Public defibrillation: increased survival from a structured response system

The Public Access Defibrillation (PAD) trial was a prospective, randomized, controlled study designed to compare the number of persons surviving to hospital discharge after experiencing an out-of-hospital cardiac arrest (OOH-CA) among "community units" randomized to receive cardiopulmonary resuscitation (CPR) only or CPR plus an automated external defibrillator (AED). In 24 centers across the United States and Canada, 993 community units, composed of 1260 individual facilities, trained more than 19,000 layperson responders in CPR-only or CPR+AED. Survival to hospital discharge in the CPR+AED arm was double that of the CPR-only arm (30 vs 15, P = .03; RR = 2.0, 95% CI [1.07-3.77]). Intense focus on facility infrastructure, including responder recruitment and training, communication, evaluation, and oversight, was necessary for implementing the emergency response systems for the trial. Use of an AED within this structured response system can increase the number of survivors to hospital discharge after OOH-CA. Trained nonmedical responders can use AEDs safely and effectively.     

调度员指导的心肺复苏对院前心脏骤停生存率影响的Meta分析北大核心CSCD

目的评价第一目击者在对院前心脏骤停(out-of-hospital cardiac arrest,OHCA)患者进行心肺复苏(cardiopulmonary resuscitation,CPR)时是否接受调度员指导(dispatcher-assisted cardiopulmonary resuscitation,DA-CPR)对OHCA患者结局是否有影响。方法通过检索在中文及英文各大数据库公开发表的临床研究,筛选出关于对院前心脏骤停患者心肺复苏时是否进行DA-CPR的文献,按照Cochrane Handbook5.1.0标准,对纳入文献质量进行评价,并提取出相关有效数据,应用Review Manager 5.3软件,对三个结局指标(自主循环恢复、存活至出院、神经功能良好)分别进行Meta分析。结果共纳入21项研究,共计349822例患者,其中DA-CPR组182125人,CPR-Only组167697人。分析结果显示:在美国、日本、韩国,DA-CPR相比CPR-Only未能提高OHCA停患者的ROSC率,RR=1.10,95%CI:0.94~1.29,P=0.24;未能提高OHCA患者的出院存活率,RR=1.10,95%CI:0.90~1.34,P=0.34;未能提高OHCA患者的神经功能良好率,RR=1.01,95%CI:0.79~1.28,P=0.97。而在中国,DA-CPR相比CPR-Only,能提高OHCA患者的ROSC率,RR=2.61,95%CI:1.53~4.46,P=0.0005;能提高OHCA患者的出院存活率,RR=6.08,95%CI:1.84~20.04,P=0.003;能提高OHCA患者的神经功能良好率,RR=9.76,95%CI:1.87~51.02,P=0.007。结论DA-CPR在世界总体范围内的效果无统计学意义。但因发现DA-CPR在不同国家的效果差别较大,所以需具体而言:在发达国家,DA-CPR与无调度员指导的BCPR相比,不能明显提高OHCA患者的ROCS率、出院生存率和神经功能良好率。而在提高我国OHCA患者的ROCS率、出院生存率和神经功能良好率方面,DA-CPR优于无调度员指导的BCPR,有统计学意义。     

Evaluating the quality of prehospital cardiopulmonary resuscitation by reviewing automated external defibrillator records and survival for out-of-hospital witnessed arrests

OBJECTIVES: Without an easy method to monitor the performance of prehospital cardiopulmonary resuscitation (CPR), earlier studies have not been able to assess the quality of CPR. In this study, we have used a new approach to evaluate prehospital CPR performance and the impact on outcome using data retrieved from the automatic external defibrillators (AED). MATERIALS AND METHODS: Electrocardiography (ECG) and voice records from AED data cards from 633 out-of-hospital cardiac arrests (OHCA) were reviewed. Fifty-two witnessed cardiac arrests in ventricular fibrillation (VF) requiring post-shock CPR underwent an independent, structured review by two physicians. The adequacy of prehospital CPR was defined on the basis of noticeable deflection of the ECG with chest compressions, the actual number of chest compressions delivered per minute, and the continuity of prehospital CPR at the scene and during transport. Outcome measures included return of spontaneous circulation (ROSC) and survival to hospital admission and discharge. RESULTS: The quality of prehospital CPR was judged as adequate in 15 (29%, 95%; CI: 18-42%) and inadequate in 37 (71%, 95%; CI: 58-82%) of the consensus. Adequate CPR performance resulted in a higher rate of ROSC at the scene (53% versus 8%, 95% CI of the difference 14-76%), and survival to hospital discharge (53% versus 8%, 95% CI of the difference 14-76%). Two reviewers agreed on whether CPR was adequate in 92.3% of cases, with a kappa of 0.82. CONCLUSIONS: The quality of prehospital CPR is associated with a greater likelihood of survival in witnessed VF arrests in need of post-shock CPR. The potential of widely available electrocardiography and voice records in AEDs in providing a convenient and real-time evaluation of prehospital CPR should be explored further.     

