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.     

Postresuscitation accelerated idioventricular rhythm: a potential prognostic factor for out-of-hospital cardiac arrest survivors

Objective Data are lacking on the relationship between postresuscitation ECG and outcome in out-of-hospital cardiac arrest (OHCA). We examined the prognostic information that postresuscitation ECG rhythm can provide for predicting outcome in OHCA survivors. Methods The retrospective observational study enrolled 56 successfully resuscitated nontraumatic adult OHCA patients. Postresuscitation 12-lead ECGs of the enrolled patients were interpreted independently by two cardiologists. We compared baseline clinical characteristics, CPR process, and outcome in the 8 patients with postresuscitation accelerated idioventricular rhythm (AIVR, n = 8) and the 48 without AIVR. Results The AIVR group had a higher proportion of patients with coronary artery disease (50% vs. 15%), initial ventricular tachycardia/fibrillation rhythm (50% vs. 8%), and cardiac origin of OHCA (75% vs. 23%). AIVR patients had longer total CPR duration (32 vs. 18 min) and higher dose of epinephrine use (10 vs. 3 mg). Postresuscitation AIVR was associated with an increased incidence of repeated CPR within 1 h after return of spontaneous circulation (38% vs. 4%), and lower 7-day survival rate (0% vs. 50%). Conclusions AIVR on postresuscitation ECG offers a prognostic factor related to a higher repeated CPR rate within 1 h after return of spontaneous circulation and a lower 7-day survival rates in successfully resuscitated OHCA victims.     

Increased return of spontaneous circulation at the expense of neurologic outcomes: Is prehospital epinephrine for out-of-hospital cardiac arrest really worth it?

IntroductionCurrent guidelines for the management of out-of-hospital cardiac arrest (OHCA) recommend the use of prehospital epinephrine by initial responders. This recommendation was initially based on data from animal models of cardiac arrest and minimal human data, but since its inception, more human data regarding prehospital epinephrine in this setting are now available. Although out-of-hospital return of spontaneous circulation (ROSC) may be higher with the use of epinephrine, worse neurologic outcomes may be associated with its use.MethodsA systematic review of the literature was conducted by search of databases including PubMed, Embase, and OVID to identify studies comparing patients with OHCA who had received epinephrine before arrival to the hospital with those who had not. Studies were assessed for quality and bias, and data were abstracted from studies deemed appropriate for inclusion. A meta-analysis was conducted using a Mantel-Haenszel model for dichotomous outcomes. Outcomes studied were prehospital ROSC, survival at 1 month, survival to discharge, and positive neurologic outcome.ResultsA total of 14 studies with 655 853 patients were included for the meta-analysis. The use of epinephrine for OHCA before arrival to the hospital was associated with a significant increase in ROSC (odds ratio, 2.86; P < .001) and a significant increase in the risk of poor neurologic outcome at the time of discharge (odds ratio 0.51, P = .008). There was no significant difference in survival at 1 month or survival to discharge.ConclusionUse of epinephrine before arrival to the hospital for OHCA does not increase survival to discharge but does make it more likely for those who are discharged to have poor neurologic outcome. There is a need for additional randomized controlled trials.     

Potential association of bystander–patient relationship with bystander response and patient survival in daytime out-of-hospital cardiac arrest

AimTo investigate whether the bystander–patient relationship affects bystander response to out-of-hospital cardiac arrest (OHCA) and patient outcomes depending on the time of day.MethodsThis population-based observational study in Japan involving 139,265 bystander-witnessed OHCAs (90,426 family members, 10,479 friends/colleagues, and 38,360 others) without prehospital physician involvement was conducted from 2005 to 2009. Factors associated with better bystander response [early emergency call and bystander cardiopulmonary resuscitation (BCPR)] and 1-month neurologically favourable survival were assessed.ResultsThe rates of dispatcher-assisted CPR during daytime (7:00–18:59) and nighttime (19:00–6:59) were highest in family members (45.6% and 46.1%, respectively, for family members; 28.7% and 29.2%, respectively, for friends/colleagues; and 28.1% and 25.3%, respectively, for others). However, the BCPR rates were lowest in family members (35.5% and 37.8%, respectively, for family members; 43.7% and 37.8%, respectively, for friends/colleagues; and 59.3% and 50.0%, respectively, for others). Large delays (≥5 min) in placing emergency calls and initiating BCPR were most frequent in family members. The overall survival rate was lowest (2.7%) for family members and highest (9.1%) for friends/colleagues during daytime. Logistic regression analysis revealed that the effect of bystander relationship on survival was significant only during daytime [adjusted odds ratios (95% CI) for survival from daytime OHCAs with family as reference were 1.51 (1.36–1.68) for friends/colleagues and 1.23 (1.13–1.34) for others].ConclusionsFamily members are least likely to perform BCPR and OHCAs witnessed by family members are least likely to survive during daytime. Different strategies are required for family-witnessed OHCAs.     

