Termination Of Resuscitation Rule Research Articles

Development and validation of a prehospital termination of resuscitation (TOR) rule for out - of hospital cardiac arrest (OHCA) cases using general purpose artificial intelligence (AI)

BackgroundPrehospital identification of futile resuscitation efforts (defined as a predicted probability of survival lower than 1%) for out-of-hospital cardiac arrest (OHCA) may reduce unnecessary transport. Reliable prediction variables for OHCA 'termination of resuscitation' (TOR) rules are needed to guide treatment decisions. The Universal TOR rule uses only three variables (Absence of Prehospital ROSC, Event not witnessed by EMS and no shock delivered on the scene) has been externally validated and is used by many EMS systems. Deep learning, an artificial intelligence (AI) platform is an attractive model to guide the development of TOR rule for OHCA. The purpose of this study was to assess the feasibility of developing an AI-TOR rule for neurologically favorable outcomes using general purpose AI and compare its performance to the Universal TOR rule. Methods: We identified OHCA cases of presumed cardiac etiology who were 18 years of age or older from 2016 to 2019 in the All-Japan Utstein Registry. We divided the dataset into 2 parts, the first half (2016–2017) was used as a training dataset for rule development and second half (2018–2019) for validation. The AI software (Prediction One®) created the model using the training dataset with internal cross-validation. It also evaluated the prediction accuracy and displayed the ranking of influencing variables. We performed validation using the second half cases and calculated the prediction model AUC. The top four of the 11 variables identified in the model were then selected as prognostic factors to be used in an AI-TOR rule, and sensitivity, specificity, positive predictive value, and negative predictive value were calculated from validation cohort. This was then compared to the performance of the Universal TOR rule using same dataset. ResultsThere were 504,561 OHCA cases, 18 years of age or older, 302,799 cases were presumed cardiac origin. Of these, 149,425 cases were used for the training dataset and 153,374 cases for the validation dataset. The model developed by AI using 11 variables had an AUC of 0.969, and its AUC for the validation dataset was 0.965. The top four influencing variables for neurologically favorable outcome were Prehospital ROSC, witnessed by EMS, Age (68 years old and younger) and nonasystole. The AUC calculated using the 4 variables for the AI-TOR rule was 0.953, and its AUC for the validation dataset was 0.952 (95%CI 0.949 –0.954). Of 80,198 patients in the validation cohort that satisfied all four criteria for the AI-TOR rule, 58 (0.07%) had a neurologically favorable one-month survival. The specificity of AI-TOR rule was 0.990, and the PPV was 0.999 for predicting lack of neurologically favorable survival, both the specificity and PPV were higher than that achieved with the universal TOR (0.959, 0.998). ConclusionsThe accuracy of prediction models using AI software to determine outcomes in OHCA was excellent and the AI-TOR rule’s variables from prediction model performed better than the Universal TOR rule. External validation of our findings as well as further research into the utility of using AI platforms for TOR prediction in clinical practice is needed.

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.

Abstract 158: Exploring the Potential for Kidney Donation in Out-of-Hospital Cardiac Arrest Cases With No Chance of Survival

Introduction: The global kidney shortage can potentially be addressed through the implementation of the uncontrolled donation after circulatory death (uDCD) pathway. However, the current Termination-of-Resuscitation (TOR) rules, although effective in identifying futile resuscitation, do not consider the potential benefits of organ donation. Objective: This study aims to assess the potential pool of uDCD kidney donors among patients with resuscitation attempts by Emergency Medical Services (EMS) who meet TOR criteria. Methods: Retrospective analysis was conducted using data from the Paris Sudden Death Expertise Center (SDEC) registry spanning from 2011 to 2020. TOR criteria evaluation and identification of potential organ donors were performed using established selection criteria from previous protocols on TOR rules and uDCD. Incidence rates (per patient-years) were calculated using data from the National Institute of Statistics and Economic Studies. Results: Out of 19,976 cases of Out-of-Hospital-Cardiac Arrest (OHCA) with resuscitation attempts by EMS, 12,890 (64.5%) did not achieve sustained Return of Spontaneous Circulation (ROSC). Among patients with no successful ROSC, the annual number and incidence of patients with no chance of survival varied across different TOR rules, ranging from 626 to 1081 cases and from 8.14 to 10.04 per 100,000 patient-years. The proportion of OHCA patients meeting both TOR criteria and extended kidney criteria ranged from 67.8% to 73.6% of total cases of OHCA who did not achieve sustained ROSC. Conclusion: Our findings demonstrate that the implementation of a uDCD program, in cases where TOR rules indicate no chance of survival, has the potential to significantly increase the pool of potential organ donors.

