Insights From the Ventricular Fibrillation Waveform Into the Mechanism of Survival Benefit From Bystander Cardiopulmonary Resuscitation

Background The mechanism by which bystander cardiopulmonary resuscitation (CPR) improves survival following out‐of‐hospital cardiac arrest is unclear. We hypothesized that ventricular fibrillation (VF) waveform measures, as surrogates of myocardial physiology, mediate the relationship between bystander CPR and survival. Methods and Results We performed a retrospective cohort study of adult, bystander‐witnessed patients with out‐of‐hospital cardiac arrest with an initial rhythm of VF who were treated by a metropolitan emergency medical services system from 2005 to 2018. Patient, resuscitation, and outcome variables were extracted from emergency medical services and hospital records. A total of 3 VF waveform measures (amplitude spectrum area, peak frequency, and median peak amplitude) were computed from a 3‐second ECG segment before the initial shock. Multivariable logistic regression estimated the association between bystander CPR and survival to hospital discharge adjusted for Utstein elements. Causal mediation analysis quantified the proportion of survival benefit that was mediated by each VF waveform measure. Of 1069 patients, survival to hospital discharge was significantly higher among the 814 patients who received bystander CPR than those who did not (0.52 versus 0.43, respectively; P <0.01). The multivariable‐adjusted odds ratio for bystander CPR and survival was 1.6 (95% CI, 1.2, 2.1), and each VF waveform measure attenuated this association. Depending on the specific waveform measure, the proportion of mediation varied: 53% for amplitude spectrum area, 31% for peak frequency, and 29% for median peak amplitude. Conclusions Bystander CPR correlated with more robust initial VF waveform measures, which in turn mediated up to one‐half of the survival benefit associated with bystander CPR. These results provide insight into the biological mechanism of bystander CPR in VF out‐of‐hospital cardiac arrest.

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Abstract 16924: Initial AMSA and Increased AMSA After CPR Predict Second Shock Success in Initially Shock-resistant VF During Out-of-hospital Cardiac Arrest

Circulation ◽

10.1161/circ.132.suppl_3.16924 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Ulrich Herken ◽

Weilun Quan

Keyword(s):

Logistic Regression ◽

Cardiac Arrest ◽

Ventricular Fibrillation ◽

Success Rate ◽

Fourier Transformation ◽

Amplitude Spectrum ◽

Fast Fourier Transformation ◽

Shock Delivery ◽

Spectrum Area ◽

Hospital Cardiac Arrest

Purpose: Amplitude spectrum area (AMSA), which is calculated from the ventricular fibrillation (VF) waveform using fast Fourier transformation, has been recognized as a predictor of successful defibrillation (DF) and as an index of myocardial perfusion and viability during resuscitation. In this study, we investigated whether a change in AMSA occurring during CPR would predict DF outcome for subsequent DF attempts after a failed DF. We hypothesized that a patient responding to CPR with an increase in AMSA would have an increased likelihood of DF success. Methods: This was a retrospective analysis of out-of-hospital cardiac arrest patients who received a second DF due to initially shock-resistant VF. A total of 193 patients with an unsuccessful first DF were identified in a manufacturer database of electrocardiographic defibrillator records. AMSA was calculated for the first DF (AMSA1) and the second DF (AMSA2) during a 2.1 sec window ending 0.5 sec prior to DF. A successful DF attempt was defined as the presence of an organized rhythm with a rate ≥ 40 / min starting within 60 sec from the DF and lasting for > 30 sec. After the failed first DF, all patients received CPR for 2 to 3 minutes before delivery of the second DF. Change in AMSA (dAMSA) was calculated as dAMSA = AMSA2 - AMSA1. Results: The overall second DF success rate was 14.5%. Multivariable logistic regression showed that both AMSA1 and dAMSA were independent predictors of second DF success with odds ratios of 1.24 (95% CI 1.12 - 1.38, p<0.001) and 1.27 (95% CI 1.16 - 1.41, p<0.001) for each mVHz change in AMSA or dAMSA, respectively. Conclusions: In initially DF-resistant VF, a high initial AMSA value predicted an increased likelihood of second shock success. An increase of AMSA in response to CPR also predicted a higher second shock success rate. Monitoring of AMSA during resuscitation therefore may be useful to guide CPR efforts, possibly including timing of second shock delivery. These findings also further support the value of AMSA as indicator of myocardial viability.

