Use of automated external defibrillators in patients with traumatic out-of-hospital cardiac arrest

Background

Because out-of-hospital cardiac arrests (OHCAs) due to a major trauma rarely present with shockable rhythms, the potential benefits of using automated external defibrillators (AEDs) at the scene of traumatic OHCAs have not been examined.

Methods

We conducted an observational, retrospective cohort study using an Utstein-style analysis in Tainan city, Taiwan. The enrollees were adult patients with traumatic OHCAs accessed by emergency medical technicians (EMTs) from January 1, 2004 to December 31, 2010. The exposure was the use or non-use of AEDs at the scene, as determined by the clinical judgment of the EMTs. The primary outcome evaluated was a sustained (≥2 h) return of spontaneous circulation (ROSC), and the secondary outcomes were prehospital ROSC, overall ROSC, survival to hospital admission, survival at one month and favorable neurologic status at one month.

Results

A total of 424 patients (313 males) were enrolled, of whom 280 had AEDs applied, and 144 did not. Only 25 (5.9%) patients had received bystander cardiopulmonary resuscitation (CPR), and merely 21 (7.5%) patients in the AED group presented with shockable rhythms. Compared to the non-AED group, the primary and secondary outcomes of the AED group were not significantly different, except for a significantly lower prehospital ROSC rate (1.1% vs 4.9%, p < 0.05). Multivariate analysis showed no significant interactions between the use of AEDs and other key variables. Use of the AED was not associated with sustained ROSC (OR 1.33; 95% CI 0.75–2.38, p = 0.33).

Conclusions

In a community with a low prevalence of shockable rhythms and administration of bystander CPR in patients with traumatic OHCA, we found no significant differences in the sustained ROSC between the AED and the non-AED groups. Considering scene safety and the possible interruption of CPR, we do not encourage the routine use of AEDs at the scene of traumatic OHCAs.     

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.     

Direction of first bystander call for help is associated with outcome from out-of-hospital cardiac arrest

Background

Preventable bystander delays following out-of-hospital cardiac arrest (OHCA) are common, and include bystanders inappropriately directing their calls for help.

Methods

We retrospectively extracted Utstein-style data from the Victorian Ambulance Cardiac Arrest Registry (VACAR) for adult OHCA occurring in Victoria, Australia, between July 2002 and June 2012. Emergency medical service (EMS) witnessed events were excluded. Cases were assigned into two groups on the basis of the first bystander call for help being directed to EMS. Study outcomes were: likelihood of receiving EMS treatment; survival to hospital, and; survival to hospital discharge.

Results

A total of 44 499 adult OHCA cases attended by EMS were identified, of which first bystander calls for help were not directed to EMS in 2842 (6.4%) cases. Calls to a relative, friend or neighbour accounted for almost 60% of the total emergency call delays. Patient characteristics and survival outcomes were consistently less favourable when calls were directed to others. First bystander call to others was independently associated with older age, male gender, arrest in private location, and arrest in a rural region. The risk-adjusted odds of treatment by EMS (OR 1.33, 95% CI 1.20–1.48), survival to hospital (OR 1.64, 95% CI 1.37–1.96) and survival to hospital discharge (OR 1.64, 95% CI 1.13–2.36) were significantly improved if bystanders called EMS first.

Conclusion

The frequency of inappropriate bystander calls following OHCA was low, but associated with a reduced likelihood of treatment by EMS and poorer survival outcomes.     

A national resuscitation registry of out-of-hospital cardiac arrest in Germany—A pilot study

Background

Survival rate after out-of-hospital cardiac arrest (OHCA) has not significantly increased over the last decade. However, survival rate has been used as a quality benchmark for many emergency medical services. A uniform resuscitation registry may be advantageous for quality management of cardiopulmonary resuscitation (CPR). This study was conducted to evaluate the establishment of a national CPR registry in Germany.

Materials and methods

A prospective cohort study was performed that included 469 patients who experienced OHCA requiring CPR in the metropolitan area of Dortmund, Germany. Cardiac arrest was defined as concomitant appearance of unconsciousness, apnoea or gasping and pulselessness. All data were collected via a secure and confidential paper-based method as the data set ‘Preclinical care’.