Usability of EtCO2 values in the decision to terminate resuscitation by integrating them into the TOR rule (an extended TOR rule): A preliminary analysis

ObjectiveEnd tidal carbon dioxide (EtCO2) is measured to confirm the placement of an endotracheal tube and evaluate the efficacy of cardiopulmonary resuscitation (CPR), and as an assistive tool for terminating CPR. However, there are no highly accurate or definitive recommendations for its use when deciding on the termination of CPR. We aimed to merge EtCO2 values with existing termination of resuscitation (TOR) rules to obtain a more accurate combination for terminating resuscitation. MethodsThis observational, prospective study included non-traumatic adult patients who were admitted to a tertiary university hospital Emergency Medicine Department due to cardiac arrest. EtCO2 cutoff values (at 5, 10, and 20 min) were integrated into currently used TOR parameters (arrest was not witnessed, no bystander CPR was provided, no return of spontaneous circulation (ROSC) after full advanced life support care in the field, and no shock was delivered) and the extended TOR rule was created. These extended TOR rules were compared at three different times (5, 10, and 20 min) for specificity and positive predictive value for ROSC. ResultsWe included a total of 86 cases. The cutoff value of EtCO2 from ROC analysis was 19.5, 23.5, and 20.5 mmHg at 5, 10, and 20 min, respectively. “The extended TOR rule created with the 20-min EtCO2 cutoff (20.5 mmHg) was the most accurate in detecting ROSC (−) patients. The specificity was 100% (95% CI 63.1–100.0) sensitivity was 20.0% (95% CI 9.1–35.7), positive predictive value was 100% and negative predictive value was 20.0% (95% CI 17.6–22.6) for ROSC (−) patients. The parameters of this rule were as follows: arrest was not witnessed, no bystander CPR was provided, no ROSC after full advanced life support care in the field, no shock was delivered, and EtCO2 value at 20 min of resuscitation <20.5 mmHg. ConclusionsIntegration of EtCO2 values into the classically used TOR criteria increases the specificity to 100% without a significant decrease in sensitivity. These results need to be validated in larger groups before this rule is used clinically. EtCO2 seems to be a beneficial tool in establishing new TOR rules.

Identifying individuals satisfying the termination of resuscitation rule but having potential to achieve favourable neurological outcome following out-of-hospital cardiac arrest

AimTo develop a simple scoring model that identifies individuals satisfying the termination of resuscitation (TOR) rule but having potential to achieve favourable neurological outcome following out-of-hospital cardiac arrest (OHCA). MethodsThis study analysed the All-Japan Utstein Registry from 1 January 2010 to 31 December 2019. We identified patients satisfying basic life support (BLS) and advanced life support (ALS) TOR rules and determined factors associated with favourable neurological outcome (cerebral performance category scale of 1 or 2) for each cohort using multivariable logistic regression analysis. Scoring models were derived and validated to identify patient subgroups that might benefit from continued resuscitation efforts. ResultsAmong 1,695,005 eligible patients, 1,086,092 (64.1%) and 409,498 (24.2%) satisfied BLS and ALS TOR rules, respectively. One month post-arrest, 2038 (0.2%) and 590 (0.1%) patients in the BLS and ALS cohorts, respectively, achieved favourable neurological outcome. A scoring model derived for the BLS cohort (2 points for age <17 years or ventricular fibrillation/ventricular tachycardia rhythm; 1 point for age <80 years, pulseless electrical activity rhythm, or transport time <25 min) effectively stratified the probability of achieving 1-month favourable neurological outcome, with patients scoring <4 having a probability of <1%, whereas those scoring 4, 5, and 6 having probabilities of 1.1%, 7.1%, and 11.1%, respectively. In the ALS cohort, the probability increased with scores; however, it remained <1%. ConclusionA simple scoring model comprising age, first documented cardiac rhythm, and transport time effectively stratified the likelihood of achieving favourable neurological outcome in patients satisfying the BLS TOR rule.