Measuring survival rates from sudden cardiac arrest: the elusive definition

BACKGROUND: Measuring survival from sudden out-of-hospital cardiac arrest (OOH-CA) is often used as a benchmark of the quality of a community's emergency medical service (EMS) system. The definition of OOH-CA survival rates depends both upon the numerator (surviving cases) and the denominator (all cases). PURPOSE: The purpose of the public access defibrillation (PAD) trial was to measure the impact on survival of adding an automated external defibrillator (AED) to a volunteer response system trained in CPR. This paper reports the definition of OOH-CA developed by the PAD trial investigators, and it evaluates alternative statistical methods used to assess differences in reported "survival." METHODS: Case surveillance was limited to the prospectively determined geographic boundaries of the participating trial units. The numerator in calculating a survival rate should include only those patients who survived an event but who otherwise would have died except for the application of some facet of emergency medical care-in this trial a defibrillatory shock. Among denominators considered were: total population of the study unit, all deaths within the study unit, and documented ventricular fibrillation cardiac arrests. The PAD classification focused upon cases that might have benefited from the early use of an AED, in addition to the likely benefit from early recognition of OOH-CA, early access of EMS, and early cardiopulmonary resuscitation (CPR). Results of this classification system were used to evaluate the impact of the PAD definition on the distribution of cardiac arrest case types between CPR only and CPR + AED units. RESULTS: Potential OOH-CA episodes were classified into one of four groups: definite, probable, uncertain, or not an OOH-CA. About half of cardiac arrests in the PAD units were judged to be definite OOH-CA events and therefore potentially treatable with an AED. However, events that occurred in CPR-only units were less likely to be classified as definite or probable OOH-CA events than those in CPR + AED units (43% versus 55%, odds ratio 0.78, 95% confidence interval 0.57-1.07). The study retained sufficient power to permit a statistical analysis of the alternative hypothesis that the CPR + AED method results in twice as many survivors as a CPR-only approach. The result is critically dependent on the denominator used for calculating survival rates; but the analysis does not require a denominator as the numerators will have identical Poisson distributions (counts for rare events) under the null hypothesis since randomization distributes the risk of cardiac arrest evenly between the two arms. CONCLUSION: Reported OOH-CA rates and survival rates vary widely, depending upon the definitions applied to events. Rigorous assessment of treatments applied to improve survival can be obscured by inappropriate definitions. Large-scale randomized interventions designed to improve survival from OOH-CA can be evaluated based upon the absolute numbers of patients surviving, rather than a change in the proportion surviving.     

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.     

EMS defibrillation-first policy may not improve outcome in out-of-hospital cardiac arrest