Results

Quality of data was classified as ‘good’ in 33.4%, ‘moderate’ in 48.4%, and ‘bad’ in 18.2% of the patients, respectively. Sixty-two percent had OHCA in private residences, 24% of the patients had a first monitored rhythm of ventricular fibrillation (VF) or ventricular tachycardia (VT), 35.2% had return of spontaneous circulation (ROSC) on scene, and patients presenting VF/VT as the first monitored rhythm had higher ROSC rates (51.3%) compared to patients with asystole (22.6%).

Conclusion

The data set ‘Preclinical care’ proved to be congruent with the Utstein style, provided further information for national and international comparisons, and enabled a detailed analysis. Optimisation of data collection and introduction of strict control mechanisms may further improve data quality.     

Implementation trial of the basic life support termination of resuscitation rule: Reducing the transport of futile out-of-hospital cardiac arrests

Background

The basic life support (BLS) termination of resuscitation (TOR) rule recommends transport and continued resuscitation when cardiac arrest is witnessed by EMT-Ds, or there is a return of spontaneous circulation, or a shock is given, and prior studies have suggested the transport rate should fall to 37%.

Methods and results

This real-time prospective multi-center implementation trial evaluated the BLS TOR rule for compliance, transport rate and provider and physician comfort. Both provider and physician noted their decision-making rationale and ranked their comfort on a 5-point Likert scale. Functional survival was measured at discharge. Of 2421 cardiac arrests, 953 patients were eligible for the rule, which was applied correctly for 755 patients (79%) of which 388 were terminated. 565 patients were transported resulting in a reduction of the transport rate from 100% (historical control) to 59% (p < 0.001). The BLS TOR rule was not followed in 198 eligible patients (21%) and they were all transported despite meeting the criteria to terminate. Providers cited 241 reasons for non-compliance: family distress, short transport time interval, younger age and public venue. All 198 transported patients, non-compliant with the rule, died. Both providers and physicians were comfortable with using the rule to guide TOR (median [IQR] of 5 [4,5]; p < 0.001).

Conclusions

This implementation trial confirmed the accuracy of the BLS TOR rule in identifying futile out-of-hospital cardiac arrest (OHCA) resuscitations, significantly reduced the transport rate of futile OHCA and most providers and physicians were comfortable following the rule's recommendations.     

New treatment bundles improve survival in out-of-hospital cardiac arrest patients: A historical comparison

Introduction

Before the introduction of the new international cardiac arrest treatment guidelines in 2005, patients with out-of-hospital cardiac arrest (OHCA) of cardiac origin in Northern Italy had very poor prognosis. Since 2006, a new bundle of care comprising use of automated external defibrillators (AEDs) and therapeutic hypothermia (TH) was started, while extracorporeal CPR program (ECPR) for selected refractory CA and dispatcher-assisted cardio-pulmonary resuscitation (CPR) was started in January 2010.

Objectives

We hypothesized that a program of bundled care might improve outcome of OHCA patients.

Methods

We analyzed data collected in the OHCA registry of the MB area between September 2007 and August 2011 and compared this with data from 2000 to 2003.

Results

Between 2007 and 2011, 1128 OHCAs occurred in the MB area, 745 received CPR and 461 of these had a CA of presumed cardiac origin. Of these, 125 (27%) achieved sustained ROSC, 60 (13%) survived to 1 month, of whom 51 (11%) were discharged from hospital with a good neurological outcome (CPC ≤ 2), and 9 with a poor neurological outcome (CPC > 2).Compared with data from the 2000 to 2003 periods, survival increased from 5.6% to 13.01% (p < 0.0001). In the 2007–2011 group, low-flow time and bystander CPR were independent markers of survival.

Conclusions

OHCA survival has improved in our region. An increased bystander CPR rate associated with dispatcher-assisted CPR was the most significant cause of increased survival, but duration of CA remains critical for patient outcome.     

Outcomes following out-of-hospital cardiac arrest with an initial cardiac rhythm of asystole or pulseless electrical activity in Victoria,Australia

Background

While internationally reported survival from out-of-hospital cardiac arrest (OHCA) is improving, much of the increase is being observed in patients presenting to emergency medical services (EMS) in shockable rhythms. The purpose of this study was to assess survival and 12-month functional recovery in patients presenting to EMS in asystole or pulseless electrical activity (PEA).