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Bystander Cardiopulmonary Resuscitation Quality: Potential for Improvements in Cardiac Arrest Resuscitation

Journal of the American Heart Association ◽

10.1161/jaha.120.017930 ◽

2021 ◽

Author(s):

Richard Chocron ◽

Julia Jobe ◽

Sally Guan ◽

Madeleine Kim ◽

Mia Shigemura ◽

...

Keyword(s):

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Performance Metrics ◽

Medical System ◽

Emergency Medical System ◽

Compression Rate ◽

Emergency Medical ◽

Bystander Cardiopulmonary Resuscitation ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

Background Bystander cardiopulmonary resuscitation (CPR) is a critical intervention to improve survival following out‐of‐hospital cardiac arrest. We evaluated the quality of bystander CPR and whether performance varied according to the number of bystanders or provision of telecommunicator CPR (TCPR). Methods and Results We investigated non‐traumatic out‐of‐hospital cardiac arrest occurring in a large metropolitan emergency medical system during a 6‐month period. Information about bystander care was ascertained through review of the 9‐1‐1 recordings in addition to emergency medical system and hospital records to determine bystander CPR status (none versus TCPR versus unassisted), the number of bystanders on‐scene, and CPR performance metrics of compression fraction and compression rate. Of the 428 eligible out‐of‐hospital cardiac arrest, 76.4% received bystander CPR including 43.7% unassisted CPR and 56.3% TCPR; 35.2% had one bystander, 33.3% had 2 bystanders, and 31.5% had ≥3 bystanders. Overall compression fraction was 59% with a compression rate of 88 per minute. CPR differed according to TCPR status (fraction=52%, rate=87 per minute for TCPR versus fraction=69%, rate=102 for unassisted CPR, P <0.05 for each comparison) and the number of bystanders (fraction=55%, rate=87 per minute for 1 bystander, fraction=59%, rate=89 for 2 bystanders, fraction=65%, rate=97 for ≥3 bystanders, test for trend P <0.05 for each metric). Additional bystander actions were uncommon to include rotation of compressors (3.1%) or application of an automated external defibrillator (8.0%). Conclusions Bystander CPR quality as gauged by compression fraction and rate approached guideline goals though performance depended upon the type of CPR and number of bystanders.

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Comorbidity and bystander cardiopulmonary resuscitation in out-of-hospital cardiac arrest

Heart ◽

10.1136/heartjnl-2019-315954 ◽

2020 ◽

Vol 106 (14) ◽

pp. 1087-1093

Author(s):

Geir Hirlekar ◽

Martin Jonsson ◽

Thomas Karlsson ◽

Maria Bäck ◽

Araz Rawshani ◽

...

Keyword(s):

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Multiple Logistic Regression ◽

Multivariable Model ◽

National Patient Registry ◽

National Patient ◽

Bystander Cardiopulmonary Resuscitation ◽

Bystander Cpr ◽

Comorbidity Index ◽

Hospital Cardiac Arrest

ObjectiveCardiopulmonary resuscitation (CPR) performed before the arrival of emergency medical services (EMS) is associated with increased survival after out-of-hospital cardiac arrest (OHCA). The aim of this study was to determine whether patients who receive bystander CPR have a different comorbidity compared with patients who do not, and to determine the association between bystander CPR and 30-day survival when adjusting for such a possible difference.MethodsPatients with witnessed OHCA in the Swedish Registry for Cardiopulmonary Resuscitation between 2011 and 2015 were included, and merged with the National Patient Registry. The Charlson Comorbidity Index (CCI) was used to measure comorbidity. Multiple logistic regression was used to examine the effect of CCI on the association between bystander CPR and outcome.ResultsIn total, 11 955 patients with OHCA were included, 71% of whom received bystander CPR. Patients who received bystander CPR had somewhat lower comorbidity (CCI) than those who did not (mean±SD: 2.2±2.3 vs 2.5±2.4; p<0.0001). However, this difference in comorbidity had no influence on the association between bystander CPR and 30-day survival in a multivariable model including other possible confounders (OR 2.34 (95% CI 2.01 to 2.74) without adjustment for CCI and OR 2.32 (95% CI 1.98 to 2.71) with adjustment for CCI).ConclusionPatients who undergo CPR before the arrival of EMS have a somewhat lower degree of comorbidity than those who do not. Taking this difference into account, bystander CPR is still associated with a marked increase in 30-day survival after OHCA.

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Trend in survival after out-of-hospital cardiac arrest and its relationship with bystander cardiopulmonary resuscitation: a six-year prospective observational study in Beijing

BMC Cardiovascular Disorders ◽

10.1186/s12872-021-02446-z ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yuling Chen ◽

Peng Yue ◽

Ying Wu ◽

Jia Li ◽

Yanni Lei ◽

...