OBJECTIVE: Early defibrillation using automated external defibrillators (AEDs) has been advocated to improve survival in witnessed out-of-hospital cardiac arrest (OHCA) due to pulseless ventricular tachycardia (VT) and ventricular fibrillation (VF). However, when VT/VF is untreated and prolonged for more than a few minutes, defibrillation using AEDs may fail. METHODS: This retrospective study reviewed the charts from local emergency medical service (EMS) between the years 1993 to 2001 to evaluate the value of the AED after its introduction into our EMS. All witnessed OHCA due to VT/VF were analysed; cases of collapse witnessed by EMS were excluded. The primary endpoint was defined as survival to hospital discharge and at 1-year follow-up, and the secondary endpoint as survival without major neurological deficit. A total of 76 patients were treated for witnessed VT/VF before the implementation of the AED and 92 patients after its implementation. RESULTS: Before the introduction of paramedic AED defibrillation, physician defibrillation was performed at 15.6 min (+/-5.5, S.D.). After the introduction of AED defibrillation, paramedic defibrillation was performed at 5.7 min (+/-2.4, S.D.); the mean response interval from the call to defibrillation was shortened significantly (P<0.001). At the same time, survival to hospital discharge decreased from 23.7% (18/76 patients) to 14.1% (13/92) (P=0.112) and at 1-year follow-up from 17.1% (13/76) to 9.8% (9/92) (P=0.161). Favourable neurological outcome at 1-year follow-up also decreased from 14.5% (11/76) to 8.7% (8/92) (P=0.239). CONCLUSION: Implementation of the AED did not improve survival or a favourable neurological outcome in patients with OHCA due to VF/VT. However, with 5.7 min time to defibrillation, our EMS did not meet the criteria for early defibrillation. For prolonged periods of VT/VF, initial basic life support (BLS) may be superior to immediate AED. If response times of <4 min cannot be attained by the emergency systems, reconsidering of resuscitation algorithms seems to be advisable.     

The effect of time on CPR and automated external defibrillator skills in the Public Access Defibrillation Trial

BACKGROUND: The time to skill deterioration between primary training/retraining and further retraining in cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) for lay-persons is unclear. The Public Access Defibrillation (PAD) trial was a multi-center randomized controlled trial evaluating survival after CPR-only versus CPR+AED delivered by onsite non-medical volunteer responders in out-of-hospital cardiac arrest. AIMS: This sub-study evaluated the relationship of time between primary training/retraining and further retraining on volunteer performance during pretest AED and CPR skill evaluation. METHODS: Volunteers at 1260 facilities in 24 North American regions underwent training/retraining according to facility randomization, which included an initial session and a refresher session at approximately 6 months. Before the next retraining, a CPR and AED skill test was completed for 2729 volunteers. Primary outcome for the study was assessment of global competence of CPR or AED performance (adequate versus not adequate) using chi(2)-test for trends by time interval (3, 6, 9, and 12 months). Confirmatory (GEE) logistic regression analysis, adjusted for site and potential confounders was done. RESULTS: The proportion of volunteers judged to be competent did not diminish by interval (3, 6, 9, and 12 months) for either CPR or AED skills. After adjusting for site and potential confounders, longer intervals to further retraining was associated with a slightly lower likelihood of performing adequate CPR but not with AED scores. CONCLUSIONS: After primary training/retraining, the CPR skills of targeted lay responders deteriorate nominally but 80% remain competent up to 1 year. AED skills do not deteriorate significantly and 90% of volunteers remain competent up to 1 year.     

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.     

Increasing first responder CPR during resuscitation of out-of-hospital cardiac arrest using automated external defibrillators

OBJECTIVE: Evidence supports that increasing the balance of "hands-on" CPR may improve survival in ventricular fibrillation out-of-hospital cardiac arrest (OHCA). We assessed whether training and/or AED reconfiguration was associated with an increase in the proportion of time during which CPR was performed between first and second stacks of shocks. METHODS: The investigation was a cohort study of 291 persons who suffered ventricular fibrillation OHCA and were treated with at least two stacks of AED shocks by emergency medical services (EMS) first-tier responders. In January 2003, first-tier providers were retrained regarding the importance of CPR. In addition, a subset of AEDs was reconfigured to remove continuous fibrillation detection and its associated voice prompts as to be comparable with other AED models. The amount of time spent on CPR was assessed through review of AED electronic and audio recordings to compare the pre-intervention (n = 241) and post-intervention periods (n = 50). RESULTS: The proportion of time spent performing hands-on CPR between first and second stacks of shocks was 0.40 in the pre-intervention period compared to 0.51 in the post-intervention period (p = 0.001). The difference was greatest for AEDs where EMS was retrained and the AED reconfigured (0.33 versus 0.50, p = 0.01). No difference in survival was detected between the pre- and post-intervention periods (24.9% versus 28.0%, p = 0.65). CONCLUSIONS: An intervention consisting of retraining and AED reconfiguration was associated with an increase in the proportion of time spent performing CPR between first and second stacks of shocks by first-tier EMS. Whether this increase improves patient outcomes requires additional study.     

