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Background: Antiarrhythmic drugs have not proven to significantly improve overall survival after out-of-hospital cardiac arrest from shock-refractory ventricular fibrillation/pulseless ventricular tachycardia. How this might be influenced by the route of drug administration is not known. Methods: In this prespecified analysis of a randomized, placebo-controlled clinical trial, we compared the differences in survival to hospital discharge in adults with shock-refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest who were randomly assigned by emergency medical services personnel to an antiarrhythmic drug versus placebo in the ALPS trial (Resuscitation Outcomes Consortium Amiodarone, Lidocaine or Placebo Study), when stratified by the intravenous versus intraosseous route of administration. Results: Of 3019 randomly assigned patients with a known vascular access site, 2358 received ALPS drugs intravenously and 661 patients by the intraosseous route. Intraosseous and intravenous groups differed in sex, time-to-emergency medical services arrival, and some cardiopulmonary resuscitation characteristics, but were similar in others, including time-to-intravenous/intrasosseous drug receipt. Overall hospital discharge survival was 23%. In comparison with placebo, discharge survival was significantly higher in recipients of intravenous amiodarone (adjusted risk ratio, 1.26 [95% CI, 1.06–1.50]; adjusted absolute survival difference, 5.5% [95% CI, 1.5–9.5]) and intravenous lidocaine (adjusted risk ratio, 1.21 [95% CI, 1.02–1.45]; adjusted absolute survival difference, 4.7% [95% CI, 0.7–8.8]); but not in recipients of intraosseous amiodarone (adjusted risk ratio, 0.94 [95% CI, 0.66–1.32]) or intraosseous lidocaine (adjusted risk ratio, 1.03 [95% CI, 0.74–1.44]). Survival to hospital admission also increased significantly when drugs were given intravenously but not intraosseously, and favored improved neurological outcome at discharge. There were no outcome differences between intravenous and intraosseous placebo, indicating that the access route itself did not demarcate patients with poor prognosis. The study was underpowered to assess intravenous/intraosseous drug interactions, which were not statistically significant. Conclusions: We found no significant effect modification by drug administration route for amiodarone or lidocaine in comparison with placebo during out-of-hospital cardiac arrest. However, point estimates for the effects of both drugs in comparison with placebo were significantly greater for the intravenous than for the intraosseous route across virtually all outcomes and beneficial only for the intravenous route. Given that the study was underpowered to statistically assess interactions, these findings signal the potential importance of the drug administration route during resuscitation that merits further investigation.

Background: While pediatric out-of-hospital cardiac arrests (OHCAs) are relatively uncommon, they have a much higher number of potential years of life lost per event. School-located public access automated external defibrillators (AED) may be beneficial to school-aged OHCAs, but also other OHCAs within the school and in the surrounding community. We sought to identify the incidence of OHCAs within and nearby schools in British Columbia (BC), to estimate the number that may benefit from school-located AEDs. Methods: We used prospectively-collected data from the BC OHCA Registry from 2013 to 2018. We examined the addresses of all OHCAs to determine those occurring in public primary and secondary schools. We geo-plotted all OHCAs to identify the number of OHCAs within walking distance of a school. Assuming an average pedestrian speed for AED retrieval of 1.8 m/second, we calculated the number of school-vicinity OHCAs for which a bystander could retrieve an AED prior to a 6.5 minute emergency medical system response interval, assuming that AEDs would be located on the exterior of a school building. Results: There were a total of 401,423 children enrolled at 824 schools annually in the study footprint. Of a total of 12,480 EMS-treated OHCAs (220 aged < 18 years), 20 were in in schools, of which 4 were Conclusion: Outcomes of school-located OHCAs are encouraging, especially those with AED application. While the incidence of school-located OHCAs is low, a substantial proportion of OHCAs occur within a retrievable distance to a school, and thus accessible external school-located AEDs may improve overall OHCA outcomes of a community.

