrillation without obtaining permission (shock first).

Results

In 143 patients who had out-of-hospital–witnessed VF, 43 patients and 100 patients were treated with the CPR-first strategy and the shock-first strategy, respectively. The duration of CPR before the first defibrillation was longer in the CPR-first group than that in the shock-first group. The CPR-first group showed a higher rate of favorable neurologic outcome 30 days after (28% vs 14%; P = .048) and 1 year after cardiac arrest (26% vs 11%; P = .033) than those of the shock-first group. In the patients with witnessed VF, a stepwise multiple logistic regression analysis showed the CPR-first strategy to improve the neurologic outcome.

Conclusions

In patients with out-of-hospital–witnessed VF, sufficient CPR before the first defibrillation is considered to improve the neurologic outcome in comparison to the performance of immediate defibrillation.     

海南省多中心心肺复苏Utstien模式注册研究

目的 本研究以心肺复苏乌斯坦因(Utstein)评估模式评价海南省13家医院心搏骤停患者流行病学特征、心肺复苏结果及其影响因素。方法 在Utstein指南基础上设计“海南省心肺复苏Utstein注册登记表”,在2007年1月1日至2010年12月31日期间对海南省13家医院急诊科心搏骤停心肺复苏患者实施注册登记。通过方差分析等统计学方法,对心肺复苏患者实施前瞻性描述性研究。结果 1125例心搏骤停患者男性占73.8％,女性26.2％,年龄为(53.9±13.1)岁,既往病史以冠心病最为多见,其次为高血压病;自主循环恢复率为23.8％,成活出院为7.4％。自主循环恢复和成活出院的患者中发病l min内获得心肺复苏患者所占比例分别为41.8％和49.4％。院内心搏骤停(IHCA)患者和院外心搏骤停(OHCA)患者ROSC率分别为36.3％,11.6％,成活出院率分别为11.5％,3.3％。心室纤颤/无脉性室性心动过速患者188例(16.7％),其自主循环恢复率及成活出院率分别为58.0％,21.8％。心源性心搏骤停448例(39.8％);其中院内与院外心搏骤停患者自主循环恢复率分别为36.3％,11.6％,成活出院率分别为11.5％,3.3％。非心源性心搏骤停677例(60.2％)。三级医院和二级医院自主循环恢复率分别为69.8％和30.2％,成活出院率分别为7.4％和7.3％。结论 心搏骤停更常见于男性。慢性疾病在本组患者中普遍存在,其中以冠心病和高血压病最为多见。院内心搏骤停患者自主循环恢复和成活出院率均明显高于院外心搏骤停患者。心室纤颤/无脉室性心动过速患者心肺复苏自主循环恢复及成活出院率高于其他类型初始心律的患者。缩短心肺复苏启动时间有助于提高自主循环恢复率及成活出院率。     

Subject Index

INTRODUCTION: Public access defibrillation (PAD) has shown potential to increase cardiac arrest survival rates. OBJECTIVES: To describe the geographic epidemiology of prehospital cardiac arrest in Singapore using geographic information systems (GIS) technology and assess the potential for deployment of a PAD program. METHODS: We conducted an observational prospective study looking at the geographic location of pre-hospital cardiac arrests in Singapore. Included were all patients with out-of-hospital cardiac arrest (OHCA) presented to emergency departments. Patient characteristics, cardiac arrest circumstances, emergency medical service (EMS) response and outcomes were recorded according to the Utstein style. Location of cardiac arrests was spot-mapped using GIS. RESULTS: From 1 October 2001 to 14 October 2004, 2428 patients were enrolled into the study. Mean age for arrests was 60.6 years with 68.0% male. 67.8% of arrests occurred in residences, with 54.5% bystander witnessed and another 10.5% EMS witnessed. Mean EMS response time was 9.6 min with 21.7% receiving prehospital defibrillation. Cardiac arrest occurrence was highest in the suburban town centers in the Eastern and Southern part of the country. We also identified communities with the highest arrest rates. About twice as many arrests occurred during the day (07:00-18:59 h) compared to night (19:00-06:59 h). The categories with the highest frequencies of occurrence included residential areas, in vehicles, healthcare facilities, along roads, shopping areas and offices/industrial areas. CONCLUSION: We found a definite geographical distribution pattern of cardiac arrest. This study demonstrates the utility of GIS with a national cardiac arrest database and has implications for implementing a PAD program, targeted CPR training, AED placement and ambulance deployment.     