Methods

The Victorian Ambulance Cardiac Arrest Registry was searched for adult OHCA patients presenting in non-shockable rhythms in Victoria, Australia between 1st July 2003 and 30th June 2013. We excluded patients defibrillated prior to EMS arrival and arrests witnessed by EMS. Twelve-month quality-of-life interviews were conducted on survivors who arrested between 1st January 2010 and 31st December 2012. The main outcome measures were survival to hospital discharge and 12-month functional recovery measured by the Extended Glasgow Outcome Scale (GOSE).

Results

A total of 38,378 non-shockable OHCA attended by EMS were included, of which 88.0% were asystole and 11.6% were PEA. Of the patients receiving resuscitation, survival to hospital discharge was 1.1% for asystole and 5.9% for PEA (p < 0.001), with no significant improvement observed over the 10 year study period. In survivors with 12-month follow-up data, the combined rate of death, vegetative state or lower severe disability was 66.7% (95% CI 41.0–80.0%) for asystole and 44.7% (95% CI 30.2–59.9%) for PEA.

Conclusion

Survival outcomes following OHCA with initial rhythms of asystole or PEA did not improve over the 10-year study period. Our findings indicate high rates of death within 12 months, and unfavourable functional recovery for survivors.     

Assessment of a three-phase model of out-of-hospital cardiac arrest in patients with ventricular fibrillation

AIM: Cardiac arrest with ventricular fibrillation (VF) has been divided into three phases in which phase-specific therapy may improve outcome. The aim of this study was to assess the relationship between call-to-shock time, bystander CPR (BCPR), and cardiac arrest outcomes. METHODS: In a retrospective analysis of prospectively-acquired data from witnessed VF out-of-hospital cardiac arrests (OHCA), patients were classified as phases 1, 2, or 3 based on call-to-shock time (<5, 5-8, and >8 min) and further stratified based on performance of BCPR. Groups were compared with regard to survival, neurological outcome, and restoration of spontaneous circulation (ROSC) with defibrillation only (no ALS interventions to achieve sustained ROSC). RESULTS: Survival, neurologically intact survival, and ROSC with defibrillation were different between phases 1 and 2 (p=0.014 and p=0.005, p<0.01) but not between phases 2 and 3. Patients were further classified as having received BCPR (N=111) or no BCPR (N=107). Neurologically intact survival with and without BCPR, respectively, was 61% versus 72% (phase 1), 44% versus 41% (phase 2), and 42% versus 29% (phase 3). ROSC with defibrillation only with and without BCPR, respectively, was 64% versus 56% (phase 1), 37.0% versus 29% (phase 2), and 33% versus 8% (phase 3). ROSC with defibrillation alone was statistically higher in univariate analysis in phase 3 with BCPR (p=0.033) but not in multivariate analysis (p=0.068). CONCLUSIONS: BCPR did not significantly improve survival in any phase of OHCA, though there was a trend toward increased neurologically intact survival and increased ROSC with defibrillation alone in phase 3.     

Evaluation of emergency medical dispatch in out-of-hospital cardiac arrest in Taipei

INTRODUCTION: Emergency medical dispatchers are the entry points to the emergency medical services (EMS). The overall performances of the dispatchers are imperative determinants of the emergency medical services dispatching system. There is little data on the cultural and language impacts on emergency medical dispatch. OBJECTIVE: This study examined the emotional content and cooperation score (ECCS) among Mandarin Chinese speaking callers for cardiac arrests, and evaluated the performances of emergency medical services dispatching system in Taipei. METHODS: This retrospective, observational study examined dispatching audio recordings obtained from the Taipei City Fire Department Dispatching Center between January 2004 to April 2004. The tapes of call relating to adult (age >or=18 years), non-traumatic cases with a presumed or field diagnosis of out-of-hospital cardiac arrest (OHCA) underwent systemic review. The caller's ECCS and the dispatcher's performances, including interview skills, provision of telephone-assisted cardiopulmonary resuscitation (T-CPR), and dispatcher's ability to identify OHCA were examined. Interrater reliability for determining ECCS and interview skills were assessed using kappa statistic. RESULTS: A total of 199 audio recordings were reviewed. A mean ECCS of 1.42+/-0.64 (95% CI: 1.33-1.51) demonstrated that most callers were emotionally stable and cooperative when calling for help, even when facing cardiac arrest patients. There was a good association between ECCS and the sex of the callers (male 1.32 versus female 1.49; p<0.05). In 82% of interviews, the interview skills of the dispatchers was high (4 or 5 points); while in one fifth the interview skills were suboptimal. About one third of the cases were provided with T-CPR by the dispatchers. The sensitivity and positive predictive value (PPV) for predicting OHCA by dispatchers were 96.9% and 97.9%, respectively. A kappa value of 0.65 and 0.68 were obtained for the interrater reliability of ECCS and interview skills. CONCLUSION: Most callers were found to be emotional stable and cooperative with dispatcher's interrogations when calling for cardiac arrest victims in this Mandarin speaking population. The dispatchers have shown satisfactory interview skills in approaching emergency calls and a good ability to identify OHCA. There is a low rate of T-CPR offered to the callers in the investigation. Efforts should be made to address the deficiencies in order to maximise the function of the EMS.     