Introduction: Drone-delivered defibrillators may improve response for out-of-hospital cardiac arrest (OHCA). Prior studies have assumed that drones may be stationed at any police, fire, or paramedic station; however, cross-service implementation may not be logistically feasible. We sought to compare estimated response times by drone base location type. Methods: We included OHCAs (Jan. 2014 to Dec. 2020) in southern Vancouver Island, British Columbia, Canada where OHCA response includes fire and paramedic services. We created four models with candidate drone base locations at: police stations, fire stations, paramedic stations, and on a grid with 1 km sides as an optimistic model. We used mathematical optimization to select 1-5 drone bases for each model. Assuming a drone system had been in place during the study period and accounting for drone availability, we estimated 9-1-1 call-to-defibrillator intervals (measured to either drone, paramedic, or fire arrival) and calculated the proportion of OHCAs where a drone would arrive prior to fire and paramedic for each model. Median response times were compared to historical response using one-sided sign tests. Results: We included 1,610 OHCAs with a median historical response time of 6.4 mins (IQR 5.0-8.6). We identified 21 police stations, 59 fire stations, 21 paramedic stations, and 7,008 grid locations in the study area. Median 9-1-1 call-to-defibrillator intervals ranged from 4.3-5.3 mins for police, 4.3-5.3 mins for fire, 4.5-5.4 mins for paramedic, and 4.2-5.4 mins for grid locations (all P Conclusion: Locating drone bases at different types of emergency service stations significantly decreases 9-1-1 call-to-defibrillator intervals, while resulting in similar response intervals to those achieved using optimistic grid-optimal locations.

Introduction: Use of bystander-administered naloxone may lead to improved likelihood of recovery from opioid overdose. We sought to determine the accessibility of public access naloxone kits on nearby opioid overdose incidents if placed at public transit stops, compared to placing kits outside pharmacies or with existing public access automated external defibrillators (PADs). Methods: We included all incidents in Metro Vancouver, British Columbia responded to by British Columbia Emergency Health Services coded as a drug overdose with naloxone administered on-scene (Dec. 2014 to Aug. 2020). We geo-coded all public transit bus stops and used a mathematical optimization model to select bus stops where publicly accessible naloxone kits could be placed to maximize accessibility (defined as ≤100 m walking distance) to opioid overdoses. We evaluated accessibility on out-of-sample OHCAs using five-fold cross validation and compared against two baseline policies: placing publicly accessible naloxone kits at all pharmacies identified by the College of Pharmacists of British Columbia, and placing kits at all PADs identified by the British Columbia AED Registry. Statistical analysis was conducted using McNemar’s test. Results: We identified 14,318 opioid overdoses, 8,972 bus stops, 736 pharmacies, and 425 PADs. Accessibility of public naloxone kits for opioid overdose locations was 5.1% when placed at all pharmacies and 3.5% when placed with all existing PADs. Optimized naloxone kit placement using bus stops as candidate locations resulted in significantly higher accessibility than both pharmacy and PAD-based placement at 14.8% with 10 optimized locations (P Conclusion: Optimizing placement of public access naloxone kits at select public transit locations can provide significantly higher accessibility to opioid overdose locations compared to placement at pharmacies or at existing PAD locations.

Introduction: Out-of-hospital cardiac arrest (OHCA) is associated with poor short-term outcomes. However, the impact of pre- and in-hospital factors on long-term outcomes is ill-defined, mainly related to challenges combining disparate data sources. Methods: We linked adult non-traumatic EMS-treated OHCAs from the British Columbia Cardiac Arrest Registry (Jan 2009 - Dec 2016) to provincial datasets describing co-morbidities, medications, procedures, mortality, and hospital admission and discharge. Among hospital-discharge survivors, we examined the 3-year composite endpoint of mortality ± all-cause readmission using the Kaplan-Meier (KM) method and multivariable Cox model for predictors. Results: Of 10,876 successfully linked OHCAs, 1325 survived to hospital discharge: mean age 62.8 years, 77.9% male, 72.6% shockable rhythms, 60.1% non-public locations, 69.1% bystander CPR, and 30.3% STEMI. During admission, 78.6% required mechanical ventilation, 69.1% received coronary angiography (37.5% PCI, 10.3% CABG), and 24.8% received an ICD. At 3 years post-discharge, the estimated KM event rates were 15.9% (95% CI 13.9%, 19.3%) for mortality and 68.2% (95% CI 65.3%, 71.0%) for mortality and readmission, which differed by age, initial rhythm, and arrest location ( Figure ). Following multivariable analysis, patients with a history of HF [HR 1.62 (95% CI 1.34 - 1.96)], age >75 [1.62 (1.35, 1.96)], anticoagulation use [2.55 (1.36, 4.79)], non-shockable rhythm [1.29 (1.07, 1.55)] and non-public arrest location [1.21(1.04, 1.40)] were more likely to experience the composite endpoint; those receiving coronary angiography were less likely [0.79 (0.64, 0.98)]. Conclusions: The long-term death or readmission risk persists even among OHCA hospital-discharge survivors, and is associated with both pre- and in-hospital factors. An enriched, linked dataset detailing the entire OHCA “journey” may be a promising tool to identify care and treatment gaps.