Outcome of out-of-hospital cardiac arrest--why do physicians withhold resuscitation attempts?

OBJECTIVE: To describe the outcome of out-of-hospital cardiac arrest (OHCA) with a focus on why physicians withhold resuscitation attempts. METHODS: Prospective collection of data during 12 months by the anaesthesiologists from the Advanced Life Support unit (ALS) of the Emergency Medical Service (EMS) according to the Utstein template. RESULTS: In total, 499 OHCA were analysed and 266 patients received cardiopulmonary resuscitation (CPR) by the ALS unit. Initial rhythm was ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT) in 35%, asystole in 38%, and other rhythm in 27%. Of the 266 treated patients, 83 (31%) patients had a spontaneous circulation on admission to hospital. Survival to discharge from hospital was 6.2% for all cases of OHCA, 11.7% for all 266 treated patients, and 20.5% for patients with witnessed cardiac arrest and presumed cardiac aetiology in VF. On arrival, the physician decided in 233 cases to withhold or discontinue CPR. The explanation for this was prolonged anoxia (74%), terminal cancer (8%), and severe trauma (7%). The most common incident locations were the patient's home and nursing homes. These locations were more common in the group where resuscitation was not attempted and these patients were older and the proportions of females and asystole were significantly higher. Bystander CPR was provided in 82 (16%) overall, but only in 8 (3%) in the group where resuscitation was not attempted. CONCLUSION: Survival to discharge from hospital in all cases of OHCA was 6.2% but 20.5% in witnessed, presumed cardiac aetiology in VF. The decision to withhold resuscitation was based upon presumed prolonged anoxia in the majority of cases.     

Early defibrillation and the chain of survival in 'in-hospital' adult cardiac arrest; minutes count

OBJECTIVE: To report the outcomes from and the impact of the chain of survival in 'in-hospital' cardiac arrest where the presenting rhythm was VF/VT, the arrest was witnessed, defibrillation was conducted rapidly and no other resuscitation interventions were required. Outcome measures: Any return of spontaneous circulation and discharge from hospital. METHODS: A 2-year prospective resuscitation audit using the Utstein style was conducted within a major London NHS Hospital Group. RESULTS: There were 124 patients who had primary VF/VT arrest. Eight were excluded from the study and 14 had non-witnessed cardiac arrest. Twenty one patients had witnessed VF/VT arrest but with delayed defibrillation, 81 patients had witnessed VF/VT arrest with rapid defibrillation, 69 patients had witnessed VF/VT arrest with rapid defibrillation, CPR and other additional interventions. There were 15 patients that had witnessed cardiac arrest with a presenting rhythm of VF/VT, who received rapid defibrillation and had no ventilation or chest compression prior to or following defibrillation. All 15 patients achieved a return of spontaneous circulation, and 12 were discharged alive. CONCLUSIONS: Rapid defibrillation prior to any other resuscitation intervention is associated with increased survival from witnessed VF/VT arrest in in-hospital cardiac arrest victims, and that the time to first shock is critical in enhancing the prospects of long-term survival in these patients.     

Characteristics of prehospital cardiac arrest patients in Japan and determinant factors for survival

Two hundred forty-seven consecutive patients who had prehospital cardiac arrest and were transferred to a municipal hospital were studied to elucidate the characteristics of these patients and to investigate factors for improving the survival rate among prehospital cardiac arrest patients. Detailed information on 130 patients with cardiac etiology was analyzed: 110 were confirmed dead in the emergency department (group A); 14 survived less than 1 week (group B); 6 survived longer than 1 week (group C). Only one patient received cardiopulmonary resuscitation (CPR) from a bystander, and none received electrical defibrillation before arriving at hospital because, at the time, emergency personnel were not allowed to perform advanced life support (ALS) in Japan. The three characteristics for better prognosis after prehospital cardiac arrest were found to be as follows: being witnessed on collapse, receiving prompt ALS, and ventricular fibrillation on arrival at hospital. The survival rate would have been higher if more lay people could have performed CPR and if emergency unit personnel had been allowed to perform ALS.     