A simpler cardiac arrest model in the mouse

OBJECTIVE: Delivering alternating currency (AC) to right ventricular endocardium to induce ventricular fibrillation (VF) in mice is complicated. We tried to validate whether transoesophageal AC stimulation could induce VF and how long AC stimulation had to be sustained to prevent the spontaneous cardioversion of VF in mice. METHODS: A pacing electrode was inserted orally into the oesophagus and AC was delivered to esophagus through the pacing electrode to stimulate the heart and induce VF in 15 mice. The incidence of VF and time of AC stimulation were recorded 4min after onset of VF cardiopulmonary resuscitation (CPR) was started. RESULTS: VF was induced by short AC stimulation in all 15 mice. With the prolongation of AC stimulation, the incidences of spontaneous cardioversion of VF decreased whereas the incidence of pulseless electrical activity (PEA) increased accordingly. Following the termination of prolonged AC stimulation, VF occurred only in 1 of 15 mice, but PEA in 14 of 15 mice. Before CPR 1 of 15 and 12 of 15 animals remained in VF and in PEA, respectively, while 2 of 15 animals developed into asystole. After CPR, 11 of 15 animals were successfully resuscitated. CONCLUSION: VF can be induced by a short period of transoesophageal AC stimulation in mice. However, prolonged AC stimulation is prone to induce PEA other than VF. Nonetheless, the development of a mouse CA model in this manner is simpler and easier, which may have practical significance for facilitating experimental investigation on CA and CPR.     

CPR before defibrillation in out-of-hospital cardiac arrest: a randomized trial

Objective: Current resuscitation guidelines recommend that defibrillation be undertaken as soon as possible in patients suffering a cardiac arrest where the cardiac rhythm is either ventricular fibrillation (VF) or ventricular tachycardia (VT). Evidence from animal and clinical studies suggests that outcomes may be improved if a period of cardiopulmonary resuscitation (CPR) is given prior to defibrillation. The objective of this study was to determine if 90 seconds of CPR before defibrillation improved survival. Methods: Patients suffering non‐paramedic witnessed VF/VT cardiac arrest were randomized to receive either 90 seconds of CPR before defibrillation (treatment) or immediate defibrillation (control). The study was carried out in Perth, Western Australia between June 2000 and June 2002. The primary endpoint was survival to hospital discharge with secondary endpoints of return of spontaneous circulation (ROSC) and survival at 1 year. Results: A total of 256 patients underwent randomization. Baseline characteristics including response intervals were similar in both groups. Survival to hospital discharge in the CPR first group was 4.2% (5/119) compared with 5.1% (7/137) for the immediate defibrillation group (OR 0.81; 95%CI. 0.25–2.64). No difference in those achieving ROSC was observed between the groups (OR 1.16; 95% CI 0.49–2.80). Conclusion: Ninety seconds of CPR before defibrillation does not improve overall survival in patients suffering VF/VT cardiac arrests. Further studies to evaluate various aspects of this treatment strategy are required as published outcomes to date are inconclusive.     

