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.     

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.     

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.     

Gender and survival after sudden cardiac arrest: A systematic review and meta-analysis

BackgroundConflicting results exist regarding the impact of gender on early survival after sudden cardiac arrest (SCA). We aimed to assess the association between female gender and early SCA survival.MethodsWe searched Embase, MEDLINE, EBM Reviews, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews (between 1948 and January 2014) for studies evaluating the association between gender and survival after SCA. Two independent reviewers selected studies of any design or language. Pooled odds-ratios (OR) and 95% confidence intervals (CIs) were estimated using a random-effects model. Additional sensitivity analyses and meta-regression were carried out to explore heterogeneity.ResultsThirteen studies were included involving 409,323 patients. Women were more likely to present with SCA at home, less likely to have witnessed SCA, had a lower frequency of initial shockable rhythm but were more likely to receive bystander CPR. After adjustment for these differences, women were more likely to survive at hospital discharge (OR 1.1, 95% CI 1.03–1.20, p = 0.006, I² = 61%). This association persisted in multiple sensitivity analyses.ConclusionThis meta-analysis of observational studies demonstrates that women have increased odds of survival after SCA. Further studies are needed to address mechanisms explaining this discrepancy.     

A model of survival from out-of-hospital cardiac arrest using the Boston EMS arrest registry

Objectives

To characterize the survival rate for out-of-hospital arrests of cardiac aetiology and predictor variables associated with survival in Boston, MA, and to develop a composite multivariate logistic regression model for projecting survival rates.

Methods

This is a retrospective analysis of all arrests of presumed cardiac aetiology (from January 1, 2004 to December 31, 2007) where resuscitation was attempted (n = 1156) by 911 emergency responders.

Results

The survival-at-hospital discharge rate was 11% (vs. 1-10% often reported). The coefficients and odds ratios in the first equation of the model show that joint presence of presenting rhythm of ventricular fibrillation/tachycardia (VF/VT) and return of spontaneous circulation in the pre-hospital setting (ROSC) is a substantial direct predictor of survival (e.g., 54% of such cases survive). Response time, public location, witnessed, and age are significant but less sizable direct predictors of survival. A second equation shows that these four variables make an additional indirect contribution to survival by affecting the probability of joint presence of VF/VT and ROSC; bystander CPR also makes such an indirect contribution but no significant direct one as shown in the first equation. The projected survival rate if cases had always experienced bystander CPR and rapid response time of less than four minutes is 21%.

Conclusions

The unique model describes the major contribution of VF/VT and ROSC, and key relationships among predictors of survival. These connections may have otherwise gone underreported using standard approaches and should be considered when allocating scarce resources to impact cardiac arrest survival.     

In-hospital cardiac arrest: incidence,prognosis and possible measures to improve survival

Design Review. Objective Medical literature on in-hospital cardiac arrest (IHCA) was reviewed to summarise: (a) the incidence of and survival after IHCA, (b) major prognostic factors, (c) possible interventions to improve survival. Results and conclusions The incidence of IHCA is rarely reported in the literature. Values range between 1 and 5 events per 1,000 hospital admissions, or 0.175 events/bed annually. Reported survival to hospital discharge varies from 0% to 42%, the most common range being between 15% and 20%. Pre-arrest prognostic factors: the prognostic value of age is controversial. Among comorbidities, sepsis, cancer, renal failure and homebound lifestyle are significantly associated with poor survival. However, pre-arrest morbidity scores have not yet been prospectively validated as instruments to predict failure to survive after IHCA. Intra-arrest factors: ventricular fibrillation/ventricular tachycardia (VF/VT) as the first recorded rhythm and a shorter interval between IHCA and cardiopulmonary resuscitation or defibrillation are associated with higher survival. However, VF/VT is present in only 25–35% of IHCAs. Short-term survival is also higher in patients resuscitated with chest compression rates above 80/min. Interventions likely to improve survival include: early recognition and stabilisation of patients at risk of IHCA to enable prevention, faster and better in-hospital resuscitation and early defibrillation. Mild therapeutic hypothermia is effective as post-arrest treatment of out-of-hospital cardiac arrest due to VF/VT, but its benefit after IHCA and after cardiac arrest with non-VF/VT rhythms has not been clearly demonstrated.     