Keyword(s):

Cardiac Arrest ◽

Survival Rate ◽

Cardiopulmonary Resuscitation ◽

Observational Study ◽

Indirect Effect ◽

Prospective Observational Study ◽

Shockable Rhythm ◽

Bystander Cardiopulmonary Resuscitation ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

Abstract Background Out-of-hospital cardiac arrest (OHCA), a global health problem with a survival rate ranging from 2 to 22% across different countries, has been a leading cause of premature death for decades. The aim of this study was to evaluate the trends of survival after OHCA over time and its relationship with bystander cardiopulmonary resuscitation (CPR), initial shockable rhythm, return of spontaneous circulation (ROSC), and survived event. Methods In this prospective observational study, data of OHCA patients were collected following the “Utstein style” by the Beijing, China, Emergency Medical Service (EMS) from January 2011 (data from February to June in 2011 was not collected) to October 2016. Patients who had a cardiac arrest and for whom an ambulance was dispatched were included in this study. All cases were followed up to determine hospital discharge or death. The trend of OHCA survival was analyzed using the Chi-square test. The relationship among bystander CPR, initial shockable rhythm, ROSC, survived event, and OHCA survival rate was analyzed using multivariate path analyses with maximum standard likelihood estimation. Results A total of 25,421 cases were transferred by the Beijing EMS; among them, 5042 (19.8%) were OHCA (median age: 78 years, interquartile range: 63–85, 60.1% male), and 484 (9.6%) received bystander CPR. The survival rate was 0.6%, which did not improve from 2012 to 2015 (P = 0.569). Overall, bystander CPR was indirectly associated with an 8.0% (β = 0.080, 95% confidence interval [CI] = 0.064–0.095, P = 0.002) increase in survival rate. The indirect effect of bystander CPR on survival rate through survived event was 6.6% (β = 0.066, 95% CI = 0.051–0.081, P = 0.002), which accounted for 82.5% (0.066 of 0.080) of the total indirect effect. With every 1 increase in survived event, the possibility of survival rate will directly increase by 53.5% (β = 0.535, 95% CI = 0.512–0.554, P = 0.003). Conclusions The survival rate after OHCA was low in Beijing which has not improved between 2012 and 2015. The effect of bystander CPR on survival rate was mainly mediated by survived event. Trial registration Chinese Clinical Trial Registry: ChiCTR-TRC-12002149 (2 May, 2012, retrospectively registered). http://www.chictr.org.cn/showproj.aspx?proj=7400

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5225Bystander cardiopulmonary resuscitation and survival in out-of-hospital cardiac arrest of non-cardiac origin

European Heart Journal ◽

10.1093/eurheartj/ehz746.0073 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

D M Christensen ◽

S Rajan ◽

K Kragholm ◽

K B Sondergaard ◽

O M Hansen ◽

...

Keyword(s):

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Temporal Trends ◽

Patient Characteristics ◽

Ohca Patient ◽

Significant Difference ◽

Bystander Cardiopulmonary Resuscitation ◽

Study Population ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

Abstract Background Knowledge about the effect of bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) of non-cardiac origin is lacking. We aimed to investigate the association between bystander CPR and survival in OHCA of presumed non-cardiac origin. Methods From the Danish Cardiac Arrest Registry and through linkage with national Danish healthcare registries we identified all adult patients with OHCA of presumed non-cardiac origin in Denmark (2001–2014). These were categorized further into OHCA of medical and non-medical cause. We analyzed temporal trends in bystander CPR and 30-day survival during the study period. Multiple logistic regression was used to examine the association between bystander CPR and 30-day survival and reported as standardized 30-day survival chances with versus without bystander CPR standardized to the prehospital OHCA-factors and patient characteristics of all patients in the study population. Results We identified 10,761 OHCAs of presumed non-cardiac origin. Bystander CPR was associated with an increased 30-day survival chance of 3.4% (95% confidence interval [CI]: 2.9–3.9) versus 1.8% (95% CI: 1.4–2.2) with no bystander CPR, corresponding to a significant difference of 1.6% (95% CI: 0.9–2.3). During the study period, the overall bystander CPR rates increased from 13.6% (95% CI: 11.2–16.5) to 62.7% (95% CI: 60.2–65.2). 30-day survival increased overall from 1.3% (95% CI: 0.7–2.6) to 4.0% (95% CI: 3.1–5.2). Similar findings were observed in subgroups of medical and non-medical OHCA. Table 1. Patient and arrest characteristics according to cause of out-of-hospital cardiac arrest Overall Medical OHCA Non-medical OHCA Patient characteristics Total patients 10761 7625 3136 Median age,y 67 70 50 Male, n (%) 6357 (59.1) 4154 (54.5) 2204 (70.4) OHCA factors Witnessed arrest, n (%) 4306 (40.0) 3574 (46.9) 732 (23.3) Public location, n (%) 6979 (64.9) 5494 (72.1) 1485 (47.4) OHCA, out-of-hospital cardiac arrest; CPR, cardiopulmonary resuscitation. Figure 1. Temporal trends Conclusion Bystander CPR was associated with a higher chance of 30-day survival among OHCA of presumed non-cardiac origin regardless of the underlying cause (medical/non-medical). Rates of bystander CPR and 30-day survival improved during the study period.

