Initial Pulseless Electrical Activity Research Articles

Association between eGFR and neurological outcomes among patients with out-of-hospital cardiac arrest: A nationwide prospective study in Japan.

We aimed to investigate the association between estimated glomerular filtration rate and prognosis in out-of-hospital cardiac arrest patients and explore the heterogeneity of the association. Patients experiencing out-of-hospital cardiac arrest due to medical causes and registered in the JAAM-OHCA Registry between June 2014 and December 2019 were stratified into shockable rhythm, pulseless electrical activity, and asystole groups according to the cardiac rhythm at the scene. The primary outcome was a 1-month favorable neurological status. Adjusted odds ratios with 95% confidence intervals were calculated to investigate the association between estimated glomerular filtration rate and outcomes using a logistic model. Of the 19,443 patients included, 2769 had initial shockable rhythm at the scene, 5339 had pulseless electrical activity, and 11,335 had asystole. As the estimated glomerular filtration rate decreased, the adjusted odds ratio for a 1-month favorable neurological status decreased among those with initial shockable rhythm (estimated glomerular filtration rate, adjusted odds ratio [95% CI]: 45-59 mL/min/1.73 m2, 0.61 [0.47-0.79]; 30-44 mL/min/1.73 m2, 0.45 [0.32-0.62]; 15-29 mL/min/1.73 m2, 0.35 [0.20-0.63]; and <15 mL/min/1.73 m2, 0.14 [0.07-0.27]). Estimated glomerular filtration rate was associated with neurological outcomes in patients aged <65 years with initial shockable rhythm but not in those aged >65 years or patients with initial pulseless electrical activity or asystole. The estimated glomerular filtration rate is associated with neurological prognosis in out-of-hospital cardiac arrest patients with initial shockable rhythm at the scene but not in those with initial non-shockable rhythm.

Termination-of-resuscitation rule in the emergency department for patients with initial pulseless electrical activity after out-of-hospital cardiac arrest

Abstract Background/Introduction In several Asian countries including Japan, emergency medical service (EMS) providers are prohibited from performing field termination-of-resuscitation (TOR) in patients with refractory out-of-hospital cardiac arrest (OHCA). In 2022, we developed a TOR rule in the emergency department for patients with initial asystole after refractory OHCA, which includes three criteria: unwitnessed arrest, EMS-initiated cardiopulmonary resuscitation (CPR) duration was more than 20 min, and there was no prehospital return of spontaneous circulation (ROSC). However, until now a TOR rule in the emergency department for patients with initial pulseless electrical activity (PEA) has not been developed. Purpose This study aimed to develop and validate a TOR rule in the emergency department for patients with initial PEA after refractory OHCA. Methods We analysed the records of 137,230 adult patients (≥18 years-old) with initial PEA from the nationwide all-Japan Utstein registry from 2016 to 2020. Patients were divided into two groups: development (n=109,642, 2016 to 2019) and validation (n=27,588, 2020). The primary outcome measures were specificity, false positive rate (FPR), and positive predictive value (PPV) of the TOR rule for patients with initial PEA in the emergency department for predicting 1-month mortality. Using recursive partitioning analysis, we developed a new TOR rule for patients with initial PEA after OHCA. Results The overall 1-month survival rate of the participants was 7.4% (95% confidence interval [CI], 7.2–7.5%). Recursive partitioning analysis for the development group in predicting 1-month mortality revealed that a TOR rule for patients with PEA could be defined if patients with OHCA met all the following four criteria immediately after hospital arrival: (1) unwitnessed arrest by any laypersons, (2) EMS-initiated CPR duration more than 20 min, (3) no prehospital ROSC, and (4) age greater than or equal to 80 years. The specificity, FPR, and PPV of the rule for predicting 1-month mortality were 99.1% (95% CI, 98.9–99.3%), 0.87% (95% CI, 0.69–1.09%), and 99.2% (95% CI, 98.9–99.3%), respectively. The proportion of patients who fulfilled the rule and the area under the receiver operating curve (AUC) was 7.8% (95% CI, 7.7–8.0%), and 0.80 (95% CI, 0.79–0.80), respectively. In the validation group, the specificity, FPR, PPV, proportion of patients who met the rule, and AUC were 99.1% (95% CI, 98.5–99.4%), 0.93% (95% CI, 0.58–1.49%), 99.3% (95% CI, 98.8–99.5%), 8.3% (95% CI, 8.0–8.6%), and 0.789 (95% CI, 0.775–0.797), respectively. Conclusions We developed and validated a TOR rule in the emergency department for patients with initial PEA after OHCA. The rule includes four criteria (unwitnessed arrest, EMS-initiated CPR duration was more than 20 min, no prehospital ROSC, and age was greater than or equal to 80 years) with a more than 99% predictor of 1-month mortality.