Modification of termination of resuscitation rule with compression time interval in South Korea

This study aimed to validate the predictive performance of the termination of resuscitation (TOR) rule and examine the compression time interval (CTI) as a criterion for modifying the rule. This retrospective observational study analyzed adult out-of-hospital cardiac arrest (OHCA) patients attended by emergency medical service (EMS) providers in mixed urban–rural areas in Korea in 2020 and 2021. We evaluated the predictive performance of basic life support (BLS) and the Korean Cardiac Arrest Research Consortium (KoCARC) TOR rule using the false-positive rate (FPR) and positive predictive value (PPV). We modified the age cutoff criterion and examined the CTI as a new criterion. According to the TOR rule, 1827 OHCA patients were classified into two groups. The predictive performance of the BLS TOR rule had an FPR of 11.7% (95% confidence interval (CI): 5.9–17.5) and PPV of 98.4% (97.6–99.2) for mortality, and an FPR of 3.6% (0.0–7.8) and PPV of 78.6% (75.9–81.3) for poor neurological outcomes at hospital discharge. The predictive performance of the KoCARC TOR rule had an FPR of 5.0% (1.1–8.9) and PPV of 98.9% (98.0–99.8) for mortality, and an FPR of 3.7% (0.0–7.8) and PPV of 50.0% (45.7–54.3) for poor neurological outcomes at hospital discharge. The modified cutoff value for age was 68 years, with an area under the receiver operating characteristic curve over 0.7. In the group that met the BLS TOR rule, the cutoff of the CTI for death was not determined and was 21 min for poor neurological outcomes. In the group that met the KoCARC TOR rule, the cutoff of the CTI for death and poor neurological outcomes at the time of hospital discharge was 25 min and 21 min, respectively. The BLS TOR and KoCARC TOR rules showed inappropriate predictive performance for mortality and poor neurological outcomes. However, the predictive performance of the TOR rule could be supplemented by modifying the age criterion and adding the CTI criterion of the KoCARC.

Application of adult prehospital resuscitation rules to pediatric out of hospital cardiac arrest

BackgroundPrehospital termination of resuscitation (TOR) rules can be recommended for adults with out-of-hospital cardiac arrests (OHCAs). This study aimed to investigate whether adult basic life support (BLS) and advanced life support (ALS) TOR rules can predict neurologically unfavorable one-month outcome for pediatric OHCA patients. MethodsFrom a nationwide population-based observational cohort study, we extracted data of consecutive pediatric OHCA patients (0–17 years old) from January 1, 2005, to December 31, 2011. The BLS TOR rule has three criteria, whereas the ALS TOR rule includes two additional criteria. We selected pediatric OHCA patients that met all criteria for each TOR rule and calculated the specificity and positive predictive value (PPV) of each TOR rule for identifying pediatric OHCA patients who did not have neurologically favorable one-month outcome. ResultsOf the 12,740 pediatric OHCA patients eligible for the evaluation of the BLS TOR rule, 10,803 patients met the BLS TOR rule, with a specificity of 0.785 and a PPV of 0.987 for predicting a lack of neurologically favorable one-month survival. Of the 2,091 for the ALS TOR rule, 381 patients met the ALS TOR rule, with a specificity of 0.986 and a PPV of 0.997 for predicting neurologically unfavorable one-month outcome. ConclusionsThe adult BLS and ALS TOR rules had a high PPV for predicting pediatric OHCA patients without a neurologically favorable survival at one month after onset.

Abstract 207: Performance Of The Universal Tor Rule For Out-of-hospital Cardiac Arrest Cases Not Witnessed By Ems Providers In The Pan Asian Resuscitation Outcomes Study

Introduction: In order to make effective use of limited medical resources in an aging society, ILCOR emphasizes the importance of considering the Termination of Resuscitation (TOR) rule in the prehospital setting. In Europe and the United States, the Universal TOR rule (no prehospital cardiac resumption, no witnessed by EMS, no shock at the scene) is utilized in the field. We used the Pan-Asian Resuscitation Outcomes (PAROS) data to examine cases of out-of-hospital cardiac arrest not witnessed by EMS providers in Singapore, Japan, Korea, and Taiwan. We also examined the validity of Universal TOR rule. Methods: This was a retrospective cohort study examining data from January 1, 2009 to June 31, 2018 of the Pan Asian Resuscitation Outcomes Study. We included patients with OHCA who were non-traumatic cardiac arrest and not witnessed by EMS providers. We examined the background of the patients, activities and response times of EMS, and survival outcomes. Then, we calculated the specificity, positive predictive value, etc. of cases that met the Universal TOR rule for poor neurological outcomes (CPC ≥ 3) . Results: The breakdown of cases was as follows: Singapore (10,976)/ Japan (117,814)/ Korea (17,926)/ Taiwan (17,063). Of these, Singapore 440 (4.0%)/ Japan 6,845 (5.8%)/ Korea 1,522 (8.5%)/ Taiwan 1,190 (7.0%) were discharged alive, and Singapore 263 (2.4%)/ Japan 3,791 (3.2%)/ Korea 679 (3.8%)/ Taiwan 457 (2.7%) were discharged alive for CPC 1 and 2. For CPC≥3 cases, the specificity of the universal TOR rule was Singapore 0.970/ Japan 0.912/ Korea 0.887/ Taiwan 0.742, and the positive predictive value was Singapore 0.999/ Japan 0.997/ Korea 0.995/ Taiwan 0.992. Conclusions: The positive predictive value for poor neurological prognosis at 1 month, among Universal TOR rule-compliant cases in the four countries was more than 99%. However, there were differences in the specificity of poor neurological outcome between countries.