Effect of the AutoPulse™ automated band chest compression device on hemodynamics in out-of-hospital cardiac arrest resuscitation

Purpose  

Guidelines for advanced life support of cardiac arrest (CA) emphasize continuous and effective chest compressions as one of the main factors of cardiopulmonary resuscitation (CPR) success. The use of an automated load distributing chest compression device for CPR is promising but initial studies on survival show contradictory results. The aim of this study was to evaluate the effects of AutoPulse™ on blood pressure (BP) in out-of-hospital CA patients.     

Trends in the incidence of presumed cardiac out-of-hospital cardiac arrest in Perth,Western Australia, 1997–2010

Aim

This study investigated temporal trends in the incidence of out-of-hospital cardiac arrests (OHCA) in metropolitan Perth (Western Australia) between 1997 and 2010.

Methods

We calculated crude and age-and-sex-standardised incidence rates (ASIRs) using the 2011 Australian population as the standard population. Incidence rates are reported per 100,000 population, and for eight age categories (0–14, 15–34, 35–64, 65–69, 70–74, 75–79, 80–84, ≥85). Temporal trends were analysed with linear regression.

Results

Over the 14-years, 12,421 OHCAs of presumed cardiac aetiology were attended by St John Ambulance Western Australia paramedics. The overall ASIR per 100,000 population decreased significantly over this time (75.7–70.6, p < 0.001), but predominantly between 1997 and 2002 (75.7–65.9) and in those aged ≥65 years (410.2–336.7, p < 0.001). This trend was observed for both males and females and across all five-year age-groups between 65 and 84 years, but not in those ≥85 years − whom by 2010 represented 30% of the older adult (65+ years) OHCAs attended, up from 16% in 1997 (p < 0.001).

Conclusions

Over the study period, a decline in the ASIR for OHCAs of presumed cardiac aetiology in Perth was observed. This is largely attributed to a decreasing incidence in the population aged 65–84 years between 1997 and 2002, and is likely the result of improvements in cardiovascular risk profiles that have previously been reported among Western Australian adults. Future studies of the impact of the ageing population are required.     

Is CPR quality improving? A retrospective study of out-of-hospital cardiac arrest

AIM OF THE STUDY: To evaluate the quality of cardiopulmonary resuscitation (CPR) performed by a physician-manned ambulance, and assess whether it changed with time influenced by developing scientific evidence and guideline changes. MATERIALS AND METHODS: A retrospective, observational study of all cardiac arrest patients (except trauma) older than 18 years treated between May 2003 and December 2006 by the physician-manned ambulance in Oslo. CPR quality was assessed from continuous electronic recordings from the defibrillators (LIFEPAK 12, Physio-Control or a modified Heartstart 4000, Philips Medical Systems). Ventilations were assessed from changes in transthoracic impedance, chest compressions from transthoracic impedance for LIFEPAK 12 and from an accelerometer for Heartstart 4000 (nine patients). Values are given as mean+/-S.D. and differences analysed with ANOVA and unpaired Student's t-test with Bonferroni correction. RESULTS: Forty-eight of 169 consecutive cases were excluded from CPR quality analysis, 47 due to missing defibrillator data and one due to a short arrest time (<1min). Hands-off intervals (fraction of time without spontaneous circulation where no chest compressions are given) were reduced from 0.18+/-0.11 in 2003 to 0.10+/-0.06 in 2006 (p=0.03). Compression and ventilation rates were significantly reduced from 122+/-12 and 16+/-3min(-1), respectively in 2003 to 111+/-10 and 12+/-3 in 2006 (p<0.0001 and p=0.001). In 2003-2004 10% were discharged alive versus 16% in 2005-2006 (p=0.3, Chi-square test). CONCLUSION: High quality CPR is achievable out-of-hospital, and the improvement with time could reflect developing scientific evidence focusing on reducing hands-off intervals and hyperventilation.     