Background: There is substantial regional variation in out-of-hospital cardiac arrest (OHCA) outcomes. We investigated whether regional-level intra-arrest transport practices were associated with patient outcomes. Methods: We performed a secondary analysis of the “CCC Trial” dataset, which included EMS-treated adult non-traumatic OHCA enrolled from 49 regional clusters. The exposure of interest was regional-level intra-arrest transport practices (RIATP), calculated as the proportion of cases within the enrolling cluster transported prior to return of spontaneous circulation (“intra-arrest transport”), divided into quartiles. We fit a multilevel mixed-effects logistic regression model to estimate the association of RIATP quartile and both survival and favorable neurologic status (mRS ≤ 3) at hospital discharge, adjusted for patient-level Utstein variables. Results: We included all 26,148 CCC-enrolled patients, 36% of whom were female, 97% were treated with prehospital ALS, and 23% had shockable initial rhythms. The median RIATP of the 49 clusters was 20% (IQR 6.2 - 30%). The figure shows outcomes stratified by RIATP quartile. Compared to the first quartile ( Conclusion: Treatment within a region that utilizes intra-arrest transport less frequently was associated with improved patient survival. These results may, in part, explain differences between regional OHCA survival outcomes.

Context: Research in an emergency setting is challenging because the window of opportunity to treat may be short, and preclude time to obtain informed consent from the patient or their representative. Such research can be conducted under exception from informed consent (EFIC) if specific criteria are met. In the United States, this includes notification of an enrolled subject or their representative as soon as feasible after enrollment so that they have autonomy to opt out from ongoing study participation. To date, there is limited empiric information about time to notification (TTN). Objective: To describe variation in TTN among sites participating in randomized trials conducted under exception from informed consent for emergency research. Methods: Notification strategies were determined at each site prior to initiation of subject enrollment, and approved by a local institutional review board or equivalent. TTN was summarized overall, as well as stratified by site and clinical outcome among patients enrolled in multiple trials conducted by the Resuscitation Outcomes Consortium (ROC). Results: Included were 34,868 patients enrolled in four trials. Of these, 33,805 had with out-of-hospital cardiac arrest; and 1,063 had life-threatening traumatic injury. TTN varied (Table). Conclusions: There is large variation in TTN in trials conducted under EFIC for emergency research. Early notification is difficult; delayed notification may reduce the autonomy of patients or their representative.

Introduction: The benefits of early CPR are evident, however the relationship between the no-flow interval and neurological outcomes may assist clinicians with resuscitation management. Methods: We examined emergency medical system-treated non-traumatic out-of-hospital cardiac arrests from two clinical trials (PRIMED and CCC; 2006-2015), including only bystander witnessed cases without bystander resuscitation. We created a subgroup to simulate ECPR-treated cases (witnessed, age ≤65, non-asystole initial rhythm, and ROSC >30 minutes). We fit an adjusted logistic regression model to estimate the relationship between the “no-flow” interval (911 call-to-initiation of CPR) and favorable neurological outcome (MRS ≤3) at hospital discharge, and created a cubic spline curve. Results: Of 43,593 trial cases, 7299 were included; 616 (8.4%; 95% CI 7.8-9.1%) favourable neurological outcomes. The no-flow interval (per minute) was associated favorable neurological outcomes (adjusted OR 0.88, 95% CI 0.85-0.91). The adjusted probability of a favorable neurological outcome decreased by 0.52% (95% CI 0.39-0.65) per no-flow minute. No patients (0%; 1-sided 97.5% CI 0-0.051%) had both a no-flow duration >20 minutes and a favorable neurological outcome. In the ECPR group, 15 (9.9%; 95% CI 5.1-15%) had favourable neurological outcomes; 0/152 (0%; 1-sided 97.5% CI 0-2.4%) had both a no-flow interval >10 minutes and a favourable neurological outcome. Conclusions: The odds of a favorable neurological outcome decrease as the no-flow interval increases, highlighting the urgency of rescuer response. We found no favorable outcomes among cases with >20 minutes of no-flow duration, which may assist providers with decisions of starting or terminating resuscitation. Among ECPR-eligible cases with prolonged resuscitative efforts there were no favourable neurological outcomes among those with a no flow-interval >10 minutes, which may assist with ECPR candidacy assessment.