Association between Conversion to Shockable Rhythms and Survival with Favorable Neurological Outcomes for Out-of-Hospital Cardiac Arrests

Background The initial cardiac rhythm in out-of-hospital cardiac arrest (OHCA) portends different prognoses and affects treatment decisions. Initial shockable rhythms are associated with good survival and neurological outcomes but there is conflicting evidence for those who initially present with non-shockable rhythms. The aim of this study is to evaluate if OHCA with conversion from non-shockable (i.e., asystole and pulseless electrical activity) rhythms to shockable rhythms compared to OHCA remaining in non-shockable rhythms is associated with better survival and neurological outcomes. Method OHCA cases from the Pan-Asian Resuscitation Outcomes Study registry in 13 countries between January 2009 and February 2018 were retrospectively analyzed. Cases with missing initial rhythms, age <18 years, presumed non-medical cause of arrest, and not conveyed by emergency medical services were excluded. Multivariable logistic regression analysis was performed to evaluate the relationship between initial and subsequent shockable rhythm, survival to discharge, and survival with favorable neurological outcomes (cerebral performance category 1 or 2). Results Of the 116,387 cases included. 11,153 (9.6%) had initial shockable rhythms and 9,765 (8.4%) subsequently converted to shockable rhythms. Japan had the lowest proportion of OHCA patients with initial shockable rhythms (7.3%). For OHCA with initial shockable rhythm, the adjusted odds ratios (aOR) for survival and good neurological outcomes were 8.11 (95% confidence interval [CI] 7.62-8.63) and 15.4 (95%CI 14.1-16.8) respectively. For OHCA that converted from initial non-shockable to shockable rhythms, the aORs for survival and good neurological outcomes were 1.23 (95%CI 1.10-1.37) and 1.61 (95%CI 1.35-1.91) respectively. The aORs for survival and good neurological outcomes were 1.48 (95%CI 1.22-1.79) and 1.92 (95%CI 1.3 − 2.84) respectively for initial asystole, while the aOR for survival in initial pulseless electrical activity patients was 0.83 (95%CI 0.71-0.98). Prehospital adrenaline administration had the highest aOR (2.05, 95%CI 1.93-2.18) for conversion to shockable rhythm. Conclusion In this ambidirectional cohort study, conversion from non-shockable to shockable rhythm was associated with improved survival and neurologic outcomes compared to rhythms that continued to be non-shockable. Continued advanced resuscitation may be beneficial for OHCA with subsequent conversion to shockable rhythms.

Abstract 214: A Counterfactual Machine Learning Model Study To Estimate The Impact Of Coronary Angiography For Out Of Hospital Cardiac Arrest

Background: The American Heart Association guidelines for resuscitation 2020 recommends emergency coronary angiography (CAG) in cases of out-of-hospital cardiac arrest (OHCA) after return of spontaneous circulation (ROSC) with ST-segment elevation(STE) and, it is unclear how much CAG actually contributes to improved outcomes in various OHCA patient populations. The aim of this study is to estimate the impact of CAG on OHCA using a counterfactual machine learning model. Methods: We analyzed adult non-traumatic OHCA patients (43,977 cases) from June 2014 to December 2019 from the JAAM (Japan Association for Acute Medicine)-OHCA registry, which includes post-hospitalization data from 140 Japanese hospitals. We defined outcomes as favorable neurological outcomes (Cerebral Performance Categories (CPC) 1-2) and survival at 30 and 90 days. We estimated the outcome assuming that all patients had received CAG using a machine learning and counterfactual hypothetical model, and also estimated the outcome assuming that all patients had not received CAG. An average of each individual difference between the two estimations was calculated as average treatment effect (ATE) (%), which represents the effect of CAG on improving outcomes for the population. In addition, subgroup analysis was performed based on ROSC, STE and initial documented rhythm. Results: The ATE(%, 95% confidence interval) of CAG in all OHCA patients for CPC 1-2 at 30 and 90 days was 3.11% (2.92-3.30) and 1.85% (1.74-1.95), and survival at 30 and 90 days was 6.25%(5.93-6.57) and 2.20%(1.88-2.52), respectively. The subgroup analysis of ATE for CPC 1-2 at 90 days was particularly lower in the no STE group, initial pulseless electrical activity (PEA) group and initial asystole group than in the STE group and initial ventricular fibrillation(VF) group (Figure). Conclusions: In the JAAM-OHCA registry, we used a counterfactual machine learning model to estimate the effect of CAG on OHCA.

