Age-specific differences in prognostic significance of rhythm conversion from initial non-shockable to shockable rhythm and subsequent shock delivery in 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 <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 < 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 < 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 <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 < 0.0001). A multivariate logistic regression model showed that subsequent shock with a delivery time of <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 < 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 <10 min from EMS-initiated CPR regardless of the type of initial rhythm.

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Abstract 12258: Out-of-hospital Cardiac Arrest With Initially Shockable Rhythm: What Are the Outcomes if No Shock is Given?

Circulation ◽

10.1161/circ.132.suppl_3.12258 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Yan Xiong ◽

Ahamed H Idris

Keyword(s):

Cardiac Arrest ◽

Hospital Discharge ◽

Spontaneous Circulation ◽

Shock Delivery ◽

Return Of Spontaneous Circulation ◽

Shockable Rhythm ◽

Multiple Variable ◽

Multiple Variable Regression ◽

Hospital Cardiac Arrest ◽

Resuscitation Attempt

Background: Prompt defibrillation is critical for termination of ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in out-of-hospital cardiac arrest (OHCA). For ethical reasons, the real impact of not shocking OHCA patients with a shockable rhythm is unlikely to be investigated in clinical trials and thus remains unknown. Objectives: To describe demographics, pre-hospital characteristics, interventions, and outcomes in OHCA patients with an initially shockable rhythm who did and did not get shocked in the field in DFW ROC site. Methods: We included all non-traumatic OHCA cases ≥18 years old with VF or VT as first known rhythms, who were treated and transported to a hospital within the DFW ROC site between 2006 - 2011. We report return of spontaneous circulation (ROSC) in the field and survival to hospital discharge for victims with and without shock delivered in the field. Multiple variable regression analysis assessed the association between shock delivery and ROSC in the field as well as survival. Results: Included were 882 adult non-traumatic OHCA cases with VF or VT as first known rhythms; mean (±SD) age was 60 ± 15 years, 71% male, bystander witnessed 56%, bystander resuscitation attempt 43%, public arrest location 26%, EMS response time 4.7 ± 2.3 min, 26.9% (237) had ROSC in the field, 14.9% (131) survived to hospital discharge; 93.4% (824) of all patients were shocked, while 6.6% (58) were not shocked. Of the 6.6% (58) who were not shocked, 12.1% (7) achieved ROSC in the field and 8.6% (5) survived to hospital discharge. For those not shocked in the field, the unadjusted and adjusted odds ratios for ROSC were 0.354 (95% CI 0.158-0.791, p=0.011) and 0.189 (95% CI 0.039-0.911, p=0.038), respectively; and for survival to hospital discharge they were 0.522 (95% CI 0.205-1.331, p=0.173) and 0.498 (95% CI 0.088-2.810, p=0.430), respectively. Conclusions: In the DFW ROC site, 6.6% of OHCA victims with an initially shockable rhythm did not receive a shock, which was significantly associated with decreased ROSC in the field. More patients survived who were shocked in the field, but this difference was not significant after adjustment for Utstein variables.

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The prognostic significance of repeated prehospital shocks for out-of-hospital cardiac arrest survival

CJEM ◽

10.1017/cem.2018.437 ◽

2018 ◽

Vol 21 (3) ◽

pp. 330-338 ◽

Cited By ~ 1

Author(s):

Alexis Cournoyer ◽

Éric Notebaert ◽

Sylvie Cossette ◽

Luc Londei-Leduc ◽

Luc de Montigny ◽

...