Cost-effectiveness analysis of termination-of-resuscitation rules for patients with out-of-hospital cardiac arrest

AimTo evaluate the cost-effectiveness of practices with and without termination-of-resuscitation (TOR) rules for out-of-hospital cardiac arrest (OHCA), using an analytic model based on a nationwide population-based registry in Japan. MethodsA combined model using a decision tree and Markov model was developed to compare costs and treatment effectiveness of three scenarios: basic life support (BLS) TOR rules (BLS-rule scenario), advanced life support (ALS) TOR rules (ALS-rule scenario), and no TOR rules (No-rule scenario). A nationwide population-based OHCA registry from January 1 to December 31, 2019 and published data were used. Analyses were performed from healthcare payers’ perspectives. Life-time incremental cost-effectiveness ratio (ICER) was determined by the difference in cost between two scenarios, divided by the difference in quality adjusted life year (QALY). ResultsThe OHCA registry included 126,271 patients (57.3% men; median age, 80 years). The BLS-rule scenario yielded lower cost and less QALY than the ALS-rule scenario and No-rule scenario. With reference to the BLS-rule scenario, the ICERs for the ALS-rule scenario and No-rule scenario were 81,000 and 98,762 USD per QALY, respectively. The BLS-rule scenario was cost-effective in 100% of simulations at the willingness-to-pay threshold in Japan (5 million JPY = 45,455 USD). The willingness-to-pay threshold higher than 80,000 and 204,000 USD were required for the ALS-rule scenario and No-rule scenarios, respectively, to be cost-effective. ConclusionNo-rule scenario was not cost-effective compared with BLS-rule scenario within acceptable willingness-to-pay thresholds. Further research on health economics of TOR rules is warranted to support constructive discussion on implementing TOR rules.

Termination-of-resuscitation rule in the emergency department for patients with refractory out-of-hospital cardiac arrest: a nationwide, population-based observational study

BackgroundIn Japan, emergency medical service (EMS) providers are prohibited from field termination-of-resuscitation (TOR) in out-of-hospital cardiac arrest (OHCA) patients. In 2013, we developed a TOR rule for emergency department physicians (Goto’s TOR rule) immediately after hospital arrival. However, this rule is subject to flaws, and there is a need for revision owing to its relatively low specificity for predicting mortality compared with other TOR rules in the emergency department. Therefore, this study aimed to develop and validate a modified Goto’s TOR rule by considering prehospital EMS cardiopulmonary resuscitation (CPR) duration.MethodsWe analysed the records of 465,657 adult patients with OHCA from the All-Japan Utstein registry from 2016 to 2019 and divided them into two groups: development (n = 231,363) and validation (n = 234,294). The primary outcome measures were specificity, false-positive rate (FPR), and positive predictive value (PPV) of the revised TOR rule in the emergency department for predicting 1-month mortality.ResultsRecursive partitioning analysis for the development group in predicting 1-month mortality revealed that a modified Goto’s TOR rule could be defined if patients with OHCA met the following four criteria: (1) initial asystole, (2) unwitnessed arrest by any laypersons, (3) EMS-CPR duration > 20 min, and (4) no prehospital return of spontaneous circulation (ROSC). The specificity, FPR, and PPV of the rule for predicting 1-month mortality were 99.2% (95% confidence interval [CI], 99.0–99.4%), 0.8% (0.6–1.0%), and 99.8% (99.8–99.9%), respectively. The proportion of patients who fulfilled the rule and the area under the receiver operating curve (AUC) was 27.5% (95% CI 27.3–27.7%) and 0.904 (0.902–0.905), respectively. In the validation group, the specificity, FPR, PPV, proportion of patients who met the rule, and AUC were 99.1% (95% CI 98.9–99.2%), 0.9% (0.8–1.1%), 99.8% (99.8–99.8%), 27.8% (27.6–28.0%), and 0.889 (0.887–0.891), respectively.ConclusionThe modified Goto’s TOR rule (which includes the following four criteria: initial asystole, unwitnessed arrest, EMS-CPR duration > 20 min, and no prehospital ROSC) with a > 99% predictor of 1-month mortality is a reliable tool for physicians treating refractory OHCAs immediately after hospital arrival.