Latest in Resuscitation Research: Highlights From the 2021 American Heart Association's Resuscitation Science Symposium.

Latest in Resuscitation Research: Highlights From the 2021 American Heart Association's Resuscitation Science Symposium.

Acute kidney injury after successful cardiopulmonary resuscitation; risk factors and prognosis: a retrospective cross-sectional study

Objective: Acute kidney injury (AKI) is an independent risk factor in critically ill patients. This study aimed to evaluate the prevalence of AKI in resuscitated cardiac arrest (CA) patients, its potential risk factors, and outcomes of AKI in cardiac arrest survivors.&#x0D; Methods: A hundred and forty-nine cases of post-CA patients that survived for at least 24 hours, admitted to three hospitals between 2016 and 2020, were studied. AKI was defined by the RIFLE (Risk, Injury, Failure, Loss, and End-stage) criteria. Baseline demographic data, resuscitation variables, the prevalence of AKI, in-hospital and six-month mortality were collected. Logistic regression evaluated the factors associated with AKI occurrence and mortality.&#x0D; Results: AKI occurred in 59 (39.6%) of the patients. Of these, 9 patients (15.3%) required renal replacement therapy (RRT) during their hospital stay. There were 47 (52.2%) in-hospital deaths in patients without AKI and 41 (69.5%) in patients with AKI (P=0.036). Post-CA AKI was significantly associated with six-month mortality (OR=1.65; 95% CI: 1.39,2.88; P=0.029). Older age, the higher cumulative dosage of epinephrine during cardiopulmonary resuscitation, post-CA shock, in-hospital CA, initial pulseless electrical activity (PEA) or asystole rhythm, longer duration of cardiac arrest, as well as higher admission creatinine and lactate levels were independently associated with AKI; in contrast, higher admission base excess level was negatively associated with AKI.&#x0D; Conclusion: AKI occurred in nearly 40% of CA patients. AKI was associated with a higher in-hospital and six-month mortality rates.

Prone restraint cardiac arrest in in-custody and arrest-related deaths.

We postulate that most atraumatic deaths during police restraint of subjects in the prone position are due to prone restraint cardiac arrest (PRCA), rather than from restraint asphyxia or a stress‐induced cardiac condition, such as excited delirium. The prone position restricts ventilation and diminishes pulmonary perfusion. In the setting of a police encounter, metabolic demand will be high from anxiety, stress, excitement, physical struggle, and/or stimulant drugs, leading to metabolic acidosis and requiring significant hyperventilation. Although oxygen levels may be maintained, prolonged restraint in the prone position may result in an inability to adequately blow off CO2, causing blood pCO2 levels to rise rapidly. The uncompensated metabolic acidosis (low pH) will eventually result in loss of myocyte contractility. The initial electrocardiogram rhythm will generally be either pulseless electrical activity (PEA) or asystole, indicating a noncardiac etiology, more consistent with PRCA and inconsistent with a primary role of any underlying cardiac pathology or stress‐induced cardiac etiology. We point to two animal models: in one model rats unable to breathe deeply due to an external restraint die when their metabolic demand is increased, and in the other model, pressure on the chest of rats results in decreased venous return and cardiac arrest rather than death from asphyxia. We present two cases of subjects restrained in the prone position who went into cardiac arrest and had low pHs and initial PEA cardiac rhythms. Our cases demonstrate the danger of prone restraint and serve as examples of PRCA.