Introduction: It is unclear if the benefits of public access defibrillator (PAD) programs are similar between men and women. We investigated the location of out-of-hospital cardiac arrests (OHCA) stratified by sex to determine what proportion was eligible for PAD application. Second, we sought to determine if patient sex was associated with PAD utilization. Methods: We analyzed prospectively collected data from the North American Resuscitation Outcomes Consortium (ROC) Epistry dataset (2011 - 2015), excluding emergency medical services (EMS)-witnessed cases, those not treated by EMS, and children aged less than 10. We compared sex-based differences in public vs private location, and location type (street or highway, public building, place of recreation, industrial place, home residence, farm or ranch, healthcare facility, residential institution, other public property, or other private location). Among public location OHCAs with bystander interventions, we fit an adjusted logistic regression model to estimate the association between sex and PAD application. Results: Among the 61,473 cases, 20,933 (34%) were female, 30,353 had resuscitation attempted by bystander, and 13,597 had initial shockable rhythms. The OHCA incidence in a public location for women and men was 8.8% and 18%, respectively (95% CI for difference 8.7 - 9.7). Women had a significantly lower proportion of OHCAs on the street/highway, in public buildings, places of recreation, and farms, but a significantly higher proportion in the home, healthcare facilities, and residential institutions. Among public location OHCAs with bystander interventions, female sex was associated with a lower odds of bystander PAD application (adjusted OR 0.83, 95% CI 0.70-0.99). Conclusion: Women had fewer OHCAs in public locations eligible for PAD application. Further, among public OHCAs with bystander interventions, women were less likely to have PADs applied.

Background: “Priority setting” is something that we do in research in order to get a range of opinions on what research questions are the most important or timely in a particular field. This is typically done with a group of expert health care providers and researchers and has not involved patients, family or the public. Methods: With funding from the Canadian Institutes of Health Research we partnered with the James Lind Alliance (JLA) in the UK to use their proven consensus methodology to build a Public Priority Setting Partnerships (PSP) on out-of-hospital Cardiac Arrest (OHCA). We developed and administered two rounds of online surveys with survivors, family members and health care professionals to create the initial priority lists. From there we held a full-day in-person workshop to come to consensus on the top 10 priorities from a short list of 25. The workshop also included survivors, family members and health care professionals. Results: The initial survey yielded more than 425 responses and 1500 “questions”/comments from survivors, family members, lay responders, physicians, nurses, rehabilitation specialists, paramedics, etc. The second survey asked participants to rank a narrowed list of 125 questions. The final top 25 questions were brought to the in-person consensus meeting and a top 10 were selected. The results will be revealed publicly for the first time at the ReSS meeting. Conclusions: The JLA methodology is world-renowned for its rigor and we now have an official PSP on OHCA. This type of inclusive research priority setting provides crucial information for the AHA and the international resuscitation research community about where to invest our limited research resources. The results will also drive our community to include questions that matter to SCA survivors and their families in all of our work.