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Abstract 194: Public Perception Towards Out-of-Hospital Cardiac Arrest Victims: Potential Reasons Influencing the Decision to Perform Bystander Cardiopulmonary Resuscitation

Circulation ◽

10.1161/circ.138.suppl_2.194 ◽

2018 ◽

Vol 138 (Suppl_2) ◽

Author(s):

Sarah S Gul ◽

Torben K Becker ◽

Carolina B Maciel ◽

Travis Murphy ◽

Teddy S Youn ◽

...

Keyword(s):

Cardiac Arrest ◽

Sexual Assault ◽

Cardiopulmonary Resuscitation ◽

Public Perception ◽

Comfort Level ◽

Categorical Variables ◽

Bystander Cardiopulmonary Resuscitation ◽

Bystander Cpr ◽

Cpr Training ◽

Hospital Cardiac Arrest

Background: Bystander cardiopulmonary resuscitation (CPR) after out-of-hospital cardiac arrest (OHCA) improves survival and neurological outcomes. Unfortunately many OHCA victims do not receive bystander CPR during a witnessed arrest. It is known that gender disparities play a role with lower rates of bystander CPR in women suffering OHCA in public places. Our aim was to identify potential factors influencing the decision to perform bystander CPR. Methods: Participants at CPR training events were surveyed prior to training. Using different scenarios, subjects were asked about their comfort level performing CPR on female, geriatric, and pediatric victims. Anonymous responses were collected and transformed into categorical variables by a psychometrist. Results: Of the 677 participants, 585 (86.4%) responded the survey, with 87.5% between 18-29 years of age, 58.8% without prior CPR training and 93.3% without prior CPR experience. Reasons to hesitate starting bystander CPR in women included concern about exposing the victim (12.9%), being accused of sexual assault (6.1%), and possible pregnancy (6.5%). In participants with prior CPR training, 61.1% reported concerns about performing CPR on women, with 18.9% having concerns about performing chest compressions in relation to breast location. In participants without prior CPR training, 73.2% reported having concerns about performing CPR on women. Causing injury and exposing the patient were top concerns to perform CPR in women amongst participants who were uncomfortable (30.5% and 17.5% respectively) and comfortable (14.5% and 9.8% respectively) performing CPR in public. Causing injury was the top concern in performing CPR on geriatric (45.4%) and pediatric patients (41.7%), followed by fragility (18.1% and 10.2% respectively). Lack of skills to perform CPR on children was reported in 22% of CPR-trained participants. Conclusion: Public perception of OHCA victims influences willingness to perform bystander CPR. Factors such as age, gender, fear of injury, pregnancy status and sexual assault concerns can negatively impact this life saving intervention. Awareness of the importance of bystander CPR on any cardiac arrest victim must be improved.

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Abstract MP73: Emergency Call First Strategy versus Bystander Cardiopulmonary Resuscitation First Strategy for Out-of-Hospital Cardiac Arrest

Circulation ◽

10.1161/circ.137.suppl_1.mp73 ◽

2018 ◽

Vol 137 (suppl_1) ◽

Author(s):

Tatsuma Fukuda ◽

Naoko Ohashi-Fukuda ◽

Yutaka Kondo ◽

Kei Hayashida ◽

Ichiro Kukita

Keyword(s):

Overall Survival ◽

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Cerebral Performance Category ◽

Population Based ◽

Spontaneous Circulation ◽

Emergency Call ◽

Bystander Cardiopulmonary Resuscitation ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