Predictive performances of ALS and BLS termination of resuscitation rules in out-of-hospital cardiac arrest for different resuscitation protocols

BackgroundResuscitation guidance has advanced; however, the predictive performance of the termination of resuscitation (TOR) rule has not been validated for different resuscitation protocols published by the American Heart Association (AHA).MethodsA retrospective study validating the basic life support (BLS) and advanced life support (ALS) TOR rules was conducted using an Utstein-style database in Tainan city, Taiwan. Adult patients with nontraumatic out-of-hospital cardiac arrests from January 1, 2015, to December 31, 2015, (using the AHA 2010 resuscitation protocol) and from January 1, 2020, to December 31, 2020, (using the AHA 2015 resuscitation protocol) were included. The characteristics of rule performance were calculated, including sensitivity, specificity, positive predictive value (PPV) and negative predictive value.ResultsAmong 1260 eligible OHCA patients in 2015, 757 met the BLS TOR rule and 124 met the ALS TOR rule. The specificity and PPV for predicting unfavorable neurological outcomes were 61.1% and 99.0%, respectively, for the BLS TOR rule and 93.8% and 99.2%, respectively, for the ALS TOR rule. A total of 970 OHCA patients were enrolled in 2020, of whom 438 met the BLS TOR rule and 104 met the ALS TOR rule. The specificity and PPV for predicting unfavorable neurological outcomes were 85.7% and 100%, respectively, for the BLS TOR rule and 99.5% and 100%, respectively, for the ALS TOR rule.ConclusionsBoth the BLS and ALS TOR rules performed better when using the 2015 AHA resuscitation protocols compared to the 2010 protocols, with increased PPVs and decreased false-positive rates in predicting survival to discharge and good neurological outcomes at discharge. The BLS and ALS TOR rules can perform differently while the resuscitation protocols are updated. As the concepts and practices of resuscitation progress, the BLS and ALS TOR rules should be evaluated and validated accordingly.

Clinical prediction rule of termination of resuscitation for out-of-hospital cardiac arrest patient with pre-hospital defibrillation given.

To derive a clinical prediction rule of termination of resuscitation (TOR) for out-of-hospital cardiac arrest (OHCA) with pre-hospital defibrillation given. This was a retrospective multicenter cohort study performed in three emergency departments (EDs) of three regional hospitals from 1/1/2012 to 31/12/2018. Patients of OHCA aged ≥18years old were included. Those with post-mortem changes, return of spontaneous circulation and receiving no resuscitation in EDs were excluded. A TOR rule was derived by logistic regression analysis based on demographics and end-tidal carbon dioxide level of included subjects with pre-hospital defibrillation given. There were 447 included patients had received pre-hospital defibrillation, in which 148 had return of spontaneous circulation (ROSC), with 22 survived to discharge (STD). Independent predictors for death on or before ED arrival (no ROSC) included EMS call to ED time>20min and ETCO2 level<20mmHg from first three sets. A 2-criteria rule predicting death on or before ED arrival by fulfilling both of the independent predictors had a specificity of 0.95 (95% CI 0.90-0.98) and positive predictive value (PPV) of 0.95 (95% CI 0.90-0.98), if 2nd set of ETCO2 was used. The positive likelihood ratio was 10.04 (95% CI 4.83-20.89). The 2-criteria TOR rule for OHCA patients with pre-hospital defibrillation had a high specificity and PPV for predicting death on or before ED arrival.