Association of Initial Pulseless Electrical Activity Heart Rate and Clinical Outcomes following Adult Non-Traumatic Out-of-Hospital Cardiac Arrest

Objective Studies evaluating the prognostic value of the pulseless electrical activity (PEA) heart rate in out-of-hospital cardiac arrest (OHCA) patients have reported conflicting results. The objective of this study was to evaluate the association between the initial PEA heart rate and favorable clinical outcomes for OHCA patients. Methods The present post-hoc cohort study used the Resuscitation Outcomes Consortium Cardiac Epidemiologic Registry Version 3, which included OHCA patients in seven US and three Canadian sites from April 2011 to June 2015. The primary outcome was survival to hospital discharge and the secondary outcome was survival with a good functional outcome. For the primary analysis, the patients were separated into eight groups according to their first rhythms and PEA heart rates: (1) initial PEA heart rate of 1-20 beats per minute (bpm); (2) 21-40 bpm; (3) 41-60 bpm; (4) 61-80 bpm; (5) 81-100 bpm; (6) 101-120 bpm; (7) over 120 bpm; (8) initial shockable rhythm (reference category). Multivariable logistic regression models were used to assess the associations of interest. Results We identified 17,675 patients (PEA: 7,089 [40.1%]; initial shockable rhythm: 10,797 [59.9%]). Patients with initial PEA electrical frequencies ≤100 bpm were less likely to survive to hospital discharge than patients with initial shockable rhythms (1-20 bpm: adjusted odds ratio [AOR] = 0.15 [95%CI 0.11-0.21]; 21-40 bpm: AOR = 0.21 [0.18-0.25]; 41-60 bpm: AOR = 0.30 [0.25-0.36]; 61-80 bpm: AOR = 0.37 [0.28-0.49]; 81-100 bpm: AOR = 0.55 [0.41-0.65]). However, there were no statistical outcome differences between PEA patients with initial electrical frequencies of >100 bpm and patients with initial shockable rhythms (101-120 bpm: AOR = 0.65 [95%CI 0.42-1.01]; >120 bpm: AOR = 0.72 [95%CI 0.37-1.39]). Similar results were observed for survival with good functional outcomes (101-120 bpm: AOR = 0.60 [95%CI 0.31-1.15]; >120 bpm: AOR = 1.08 [95%CI 0.50-2.28]). Conclusions We observed a good association between higher initial PEA electrical frequency and favorable clinical outcomes for OHCA patients. As there is no significant difference in outcomes between patients with initial PEA heart rates of more than 100 bpm and those with initial shockable rhythms, we can hypothesize that these patients could be considered in the same prognostic category.

A Woman with Chest Pain and Collapse

A 79-year-old woman with a history of hypertension and diabetes mellitus called emergency medical services for sudden chest pain with shortness of breath. She experienced cardiac arrest with initial pulseless electrical activity while en route in the ambulance. In the emergency department, resuscitation continued, and the findings of transesophageal echocardiography showed a hematoma within the aortic wall occluding the ostium of the right coronary artery (Figure 1, Video).

Higher chance of survival in patients with out-of-hospital cardiac arrest attributed to poisoning

Aim of the studyDescription and comparison of cohort characteristics and outcome of adult patients with out-of-hospital cardiac arrest (OHCA) attributed to poisoning (P-OHCA) versus patients with OHCA attributed to other medical causes (NP-OHCA). MethodsWe included all patients who received cardiopulmonary resuscitation after OHCA between January 2011 and December 2020 from German emergency medical services with good data quality in the German Resuscitation Registry. Exclusion criteria: patients < 18 years of age or OHCA attributed to trauma, drowning, intracranial bleeding or exsanguination. ResultsPatients with P-OHCA (n = 574) were significantly younger compared to NP-OHCA (n = 40,146) (median age of 43 (35–54) years vs. 73 (62–82) years; p < 0.001). Cardiac arrest in P-OHCA patients was significantly less often witnessed by bystanders (41.8 % vs. 66.2 %, p < 0.001). Asystole was the predominant initial rhythm in P-OHCA patients (73.5% vs. 53.7%, p < 0.001) while ventricular fibrillation (VF) and pulseless electrical activity (PEA) were less common (9.2% vs. 25.1% and 16.2 % vs. 20.5%, p < 0.001). P-OHCA had a higher chance of survival with good neurological outcome at hospital discharge (15.2 vs. 8.8 % p < 0.001) and poisoning was an independent protective prognostic factor in multivariate analysis (OR 2.47, 95%-CI [1.71–3.57]). P-OHCA patients with initial PEA survival with good neurological outcome was comparable to initial VF (34.3 % vs. 37.7%). ConclusionPatients in the P-OHCA group had a significantly higher chance of survival with good neurological outcome and PEA as initial rhythm was as favourable as initial VF. Therefore, in P-OHCA patients resuscitation efforts should be extended.