Keyword(s):

Cardiac Arrest ◽

Confidence Interval ◽

Hospital Discharge ◽

Prognostic Significance ◽

Probability Of Survival ◽

Shockable Rhythm ◽

Malignant Arrhythmia ◽

The Relationship ◽

Cardiac Arrest Survival ◽

Hospital Cardiac Arrest

ABSTRACTObjectivesPatients suffering from an out-of-hospital cardiac arrest (OHCA) associated with an initial shockable rhythm have a better prognosis than their counterparts. The implications of recurrent or refractory malignant arrhythmia in such context remain unclear. The objective of this study is to evaluate the association between the number of prehospital shocks delivered and survival to hospital discharge among patients in OHCA.MethodsThis cohort study included adult patients with an initial shockable rhythm over a 5-year period from a registry of OHCA in Montreal, Canada. The relationship between the number of prehospital shocks delivered and survival to discharge was described using dynamic probabilities. The association between the number of prehospital shocks delivered and survival to discharge was assessed using multivariable logistic regression.ResultsA total of 1,788 patients (78% male with a mean age of 64 years) were included in this analysis, of whom 536 (30%) received treatments from an advanced care paramedic. A third of the cohort (583 patients, 33%) survived to hospital discharge. The probability of survival was highest with the first shock (33% [95% confidence interval 30%-35%]), but decreased to 8% (95% confidence interval 4%-13%) following nine shocks. A higher number of prehospital shocks was independently associated with lower odds of survival (adjusted odds ratio=0.88 [95% confidence interval 0.85-0.92], p < 0.001).ConclusionSurvival remains possible even after a high number of shocks for patients suffering from an OHCA with an initial shockable rhythm. However, requiring more shocks is independently associated with worse survival.

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

Cardiology Research and Practice ◽

10.1155/2020/3786408 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Wanwan Zhang ◽

Shengyuan Luo ◽

Daya Yang ◽

Yongshu Zhang ◽

Jinli Liao ◽

...

Keyword(s):

Cardiac Arrest ◽

Functional Outcome ◽

Hospital Discharge ◽

Prognostic Significance ◽

Heart Rhythm ◽

Shockable Rhythm ◽

Initial Rhythm ◽

Conversion Time ◽

Hospital Cardiac Arrest ◽

Favorable Functional Outcome

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.

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Abstract 254: High Shock Efficacy and Algorithm Performance for a 150J Biphasic Waveform AED Used by Lay and BLS Responders During Out-of-hospital Cardiac Arrest

Circulation ◽

10.1161/circ.142.suppl_4.254 ◽

2020 ◽

Vol 142 (Suppl_4) ◽

Author(s):

Stacy Gehman ◽

Edward Kompare ◽

Barbara Fink ◽

Tim Johnson ◽

Walter Hufford ◽

...

Keyword(s):

Cardiac Arrest ◽

Normal Sinus Rhythm ◽

Convenience Sample ◽

Shock Delivery ◽

Shockable Rhythm ◽

Normal Sinus ◽

High Shock ◽

Biphasic Waveform ◽

Post Shock ◽

Hospital Cardiac Arrest

Introduction: Effective AED defibrillation of out of hospital cardiac arrest (OHCA) depends on the safe and effective identification of shockable rhythms, and on delivery of effective defibrillation energy. This report summarizes rhythm detection performance and shock efficacy during OHCA uses of Philips HeartStart Home and OnSite AEDs using non-escalating 150 J therapy. Methods: A convenience sample of 185 OHCA AED patient uses were reviewed by clinical experts. All analysis periods that resulted in AED rhythm advisories (Shock Advised or No Shock Advised) were annotated. Shockable rhythm categories include VF and polymorphic VT/flutter. Non-Shockable rhythm categories include normal sinus rhythm, other rhythms (e.g., atrial fibrillation/flutter, bradycardia, SVT, idioventricular, bundle branch block), and asystole. Intermediate rhythms (benefits of defibrillation are limited or uncertain) were not included. Post-shock rhythm was categorized as shockable, non-shockable, or undeterminable (rhythms corrupted by CPR artifact or pads removal within 5-s of shock delivery). Shock success was defined as conversion to a non-shockable rhythm within 5-s post-shock. Results: A total of 487 analysis periods resulted in AED rhythm advisories, with 175 annotated as Shockable and 312 Non-shockable. Sensitivity and specificity (n/N, Exact 95% CI) were 97.7% (171/175, 94.3%, 99.4%) and 100% (312/312, 98.8%, 100.0%) respectively. A total of 165 shocks were delivered to 100 patients with 5 undeterminable post-shock rhythms. The remaining 160 shocks were delivered to 156 Shockable rhythm episodes. All shock efficacy was 96.9% (155/160, 92.9%, 99.0%): 150 episodes converted to non-shockable rhythms after one shock (96.2% (150/156, 91.8%, 98.6%)); 154 after two shocks (98.7% (154/156, 95.4%, 99.8%)); and 155 after three shocks, the first two of which were undeterminable (99.4% (155/156, 96.5%, 100.0%)). The remaining episode had a failed first shock, followed by an undeterminable second shock, which was the last shock of the use. Conclusion: For these 150J fixed-energy AEDs, OHCA defibrillation is safe (100% specificity), and effective (97.7% sensitivity; 96.2% single shock effectiveness; 98.7% after two shocks; 99.4% after three shocks).