Dual dispatch early defibrillation in out-of-hospital cardiac arrest in a mixed urban–rural population

Aims

The effects of a system based on minimally trained first responders (FR) dispatched simultaneously with the emergency medical services (EMS) of the local hospital in a mixed urban and rural area in Northwestern Switzerland were examined.

Methods and results

In this prospective study 500 voluntary fire fighters received a 4-h training in basic-life-support using automated-external-defibrillation (AED). FR and EMS were simultaneously dispatched in a two-tier rescue system. During the years 2001–2008, response times, resuscitation interventions and outcomes were monitored. 1334 emergencies were included. The FR reached the patients (mean age 60.4 ± 19 years; 65% male) within 6 ± 3 min after emergency calls compared to 12 ± 5 min by the EMS (p < 0.0001). Seventy-six percent of the 297 OHCAs occurred at home. Only 3 emergencies with resuscitation attempts occurred at the main railway station equipped with an on-site AED. FR were on the scene before arrival of the EMS in 1166 (87.4%) cases. Of these, the FR used AED in 611 patients for monitoring or defibrillation. CPR was initiated by the FR in 164 (68.9% of 238 resuscitated patients). 124 patients were defibrillated, of whom 93 (75.0%) were defibrillated first by the FR. Eighteen patients (of whom 13 were defibrillated by the FR) were discharged from hospital in good neurological condition.

Conclusions

Minimally trained fire fighters integrated in an EMS as FR contributed substantially to an increase of the survival rate of OHCAs in a mixed urban and rural area.     

Derangements in blood glucose following initial resuscitation from in-hospital cardiac arrest: A report from the national registry of cardiopulmonary resuscitation

Study aims

Hyperglycemia is associated with poor outcomes in critically ill patients. We examined blood glucose values following in-hospital cardiac arrest (IHCA) to (1) characterize post-arrest glucose ranges, (2) develop outcomes-based thresholds of hyperglycemia and hypoglycemia, and (3) identify risk factors associated with post-arrest glucose derangements.

Methods

We retrospectively studied 17,800 adult IHCA events reported to the National Registry of Cardiopulmonary Resuscitation (NRCPR) from January 1, 2005 through February 1, 2007.

Results

Data were available from 3218 index events. Maximum blood glucose values were elevated in diabetics (median 226 mg/dL [IQR, 165–307 mg/dL], 12.5 mmol/L [IQR 9.2–17.0 mmol/L]) and non-diabetics (median 176 mg/dL [IQR, 135–239 mg/dL], 9.78 mmol/L [IQR 7.5–13.3 mmol/L]). Unadjusted survival to hospital discharge was higher in non-diabetics than diabetics (45.5% [95% CI, 43.3–47.6%] vs. 41.7% [95% CI, 38.9–44.5%], p = 0.037). Non-diabetics displayed decreased adjusted survival odds for minimum glucose values outside the range of 71–170 mg/dL (3.9–9.4 mmol/L) and maximum values outside the range of 111–240 mg/dL (6.2–13.3 mmol/L). Diabetic survival odds decreased for minimum glucose greater than 240 mg/dL (13.3 mmol/L). In non-diabetics, arrest duration was identified as a significant factor associated with the development of hypo- and hyperglycemia.

Conclusions

Hyperglycemia is common in diabetics and non-diabetics following IHCA. Survival odds in diabetics are relatively insensitive to blood glucose with decreased survival only associated with severe (>240 mg/dL, >13.3 mmol/dL) hyperglycemia. In non-diabetics, survival odds were sensitive to hypoglycemia (<70 mg/dL, <3.9 mmol/L).     