Delayed administration of epinephrine is associated with worse neurological outcomes in patients with out-of-hospital cardiac arrest and initial pulseless electrical activity: insight from the nationwide multicentre observational JAAM-OHCA (Japan Association for Acute Medicine) registry.

AimsThe delayed administration of epinephrine has been proven to worsen the neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) and shockable rhythm or asystole. We aimed to investigate whether the delayed administration of epinephrine might also worsen the neurological outcomes of patients with witnessed OHCA and initial pulseless electrical activity (PEA).Methods and resultsThe JAAM-OHCA Registry is a multicentre registry including OHCA patients between 2014 and 2017. Patients with emergency medical services (EMS)-treated OHCA and initial PEA rhythm were included. The primary exposure was the time from the EMS call to the administration of epinephrine. The secondary exposure was the time to epinephrine dichotomized as early (≤15 min) or delayed (>15 min). The primary outcome was the achievement of a favourable neurological outcome, defined as Cerebral Performance Categories Scale 1–2 at 30 days after OHCA. Out of 34 754 patients with OHCA, 3050 patients were included in the present study. After adjusting for potential confounders, the delayed administration of the epinephrine was associated with a lower likelihood of achieving a favourable neurological outcome [adjusted odds ratio (OR) 0.96; 95% confidence interval (CI) 0.93–0.99; P = 0.016]. The percentage of patients who achieved a favourable neurological outcome in the delayed epinephrine group was lower than that in the early epinephrine group (1.3% vs. 4.7%; adjusted OR 0.33; 95% CI 0.15–0.72; P = 0.005). A restricted cubic spline analysis demonstrated that delayed epinephrine administration could decrease the likelihood of achieving a favourable neurological outcome; this was significant within the first 10 min.ConclusionsThe delayed administration of epinephrine was associated with worse neurological outcomes in patients with witnessed OHCA patients with initial PEA.

The factors related to adrenaline administration during resuscitation in patients with initial pulseless electrical activity in out-of-hospital cardiac arrest

The factors related to adrenaline administration during resuscitation in patients with initial pulseless electrical activity in out-of-hospital cardiac arrest

A Man With Out-of-Hospital Cardiac Arrest

A previously healthy 50-year-old man experienced a witnessed cardiac arrest with initial pulseless electrical activity. The patient was intubated on-scene, and chest compressions were initiated utilizing a mechanical device at the midpoint of the internipple line by emergency medical technicians. Transesophageal echocardiography was performed in the emergency department (Figure 1 and Videos E1 and E2).

Pulseless electrical activity vs. asystole in adult in-hospital cardiac arrest: Predictors and outcomes

AimThis observational cohort study aimed to identify factors associated with pulseless electrical activity (PEA) and asystole in in-hospital cardiac arrest (IHCA) patients and to determine whether differences in outcome based on the initial rhythm were explained by patient- and cardiac arrest characteristics. MethodsAdults with IHCA from 2017 to 2018 were included from the Danish IHCA Registry (DANARREST). Additional data came from population-based registries. Unadjusted (RRs) and adjusted risk ratios (aRRs) were estimated for predictors of initial rhythm, return of spontaneous circulation (ROSC), and survival. ResultsWe included 1495 PEA and 1285 asystole patients. The patients did not differ substantially in patient characteristics. Female sex, age>90 years, pulmonary disease, and obesity were associated with initial asystole. Ischemic heart disease and witnessed and monitored cardiac arrest were associated with initial PEA. In unadjusted and adjusted analyses, PEA was associated with increased ROSC (aRR = 1.21, 95% confidence interval [CI] 1.10; 1.33). PEA was also associated with increased 30-day and 1-year survival in the unadjusted analysis, while there was no clear association between the initial rhythm and 30-day (aRR = 0.88, 95% CI 0.71; 1.11) and 1-year (aRR = 0.85, 95% CI 0.69; 1.04) survival when patient- and cardiac arrest characteristics were adjusted for. ConclusionIn patients with IHCA presenting with PEA or asystole, there were no major differences in patient demographics and comorbidities. The patients differed substantially in cardiac arrest characteristics. Initial PEA was associated with higher risk of ROSC, but there was no difference in 30-day and 1-year survival.