Outcomes from out-of-hospital cardiac arrest in Detroit

OBJECTIVE: To determine the out-of-hospital cardiac arrest survival rate, and prevalence of modifiable factors associated with survival, in Detroit, Michigan, over a 6-month period of time in 2002. METHODS: A retrospective review of all out-of-hospital cardiac arrests responded to by the Detroit Fire Department, Division of Emergency Medical Services. All elements of the EMS runsheet were transcribed to a database for analysis. Patient hospital records were reviewed to determine survival to hospital admission. All survivors to hospital admission were surveyed later in the Michigan Department of Vital Records death registry search. RESULTS: During this study timeframe, there were 538 confirmed out-of-hospital cardiac arrests within the City of Detroit, of which 67 were excluded for being dead on scene [51 (12.5%)] or having no available hospital records [16 (3.0%)]. Of the remaining 471 patients, 443 (94.1%) died before hospital admission. Only 44 (9.9%) of the 471 patients had a first recorded rhythm of ventricular fibrillation (VF), and 339 (76.5%) were asystolic. Of the 28 patients who survived to hospital admission, only 2 (7.1%) were noted to have a first rhythm of VF, and 15 (53.6%) were asystolic. Only one patient survived to hospital discharge. CONCLUSIONS: In this urban setting, out-of-hospital cardiac arrest is an almost uniformly fatal event.     

Scene time interval and good neurological recovery in out-of-hospital cardiac arrest

Objectives

It is unclear whether scene time interval (STI) is associated with better neurological recovery in the emergency medical service (EMS) system with intermediate service level.

The time dependent association of adrenaline administration and survival from out-of-hospital cardiac arrest

BackgroundRecommended for decades, the therapeutic value of adrenaline (epinephrine) in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) is controversial.PurposeTo investigate the possible time-dependent outcomes associated with adrenaline administration by Emergency Medical Services personnel (EMS).MethodsA retrospective analysis of prospectively collected data from a near statewide cardiac resuscitation database between 1 January 2005 and 30 November 2013. Multivariable logistic regression was used to analyze the effect of the time interval between EMS dispatch and the initial dose of adrenaline on survival. The primary endpoints were survival to hospital discharge and favourable neurologic outcome.ResultsData from 3469 patients with witnessed OHCA were analyzed. Their mean age was 66.3 years and 69% were male. An initially shockable rhythm was present in 41.8% of patients. Based on a multivariable logistic regression model with initial adrenaline administration time interval (AATI) from EMS dispatch as the covariate, survival was greatest when adrenaline was administered very early but decreased rapidly with increasing (AATI); odds ratio 0.94 (95% Confidence Interval (CI) 0.92–0.97). The AATI had no significant effect on good neurological outcome (OR = 0.96, 95% CI = 0.90–1.02).ConclusionsIn patients with OHCA, survival to hospital discharge was greater in those treated early with adrenaline by EMS especially in the subset of patients with a shockable rhythm. However survival rapidly decreased with increasing adrenaline administration time intervals (AATI).     

Survival rates in out-of-hospital cardiac arrest patients transported without prehospital return of spontaneous circulation: An observational cohort study

Background

Some Emergency Medical Services currently use just one component of the Universal Termination of Resuscitation (TOR) Guideline, the absence of prehospital return of spontaneous circulation (ROSC), as the single criteria to terminate resuscitation, which may deny transport to potential survivors.

Objective

This study aimed to report the survival to hospital discharge rate in non-traumatic, adult out-of-hospital cardiac arrest (OHCA) patients transported to hospital without a prehospital ROSC.

Methods

An observational study of OHCA patients without a prehospital ROSC who met the Universal TOR Guideline for transport to hospital with ongoing resuscitation. Multivariable logistic regression was used to determine the association of each variable with survival to hospital discharge.

Results

Of 20,207 OHCA treated by EMS, 3374 (16.4%) did not have a prehospital ROSC but met the Universal TOR guideline for transport to hospital with ongoing resuscitation. Of these patients, 122 (3.6%) survived to hospital discharge. Survival to discharge was associated with initial shockable VF/VT rhythms (OR 5.07; 95% CI 2.77–9.30), EMS-witnessed arrests (OR 3.51; 95% CI 1.73–7.15), bystander-witnessed arrests (OR 2.11; 95% CI 1.18–3.77), and public locations (OR 1.57; 95% CI 1.02–2.40).

Conclusion

In OHCA patients without a prehospital ROSC who met the Universal TOR Guideline for transport with ongoing resuscitation survival rates were above the 1% futility rate. Employing only the lack of ROSC as criteria for termination of resuscitation may miss survivors after OHCA.     

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.     