An analysis of time factors in out-of-hospital cardiac arrest in Osaka Prefecture

OBJECTIVE: To ascertain important factors in the improvement of out-of-hospital cardiac arrest survival rates through analysis of data for Osaka Prefecture with the focus on time factors. DESIGN: Prospective cohort study according to the Utstein style. SETTING: Osaka Prefecture (population 8,830,000) served by a single emergency medical services system. PATIENTS: Consecutive prehospital cardiac arrests occurring between May 1998 and April 1999. MAIN OUTCOME MEASURES: One-year survival from cardiac arrest, and time factors. RESULT: Of the 5047 cases of confirmed cardiac arrests, resuscitation was attempted in 4871 subjects. Of the 982 cases of cardiac origin and witnessed by bystanders, 31 (3.2%) were still alive, and of the 576 cases of non-cardiac origin and witnessed by bystanders, ten (1.7%) were still alive at the 1 year follow-up. The median time from receipt of the emergency call until ambulance arrival was 5 min and that from receipt of the call until the start of cardiopulmonary resuscitation (CPR) was 7 min. For the 214 patients for whom defibrillation was attempted, the median time from receipt of the call until the first shock was 15 min. The median time from receipt of the call until departure of the ambulance from the scene was 16 min and that until arrival of the ambulance at a hospital was 22 min. CONCLUSIONS: This study using the standardized format according to the Utstein style clearly elucidates the specific delay of the start of defibrillation by paramedics and also indicates the inappropriate rule for this procedure in Japan.     

Survival rate and factors associated with 1-month survival of witnessed out-of-hospital cardiac arrest of cardiac origin with ventricular fibrillation and pulseless ventricular tachycardia: the Utstein Osaka project

OBJECTIVE: We reassessed 1-month survival of patients with witnessed out-of-hospital cardiac arrest (OHCA) of cardiac origin with ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in Osaka, Japan, and identified factors associated with 1-month survival using updated data from 1998 to 2004 collected based on the Utstein Style. METHODS: Using the Utstein Osaka Project database, we analyzed 1028 cases which met the following criteria: (1) patient age 18 years or older; (2) presumed cardiac origin based on the definition of the Utstein Style; (3) witnessed by citizens; (4) VF or pulseless VT at the time of arrival of the ambulance. The main outcome measure was survival at 1 month after collapse. Variables to develop a predictive model for 1-month survival were selected by stepwise logistic regression. RESULTS: Survival at 1 month was 19.6%. Factors retained in the final logistic regression were age, sex, type of witness, and time interval from (a) ambulance call receipt to cardiopulmonary resuscitation (CPR) by the ambulance crew; (b) ambulance call to defibrillation; (c) CPR by the ambulance crew to hospital arrival. Area under the receiver-operating characteristic curve for the model developed with the six variables was 0.738 and Hosmer-Lemshow goodness-of-fit p-value was 0.94. CONCLUSION: We successfully developed a model to estimate the probability of 1-month survival using variables easy to collect in the early phase of resuscitation, and this model would help physicians and family members predict the likelihood of 1-month survival of OHCA patients on admission.     

Do dispatcher instructions facilitate bystander-initiated cardiopulmonary resuscitation and improve outcomes in patients with out-of-hospital cardiac arrest? A comparison of family and non-family bystanders

Objectives

Bystander-initiated cardiopulmonary resuscitation (CPR) has been reported to increase the possibility of survival in patients with out-of-hospital cardiopulmonary arrest (OHCA). We evaluated the effects of CPR instructions by emergency medical dispatchers on the frequency of bystander CPR and outcomes, and whether these effects differed between family and non-family bystanders.

Methods

We conducted a retrospective cohort study, using Utstein-style records of OHCA taken in a rural area of Japan between January 2004 and December 2009.

Results

Of the 559 patients with non-traumatic OHCA witnessed by laypeople, 231 (41.3%) were given bystander CPR. More OHCA patients received resuscitation when the OHCA was witnessed by non-family bystanders than when it was witnessed by family members (61.4% vs. 34.2%). The patients with non-family-witnessed OHCA were more likely to be given conventional CPR (chest compression plus rescue breathing) or defibrillation with an AED than were those with family-witnessed OHCA. Dispatcher instructions significantly increased the provision of bystander CPR regardless of who the witnesses were. Neurologically favorable survival was increased by CPR in non-family-witnessed, but not in family-witnessed, OHCA patients. No difference in survival rate was observed between the cases provided with dispatcher instructions and those not provided with the instructions.