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Prognostic Value of the Conversion to a Shockable Rhythm in Out-of-Hospital Cardiac Arrest Patients with Initial Non-Shockable Rhythm

Journal of Clinical Medicine ◽

10.3390/jcm8050644 ◽

2019 ◽

Vol 8 (5) ◽

pp. 644 ◽

Cited By ~ 1

Author(s):

Kap Su Han ◽

Sung Woo Lee ◽

Eui Jung Lee ◽

Su Jin Kim

Keyword(s):

Cardiac Arrest ◽

Prognostic Value ◽

Primary Outcome ◽

Prognostic Significance ◽

Spontaneous Circulation ◽

Neurologic Outcome ◽

Shockable Rhythm ◽

Control And Prevention ◽

Good Neurologic Outcome ◽

Hospital Cardiac Arrest

In patients with out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm, the prognostic significance of conversion to a shockable rhythm (or hereafter “conversion”) during resuscitation remains unclear. We investigated whether conversion is associated with good neurologic outcome. We included patients with OHCA with medical causes and an initial non-shockable rhythm by using the national OHCA surveillance cohort database of the Korea Centers for Disease Control and Prevention for 2012~2016. The primary outcome was good neurologic outcome at hospital discharge. Of 85,602 patients with an initial non-shockable rhythm, 17.9% experienced conversion. Patients with and those without conversion had good neurologic outcome rates of 3.2% and 1.0%, respectively (p < 0.001). In multiple regression analysis, conversion was associated with good neurologic outcome (adjusted odds ratio (OR) 2.604; 95% confidence interval (CI) 2.248–3.015) in the patients with an initial non-shockable rhythm, and had the association with good neurologic outcome (adjusted OR 3.972, 95% CI 3.167–4.983) in unwitnessed patients by emergency medical services (EMS) without pre-hospital return of spontaneous circulation (ROSC) among the population. In patients with OHCA with an initial non-shockable rhythm, even if with unwitnessed arrest by EMS and no pre-hospital ROSC, continuing resuscitation needs to be considered if conversion to a shockable rhythm occurred.

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Abstract 123: Field Accuracy of Paramedic Shock Delivery Using a Filtered ECG Rhythm

Circulation ◽

10.1161/circ.140.suppl_2.123 ◽

2019 ◽

Vol 140 (Suppl_2) ◽

Author(s):

Hill Stoecklein ◽

Andrew Pugh ◽

Michael Stroud ◽

Scott Youngquist

Keyword(s):