Introduction: The incidence and details of sudden cardiac arrest (SCA) during exercise in the general population are not well described. We describe a cohort ages 2-85 who experienced an SCA within ≤ 1 hour of moderate to vigorous activity in 4 metropolitan areas of British Columbia, Canada. Methods: We reviewed prehospital records of consecutive out-of-hospital cardiac arrests (OHCAs) in the provincial BC OHCA Registry from June 17 2017 to August 16 2018. We included non-traumatic OHCAs treated by EMS occurring within ≤ 1 hour of exercise. We defined SCA as an OHCA of no obvious cause, witnessed/unwitnessed, survived/died. We assigned an estimated metabolic equivalent (MET) score to each type of physical activity. We defined moderate exercise as a MET score of 3-5.9 and vigorous as ≥6. Results: A total of 2674 OHCAs occurred during the study period of which 56 SCAs (2.1%) occurred within ≤1 hour of participation in 23 types of exercise (Figure 1). The incidence of SCA during exercise was 1.45 (95% CI 1.10-1.88) per 100,000 population. The median age was 56.5 [IQR 45-69] and 87.5% (49/56) were male. Most exercise related SCAs occurred in public (49/56 87.5%), 83.3% (45/54) were bystander witnessed and 85% (46/54) received bystander CPR. Over 70% (40/56) had a shockable rhythm. The survival rate was 55.4% (31/56). Half of the SCAs collapsed during exercise (49.1%; 26/53) while the other half collapsed within ≤1 hour after exercising (51%; 27/53). Symptom data were available in 46% of patients (23/50) with most experiencing chest pain, dizziness, feeling unwell or seizure just prior to collapse. Conclusions: SCAs during exercise are rare and frequently occur in a public location. Survival is high and may be related to witnessed and public location status. Equal numbers of SCAs collapsed during or ≤ 1 hour of exercising and symptoms were present in almost half. Future research is needed to determine what factors could predict those at highest risk for SCA in order to prevent future events.

Background: Out-of-hospital cardiac arrest (OHCA) commonly presents with nonshockable rhythms (asystole and pulseless electric activity). It is unknown whether antiarrhythmic drugs are safe and effective when nonshockable rhythms evolve to shockable rhythms (ventricular fibrillation/pulseless ventricular tachycardia [VF/VT]) during resuscitation. Methods: Adults with nontraumatic OHCA, vascular access, and VF/VT anytime after ≥1 shock(s) were prospectively randomized, double-blind, to receive amiodarone, lidocaine, or placebo by paramedics. Patients presenting with initial shock-refractory VF/VT were previously reported. The current study was a prespecified analysis in a separate cohort that initially presented with nonshockable OHCA and was randomized on subsequently developing shock-refractory VF/VT. The primary outcome was survival to hospital discharge. Secondary outcomes included discharge functional status and adverse drug-related effects. Results: Of 37 889 patients with OHCA, 3026 with initial VF/VT and 1063 with initial nonshockable-turned-shockable rhythms were treatment-eligible, were randomized, and received their assigned drug. Baseline characteristics among patients with nonshockable-turned-shockable rhythms were balanced across treatment arms, except that recipients of a placebo included fewer men and were less likely to receive bystander cardiopulmonary resuscitation. Active-drug recipients in this cohort required fewer shocks, supplemental doses of their assigned drug, and ancillary antiarrhythmic drugs than recipients of a placebo ( P P =0.24). No significant interaction between treatment assignment and discharge survival occurred with the initiating OHCA rhythm (asystole, pulseless electric activity, or VF/VT). Survival in each of these categories was consistently higher with active drugs, although the trends were not statistically significant. Adjusted absolute differences (95% confidence interval) in survival from nonshockable-turned-shockable arrhythmias with amiodarone versus placebo were 2.3% (−0.3, 4.8), P =0.08, and for lidocaine versus placebo 1.2% (−1.1, 3.6), P =0.30. More than 50% of these survivors were functionally independent or required minimal assistance. Drug-related adverse effects were infrequent. Conclusions: Outcome from nonshockable-turned-shockable OHCA is poor but not invariably fatal. Although not statistically significant, point estimates for survival were greater after amiodarone or lidocaine than placebo, without increased risk of adverse effects or disability and consistent with previously observed favorable trends from treatment of initial shock-refractory VF/VT with these drugs. Together the findings may signal a clinical benefit that invites further investigation. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01401647.