Conclusions

Dispatcher instructions increased the frequency of bystander CPR, but did not improve the rate of neurologically favorable survival in patients with witnessed OHCA. Efforts to enhance the frequency and quality of resuscitation, especially by family members, are required for dispatcher-assisted CPR.     

CPR Induced Consciousness During Out-of-Hospital Cardiac Arrest: A Case Report on an Emerging Phenomenon

Background: High quality cardiopulmonary resuscitation (CPR) has produced a relatively new phenomenon of consciousness in patients with vital signs absent. Further research is necessary to produce a viable treatment strategy during and post resuscitation. Objective: To provide a case study done by paramedics in the field illustrating the need for sedation in a patient whose presentation was consistent with CPR induced consciousness. Resuscitative challenges are provided as well as potential future treatment options to minimize harm to both patients and prehospital providers. Case Report: A 52-year-old male presented as a witnessed out-of-hospital cardiac arrest (OHCA). During CPR the patient began to exhibit signs of life including severe agitation and thrashing of his limbs while CPR was ongoing for ventricular fibrillation prior to defibrillation. Resuscitation became considerably more complicated due to the violent and counterintuitive motions done by the patient during their own resuscitation. Despite the atypical presentation of cardiac arrest the patient was successfully resuscitated employing high quality CPR, standard advanced life support (ALS) care as well as two double sequential external defibrillation shocks. The patient underwent emergency percutaneous coronary intervention (PCI) for a 100% occlusion of his left anterior descending artery (LAD). The patient returned home 3 days later fully recovered with a Cerebral Performance Score of 1. Conclusion: CPR induced consciousness is emerging as a new phenomenon challenging providers of high quality CPR during cardiac arrest resuscitation. Our case report describes the manifestations of CPR induced consciousness as well as the resuscitative challenges which occur during resuscitation. Further research is required to determine the true frequency of this condition as well as treatment algorithms that would allow for appropriate and safe management for both the patient and EMS providers.     

Utstein style analysis of out-of-hospital cardiac arrest--bystander CPR and end expired carbon dioxide

INTRODUCTION: The aim of this prospective cohort study was to describe the outcome for patients with out-of-hospital cardiac arrest in Maribor (Slovenia) over a 4 year period using a modified Utstein style, and to investigate elementary knowledge of basic life support among potential bystanders in our community. PATIENTS AND METHODS: Through the prehospital and the hospital database system we followed up a consecutive group of patients with out-of-hospital cardiac arrest (OHCA) between January 2001 and December 2004. We investigated the effects of various factors on outcome in OHCA, especially partial end-tidal CO2 pressure (petCO2), efficacy of bystander CPR and their elementary knowledge of basic life support (BLS). We also examined motivation among potential bystanders and possible implementation for BLS education in our community. RESULTS: OHCA was confirmed in 592 patients. Advanced cardiac life support was initiated in 389 patients, of which 277 were of cardiac aetiology. In 287 patients the event was bystanders witnessed and lay-bystander basic life support was performed only in 83 (23%). After treating OHCA by a physician-based prehospital medical team ROSC was obtained in 61%, the ROSC on admission was 50% and the overall survival to discharge was 21%. Initial petCO2 (OR: 22.04; 95%CI: 11.41-42.55), ventricular fibrillation or pulseless ventricular tachycardia as initial rhythm (OR: 2.13; 95%CI: 1.17-4.22), bystander CPR (OR: 2.55; 95%CI: 1.13-5.73), female sex (OR: 3.08; 95%CI: 1.49-6.38) and arrival time (OR: 1.29; 95%CI: 1.11-1.82) were associated with improved ROSC when using multivariate analysis. Using the same method we found that bystander CPR (OR: 5.05; 95%CI: 2.24-11.39), witnessed arrest (OR: 9.98; 95%CI: 2.89-34.44), final petCO2 (OR: 2.37; 95%CI: 1.67-3.37), initial petCO2 (OR: 1.61; 95%CI: 1.28-2.64) and arrival time (OR: 1.39; 95%CI: 1.33-1.60) were associated with improved survival. A questionnaire to potential bystanders has revealed disappointing knowledge about BLS fundamentals. On the other side, there is a welcomed willingness of potential bystanders to take BLS training and to follow dispatchers instructions by telephone on how to perform CPR. CONCLUSION: After OHCA in a physician-based prehospital setting in our region, the overall survival to discharge was 21%. The potential bystander in our community is generally poorly educated in performing CPR, but willing to gain knowledge and skills in BLS and to follow dispatchers instructions. Arrival time, witnessed arrest, bystander CPR, initial petCO2 and final petCO2 were significantly positively related with ROSC on admission and with survival. Prehospital data from this and previous studies provide strong support for a petCO2 of 1.33 kPa to be a resuscitation threshold in the field. In our opinion the initial value of petCO2 should be included in every Utstein style analysis.     