Association of gender to outcome after out-of-hospital cardiac arrest – a report from the International Cardiac Arrest Registry

IntroductionPrevious studies have suggested an effect of gender on outcome after out-of-hospital cardiac arrest (OHCA), but the results are conflicting. We aimed to investigate the association of gender to outcome, coronary angiography (CAG) and adverse events in OHCA survivors treated with mild induced hypothermia (MIH).MethodsWe performed a retrospective analysis of prospectively collected data from the International Cardiac Arrest Registry. Adult patients with a non-traumatic OHCA and treated with MIH were included. Good neurological outcome was defined as a cerebral performance category (CPC) of 1 or 2.ResultsA total of 1,667 patients, 472 women (28%) and 1,195 men (72%), met the inclusion criteria. Men were more likely to receive bystander cardiopulmonary resuscitation, have an initial shockable rhythm and to have a presumed cardiac cause of arrest. At hospital discharge, men had a higher survival rate (52% vs. 38%, P <0.001) and more often a good neurological outcome (43% vs. 32%, P <0.001) in the univariate analysis. When adjusting for baseline characteristics, male gender was associated with improved survival (OR 1.34, 95% CI 1.01 to 1.78) but no longer with neurological outcome (OR 1.24, 95% CI 0.92 to 1.67). Adverse events were common; women more often had hypokalemia, hypomagnesemia and bleeding requiring transfusion, while men had more pneumonia. In a subgroup analysis of patients with a presumed cardiac cause of arrest (n = 1,361), men more often had CAG performed on admission (58% vs. 50%, P = 0.02) but this discrepancy disappeared in an adjusted analysis.ConclusionsGender differences exist regarding cause of arrest, adverse events and outcome. Male gender was independently associated with survival but not with neurological outcome.     

Does the end-tidal carbon dioxide (EtCO2) concentration have prognostic value during out-of-hospital cardiac arrest?

We aimed to investigate the utility of end-tidal carbon dioxide concentration as a prognostic indicator of initial outcome of resuscitation, we conducted a prospective study of EtCO2 in adult victims of out-of-hospital non-traumatic cardiac arrest. We prospectively studied 139 adult patients. The initial, final, average, minimal and maximal EtCO2 was significantly higher in resuscitated patients than in non-resuscitated patients. Using an initial, average and final EtCO2 value of 10 mmHg correctly identified 100% of the patients who were subsequently resuscitated with an acceptable specificity (74.1%; 90%; 81.4%). Important observation from this study is that none of the patients with an average, initial and final EtCO2 level of less than 10 mmHg were resuscitated. Data from this prospective clinical trial indicate that initial, average and final EtCO2 monitoring during CPR is correlated with resuscitation. End-tidal CO2 monitoring has potential as a noninvasive indicator of cardiac output during resuscitation and a prognostic indicator for resuscitation.     

Comparison of myocardial metabolism by using PET after resuscitation between ventricular fibrillation cardiac arrest and asphyxia cardiac arrest北大核心CSCD

Objective To characterize myocardial metabolism using positron emission tomography (PET) in porcine models of ventricular fibrillation cardiac arrest (VFCA) and asphyxiation cardiac arrest (ACA) after resuscitation. Methods Thirty-Two healthy miniature pigs were randomized into two groups. The pigs of VFCA group (a = 16) were subject to programmed electric stimulation to create a ventricular fibrillation cardiac arrest, and the pigs of ACA group (n = 16) were subjected to endotracheal tube clamping to establish a cardiac arrest (CA). Once modeling was established, pigs with CA were left untreated for a period of 8 mm. Two minutes following initiation of cardiopulmonary resuscitation (CPR), defibrillation was attempted until the restoration of spontaneous circulation (ROSC) was achieved or animals died. To assess myocardial metabolism, PET was performed before modeling, 4 hrs and 24hrs after ROSC. To analyze 18F-FDG myocardial uptake in PET, the maximum standardized uptake value (SUV1) was measured. Results ROSC was obtained in 100% of pigs in VFCA group and only 50% in ACA group. The average survival time in VFCA pigs was significantly longer than that in ACA pigs (22. 63 ± 0. 95) hvs. (8. 75 ± 2. 54) h, P <0.01. VFCA pigs had better mean arterial pressure and cardiac output after ROSC than ACA pigs. Myocardial metabolism imaging using PET demonstrated that myocardial metabolism injuries after ACA were more severe and widespread than those after VFCA at 4 hrs and 24hrs after ROSC and SUV> was much higher in VFCA group than that in ACA group [4 h after ROSC: (1.9 ± 0. 3) vs. (1.0 ±0.4), P <0. 01; 24 h after ROSC: (2.4 ±0.6) vs. (1.2±0.5), P <0.01]. Conclusions Compared with VFCA, ACA causes more severe cardiac metabolism dysfunction associated with less successful resuscitation and shorter survival time; therefore they should he treated as different pathological entities.     

Improved outcome of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest – A comparison with that for extracorporeal rescue for in-hospital cardiac arrest

Purpose

The aim was to investigate the effects of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) and compare the results with those of in-hospital cardiac arrest (IHCA).

Methods

We analyzed our extracorporeal membrane oxygenation (ECMO) results for patients who received ECPR for OHCA or IHCA in the last 5 years. Pre-arrest, resuscitation, and post-resuscitative data were evaluated.