Legal aspects of the application of the lay rescuer automatic external defibrillator (AED) program in South Korea

The American Heart Association has stated that the automatic external defibrillator (AED) is a promising method for achieving rapid defibrillation, and emphasized that AED training and use should be available in every community. The demonstrated safety and effectiveness of the AED make it ideally suited for the delivery of early defibrillation by trained laypersons, and the placement of AEDs in selected locations for immediate use by trained laypersons may enable critical intervention that can significantly increase survival from out-of-hospital cardiac arrest. The American Heart Association recommends the installation of AEDs in public locations such as airports, thus allowing laypersons to conduct defibrillation and cardiopulmonary resuscitation on the occasion of adverse cardiopulmonary events. In Korea, the Ministry of Health and Welfare officially prohibits the installation of AEDs in public locations on the grounds that cardiopulmonary resuscitation and defibrillation are understood as medical practices that can be conducted only by licensed medical practitioners. The purpose of this article is to discuss the necessity for AEDs and the appropriate process for their implementation in Korea, by examining the current pre-AED status of Korea and the relevant legal aspects.     

Compression-only cardiopulmonary resuscitation vs standard cardiopulmonary resuscitation: an updated meta-analysis of observational studies

Objectives

To perform an updated meta-analysis of observational studies with unstratified cohort addressing whether compression-only cardiopulmonary resuscitation (CPR), compared with standard CPR, improves outcomes in adult patients with out-of-hospital cardiac arrest and a subgroup meta-analysis for the patients with cardiac etiology arrest.

Methods

We searched the relevant literature from MEDLINE and EMBASE databases. The baseline information and outcome data (survival to hospital discharge, favorable neurologic outcome at hospital discharge, and return of spontaneous circulation on hospital arrival) were extracted both in an out-of-hospital cardiac arrest and cardiac origin arrest subgroup. Meta-analyses were performed by using Review Manager 5.0.

Results

Eight studies involving 92?033 patients were eligible. Overall meta-analysis showed that standard CPR was associated with statistically improved survival to hospital discharge (risk ratio [RR], 0.95 [95% confidence interval, 0.91-0.99]) and return of spontaneous circulation on hospital arrival (RR, 0.95 [95% confidence interval, 0.92-0.99]) compared with compression-only CPR, but there is no significant difference in favorable neurologic outcome at hospital discharge between 2 CPR methods (RR, 0.97 [95% confidence interval, 0.91-1.04]). In the subgroup of patients with a cardiac cause of arrest, the pooled meta-analysis found compression-only CPR resulted in the similar survival to hospital discharge as standard CPR (RR, 0.99 [95% confidence interval, 0.94-1.05]).

Conclusions

This meta-analysis found that compression-only CPR resulted in the similar survival rate as the standard CPR in the cardiac etiology subgroup. It is unclear for the patients with noncardiac cause of arrest and with long periods of untreated arrest.     

Attitudes of Law Enforcement Officers Regarding Automated External Defibrillators

OBJECTIVE: To assess the knowledge and attitudes of law enforcement officers regarding treating out-of-hospital cardiac arrest (OHCA) and using automated external defibrillators (AEDs). METHODS: This was a survey conducted among officers serving Marion County, Indiana. RESULTS: Of 1,130 surveys distributed, 929 (82.2%) were returned. Among these officers, 603 (66.4%) were certified in cardiopulmonary resuscitation (CPR) and 103 (11.3%) had received AED training. Most officers had limited knowledge regarding OHCA. A 100-point knowledge score (mean +/- SD: 31.9 +/- 14.3) was higher in officers who had performed CPR while on duty [35.0, 95% confidence interval (95% CI) = 32.9 to 37.2, p = 0.005] and who were AED-trained (40.8, 95% CI = 38.0 to 43.6, p < 0.001). Of the respondents, 367 (40.1%) believed that AED usage by local law enforcement was needed, and 323 (35.6%) stated that they would feel comfortable using an AED if trained. A 100-point attitude score (mean +/- SD: 32.1 +/- 21.0) was higher in officers who had CPR certification (38.2, 95% CI = 35.6 to 40.8), who had performed CPR while on duty (40.6, 95% CI = 37.7 to 43.5), who were AED-trained (39.5, 95% CI = 35.6 to 43.4), and who had improved OHCA knowledge (+3.8 per 10 points knowledge score, 95% CI = 3.0 to 4.7), p < 0.001, all significant factors. CONCLUSIONS: Limited knowledge and negative attitudes of law enforcement officers regarding their involvement in treating OHCA and using AEDs are commonly present. These factors could result in barriers that negatively impact law enforcement AED programs.     