Causes for the declining proportion of ventricular fibrillation in out-of-hospital cardiac arrest

AimsThe reported proportion of ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OHCA) has declined worldwide. VF decline may be caused by less VF at collapse and/or faster dissolution of VF into asystole. We aimed to determine the causes of VF decline by comparing VF proportions in relation to delay from emergency medical services (EMS) call to initial ECG (call-to-ECG delay), and VF dissolution rates between two study periods.MethodsData from the AmsteRdam REsuscitation STudies (ARREST), an ongoing OHCA registry in the Netherlands, were used. We studied cardiac OHCA in the study periods 1995–1997 (n = 917) and 2006–2012 (n = 5695). Cases with available ECG and information on call-to-ECG delay were included. We tested whether initial VF proportion and VF dissolution rates differed between both study periods using logistic regression.ResultsDespite a 15% VF decline between the periods, VF proportion around EMS call remained high in 2006–2012 (64%). The odds ratio (OR) for VF proportion in 2006–2012 vs. 1995–1997 was 0.52 (95%-CI 0.45–0.60, P < 0.001), with similar rates of VF dissolution in both periods (P = 0.83). VF decline was higher for unwitnessed collapse (OR 0.41, 95%-CI 0.28–0.58) and collapse at home (OR 0.50, 95%-CI 0.42–0.59), but not for categories of bystander CPR, age or sex.ConclusionVF proportion early after collapse remains high. VF decline is explained by the occurrence of less initial VF, rather than faster dissolving VF. An increase in unwitnessed OHCA and collapse at home contributes to the observed VF decline.     

Comparison of out-of-hospital cardiac arrest occurring before and after paramedic arrival: Epidemiology,survival to hospital discharge and 12-month functional recovery

BackgroundDespite immediate resuscitation, survival rates following out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) are reportedly low. We sought to compare survival and 12-month functional recovery outcomes for OHCA occurring before and after EMS arrival.MethodsBetween 1st July 2008 and 30th June 2013, we included 8648 adult OHCA cases receiving an EMS attempted resuscitation from the Victorian Ambulance Cardiac Arrest Registry, and categorised them into five groups: bystander witnessed cases ± bystander CPR, unwitnessed cases ± bystander CPR, and EMS witnessed cases. The main outcomes were survival to hospital and survival to hospital discharge. Twelve-month survival with good functional recovery was measured in a sub-group of patients using the Extended Glasgow Outcome Scale (GOSE).ResultsBaseline and arrest characteristics differed significantly across groups. Unadjusted survival outcomes were highest among bystander witnessed cases receiving bystander CPR and EMS witnessed cases, however outcomes differed significantly between these groups: survival to hospital (46.0% vs. 53.4% respectively, p < 0.001); survival to hospital discharge (21.1% vs. 34.9% respectively, p < 0.001). When compared to bystander witnessed cases receiving bystander CPR, EMS witnessed cases were associated with a significant improvement in the risk adjusted odds of survival to hospital (OR 2.02, 95% CI: 1.75–2.35), survival to hospital discharge (OR 6.16, 95% CI: 5.04–7.52) and survival to 12 months with good functional recovery (OR 5.56, 95% CI: 4.18–7.40).ConclusionWhen compared to OHCA occurring prior to EMS arrival, EMS witnessed arrests were associated with significantly higher survival to hospital discharge rates and favourable neurological recovery at 12-month post-arrest.     

Clinical experience with a low-energy pulsed biphasic waveform in out-of-hospital cardiac arrest

The efficiency of a pulsed biphasic waveform (PBW) was compared with that of biphasic truncated exponential (BTE) waveforms. First defibrillation shock outcome was studied in a population of 104 out-of-hospital cardiac arrest patients in ventricular fibrillation as the presenting rhythm. The call to first shock time was 8.2+/-5.4 min. At 5s post-shock, defibrillation efficiency was 90%. The arrest was witnessed in only 50% of the patients and only 5% received bystander CPR. Despite these limitations 38% of the patients achieved restoration of a spontaneous circulation at departure from scene and 9.8% were discharged from the hospital. These observations demonstrate a rate of first shock success in termination of ventricular fibrillation comparable to that reported with biphasic truncated exponential waveforms in out-of-hospital cardiac arrest.     

Association of the time to first epinephrine administration and outcomes in out-of-hospital cardiac arrest: SOS-KANTO 2012 study

Objective

This study assessed the association between the timing of first epinephrine administration (EA) and the neurological outcomes following out-of-hospital cardiac arrests (OHCAs) with both initial shockable and non-shockable rhythms.