Out-of-hospital cardiac arrests occurring in primary health care facilities in Singapore

OBJECTIVES: To study out-of-hospital cardiac arrests (OHCA) occurring in primary healthcare facilities (HCF) in Singapore and to compare these with arrests occurring in the community. METHODS: This prospective observational study was part of the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Included were all patients with OHCA occurring in HCF. Patient characteristics, cardiac arrest circumstances, EMS response and outcomes were recorded according to the Utstein style. RESULTS: From 1 October 2001 to 14 October 2004, the data from 2428 subjects were received of which 138 patients were OHCA occurring in HCF. This is an incidence of 1.12/100,000 population per year and constituted 6.0% of all OHCA. Arrest occurring in HCF were more likely to be witnessed (p<0.01), or have bystander CPR (p<0.01). The HCF group was also more likely to receive CPR with both compression and ventilation (p<0.01) and have a non-trauma cause of arrest (p=0.03). HCF arrests also had a shorter collapse to call (EMS number) than the non-HCF group (HCF 1.54min versus non-HCF 5.36min, p=0.01). However, no HCF patient received defibrillation prior to EMS arrival. HCF patients were more likely to have return of spontaneous circulation at any time (p=0.05), survival to hospital admission (p<0.01) and survival to discharge (p<0.01) compared to non-HCF patients. CONCLUSION: This study suggests that primary health care providers do have an important role locally in managing out-of-hospital cardiac arrest. We propose an initiative to encourage early defibrillation by primary health care providers.     

Primary respiratory arrest recognised by emergency medical technicians and followed by cardiac arrest in Japan: identification of a subgroup of EMT-witnessed cardiac arrests with an extremely poor outcome

ReviewSome unconscious patients are found to be in primary respiratory arrest (PRA) by emergency medical technicians (EMTs). In contrast to citizens, EMTs manage PRA with artificial ventilation but not with cardiopulmonary resuscitation (CPR). This study aimed to investigate the characteristics and outcomes of PRA prior to EMT arrival and compare these data with those of a PRA-related group: patients with out-of-hospital cardiac arrests (OHCAs).MethodsBaseline data were prospectively collected by fire departments for their adult (16 years or older) OHCA and PRA patients from April 2003 through March 2010. We extracted those who had PRA prior to EMT arrival. The EMT- and bystander-witnessed OHCA patients who underwent CPR were also extracted as control groups.ResultsThere were 178 cases of PRA prior to EMT arrival. The majority (164/178) of these individuals were in a deep coma and met the criteria for the initiation of bystander CPR. Approximately 61% (108/178) of these PRAs were followed by cardiac arrests, which were classified as EMT-witnessed OHCAs by the Utstein template. The EMTs manually ventilated the patients until the cardiac arrest occurred. The 1-Y survival of this subgroup was the lowest of the PRA and PRA-related OHCA subgroups and was significantly lower than that of bystander-witnessed OHCAs with bystander CPR, when trauma and terminal illness cases were excluded (adjusted odds ratio = 3.888 (1.103–24.827)).ConclusionsWe identified a subgroup of PRAs with unexpectedly poor outcomes. The BLS guidelines for healthcare providers including EMTs should be re-evaluated by a large prospective study.     