Introduction: FRONTIER (NCT02315443) and ESCAPE-NA1 (NCT02930018) are two pivotal trials investigating the safety and efficacy of the neuroprotectant NA-1 in acute ischemic stroke (AIS). NA-1 administration is weight-based (2.6mg/Kg), requiring the rapid estimation of body weight by paramedics in the field (FRONTIER) and by hospital staff upon ED arrival (ESCAPE-NA1). Alteplase, which is administered after hospital arrival, also requires weight-based dosing. Here we evaluated the accuracy of the body weight estimated by paramedics and by hospital staff prior to administering study drug (NA-1 or placebo) as compared to the actual subject weight collected using in-hospital scales during the subsequent in-hospital stay. Methodology: In both these studies, FRONTIER and ESCAPE-NA1, paramedics in the field and Hospital staff will be determining weight by first asking the subject, second asking a family member or third by estimation. Subsequently, in each trial, in-hospital scales are used during the subject’s admission to measure body weight accurately. The subject’s actual weight will be measured in hospital using standard hospital scales (i.e., stand up or in-bed scales if the subject is not ambulatory), as soon as possible, but within five days. Data were obtained from the trial database. Results: As of August 1 st 2018, 264 subjects were enrolled in FRONTIER of which 206 had all body weight data available, and 444 subjects were enrolled in ESCAPE-NA1 of which 218 had all body weight data available. As compared with in-hospital scales, paramedics over estimated patient weight by an average of 2.57 kg (SD = 6.94 P< 0.001). In-hospital staff under estimated patient weight by an average of 1.82kg (SD = 8.93 P=0.003). The difference is statistically significant but not clinically meaningful. Overall, the weight estimated by paramedics and by hospital staff was 93% accurate, when compared to the actual weight collected. Conclusion: Both paramedics and hospital staff were mostly accurate when estimating patient weight in the acute care settings of FRONTIER and ESCAPE-NA1. This suggests that when time is of the essence, weight may be estimated effectively for the purpose of administering stroke drugs.

Objective: There is conflicting data in studies investigating the effectiveness of advanced life support (ALS) for out-of-hospital cardiac arrest (OHCA). Within a tiered BLS-ALS system, we sought to determine if the ALS response interval was associated with patient outcomes. Methods: This secondary analysis examined prospectively identified consecutive non-traumatic adult OHCAs from 2006-2016 in British Columbia. We excluded EMS-witnessed arrests and those not treated by ALS. The primary and secondary outcomes were survival and favorable neurological outcomes (mRS ≤3) at hospital discharge. Using logistic regression we estimated the association of ALS response interval (9-1-1 call to ALS arrival) and outcomes, adjusting for treatment year, response interval of the first EMS unit, and other baseline characteristics. We drew spline curves to illustrate this relationship. Results: Of 12,722 included cases, survival was 12%. The median response interval for the first EMS unit was 6.4 minutes (IQR 5.2 - 8.3) and for ALS was 11.8 minutes (IQR 8.7 - 16.5).The adjusted odds of survival and favourable neurological outcome for each additional minute in ALS response interval were 0.98 (95 % CI 0.96-0.99) and 0.98, (95% CI 0.97-0.99) respectively. The spline curve demonstrated an initial decline in survival probability that moderated at approximately 11 minutes. Conclusion: Among ALS-treated subjects within our tiered EMS system, earlier ALS arrival was associated with improved survival and favorable neurological outcomes. The greatest yield of ALS care may be prior to 11 minutes. This may help inform the optimal deployment configuration of prehospital providers.

Guidelines for cardiopulmonary resuscitation recommend a chest compression rate of at least 100 compressions/min. A recent clinical study reported optimal return of spontaneous circulation with rates between 100 and 120/min during cardiopulmonary resuscitation for out-of-hospital cardiac arrest. However, the relationship between compression rate and survival is still undetermined.Prospective, observational study.Data is from the Resuscitation Outcomes Consortium Prehospital Resuscitation IMpedance threshold device and Early versus Delayed analysis clinical trial.Adults with out-of-hospital cardiac arrest treated by emergency medical service providers.None.Data were abstracted from monitor-defibrillator recordings for the first five minutes of emergency medical service cardiopulmonary resuscitation. Multiple logistic regression assessed odds ratio for survival by compression rate categories (80, 80-99, 100-119, 120-139, ≥140), both unadjusted and adjusted for sex, age, witnessed status, attempted bystander cardiopulmonary resuscitation, location of arrest, chest compression fraction and depth, first rhythm, and study site. Compression rate data were available for 10,371 patients; 6,399 also had chest compression fraction and depth data. Age (mean±SD) was 67±16 years. Chest compression rate was 111±19 per minute, compression fraction was 0.70±0.17, and compression depth was 42±12 mm. Circulation was restored in 34%; 9% survived to hospital discharge. After adjustment for covariates without chest compression depth and fraction (n=10,371), a global test found no significant relationship between compression rate and survival (p=0.19). However, after adjustment for covariates including chest compression depth and fraction (n=6,399), the global test found a significant relationship between compression rate and survival (p=0.02), with the reference group (100-119 compressions/min) having the greatest likelihood for survival.After adjustment for chest compression fraction and depth, compression rates between 100 and 120 per minute were associated with greatest survival to hospital discharge.