Association of subsequent shock after conversion to shockable rhythm with outcomes stratified by the type of initial non-shockable rhythm in children with out-of-hospital cardiac arrest

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research) Background/Introduction: The rhythm conversion from initial non-shockable to shockable rhythm during cardiopulmonary resuscitation (CPR) by emergency medical services (EMS) providers may be associated with neurologically intact survival after out-of-hospital cardiac arrest (OHCA) in children with an initial non-shockable rhythm. However, the prognostic significance of rhythm conversion stratified by the type of initial non-shockable rhythm is still unclear. Purpose We aimed to investigate the association of subsequent shock after rhythm conversion to shockable rhythm with neurologically intact survival and shock delivery time (time from EMS-initiated CPR to first shock delivery) by the type of initial non-shockable rhythm in children with OHCA. Methods We analysed the records of 19,095 children (age &amp;lt;18 years) with OHCA treated by EMS providers. Data were obtained from a prospectively recorded Japanese nationwide Utstein-style database for a 13-year period (2005–2017). The primary outcome measure was 1-month neurologically intact survival, defined as cerebral performance category score of 1 to 2. Patients were divided into the initial pulseless electrical activity (PEA) (n = 3,326 [17.4%]) and initial asystole (n = 15,769 [82.6%]) groups. Results The proportion of patients who received subsequent shock after conversion to shockable rhythm was significantly higher in the initial PEA than in the initial asystole groups (3.3% [109/3,326] vs. 1.4% [227/15,769], p &amp;lt; 0.0001). The shock delivery time was significantly shorter in the initial PEA than in the initial asystole groups (median [IQR], 8 min [5 min – 12 min] vs. 10 min [6 min – 16 min], p &amp;lt; 0.01). Among the initial PEA patients, there was no significant difference between subsequently shocked (10.0% [11/109]) and subsequently non-shocked patients (6.0% [192/3,217], p = 0.10) regarding the rate of 1-month neurologically intact survival. However, after adjusting for 9 pre-hospital variables, subsequent shock with a delivery time of &amp;lt;10 min was associated with increased odds of neurologically intact survival compared with no shock delivery (adjusted odds ratio [OR], 2.45; 95% confidence interval [CI], 1.16–5.16], p = 0.018). Among the initial asystole patients, the rate of 1-month neurologically intact survival was significantly higher in the subsequently shocked (4.4% [10/227]) than in the subsequently non-shocked (0.7% [106/15,542], p &amp;lt; 0.0001). A multivariate logistic regression model showed that subsequent shock with a delivery time of &amp;lt;10 min was associated with increased odds of neurologically intact survival compared with no shock delivery (adjusted OR, 9.77 [95% CI, 4.2–22.5], p &amp;lt; 0.0001). Conclusions In children with OHCA with an initial non-shockable rhythm, subsequent shock after conversion to shockable rhythm during CPR was associated with increased odds of 1-month neurologically intact survival only when shock was delivered &amp;lt;10 min from EMS-initiated CPR regardless of the type of initial rhythm.

Subsequent shock delivery and outcomes in out-of-hospital cardiac arrests with initial unshockable rhythm