窒息法与室颤法复苏模型心脏损伤的比较研究

目的 对比大鼠窒息法和室颤法心搏骤停模型在复苏后不同时期心脏的损伤及恢复情况.方法 动物模型在中山大学心肺脑复苏研究所病理生理实验室完成;35只SD雄性大鼠随机(随机数字法)分组制作窒息法与室颤法诱导8 min心搏骤停的心肺复苏模型及假手术组,于复苏成功后4、24、72 h行心肌HE染色、心肌线粒体呼吸控制率(RCR)、心脏彩超的比较.计量资料用均数±标准差(-x±s)表示,两组均数比较采用t检验,多组比较采用单因素方差分析,以P＜0.05为差异具有统计学意义.结果 HE染色4h室颤组肌溶解较窒息组明显,72 h二组肌纤维排列紊乱;RCR4h室颤组低于窒息组,24 h恢复且两组间差异无统计学意义;心脏彩超示左室射血分数(LVEF)室颤组4h低于窒息组(29.68％ vs.42.16％,P=0.031),24 h室颤组与假手术组无异,而窒息组72 h方与假手术组间差异无统计学意义,72 h两组左室前壁厚度均较假手术组增加(2.41 mm vs.1.72 mm,P=0.013; 2.61 mmvs.1.72 mm,P=0.007),组间差异无统计学意义.结论 室颤模型在复苏后早期心肌损伤较窒息模型严重;中间期两种模型均有所恢复,且室颤组较窒息组更早恢复;复苏后后期两组均出现代偿性心肌肥厚,心功能差异无统计学意义.     

Molecular mechanisms of therapeutic hypothermia on neurological function in a swine model of cardiopulmonary resuscitation

Objective

To explore the molecular mechanisms by which mild hypothermia following resuscitation improves neurological function in a porcine model of cardiac arrest.

Methods

Thirty-three inbred Chinese Wuzhishan (WZS) minipigs were used. After 8 min of untreated ventricular fibrillation (VF), the surviving animals (n = 29) were randomly divided into two groups including serum group (n = 16) and molecular group (n = 13). Serum group animals were used to measure porcine-specific tumour necrosis factor-alpha (TNF-α), interleukin (IL-6, IL-10), matrix metalloproteinase (MMP9), Aquaporin-4 (AQP4), tissue inhibitor to metalloproteinase-1 (TIMP1), neuron-specific enolase (NSE) and S100B at 0.5 h, 6 h, 12 h, 24 h and 72 h recovery by enzyme-linked immunosorbent assay (ELISA). Molecular group animals were used to measure cerebral cortex messenger RNA (mRNA) and protein expression of nuclear factor-κB (NF-κB), MMP9 and AQP4 by real-time (RT) quantitative polymerase chain reaction (PCR) and Western blotting at 24 h and 72 h recovery. Animals were further divided into either normothermia or hypothermia groups. Hypothermia (33 °C) was maintained for 12 h using an endovascular cooling device. Swine neurologic deficit scores (NDS) were used to evaluate neurological function at 24-h and 72-h recovery.

Results

Twenty-nine of the 33 (87.9%) animals were successfully resuscitated. The hypothermia group exhibited higher survival rates at 24 h (75%) and 72 h (62.5%) compared to the normothermia group (37.5% and 25%, respectively). Hypothermia markedly inhibited expression of NF-κB, TNF-α, MMP9 and NSE, and promoted expression of TIMP1 (P < 0.01). The mean NDS at 24-h and 72-h recovery was 112.5 and 61, respectively, in the hypothermic group, and 230 and 207.5, respectively, in the normothermia group.

Conclusion

Brain protection induced by hypothermia involves inhibition of inflammatory and brain edema pathways.     

Comparison of myocardial injures between asphyxia and ventricular fibrillation models of cardiac arrests北大核心CSCD

Objective: To compare the difference in cardiac injuries between asphyxia and ventricular fibrillation modes in different periods after cardiac arrest (CA). Methods: The model was established in Cardiopulmonary Resuscitation Lab, Sun Yat-sen University. A total of 35 male SD rats were used to produce the asphyxia or ventricular fibrillation (VF) cardiac arrest models randomly. Both of the two modes were induced 8 minutes cardiac arrest. The myocardial HE stains, mitochondrial respiratory control ratio (RCR), and echocardiography were observed at 4 h, 24 h and 72 h after ROSC (restoration of spontaneous circulation). The results were expressed as (x¯±s), t test was performed to compare between two groups, and one way analysis of variance was used to compare multiple groups. P <0. 05 was considered as significant difference. Results: HE stains showed damages were more serious in the VF mode than in asphyxia mode at 4 h, and both of them had a disorderly-arranged myocardium at 72 h. RCR in VF mode became worse at 4 h, and RCR resumed at 24 h in both modes without significant difference compared with the sham operated rats. The echocardiography showed VF mode had a lower left ventricular ejection fraction (LVEF) than asphyxia mode at 4 h (29.68% vs. 42. 16%, P =0. 03), and there was no difference in LVEF between VF mode and the sham operated rats at 24 h, however no difference in LVEF between the asphyxia and sham operated rats at 72 h. Both of them had a thicker left ventricular anterior wall than the sham operated rats at 72 h (2. 41 mm vs. 1. 72 mm, P = 0. 013; 2. 61 mm vs. 1. 72 mm, P = 0. 007), and there was no significant difference between them. Conclusions: The ventricular fibrillation mode has a more severe injuries in early period, but it recovers sooner than asphyxia one. Both of two groups get compensatory left ventricular hypertrophy in later period of ROSC.     