A prospective,randomised and blinded comparison of first shock success of monophasic and biphasic waveforms in out-of-hospital cardiac arrest

BACKGROUND: Evidence suggests that biphasic waveforms are more effective than monophasic waveforms for defibrillation in out-of-hospital cardiac arrest (OHCA), yet their performance has only been compared in un-blinded studies. METHODS AND RESULTS: We compared the success of biphasic truncated exponential (BTE) and monophasic damped sine (MDS) shocks for defibrillation in OHCA in a prospective, randomised, double blind clinical trial. First responders were equipped with MDS and BTE automated external defibrillators (AEDs) in a random fashion. Patients in ventricular fibrillation (VF) received BTE or MDS first shocks of 200 J. The ECG was recorded for subsequent analysis continuously. The success of the first shock as a primary endpoint was removal of VF and required a return of an organized rhythm for at least two QRS complexes, with an interval of <5 s, within 1 min after the first shock. The secondary endpoint was termination of VF at 5 s. VF was the initial recorded rhythm in 120 patients in OHCA, 51 patients received BTE and 69 received MDS shocks. The success rate of 200 J first shocks was significantly higher for BTE than for MDS shocks, 35/51 (69%) and 31/69 (45%), P=0.01. In a logistic regression model the odds ratio of success for a BTE shock was 4.01 (95% CI 1.01-10.0), adjusted for baseline cardiopulmonary resuscitation, VF-amplitude and time between collapse and first shock. No difference was found with respect to the secondary endpoint, termination of VF at 5 s (RR 1.07 95% CI: 0.99-1.11) and with respect to survival to hospital discharge (RR 0.73 95% CI: 0.31-1.70). CONCLUSION: BTE-waveform AEDs provide significantly higher rates of successful defibrillation with return of an organized rhythm in OHCA than MDS waveform AEDs.     

Limited Response to Cardiac Arrest by Police Equipped with Automated External Defibrillators: Lack of Survival Benefit in Suburban and Rural Indiana—The Police as Responder Automated Defibrillation Evaluation (PARADE)

OBJECTIVE: To assess the out-of-hospital cardiac arrest (OHCA) survival advantage after providing police with automated external defibrillators (AEDs) in rural and suburban Indiana. METHODS: An observational evaluation was conducted in six Indiana counties (population: 464,741) before (retrospective) and after (prospective) training and equipping police with AEDs. The primary outcome evaluated was survival to hospital discharge for all cases of ventricular tachycardia/ventricular fibrillation (VT/VF) OHCA. Other factors evaluated include age, gender, race, arrest location, witnessed arrest, bystander cardiopulmonary resuscitation, response intervals, and survival to discharge for all OHCAs. Results are reported using chi-square, Student's t-test, and logistic regression. RESULTS: Police were equipped with 112 AEDs, increasing total defibrillator capability by 43.2%. During the study period, AED-equipped police responded prior to emergency medical services (EMS) in 26 of 388 cases (6.7%). The time intervals from 911 call-to-scene and 911 call-to-shock were shortened by 1.6 minutes (95% confidence interval [95% CI] = 0.0 to 3.1, p = 0.05) and 4.8 minutes (95% CI = 1.3 to 8.3, p = 0.008), respectively, with police response as compared with EMS response. Survival to hospital discharge for VT/VF OHCA was 15.0% (3/20) in cases in which police responded first and 10.0% (16/160) in cases in which EMS responded first (relative risk [RR] 0.63, 95% CI = 0.17 to 2.39, p = 0.45). Survival to hospital discharge for VT/VF OHCA did not improve from the prestudy period (16/204, 7.8%) to after police AED availability (19/180, 10.6%) (RR 0.72, 95% CI = 0.36 to 1.45, p = 0.38). CONCLUSIONS: Out-of-hospital cardiac arrest survival in suburban and rural Indiana did not improve after police were equipped with AEDs, likely related to poor police response.     