Abstract 13678: Validation of the Termination of Resuscitation Rules in Detroit

Introduction: 326,000 patients suffer from an out of hospital cardiac arrest (OHCA) each year. The Termination of Resuscitation (TOR) criteria, which recommends termination when the arrest is unwitnessed by EMS, no shocks are administered, and no ROSC occurs, guides physicians in determining the futility of continuing CPR and transporting patients to the hospital. We examined compliance with current BLS TOR rules as well as assessed an alternate set of rules, with the goal of retrospectively deriving improved TOR guidelines for OHCAs in Detroit. Methods: This is a retrospective study utilizing non-traumatic OHCA cases in Detroit from January 1, 2017 to December 31, 2019, which includes time before and after BLS TOR guidelines were officially implemented (June 1, 2018). Data is extracted from the Detroit Cardiac Arrest Registry (DCAR). Patients younger than 18 years of age and arrests of traumatic origin or those with no resuscitation attempted were excluded. Results: BLS TOR criteria was applied to the pre-TOR implementation data with resulting specificity of 79% (95% CI: 50.7-80.8) and PPV of 97.3% (95% CI: 95.5-98.6). Survival to hospital discharge when termination was recommended was projected at 2.9% (13/444). Overall transportation rate was 85% (559/656). Post-TOR implementation, specificity was 88.9% (95% CI: 78.6-99.1) and PPV was 99.1% (95% CI: 98.3-99.9). Survival to hospital discharge was 0.88% (4/453) with a 69% (451/650) overall transportation rate. Post-hoc addition of age or EMS time to patient side increased transportation rates to 81% (529/650) and 88% (571/650), respectively, and decreased false positive terminations to 0.84% (2/237) and 0% (0/148), respectively. Conclusion: Overall survival when TOR was recommended as well as futile transportation rates decreased since the implementation of the BLS TOR guidelines in Detroit. Addition of EMS time to patient side or patient age to the current TOR guidelines suggested improved performance. Although the additional criteria resulted in higher transportation rates, these factors may be useful for physicians to consider when deciding to transport patients who meet the current TOR criteria. However, further derivation and validation are needed to create optimal TOR guidelines.

Outcomes of patients with OHCA of presumed cardiac etiology that did not achieve prehospital restoration of spontaneous circulation: The All-Japan Utstein Registry experience

BackgroundCorrect identification of futile prehospital resuscitation for out-of-hospital cardiac arrest (OHCA) may reduce unnecessary transports. Prehospital return of spontaneous circulation (ROSC) is considered by many to be an important predictor of outcome. The purpose of this study was to evaluate OHCA victims without prehospital ROSC characteristics and their outcomes in relation to the universal Termination of Resuscitation (TOR) rule. MethodsA retrospective, population-based review of OHCA victims without prehospital ROSC from January 1, 2010 to December 31, 2017 in the All-Japan Utstein Registry. We compared those that met the universal TOR rule and those that did not for the primary outcome: one-month survival with neurologically favorable Cerebral Performance Category (CPC) 1 or 2. Results989,929 OHCA cases, 18 years of age or older, were registered in the All-Japan Utstein Registry and 525,801 cases were of presumed cardiac origin and had no prehospital ROSC. Of these, the one-month CPC was 1 or 2 for 3957 cases (0.8%). In the ‘no ROSC’ group who also met the TOR rule, the number of cases was 433,571 with a one-month survival of 0.9% (3799 cases), and the proportion with a CPC 1or 2 was 0.2% (699 cases). ConclusionsContinued resuscitation and transport of cases with no field ROSC who fulfill the TOR rule is futile and could be considered for adoption in Japan.

External validation of multimodal termination of resuscitation rules for out-of-hospital cardiac arrest patients in the COVID-19 era

BackgroundFutile resuscitation for out-of-hospital cardiac arrest (OHCA) patients in the coronavirus disease (COVID)-19 era can lead to risk of disease transmission and unnecessary transport. Various existing basic or advanced life support (BLS or ALS, respectively) rules for the termination of resuscitation (TOR) have been derived and validated in North America and Asian countries. This study aimed to evaluate the external validation of these rules in predicting the survival outcomes of OHCA patients in the COVID-19 era.MethodsThis was a multicenter observational study using the WinCOVID-19 Daegu registry data collected during February 18–March 31, 2020. The subjects were patients who showed cardiac arrest of presumed cardiac etiology. The outcomes of each rule were compared to the actual patient survival outcomes. The sensitivity, specificity, false positive value (FPV), and positive predictive value (PPV) of each TOR rule were evaluated.ResultsIn total, 170 of the 184 OHCA patients were eligible and evaluated. TOR was recommended for 122 patients based on the international basic life support termination of resuscitation (BLS-TOR) rule, which showed 85% specificity, 74% sensitivity, 0.8% FPV, and 99% PPV for predicting unfavorable survival outcomes. When the traditional BLS-TOR rules and KoCARC TOR rule II were applied to our registry, one patient met the TOR criteria but survived at hospital discharge. With regard to the FPV (upper limit of 95% confidence interval < 5%), specificity (100%), and PPV (> 99%) criteria, only the KoCARC TOR rule I, which included a combination of three factors including not being witnessed by emergency medical technicians, presenting with an asystole at the scene, and not experiencing prehospital shock delivery or return of spontaneous circulation, was found to be superior to all other TOR rules.ConclusionAmong the previous nine BLS and ALS TOR rules, KoCARC TOR rule I was most suitable for predicting poor survival outcomes and showed improved diagnostic performance. Further research on variations in resources and treatment protocols among facilities, regions, and cultures will be useful in determining the feasibility of TOR rules for COVID-19 patients worldwide.