Results

In the last 5 years, ECPR was used 230 times for OHCA (n = 31) and IHCA (n = 199). The basic demographic data showed significant differences in age, cardiomyopathy, and location of the initial CPR. Duration of ischemia was shorter in the IHCA group (44.4 ± 24.7 min vs. 67.5 ± 30.6 min, p < 0.05). About 50% of each group underwent a further intervention to treat the underlying etiology. ECMO was maintained for a shorter duration in the OHCA patients (61 ± 48 h vs. 94 ± 122 h, p < 0.05). Survival to discharge was similar in the two groups (38.7% for OHCA vs. 31.2% for IHCA, p > 0.05), as was the favorable outcome rate (25.5% for OHCA vs. 25.1% for IHCA, p > 0.05). Survival was acceptable (about 33%) in both groups when the duration of ischemia was no longer than 75 min.

Conclusions

In addition to having a beneficial effect in IHCA, ECPR can lead to survival and a positive neurological outcome in selected OHCA patients after prolonged resuscitation. Our results suggest that further investigation of the use of ECMO in OHCA is warranted.     

Infections in the survivors of out-of-hospital cardiac arrest in the first 7 days

Objective To evaluate the incidence, risk factors, foci, isolated organisms, and outcomes of infections in the survivors of out-of-hospital cardiac arrest (OHCA) within the first 7 days after resuscitation.Design and setting Retrospective cohort study in the intensive care unit of a university hospital.Patients and participants We enrolled 117 survivors of adult nontraumatic OHCA victims who survived more than 24 h between January 1999 and May 2004. We collected patients demographics, the causes and initial electrocardiographic rhythm of cardiac arrest, and the process of cardiopulmonary resuscitation. The incidence, clinical presentations and outcomes of infections occurring in the first 7 days after resuscitation were evaluated. Variables were compared between the infected and noninfected patients.Measurements and results Among our OHCA survivors asystole was the most common initial rhythm (66%). Eighty-three patients (71%) were found to have infection. Pneumonia was the most common infection (61%) followed by bacteremia (13%). Although the Gram-negative bacteria were responsible for most infections, the most commonly isolated organism was Staphylococcus aureus. The infection group had more patients with dementia and noncardiac causes of OHCA. The survival curves did not differ significantly between infection and noninfection groups.Conclusions Infections were common in OHCA survivors during the first 7 days. The most common responsible organisms were Gram-negative bacteria, and the most commonly isolated organism was S. aureus. Infections in the early stage after return of spontaneous circulation did not change the hospital mortality and hospitalization duration.     

What is the appropriate outcome for studies of treatments for out-of-hospital cardiac arrest?

BACKGROUND: A good outcome following out-of-hospital medical care for cardiac arrest is survival to hospital discharge. Because a large number of patients are required to detect a minimum clinically important difference in survival, an intermediate outcome such as hospital admittance is commonly used. For an intermediate outcome to be a useful surrogate, the survival rate conditional on achieving the intermediate outcome should not depend upon the field treatment. If so, an advantage of the intermediate outcome may be a smaller sample size. However, recent trials demonstrate that survival conditional on admittance may depend upon the field treatment. Even if the resources are available to power a study for survival, is survival the right outcome? For example, no increase in survival and a large increase in admittance could be considered a bad result, as it represents a substantial waste of resources. Similarly no increase in mortality and a decrease in admittance should be considered a good result, as it represents a substantial cost savings without any sacrifice of life. Both admittance and survival are important outcomes and need to be considered jointly, that is, as a bivariate outcome. METHODS: Cost-effectiveness concepts are used to distinguish between a good and bad (bivariate) outcome. Simulations are conducted to compare the impact of the univariate and the bivariate outcomes in a variety of trial scenarios. A table of sample sizes is computed for the bivariate outcome across a range of trial scenarios. RESULTS: The bivariate outcome outperforms both univariate outcomes for most alternatives. The required sample size for the joint outcome of admittance and survival may be substantially, over 50%, less than that for the survival outcome alone. CONCLUSION: Use of the bivariate outcome could provide more informed decision making about resuscitation strategies and at less cost then the current gold standard of hospital survival.     

Targeted temperature management after out-of-hospital cardiac arrest: Who,when, why,and how?

ObjectiveTo provide a succinct review of the evidence, framed for the emergency department clinician, for the application of targeted temperature management (TTM) for patients after out-of-hospital cardiac arrest (OHCA).ConclusionTargeted temperature management, with a target temperature between 32°C and 36°C, as a component of comprehensive critical care is a beneficial intervention for comatose patients with return of spontaneous circulation after OHCA.