Biphasic versus monophasic defibrillation in out-of-hospital cardiac arrest: a systematic review and meta-analysis

ObjectiveBiphasic defibrillation is more effective than monophasic one in controlled in-hospital conditions. The present review evaluated the performance of both waveforms in the defibrillation of patients of out-of-hospital cardiac arrest (OHCA) with initial ventricular fibrillation (Vf) rhythm under the context of current recommendations for cardiopulmonary resuscitation.MethodsFrom inception to June 2012, Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched systemically for randomized controlled trials (RCTs) and observational cohort studies that compared the effects of biphasic and monophasic shocks on Vf termination, return of spontaneous circulation (ROSC), and survival to hospital discharge in OHCA patients with initial Vf rhythm. No restrictions were applied regarding language, population, or publication year.ResultsFour RCTs including 572 patients were identified from 131 potentially relevant references for meta-analysis. The synthesis of these RCTs yielded fixed-effect pooled risk ratios (RRs) for biphasic and monophasic waveforms on Vf termination survival to hospital discharge (RR, 1.14; 95% CI, [0.84-1.54]).ConclusionBiphasic waveforms did not seem superior to monophasic ones with respect to Vf termination, ROSC, or survival to hospital discharge in OHCA patients with initial Vf rhythm under the context of current guidelines. However, most trials were conducted in accordance with previous guidelines for cardiopulmonary resuscitation. Therefore, further trials are needed to clarify this issue.     

机械心肺复苏对心脏骤停患者复苏效果影响的Meta分析

目的:评价使用机械心肺复苏对心脏骤停患者复苏结局的影响。方法:系统检索中国知网、维普、万方、PUBMED、Web of Science等数据库中关于机械心肺复苏和徒手心肺复苏的相关文献,提取有效数据后用RevMan5.3软件进行Meta分析。结果:共计纳入20项临床研究,包含29 727例患者,其中11 104例患者在...     

Characteristics of volunteers responding to emergencies in the Public Access Defibrillation Trial

OBJECTIVES: To evaluate the characteristics of volunteers responding to emergencies in the North American Public Access Defibrillation (PAD) Trial. METHODS: The PAD Trial was a prospective evaluation of cardiac arrest survival in community facilities randomized to cardiopulmonary resuscitation (CPR) or to CPR with automated external defibrillators (AEDs). The PAD volunteers' characteristics were analyzed using Poisson regression clustered on the facility and offset by the number of emergency episodes to which volunteers were exposed. RESULTS: A total of 19,320 volunteers in 1260 facilities were trained to provide emergency care. Of these, 8169 volunteers were participating actively at their facility during a time when one or more emergency episodes occurred. There were 1971 emergency episodes responded to by 1245 volunteers. The treatment arm (CPR-only versus CPR+AED) was not associated with the likelihood of volunteer participation in an episode. Likewise, the volunteers' age or sex did not affect response. Volunteers more likely to respond were supervisory/management or security personnel, non-minority participants, volunteers with previous CPR training, volunteers with previous experience in emergency care and those who passed the PAD CPR skills follow-up test. Volunteers who had a formal education beyond a high school level were less likely to respond. CONCLUSIONS: Volunteers with previous emergency training and positions of responsibility in their facility had a greater likelihood of participation in medical emergencies in the PAD Trial.     

溺水儿童非传统顺序心肺复苏成功的原因探讨

目的　探讨溺水儿童院前非传统顺序心肺复苏 (CPR)的可行性。方法　 4 3例因溺水而心搏骤停即行院前CPR的患儿 ,CPR顺序按ABC (开放气道人工呼吸胸外按压 )和CAB (胸外按压开放气道人工呼吸 )分为传统顺序组 (2 1例 )和非传统顺序组 (2 2例 ) ,分析比较两组复苏效果。结果　两组基本情况及初步复苏成功率、复苏无效率、神经系统病残率无明显差异 ,入院初HR、RR、MBP和血气分析基本相似 ;非传统顺序组复苏成功存活及入院初PaCO2 均明显高于传统顺序组 (P <0 0 0 1) ,复苏成功未存活明显少于传统顺序组 (P <0 0 5 )。结论　限于条件 ,儿童溺水院前急救CPR初期 ,先行胸外按压、开放气道 ,人工通气相对延后 ,其方法简单有效 ,值得探索。