Introduction: Lay rescuers have a crucial role in successful cardiopulmonary resuscitation (CPR), specifically the first three links in the chain of survival, for out-of-hospital cardiac arrest (OHCA). However, randomized controlled trials on the priority of emergency call (Call first) versus bystander CPR (CPR first) do not exist, and comparative data are very limited. We aimed to assess the association between the priority of bystander’s action (Call first vs. CPR first) and neurologic outcome after OHCA. Methods: This nationwide population-based study of patients who experienced OHCA from January 2005 to December 2014 was based on the data from the Japanese government-managed registry of OHCA. Patients provided bystander’s action (both emergency call and bystander CPR) within 1 minute of witness were included, and Call first strategy was compared with CPR first strategy. The primary outcome was one-month neurologically favorable survival, defined as a Glasgow-Pittsburgh cerebral performance category (CPC) score of 1(good performance) or 2(moderate disability). The secondary outcomes were prehospital return of spontaneous circulation (ROSC) and one-month overall survival. Results: A total of 25,840 patients were included; 4,430 (17.1%) were treated with Call first approach, and 21,410 (82.9%) were treated with CPR first approach. Among total cohort, 2,696 (10.4%) survived with neurologically favorable status one month after OHCA. In the propensity score-matched cohort, one-month neurologically favorable survival was lower among Call first group compared with CPR first group: 364 of 4,430 patients (8.2%) vs. 457 of 4,430 patients (10.3%), respectively (Risk ratio [RR], 0.80; 95% confidence interval [CI], 0.70-0.91). Similar associations were observed for one-month overall survival (RR, 0.90; 95%CI, 0.82-0.99), although there were no significant differences in prehospital ROSC (RR, 0.94; 95%CI, 0.86-1.02) between the Call first and CPR first groups. In subgroup analyses, the association between delayed bystander CPR and worse neurological outcome did not change regardless of subgroup characteristics. Conclusions: In witnessed OHCA, Call first approach was associated with a decreased chance of one-month neurologically favorable survival compared with CPR first approach. These observational findings warrant a randomized clinical trial to determine the priority of emergency call or bystander CPR for OHCA.

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Are Canadians more willing to provide chest-compression-only cardiopulmonary resuscitation (CPR)?—a nation-wide public survey

CJEM ◽

10.1017/cem.2015.113 ◽

2015 ◽

Vol 18 (4) ◽

pp. 253-263 ◽

Cited By ~ 6

Author(s):

Lindsay Cheskes ◽

Laurie J. Morrison ◽

Dorcas Beaton ◽

Janet Parsons ◽

Katie N. Dainty

Keyword(s):

Cardiac Arrest ◽

Cardiopulmonary Resuscitation ◽

Chest Compression ◽

Barriers And Facilitators ◽

Public Knowledge ◽

Response Distribution ◽

Public Survey ◽

Bystander Cardiopulmonary Resuscitation ◽

Bystander Cpr ◽

Hospital Cardiac Arrest

AbstractBackgroundBystander cardiopulmonary resuscitation (CPR) improves the likelihood of survival from out-of-hospital cardiac arrest (OHCA), yet it is performed in only 30% of cases. The 2010 guidelines promote chest-compression-only bystander CPR—a change intended to increase willingness to provide CPR.Objectives1) To determine whether the Canadian general public is more willing to perform chest-compression-only CPR compared to traditional CPR; 2) to characterize public knowledge of OHCA; and 3) to identify barriers and facilitators to bystander CPR.MethodsA 32-item survey assessing resuscitation knowledge, and willingness to provide CPR were disseminated in five Canadian regions. Descriptive statistics were used to characterize response distribution. Logistic regression analysis was applied to assess shifts in intention to provide CPR.ResultsA total of 428 completed surveys were analysed. When presented with a scenario of being a bystander in an OHCA, a greater proportion of respondents were willing to provide chest-compression-only CPR compared to traditional CPR for all victims (61.5% v. 39.7%,p<0.001), when the victim was a stranger (55.1% v. 38.8%,p<0.001), or when the victim was an unkempt individual (47.9% v. 28.5%,p<0.001). When asked to describe an OHCA, 41.4% said the heart stopped beating, and 20.8% said it was a heart attack. Identified barriers and facilitators included fear of litigation and lack of skill confidence.ConclusionsThis study identified gaps in knowledge, which may impair the ability of bystanders to act in OHCA. Most respondents expressed greater willingness to provide chest-compression-only CPR, but this was mediated by victim characteristics, skill confidence, and recognition of a cardiac arrest.

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