Double Sequential External Defibrillation and Survival from Out-of-Hospital Cardiac Arrest: A Case Report

Background: Patients who present in ventricular fibrillation are typically treated with cardiopulmonary resuscitation (CPR), epinephrine, antiarrhythmic medications, and defibrillation. Although these therapies have shown to be effective, some patients remain in a shockable rhythm. Double sequential external defibrillation has been described as a viable option for patients in refractory ventricular fibrillation. Objective: To describe the innovative use of two defibrillators used to deliver double sequential external defibrillation by paramedics in a case of refractory ventricular fibrillation resulting in prehospital return of spontaneous circulation and survival to hospital discharge with good neurologic function. Case: A 28-year-old female sustained a witnessed out-of-hospital cardiac arrest (OHCA). Bystander CPR was performed by her husband followed by paramedics providing high-quality CPR, antiarrhythmic medication, and 6 biphasic defibrillations using standard energy levels. Double sequential external defibrillation was applied and a return of spontaneous circulation was attained on scene and maintained through to arrival to the emergency department. Following admission to hospital the patient was diagnosed with long QT syndrome. An implantable cardioverter defibrillator was placed and the patient was discharged with a Cerebral Performance Category of 2 as well as a modified Rankin Scale of 2 after an 18-day hospital stay. The patient's functional status continued to improve post discharge. Conclusion: The addition of double sequential external defibrillation as part of a well-organized resuscitation effort may be a valid treatment option for OHCA patients who present in refractory ventricular fibrillation.     

Out-of-hospital cardiac arrest due to drowning: An Utstein Style report of 10 years of experience from St. Mary's Hospital

Background

Drowning is a unique form of cardiac arrest and is often preventable. “Utstein Style for Drowning” was published in 2003 by the International Liaison Committee on Resuscitation (ILCOR) to improve the knowledge-base, to provide epidemiological stratification, to recommend appropriate treatments and to ultimately save lives. We report on the largest single-center study of the Utstein Style resuscitation for drowning.

Methods

All patients with out-of-hospital cardiac arrest (OHCA) due to drowning admitted to St. Mary's Hospital between 1998 and 2007 were included. Utstein Style variables and other time intervals not included in the Utstein Style guidelines were evaluated for their ability to predict survival. The primary end point of this study was survival to discharge.

Results

We enrolled 131 patients with OHCA due to drowning; 21 patients (16.03%) had survival to discharge and 9 patients (6.87%) were discharged with a good neurologic outcome, i.e., cerebral performance categories (CPC) of 1 or 2. For the Utstein Style variables witnessed, the duration of submersion and the time of first emergency medical systems (EMS) resuscitation attempt influenced survival. For other time intervals, the transportation time (i.e., time interval from witnessing of the drowning to EMS arrival at the hospital, or if events were not witnessed, the time interval from calling the EMS to EMS arrival at the hospital), the duration of advanced cardiovascular life support (ACLS) and the duration of total arrest time were associated with survival.

Conclusions

Our report is the largest single-center study of OHCA due to drowning reported according to the guidelines of the Utstein Style. Being witnessed, having a short duration of submersion, having early resuscitation by EMS, and rapid transportation are important for survival after drowning.     

874例院外猝死临床分析与急救干预

目的　分析探讨院外猝死及现场复苏成败的原因,以进一步提高现场复苏成功率,强化院外猝死的急救干预。方法　收集1999年1～12月经本中心院外急救的874例猝死病历,参照Utstein模式进行资料报告方法统计,进行回顾性研究。结果　猝死前有心血管病史者占70.44%;猝死高发年龄为60～84岁,占64.48%,且男性多于女性;发病地点以家庭为主,占93.8%;先由目击者进行心肺复苏(CPR)的24例中16例复苏有效,有效率66.67%,而后再由医生进行CPR的815例中43例复苏有效,有效率仅为5.28%,二者差别有显著意义(P＜0.01);呼叫～到达现场平均间期在复苏有效组与无效组中分别为8.16分钟和9.90分钟;经除颤、气管插管后复苏有效率分别为12.59%和28.22%,面未用除颤、气管插管的有效率仅为5.89%和1.92%,二者差别有显著意义(P＜0.01);现场复苏有效58例(6.91%),复苏成功1例(0.12%)。院外猝死率在12个月中的高峰期为冬季。在平均一昼夜中的高峰点为早晨7点。结论　降低院外猝死发生率的急救干预①要识别、防治猝死的高危因素;②在人群中普及以CPR为主的初级救护知识;③努力缩短急救反应时间即呼叫～到达现场间期;④要针对不同季节和时间,及时调整急救力量。     