The "2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" increased the focus on methods to ensure that high-quality cardiopulmonary resuscitation (CPR) is performed in all resuscitation attempts. There are 5 critical components of high-quality CPR: minimize interruptions in chest compressions, provide compressions of adequate rate and depth, avoid leaning between compressions, and avoid excessive ventilation. Although it is clear that high-quality CPR is the primary component in influencing survival from cardiac arrest, there is considerable variation in monitoring, implementation, and quality improvement. As such, CPR quality varies widely between systems and locations. Victims often do not receive high-quality CPR because of provider ambiguity in prioritization of resuscitative efforts during an arrest. This ambiguity also impedes the development of optimal systems of care to increase survival from cardiac arrest. This consensus statement addresses the following key areas of CPR quality for the trained rescuer: metrics of CPR performance; monitoring, feedback, and integration of the patient’s response to CPR; team-level logistics to ensure performance of high-quality CPR; and continuous quality improvement on provider, team, and systems levels. Clear definitions of metrics and methods to consistently deliver and improve the quality of CPR will narrow the gap between resuscitation science and the victims, both in and out of the hospital, and lay the foundation for further improvements in the future.

Background: Many patients with witnessed out-of-hospital cardiac arrest (OHCA) will not have CPR attempted until emergency medical services (EMS) personnel arrive. The potential for favourable outcomes in patients with increasing no-flow durations is unclear. While some extra-corporeal CPR programs have excluded patients without bystander CPR, others have treated these patients provided short durations to EMS arrival. We sought to describe the outcomes of patients with increasing no-flow durations to determine the potential viability of these patients. Methods: This study examined consecutive non-traumatic OHCA’s collected by a prospective registry in British Columbia (2007 and 2011). We included adult patients with bystander-witnessed OHCA but no attempt at bystander chest compressions. The primary variable of interest was the duration from the bystander 9-1-1 call to the time of CPR commencement by EMS. The primary endpoint was survival at hospital discharge. Multivariable logistic regression, with adjustment for sex, age, public location of arrest, and initial shockable rhythm, was used to assess the association of time to CPR and survival to hospital discharge. Results: Of 6571 EMS-treated OHCA’s, 1062 were included. The median age was 73 (IQR 58-82), 69% were male, and 35% had initial shockable rhythms. Overall survival was 13%. The median time to CPR commencement was 8.5 minutes (IQR 6.9 - 10.5). Time to CPR was independently associated with survival to hospital discharge (adjusted OR 0.85 per minute increase; 95% CI 0.78-0.92). Among survivors, the 90th percentile of time from 9-1-1 call to CPR was 10.3 minutes. Conclusion: In adult OHCA patients, no-flow durations were negatively correlated with outcome, however survival was observed with prolonged durations without CPR extending to 16 minutes. Patients with witnessed OHCA and no bystander CPR include survivors and aggressive resuscitation strategies are warranted.

Background Children who require basic life support (BLS) and advanced life support (ALS) interventions account for 5% to 10% of all ambulance runs and approximately one quarter of emergency department visits in the United States. The principles, equipment, and drugs used for pediatric BLS and ALS are similar to those used for adults. However, the care of seriously ill or injured children requires specific knowledge of pediatric anatomy, physiology, and psychology plus practical pediatric expertise. ### Key Interventions to Prevent Arrest In infants and children, respiratory distress and failure is a much more common cardiac arrest etiology than sudden dysrhythmia or ventricular fibrillation. As a result, hypoxia, hypercarbia, and global ischemia often precede cardiac arrest. Critical organ perfusion is dependent on more rapid heart and respiratory rates than for adults. Therefore, additional attention is focused on early recognition and intervention for respiratory failure and shock, and less emphasis is placed on rapid early defibrillation than for adult cardiac arrest victims. ### BLS and ALS Interventions During Arrest Commentary on the specific application of BLS and ALS principles to pediatric patients is contained in the accompanying ILCOR pediatric advisory statements. 1. Tsai A, Kallsen G. Epidemiology of pediatric prehospital care. Ann Emerg Med . 1987;16:284-292. 2. Cummins RO, ed. Textbook of Advanced Cardiac Life Support. Dallas, Tex: American Heart Association; 1994:60-68. 3. Zaritsky A, Nadkarni V, Getson P, Kuehl K. CPR in children. Ann Emerg Med . 1987;16:1107-1111. ### Background Cardiac arrest due to electrolyte abnormalities is uncommon except in the case of hyperkalemia. Electrolyte concentrations change during cardiac arrest due to the rapidly changing acid-base status, catecholamine levels, and hypoxia. These changes do not require intervention unless the cardiac arrest is primarily caused by the electrolyte abnormality. ### Key Interventions to Prevent Arrest