Cardiac Arrest ◽

Salt Lake ◽

Survival Rates ◽

Salt Lake City ◽

Fire Department ◽

Shock Delivery ◽

Shockable Rhythm ◽

Lake City ◽

Neurologically Intact ◽

Hospital Cardiac Arrest

Introduction: Recognition and rapid defibrillation of shockable rhythms is strongly associated with increased survival from out-of-hospital cardiac arrest (OHCA). The Salt Lake City Fire Department (SLCFD) adopted ECG rhythm filtering technology in 2011, along with a protocol to rapidly defibrillate shockable rhythms without awaiting the end of the 2-minute CPR epoch. Paramedics were also trained to empirically shock asystole, as studies have shown poor agreement in cases of fine and moderate amplitude Ventricular Fibrillation (VF). Hypothesis: We hypothesized that the mandate to shock perceived asystole plus the use of filtering technology would result in high case sensitivity for shockable rhythms at the expense of an unknown frequency of shock delivery to organized rhythms. Methods: Prospectively collected defibrillator data from cardiac arrest cases treated by SLCFD between Dec 2011 and June 2019 were analyzed. Timing of rhythm changes and defibrillation events was manually abstracted using the manufacturer’s review software. The gold standard for rhythm interpretation was post-incident physician interpretation. Results: Paramedics attempted resuscitation in 942 OHCAs. We excluded 41 pediatric cases, 140 cases of BLS or bystander-only AED resuscitation, and 65 cases in which the defibrillator file was unavailable. Overall, 696 adult cardiac arrests with 1,389 shocks delivered were available for analysis. Shocks were delivered to 958 (69%) shockable, 261 (19%) asystole, 158 (11%) PEA, 4 (0.3%) SVT, and 8 (0.6%) unknown underlying rhythms. In 280 cases no shock was delivered despite an initial shockable rhythm in 3 of these cases. Shock delivery case sensitivity was 180/183 (0.98, 95% confidence interval [CI]:0.97-1.0) with false positive proportion of delivered shocks of 158/1,389 (0.11, 95% CI:0.10-0.13) for PEA only and 419/1,389 (0.30, 95% CI:0.28-0.33) for combined PEA and asystole. Neurologically intact (CPC 1-2) overall and Utstein survival rates were 15% and 46% respectively. Conclusions: Using ECG rhythm-filtering technology and an aggressive protocol to defibrillate VF and empirically shock asystole, we demonstrated high case sensitivity for VF at the expense of an 11% rate of shock delivery to underlying PEA.

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LO03: Impact of the conversion to a shockable rhythm from a non-shockable rhythm for patients suffering from out-of-hospital cardiac arrest

CJEM ◽

10.1017/cem.2018.65 ◽

2018 ◽

Vol 20 (S1) ◽

pp. S7-S7

Author(s):

A. Cournoyer ◽

E. Notebaert ◽

S. Cossette ◽

J. Morris ◽

L. de Montigny ◽

...

Keyword(s):