Abstract 258: Adherence to the Transport Recommendations in the Universal Termination of Resuscitation Rule and Survival After Out-of-Hospital Cardiac Arrest

Introduction: Survival after out-of-hospital cardiac arrest (OHCA) varies across emergency medical services (EMS) systems. The contribution of EMS practices variation on the outcome disparities is unclear. We evaluated the association between EMS agency variation in adherence to the transport recommendations in the Universal Termination of Resuscitation (TOR) Rule and survival after OHCA. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry. We included adults (≥ 18 years) with OHCA for whom EMS providers attempted resuscitation from 2011 through 2015. The main exposure was the proportion of patients for whom the Universal TOR Rule recommended transport (i.e., meeting any one of the following criteria, EMS-witnessed arrest; return of spontaneous circulation prior to transport; or shock delivery prior to transport) among those transported to hospitals, at the level of EMS agency. We then categorized EMS agencies into quartiles. Our primary outcome was survival to hospital discharge. We used multilevel modified Poisson regression model, including patient-level and EMS-level covariates with patients nested within EMS agencies. Results: We included 42,584 EMS-treated OHCAs from 112 EMS agencies. The median proportion of patients for whom the TOR rule recommended transport among those transported was 88.2% (interquartile range [IQR] 76.1-96.7) across EMS agencies. Compared with the patients treated at EMS agencies in the quartile of the lowest proportion (the median proportion 66.7%[ IQR 50.9-71.7]), survival to hospital discharge was associated with treatment at EMS agencies in the second quartile (the median proportion 83.0% [IQR 79.8-85.3]) (adjusted risk ratio [aRR] 1.12, 95% confidence interval [CI] 0.96-1.31), the third quartile (the median proportion 93.0% [IQR 89.7-95.6]) (aRR 1.58, 95% CI 1.32-1.87), and the fourth quartile (the median proportion 100% [IQR 98.5-100]) (aRR 1.86, 95% CI 1.59-2.19). Conclusions: In this large cohort study of adult patients with OHCA, treatment at EMS agencies with higher proportion of patients who met transport criteria of the Universal TOR rule among transported patients was associated with survival to hospital discharge.

Abstract 234: Validation of a Termination-of-resuscitation Rule for Patients with Refractory Out-of-hospital Cardiac Arrest at an Emergency Department in Japan

Introduction: In Japan, emergency medical service (EMS) providers are prohibited from cardiopulmonary resuscitation (CPR) termination in the field and must transport all out-of-hospital cardiac arrest (OHCA) patients to a hospital, regardless of the return of spontaneous circulation (ROSC). We previously developed a termination of resuscitation (TOR) rule for emergency department physicians (ED-TOR) treating OHCA patients using data from the All-Japan Utstein Registry between 2005 and 2009, when CPR was performed according to the 2005 guidelines. The ED-TOR rule recommends CPR termination when patients in the emergency department meet all of the following criteria: initial unshockable rhythm, arrest unwitnessed by bystanders and no prehospital ROSC. Hypothesis: We aimed to validate the ED-TOR rule using more recent data, where CPR was performed according to the 2010 and 2015 guidelines, comparing the relevance of the ED-TOR rule with the universal basic life support TOR (BLS-TOR) rule, which consists of the following criteria: no prehospital ROSC, unwitnessed arrest by EMS providers and no shock received. Methods: We analysed 552,554 OHCA patients (age ≥ 18 years) treated by EMS providers. OHCA patients witnessed by EMS providers were excluded. Data were obtained from a prospectively recorded All-Japan Utstein Registry from 2013 to 2017. The study endpoints were specificity and a positive predictive value (PPV) for predicting 1-month mortality after OHCA with the ED-TOR and BLS-TOR rules. Results: The overall 1-month survival rate was 4.3% (23,733/552,554). The proportions of OHCA patients who fulfilled the ED-TOR and BLS-TOR criteria were 59.6% and 83.8%, respectively. The specificity and PPV of the ED-TOR and BLS-TOR rules for predicting 1-month mortality were 93.2% (95% confidence interval [CI], 92.8%-93.5%) and 99.5% (95% CI, 99.5%-99.5%) and 82.6% (95% CI, 82.1%-83.1%) and 99.1% (95% CI, 99.1%-99.1%), respectively. Conclusions: The ED-TOR rule was successfully validated using more recent data from a Japanese registry where CPR was performed according to the 2010 and 2015 guidelines. The ED-TOR rule was slightly superior to the BLS-TOR rule in Japanese EMS systems showing high specificity and PPV for predicting 1-month mortality.

