A model of survival following pre-hospital cardiac arrest based on the Victorian Ambulance Cardiac Arrest Register

AIMS: This study describes the epidemiology of sudden cardiac arrest patients in Victoria, Australia, as captured via the Victorian Ambulance Cardiac Arrest Register (VACAR). We used the VACAR data to construct a new model of out-of-hospital cardiac arrest (OHCA), which was specified in accordance with observed trends. PATIENTS: All cases of cardiac arrest in Victoria that were attended by Victorian ambulance services during the period of 2002-2005. RESULTS: Overall survival to hospital discharge was 3.8% among 18,827 cases of OHCA. Survival was 15.7% among 1726 bystander witnessed, adult cardiac arrests of presumed cardiac aetiology, presenting in ventricular fibrillation or ventricular tachycardia (VF/VT), where resuscitation was attempted. In multivariate logistic regression analysis, bystander CPR, cardiac arrest (CA) location, response time, age and sex were predictors of VF/VT, which, in turn, was a strong predictor of survival. The same factors that affected VF/VT made an additional contribution to survival. However, for bystander CPR, CA location and response time this additional contribution was limited to VF/VT patients only. There was no detectable association between survival and age younger than 60 years or response time over 15min. CONCLUSION: The new model accounts for relationships among predictors of survival. These relationships indicate that interventions such as reduced response times and bystander CPR act in multiple ways to improve survival.     

Characteristics and short-term survival of individuals with out-of-hospital cardiac arrests in the East Bohemian region

AIM: We describe survival after admission to hospital from out-of-hospital cardiac arrest (OHCA) in the East Bohemian region, according to the Utstein Style guidelines and have identified the main diagnosis including in those who died and had an autopsy. PATIENT GROUP: Over a period of 29 months we used a questionnaire supplied to 24 rescue stations, to identify 718 individuals (511 men and 207 women, aged 16-97 years) with confirmed cardiac arrest who were considered for resuscitation. RESULTS: Out of 560 patients in whom cardiopulmonary resuscitation for OHCA of confirmed cardiac aetiology was attempted, 350 patients (62.5%) died in the field and 61 (10.9%) died during transport. Hospital admission was achieved in 149 cases (26.6%) and, of these, 96 patients died. Fifty-three patients (9.5%) were discharged home alive, 36 (6.4%) with an intact CNS. The first monitored rhythm showed asystole in 264 cases (47.1%) followed by ventricular fibrillation in 227 cases (40.5%). The main diagnosis of coronary heart disease (CHD) was established clinically in 467 cases (83.4%). In 175 autopsy reports this diagnosis was noted in 152 cases (86.9%). CONCLUSION: Of patients resuscitated for OHCA of cardiac aetiology, 9.5% survived to leave the acute hospital. CHD was the principle diagnosis in the entire group and this correlated with the same finding in the group of patients who received an autopsy.     

Extracorporeal Resuscitation of Cardiac Arrest

OBJECTIVE: Extracorporeal support of heart and lung function (venoarterial perfusion) during cardiac arrest (ECPR) has been advocated as a means of improving survival following cardiac arrest. The authors retrospectively reviewed their institution's seven-year experience with this intervention. METHODS: Emergency department patients and inpatients in cardiac arrest or immediately postarrest were considered candidates. ECPR was instituted using venoarterial bypass and was continued until patients regained sufficient cardiopulmonary function to allow weaning from the device or until their condition was deemed irrecoverable. RESULTS: ECPR was attempted in 25 patients and successfully instituted in 21. Four patients (16%) were converted from ECPR to ventricular assist devices, two of whom survived and await transplantation. Seven additional patients were discharged from the hospital, resulting in an overall survival of 36%. Because none of the children treated survived, there was a trend toward higher age among survivors (survivors 40 +/- 14 yr, nonsurvivors 33 +/- 15 yr, p = 0.29). The duration of conventional CPR was shorter among survivors (survivors 21 +/- 16 min, nonsurvivors 43 +/- 32 min, p = 0.04), as was the duration of extracorporeal support (survivors 44 +/- 21 hr, nonsurvivors 87 +/- 96 hr, p = 0.18). Survival was seen only in patients whose conditions were amenable to a definitive therapeutic intervention, particularly cardiac arrest due to respiratory or pulmonary embolic disease. While four of the five patients treated in the ED were successfully supported, none survived to discharge. CONCLUSION: In select patients with reversible disease, extracorporeal CPR can be used to successfully treat cardiac arrest. Further investigation into its most appropriate application is warranted.     