A phased approach to cardiac arrest resuscitation involving ventricular fibrillation and pulseless ventricular tachycardia

With the release of the 2010 American Heart Association (AHA) Guidelines for cardiopulmonary resuscitation and emergency cardiac care, evidence regarding management of out-of-hospital cardiac arrest suggests a more fundamental approach. To aid in understanding and learning, this article proposes a method that optimizes the timing and delivery of evidence-proven therapies with a 3-phase approach for out-of-hospital resuscitation from ventricular fibrillation and pulseless ventricular tachycardia. Although this model is not a new concept, it is largely based on the 2010 AHA Guidelines, enhancing the philosophy of the "CAB" concept (Chest compressions/Airway management/Breathing rescue).     

晚电位的临床观察及有关问题的探讨

通过对６０００例不同类型心血管病人晚电位（ＬＰ）的检测：对其方法学及判定标准进行探讨，认为应以ＲＭＳ４０＜２０μＶ（４０Ｈｚ），ＶＡＴ１１０ｔ１１ｓ，ＨＦＬＡ４０ｍｓ三条为阳性标准；同时对滤波、平均迭加、导联系统及生理状态变动的影响亦进行了讨论，强调ＬＰ的动态分析和个体化，在ＬＰ与猝死关系中，认为与广泛心肌损害、持续性／反复发作性室速／室颤、ＱＴｃ延长，以及ＬＰ持续时间＞１００ｍｓ者，可视为亚临床心脏事件预兆。在ＬＰ转阴的观察中，加用中药刺五加是值得重视的问题。     

Effect of cardiopulmonary resuscitation on restoration of myocardial ATP in prolonged ventricular fibrillation

Background

There has been controversy over whether a short period of cardiopulmonary resuscitation (CPR) prior to defibrillation improves survival in patients who experienced a sudden cardiac arrest. However, there have been no reports about whether CPR restores the myocardial energy source during prolonged ventricular fibrillation (VF). The aim of this study is to investigate the effect of CPR in restoring myocardial high energy phosphates during prolonged VF.

Methods and results

Seventy-two adult male Sprague-Dawley rats were used in this study. Baseline adenosine triphosphate (ATP) and adenosine diphosphate (ADP) prior to induction of VF were measured in nine rats, the No-VF group. Sixty-three rats were subjected to 4 min of untreated VF. Animals were then randomized into two groups: No-CPR (n = 37) and CPR (n = 26). In the No-CPR group, ATPs and ADPs were measured at 4 min (No-CPR4), 6 min (No-CPR6), 8 min (No-CPR8) or 10 min (No-CPR10) after the induction of VF. The CPR group received 2 min (CPR2), 4 min (CPR4) or 6 min (CPR6) of mechanical chest compressions before ATP was measured.Myocardial ATP (nmol/mg protein) was decreased as VF duration was prolonged (No-VF: 5.49 ± 1.71, No-CPR4: 4.27 ± 1.58, No-CPR6: 4.13 ± 1.31, No-CPR8: 3.77 ± 1.42, No-CPR10: 3.52 ± 0.90, p < 0.05 between each of No-CPRs vs. No-VF). Two minutes of CPR restored myocardial ATP to the level of No-VF group (5.27 ± 1.67 nmol/mg protein in CPR2, p > 0.05 vs. No-VF group). However, myocardial ATP (nmol/mg protein) decreased if the duration of CPR was longer than 2 min (CPR4: 3.77 ± 1.05, CPR6: 3.49 ± 1.08, p < 0.05 between CPR4 and CPR6 vs. No-VF).

Conclusions

CPR for 2 min helps to maintain myocardial ATP after prolonged VF.