Cardiac Arrest ◽

Outcome Measure ◽

Prognostic Significance ◽

Pulseless Electrical Activity ◽

Primary Outcome Measure ◽

Absolute Difference ◽

Secondary Outcome ◽

Secondary Outcome Measure ◽

Shockable Rhythm ◽

Hospital Cardiac Arrest

Introduction: Patients suffering from out-of-hospital cardiac arrest (OHCA) with an initial shockable rhythm (ventricular tachycardia or ventricular fibrillation) have higher odds of survival than those suffering from non-shockable rhythm (asystole or pulseless electrical activity). Because of that prognostic significance, patients with an initial non-shockable rhythm are often not considered for advanced resuscitation therapies such as extracorporeal resuscitation. However, the prognostic significance of the conversion to a shockable rhythm from an initially non-shockable rhythm remains uncertain. This study aimed to determine the degree of association between the conversion (or not) of a non-shockable rhythm to a shockable rhythm and resuscitation outcomes in patients with OHCA. It was hypothesized that such a conversion would be associated with a higher survival to discharge. Methods: The present study used a registry of adult OHCA between 2010 and 2015 in Montreal, Canada. Adult patients with non-traumatic OHCA and an initial non-shockable rhythm were included. The primary outcome measure was survival to hospital discharge, and the secondary outcome measure was prehospital return of spontaneous circulation (ROSC). The associations of interest were evaluated with univariate logistic regressions and multivariate models controlling for demographic and clinical variables (e.g. age, gender, type of initial non-shockable rhythm, witnessed arrest, bystander cardiopulmonary resuscitation). Assuming a survival rate of 3% and 25% of the variability explained by the control variables, including more than 4580 patients would allow to detect an absolute difference of 4% in survival between both groups with a power of more than 90%. Results: A total of 4893 patients (2869 men and 2024 women) with a mean age of 70 years (standard deviation 17) were included, of whom 450 (9.2%) experienced a conversion to a shockable rhythm during the course of their prehospital resuscitation. Among all patients, 146 patients (3.0%) survived to discharge and 633 (12.9%) experienced prehospital ROSC. In the univariate models, there was no association between the conversion to a shockable rhythm and survival (odds ratio [OR] 1.14 [95% confidence interval {CI} 0.66-1.95]), but a significant assocation was observed with ROSC (OR 2.00 [95% CI 1.57-2.55], p<0.001). However, there was no independent association between the conversion to a shockable rhythm and survival (adjusted OR [AOR] 0.92 [95% CI 0.51-1.66], p=0.78) and prehospital ROSC (AOR 1.30 [95% CI 0.98-1.72], p=0.073). Conclusion: There is no clinically significant association between the conversion to a shockable rhythm and resuscitation outcomes in patients suffering from OHCA. The initial rhythm remains a much better outcome predictor than subsequent rhythms and should be preferred when evaluating the eligibility for advanced resuscitation procedures.

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Prognostic significance of spontaneous shockable rhythm conversion in adult out-of-hospital cardiac arrest patients with initial non-shockable heart rhythms: A systematic review and meta-analysis

Resuscitation ◽

10.1016/j.resuscitation.2017.09.014 ◽

2017 ◽

Vol 121 ◽

pp. 1-8 ◽

Cited By ~ 12

Author(s):

Shengyuan Luo ◽

Yongshu Zhang ◽

Wanwan Zhang ◽

Ruiying Zheng ◽

Jun Tao ◽

...

Keyword(s):

Systematic Review ◽

Cardiac Arrest ◽

Meta Analysis ◽

Prognostic Significance ◽

Shockable Rhythm ◽

Hospital Cardiac Arrest

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Outcomes of out-of-hospital cardiac arrest in Beijing: a 5-year cross-sectional study

BMJ Open ◽

10.1136/bmjopen-2020-041917 ◽

2021 ◽

Vol 11 (4) ◽

pp. e041917

Author(s):

Fei Shao ◽

Haibin Li ◽

Shengkui Ma ◽

Dou Li ◽

Chunsheng Li

Keyword(s):

Cardiac Arrest ◽

Urban Areas ◽

Patient Characteristics ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Term Survival ◽

Shockable Rhythm ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

ObjectiveThe purpose of this study was to assess the trends in outcomes of out-of-hospital cardiac arrest (OHCA) in Beijing over 5 years.DesignCross-sectional study.MethodsAdult patients with OHCA of all aetiologies who were treated by the Beijing emergency medical service (EMS) between January 2013 and December 2017 were analysed. Data were collected using the Utstein Style. Cases were followed up for 1 year. Descriptive statistics were used to characterise the sample and logistic regression was performed.ResultsOverall, 5016 patients with OHCA underwent attempted resuscitation by the EMS in urban areas of Beijing during the study period. Survival to hospital discharge was 1.2% in 2013 and 1.6% in 2017 (adjusted rate ratio=1.0, p for trend=0.60). Survival to admission and neurological outcome at discharge did not significantly improve from 2013 to 2017. Patient characteristics and the aetiology and location of cardiac arrest were consistent, but there was a decrease in the initial shockable rhythm (from 6.5% to 5.6%) over the 5 years. The rate of bystander cardiopulmonary resuscitation (CPR) increased steadily over the years (from 10.4% to 19.4%).ConclusionSurvival after OHCA in urban areas of Beijing did not improve significantly over 5 years, with long-term survival being unchanged, although the rate of bystander CPR increased steadily, which enhanced the outcomes of patients who underwent bystander CPR.

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