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research) Background The conversion from initial non-shockable to shockable rhythms during cardiopulmonary resuscitation (CPR) by emergency medical service (EMS) providers may be associated with neurologically intact survival after out-of-hospital cardiac arrest (OHCA). However, the prognostic significance of rhythm conversion according to the type of initial nonshockable rhythm is unclear. Purpose To determine the association between shock after conversion to shockable rhythm with neurologically intact survival after OHCA and shock delivery time (time from EMS-initiated CPR to first shock delivery) in patients with two types of initial unshockable rhythm. Methods We analyzed the records of 90,334 adult patients with witnessed OHCA of cardiac origin who were treated by EMS providers and had an initial unshockable rhythm. Data were obtained from a prospectively recorded Japanese nationwide Utstein-style database for a 5-year period (2013–2017). The primary outcome was 1-month neurologically intact survival, defined as a cerebral performance categories score from 1 to 2. Patients were divided into initial pulseless electrical activity (PEA) (n = 37,977 [42.0%]) and initial asystole (n = 52,357 [58.0%]) groups. Results In the initial PEA group, the crude rate of 1-month neurologically intact survival was significantly higher in the subsequently shocked than in the non-shocked patients (4.2% [121/2,896]) vs. 2.4% [857/35,081], p &amp;lt;0.0001). After adjustment for ten prehospital variables, the adjusted odds ratios (aORs) of subsequent shock for 1-month neurologically intact survival compared to no shock delivery were as follows: shock delivery time &amp;lt;10 min, 2.21 (95% confidence interval [CI], 1.77–2.77, p&amp;lt; 0.0001); 10–14 min, 1.43 (0.89–2.28, p = 0.14); and ≥15 min, 0.36 (0.16–0.81; p = 0.013). In the initial asystole group, the crude rate of 1-month neurologically intact survival was significantly higher in the subsequently shocked than in the non-shocked (1.7% [47/2,687] vs. 0.4% [203/49,670], p &amp;lt;0.0001). A multivariate logistic regression model showed that subsequent shock with a shock delivery time &amp;lt;10 min was associated with increased odds of neurologically intact survival compared to no shock delivery (aOR, 5.67; 95% CI, 3.92–8.18; p &amp;lt;0.0001). However, there were no significant differences in neurological outcomes between subsequently shocked and non-shocked patients when the shock delivery time was 10–14 min (p = 0.21) or ≥15 min (p = 0.91). Conclusions In patients with witnessed OHCA of cardiac origin and initial nonshockable rhythm, subsequent shock after conversion to shockable rhythm during CPR was associated with increased odds of 1-month neurologically intact survival only when shock was delivered &amp;lt;10 min from EMS-initiated CPR, regardless of the type of initial rhythm. Further, in patients with initial PEA, subsequent shock was associated with decreased odds of neurologically intact survival when shock was delivered ≥15 min from EMS-initiated CPR.

Abstract 232: Delayed Administration of Epinephrine is Associated with Worse Neurological Outcomes in Patients with Out-of-hospital Cardiac Arrest and Initial Pulseless Electrical Activity

Background: Delayed administration of epinephrine has been proven to worsen the neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) and initial shockable rhythm. We aimed to investigate whether delayed administration of epinephrine might also worsen the neurological outcomes of patients with witnessed OHCA and initial pulseless electrical activity (PEA). Methods: The Japanese Association for Acute Medicine - out-of-hospital cardiac arrest (JAAM-OHCA) Registry is a multicenter, prospective, observational registry including 34,754 OHCA patients between 2014 and 2017. The present study assessed the impact of the time to epinephrine administration on neurological outcomes in patients with witnessed non-traumatic OHCA with initial rhythm of PEA. The primary outcome was defined as Cerebral Performance Categories (CPC) Scale 1-2 at 30 days after OHCA. The association between the odds ratio for the primary outcome and the time from witnessed OHCA to epinephrine administration was assessed with a restricted cubic spline analysis. Results: Out of 34,754 patients with OHCA, 3,050 patients with OHCA and initial PEA who received epinephrine were included in the present study. Mean age was 73.7 years and 1836 (60.2%) was male. After adjusting for potential confounders, the time from witnessed OHCA to epinephrine administration was associated with lower likelihood of favorable neurological outcomes (odds ratio [OR] 0.92; 95% confidence interval [CI] 0.89-0.96; P&amp;lt;0.001). The restricted cubic spline analysis demonstrated that delayed epinephrine administration could decrease the likelihood of a favorable neurological outcome; this was significant within the first 10 minutes. Conclusions: Delayed administration of epinephrine was associated with worse neurological outcomes in patients with witnessed OHCA patients with initial PEA.

Changes in the incidence of out-of-hospital cardiac arrest: Differences between cardiac and non-cardiac aetiologies