Improved Survival from Cardiac Arrest in the Community

We now know that the elements required to achieve the highest survival rates from out-of-hospital cardiac arrest include: witnessed arrest, rapid telephone notification of the emergency medical service, early initiation of cardiopulmonary resuscitation, rapid arrival within minutes of emergency personnel equipped with a defibrillator, and early advanced airway management and intravenous pharmacology. In the United States, and in several other countries innovative approaches have been tried to bring all these elements together in one system. These approaches include community-wide CPR training programs, telephone-assisted CPR instruction delivered at the time of a cardiac arrest, early defibrillation performed by family members of high risk patients, early defibrillation performed by minimally trained community responders, and early defibrillation performed by minimally trained ambulance personnel. Controlled, prospective studies have demonstrated the effectiveness and practicality of all of these approaches. New studies are in progress with the prehospital use of early transcutaneous cardiac pacing and these show promise. This article reviews the evidence that supports these multi-layered and innovative approaches to the treatment of out-of-hospital cardiac arrest.     

院内复苏Utstein模式的临床应用

目的：对国外推荐的院内Utstein模式的适用性及影响复苏预后有关因素等进行初步的探讨。方法：前瞻性地研究本部门一年内心肺复苏抢救的情况。结果：（1）2000年中山医附一院急诊科内执行内肺复苏抢救228例;属于心源性起病者64例,6例（9．4％）存活出院;心源性患者中以室颤为初始心电图者21例,4例（19．0％）存活出院。（2）心源性发病,心室颤为初始心电图,气管插管是影响预后的有利因素,开始复苏间期,开始使用肾上腺素间期,开始除颤间期越短,预后越好。结论：（1）此模式在应用于本部门的心肺复苏研究过程中体现出较好的可行性。（2）为了提高心肺复苏的成功率,对确诊为心搏骤停的患者应尽早开始复苏,尽早使用肾上腺素,室颤患者应尽早行电击除颤,经基本生命支持尚未实现自主呼吸者宜行气管插管。     

Results of the first five years of the prehospital automatic external defibrillation project in Singapore in the "Utstein style"

In 1994, all emergency medical services (EMS) ambulance officers in Singapore were trained to perform pre-hospital defibrillation with semi-automated external defibrillators (AED). All non-traumatic cardiac arrest patients over 10 years old were included, excluding those who were obviously dead and children below 36 kg. The data were collected by the ambulance officers according to the Utstein guidelines. From 1 February 1994 to 31 January 1999; resuscitation was attempted in 968 non-trauma cardiac arrests. Fifteen percent of the cases were of non-cardiac origin. The overall survival rate was 40/968 (4.1%, 95% CI 2.9-5.6%). Of 968 patients, 22/136 (16.2%, 95% CI 10.4-23.5%), 18/622 (2.9%, 95% CI 1.7-4.5%) and 0/210 (0%, 95% CI 0-1.7%) survived in the EMS witnessed, bystander witnessed and un-witnessed groups, respectively (P < 0.001). Within the EMS witnessed group, those with an initial rhythm of VF/VT had a higher survival rate (30.6%) than those without VF/VT (4.1%). P < 0.001, OR = 10.3, 95% CI 2.9-36.9. Similarly, the VF/VT survival rate in the bystander witnessed group (4.5%) was higher than the non-VF/VT (1.0%) (P = 0.011, OR = 4.4, 95% CI 1.3-15.4). The survival rate of patients with bystander witnessed VF/VT arrest who received bystander CPR was 9.4% compared to 1.0% in those who did not (P = 0.037, OR = 4.4, 95% CI 1.01-20.1). Our survival rate of bystander witnessed VF/VT arrest is comparable to large metropolitan cities in the USA. The determinants of survival include EMS witnessed arrest and VF/VT arrest. Increased quantity and quality of bystander CPR rate may improve the outcome in bystander witnessed cardiac arrest.