Introduction: Current CPR compression depth guidelines were empirically derived. We sought to study patterns of CPR compression depth and their associations with patient outcomes in out-of-hospital cardiac arrest (OOHCA). Methods: We studied OOHCA patients from the Resuscitation Outcomes Consortium Epistry - Cardiac Arrest for whom electronic CPR data were available from proprietary accelerometer technology attached to the prehospital defibrillators. We calculated anterior chest wall depression in millimeters and the period of active CPR (chest compression fraction [CCF]) for each minute of CPR. We controlled for covariates including compression rate and calculated adjusted odds ratios (OR) for any return of circulation (ROSC) and 24 hour survival. We calculated unadjusted OR for hospital discharge. Results: We included 615 adult patients from 6 U.S. and Canadian cities with these characteristics: mean age 68.9; male 62 %; witnessed 43%; bystander CPR 31%; initial rhythms - VF/VT 25%, PEA 17%, asystole 43%, unspecified non-shockable 15%; mean compression rate 103/min; mean compression depth 51mm 11%; median CCF 0.66; outcomes - ROSC 57%, 24 hour survival 18%, discharge 5%. We found an inverse association between depth and compression rate (P ), no association between depth and CCF (P=0.30), and a positive association between CCF and rate (P Conclusions: We found half of patients received suboptimal compression depth, an inverse association between compression depth and rate, and no clear association between survival and increased compression depth. Further study is required to determine the optimum chest compression depth and its interaction with rate and CCF in order to maximize outcomes. Compression Rate versus Compression Depth

We appreciate the interest of Tang and colleagues, who have made substantial contributions to advancing care for patients with cardiac arrest. We provide additional information here to clarify the issues they raise, beginning with their last point. The letter expresses concern about an imbalance between groups1 in the incidence of asystole as an initial rhythm. However, the multishock groups, on which the primary end point is based, are nearly balanced: 2 of 55 versus 0 of 51 patients initially in asystole. The letter expresses concern about aggregating first and subsequent shocks in the primary analysis. An abstract of our study reported separate results for subsequent shocks in which energy levels differ most between groups, revealing a larger advantage for higher-energy shocks: ventricular fibrillation termination, …

Valid scientific evidence supports only three interventions as unequivocally effective in adult cardiac resuscitation: The universal algorithm presents these interventions simplistically and recommends a specific sequence that rescuers should follow. The sequence of interventions is based, whenever possible, on sound scientific information. But there is a paucity of convincing human data on some aspects of resuscitation. Until such time as new information becomes available, the working group made no changes to well-established procedures but suggested some modifications on educational rather than scientific grounds. Cardiac arrest rhythms can be divided into two subsets: ventricular fibrillation/pulseless ventricular tachycardia (VF/VT) and non-VF/VT. Non-VF/VT incorporates both asystole and pulseless electrical activity (PEA). The only difference in management between the two arrest rhythms is the need for rescuers to perform defibrillation for patients in VF/VT. Otherwise the actions and interventions are essentially the same: basic CPR, tracheal intubation, epinephrine administration, and correction of reversible causes. …

RESULTS: PBMCs differentiate into mature and functional OC in the presence of all drugs. Osteoclastic resorption of SS was noted with differences in the resorption pattern under all drug treatments. Under drug treatment single areas of osteoclastic resorption were larger in size but less abundant when compared to positive controls. None of the used drugs was able to inhibit osteoclastic biocorrosion of SS.