AimWe aimed to assess temporal changes in the incidence of OHCAs of presumed cardiac and non-cardiac aetiologies. MethodsWe conducted a retrospective cohort study of OHCAs in Victoria, Australia between 2000−2017. Annual adjusted incidence rates in presumed cardiac and non-cardiac OHCA were calculated with 95% confidence intervals (95% CI), assuming a Poisson distribution. Annual percent changes in the adjusted rates were calculated from Poisson regression models. ResultsDuring an 18-year period, 90,688 emergency medical service (EMS)-attended OHCAs were included. Of those, 64,422 (71.0%) were of presumed cardiac and 26,266 (29.0%) were of non-cardiac aetiology. Over the 18-year period, there was a 12.6% (95% CI: 10.8%, 14.4%) relative decline in presumed cardiac events and this was driven largely by a reduction in cases with an initial shockable rhythm (23.4%; 95% CI: 19.8%, 27.0%) and cases in patients aged 65−79 years (48.6%; 95% CI: 45.0%, 50.4%). Conversely, there was a 28.8% (95% CI: 27.0%, 32.4%) relative increase in non-cardiac events over the 18-year period, and this was driven by an increase in initial pulseless electrical activity events (93.6%; 95% CI: 86.4%, 100.8%) and cases in patients aged ≥80 years (93.6%; 95% CI: 86.4%, 100.8%). Precipitating events with the largest 18-year increase in incidence were non-traumatic exsanguination (115.2%; 95% CI: 95.4%, 133.2%), respiratory (66.6%; 95% CI: 59.4%, 73.8%), and neurological (63.0%; 95% CI: 50.4%, 77.4%). ConclusionOur data indicates that by 2052, non-cardiac aetiologies could be the leading cause of OHCA in our region. These findings have important EMS-system and public health implications.

Conversion from Nonshockable to Shockable Rhythms and Out-of-Hospital Cardiac Arrest Outcomes by Initial Heart Rhythm and Rhythm Conversion Time.

Background The conversion from a nonshockable rhythm (asystole or pulseless electrical activity (PEA)) to a shockable rhythm (pulseless ventricular tachycardia or ventricular fibrillation) may be associated with better out-of-hospital cardiac arrest (OHCA) outcomes. There are insufficient data on the prognostic significance of such conversions by initial heart rhythm and different rhythm conversion time. Methods Among 24,849 adult OHCA patients of presumed cardiac etiology with initial asystole or PEA in the Resuscitation Outcomes Consortium Cardiac Epidemiologic Registry (version 3, 2011–2015), we examined the association of shockable rhythm conversion with prehospital return of spontaneous circulation (ROSC), survival, and favorable functional outcome (modified Rankin Scale score ≤3) at hospital discharge by initial rhythm and rhythm conversion time (time from cardiopulmonary resuscitation (CPR) initiation by emergency medical providers to first shock delivery), using logistic regression adjusting for key clinical characteristics. Results Of 16,516 patients with initial asystole and 8,333 patients with initial PEA, 16% and 20% underwent shockable rhythm conversions; the median rhythm conversion time was 12.0 (IQR: 6.7–18.7) and 13.2 (IQR: 7.0–20.5) min, respectively. No difference was found in odds of prehospital ROSC across rhythm conversion time, regardless of initial heart rhythm. Shockable rhythm conversion was associated with survival and favorable functional outcome at hospital discharge only when occurred during the first 15 min of CPR, for those with initial asystole, or the first 10 min of CPR, for those with initial PEA. The associations between shockable rhythm conversion and outcomes were stronger among those with initial asystole compared with those with initial PEA. Conclusions The conversion from a nonshockable rhythm to a shockable rhythm was associated with better outcomes only when occurred early in initial nonshockable rhythm OHCA, and it has greater prognostic significance when the initial rhythm was asystole.

The effect of intravenous adrenaline on electrocardiographic changes during resuscitation in patients with initial pulseless electrical activity in out of hospital cardiac arrest

IntroductionPresence of electrocardiographic rhythm in the absence of palpable pulses defines pulseless electrical activity (PEA) and the electrocardiogram (ECG) may provide a source of information during resuscitation. The aim of this study was to examine the development of ECG characteristics during advanced life support (ALS) from Out-of-hospital cardiac arrest (OHCA) with initial PEA, and to explore the potential effects of adrenaline on these characteristics. MethodsPatients with OHCA and initial PEA, part of randomized controlled trial of ALS with or without intravenous access and medications, were included. A total of 4840 combined observations of QRS complex rate (heart rate) and width were made by examining defibrillator recordings from 170 episodes of cardiac arrest. ResultsWe found Increased heart rate (47 beats per minute) and reduced QRS complex width (62 ms) during ALS in patients who obtained return of spontaneous circulation (ROSC); while patients who received adrenaline but died increased their heart rate (22 beats per minute) without any concomitant decrease in QRS complex width. ConclusionECG changes during ALS in cardiac arrest were associated with prognosis, and the administration of adrenaline impacted on these changes.