心脏缓慢性与快速性心律失常交替引起猝死的抢救

目的　研究快速性心律失常与缓慢性心律失常引起猝死的抢救。方法　 7例病人因不同疾病住院期间突发心源性猝死 ,心电监护显示猝死时心电图表现形式为快速性心律失常与缓慢性心律失常两者交替出现。应用胸前捶击及胸外按压的方法可立即终止这两种心律失常的发作 ,并最终恢复窦律 ,在抢救过程中 4例病人使用了升压药 ,1例辅助使用了人工呼吸器 ,1例使用了临时心内起搏器。结果　 7例病人全部抢救成功。结论　快速性心律失常与缓慢性心律失常引起的心源性猝死用胸前捶击及胸外按压方法抢救是有效的。     

Recurrent ventricular fibrillation: Experience with first responders prior to advanced life support interventions

AimFollowing defibrillation, ventricular fibrillation (VF) frequently recurs during out-of-hospital cardiac arrest (OHCA). Prior studies have reported conflicting results regarding its association with survival. The aim of this study was to examine the impact of recurrent VF in the presence of first responders before advanced life support (ALS) interventions.MethodsElectrocardiographic data from first responder automated external defibrillators (AEDs) were analyzed. A successful shock was defined as termination of VF for 5 s or longer. Recurrent VF was defined as any VF that occurred after a successful shock. The primary outcome was neurologically intact survival to hospital discharge (CPC 1–2).Results108 patients within our emergency system experienced a witnessed VF arrest. Of these, 73 (68%) had at least one recurrence of VF. Median time to recurrence of VF was 25 s [interquartile range (IQR) 11–66 s]. Median time in recurrent VF was 180 s (IQR 105–266 s). Survival was observed in 25 (71%) of patients with no recurrent VF and in 36 (49%) who had recurrence. Recurrent VF was associated with a lower odds of survival on univariate analysis (OR 0.39, 95% CI 0.16–0.92, p = 0.0325). After adjusting for bystander CPR, gender and age, recurrent VF had a similar direction of effect but was no longer significantly associated with neurologically intact survival (OR 0.44, 95% CI 0.17–1.11, p = 0.081).ConclusionsIn the presence of first responders, VF recurred in 68% of patients. Recurrent VF was associated with a lower odds of survival, though its prognostic significance appeared to be blunted when considered in light of confounding variables. Recurrent VF may have significant survival implications, and further studies to assess its prognostic significance should be performed.     

Reversible Myocardial Depression in Survivors of Cardiac Arrest

Three patients under 40-years old who survived cardiac arrest due to ventricular fibrillation were originally diagnosed as having idiopathic dilated cardiomyopathy. Shortly after cardiac arrest, assessment of myocardial function revealed a globally dilated left ventricle in each patient with an estimated ejection fraction between 20% and 30%. Serial assessment of myocardial function, however, showed either normal or near-normal function by 2 weeks postevent. These findings suggest that myocardial stunning due to hypoperfusion during ventricular fibrillation or the effects of transthoracic shocks may result in profound, reversible myocardial depression in survivors of cardiac arrest. Serial evaluation of left ventricular function may be of value in selected survivors of cardiac arrest in order to evaluate time-dependent resolution of myocardial dysfunction and may prevent misdiagnosis of idiopathic dilated cardiomyopathy.     

126例心跳骤停心肺复苏临床分析

目的：探讨急诊抢救心跳骤停的程序及方法,以便提高心肺复苏成功率。方法：回顾性分析126例在急诊抢救心跳骤停患者的临床资料,分析抢救程序及方法对心肺复苏的影响。结果：126例患者中31例复苏成功,63例复苏有效,32例复苏无效。结论：心肺复苏抢救成功与开始抢救时间、胸外按压方法、抢救药物及仪器的合理应用有密切关系。     

Emergency Medicine Myths: Epinephrine in Cardiac Arrest

Background

Sudden cardiac arrest accounts for approximately 15% of deaths in developed nations, with poor survival rate. The American Heart Association states that epinephrine is reasonable for patients with cardiac arrest, though the literature behind its use is not strong.

Idiopathic Ventricular Fibrillation in Out-of-Hospital Cardiac Arrest Survivors

This study examined diagnostic and therapeutic roles of electrophysiological testing and long-term clinical outcome after out-of-hospital cardiac arrest due to idiopathic ventricular fibrillation. This is defined as ventricular fibrillation occurring in the absence of detectable underlying heart disease or metabolic or electrolyte disturbance. Out-of-hospital cardiac arrest resulting from idiopathic ventricular fibrillation is uncommon. Records of all patients who underwent electrophysiological testing between June 1979 and June 1992 were reviewed. Patients with out-of-hospital cardiac arrest due to idiopathic ventricular fibrillation were identified. Follow-up information was obtained by telephone interview in June 1992. Of 194 patients who underwent electrophysiological study after out-of-hospital cardiac arrest not associated with acute myocardial infarction, only six (4 male and 2 female) had idiopathic ventricular fibrillation. It was induced in only two patients by programmed ventricular stimulation. No sustained ventricular arrhythmias were induced in the remaining four patients. Four patients received implantable cardioverter defibrillators, one was treated with a β-adrenergic blocker, and one received no treatment. All patients were alive at a mean follow-up of 50 months. Two of the four patients without inducible sustained ventricular arrhythmias had events during follow-up. Of the two patients with inducible ventricular fibrillation, one experienced a cardiac arrest and documented ventricular fibrillation at 41 months after the index event and the other had had no recurrence at 15-month follow-up. All four patients with implantable cardioverter defibrillators were alive at last follow-up, and two had device discharges. In survivors of out-of-hospital cardiac arrest due to idiopathic ventricular fibrillation: (1) programmed electrical stimulation is of limited value for evaluating cause and guiding therapy; (2) a high rate of recurrent events is observed (50%); and (3) an implantable cardioverter defibrillator is effective for preventing a fatal outcome.