Abstract 257: Adherence to the Termination Recommendations in the Universal Termination of Resuscitation Rule and Survival After Out-of-hospital Cardiac Arrest

Introduction: Survival after out-of-hospital cardiac arrest (OHCA) varies across emergency medical services (EMS) systems, but the EMS practices that contribute to the outcome variation are unclear. We evaluated the association between EMS agency variation in adherence to the termination recommendations in the Universal Termination of Resuscitation (TOR) rule and survival after OHCA. Methods: We conducted a secondary analysis of the Resuscitation Outcomes Consortium Epistry, a prospective multicenter OHCA registry in North America. We included adults (≥ 18 years) with OHCA for whom EMS providers attempted resuscitation from 2011 through 2015. The main exposure was proportion of patients meeting the Universal TOR rule (not EMS-witnessed arrest, no return of spontaneous circulation prior to transport, and no shock delivery prior to transport) among those who had prehospital TOR at the level of EMS agency. We categorized EMS agencies into quartiles based on the adherence to the Universal TOR rule. Our primary outcome was survival to hospital discharge. We used multilevel modified Poisson regression model, including patient-level and EMS-level covariates with patients nested within EMS agencies. Results: We included 43,656 EMS-treated OHCAs from 112 EMS agencies. The median adherence to the Universal TOR rule was 75.6% (interquartile range [IQR] 67.5-83.7) across EMS agencies. Compared with patients resuscitated at EMS agencies in the quartile of the lowest adherence (median adherence 62.5% [IQR 58.9-65.7]), survival to hospital discharge was inversely associated with treatment at EMS agencies in the second quartile (median adherence 72.6% [IQR 70.2-74.7]) (adjusted risk ratio [aRR] 0.83, 95% confidence interval [CI] 0.71-0.96), the third quartile (median adherence 80.6% [IQR 78.5-81.9]) (aRR 0.71, 95% CI 0.60-0.85), and the fourth quartile (median adherence 90.6% [IQR 86.2-93.7]) (aRR 0.68, 95% CI 0.58-0.80). Conclusions: In this large cohort study of adult patients with OHCA, we observed variation in the adherence to the Universal TOR rule’s termination recommendations across EMS agencies, and an association between higher EMS-level adherence and worse survival to hospital discharge after OHCA.

Identifying out-of-hospital cardiac arrest patients with no chance of survival: An independent validation of prediction rules

BackgroundThe Basic life support (BLS) and Advanced life support (ALS) are known prediction rules for termination of resuscitation (TOR) in out-of-hospital cardiac arrest (OHCA). Recently, a new rule was developed by Jabre et al. We aimed to independently validate and compare the predictive accuracy of these rules. MethodsOHCA cases in Iceland from 2008 to 2017 from a population-based, prospectively registered database. Primary outcome was survival to discharge among patients that met all conditions of abovementioned rules: BLS (not witnessed by EMS personnel, no defibrillation nor ROSC before transport), ALS (BLS criteria plus not witnessed nor CPR by bystander) and Jabre (not witnessed by EMS personnel, initial rhythm non-shockable, no sustainable ROSC before third dose of adrenaline). ResultsOverall, 568 OHCA patients were included in validation of TOR rules. Mean age 67, males 74%, witnessed by EMS 11%, by bystander 66% that attempted CPR in 50%, transported to hospital 60%, overall survival 20%. All rules had high specificity for mortality, 99.6–100% (95%CI 95–100). The Jabre and BLS rules had similar sensitivity 47% (43–52) vs. 44% (40–49), respectively, the sensitivity of ALS was lower, 8% (5–11). Combined use of positive BLS and Jabre rules performed the best, identifying 88/226 (39%) of futile cases transported to hospital, specificity 100% (97–100) and sensitivity 59% (55–64). ConclusionsThe accuracy of the BLS and Jabre TOR rules to predict mortality after OHCA is very good and their combined use may be superior to the use of either one.

Meta-analysis of the accuracy of termination of resuscitation rules for out-of-hospital cardiac arrest

BackgroundOur objective was to perform a systematic review of studies reporting the accuracy of termination of resuscitation rules (TORRs) for out-of-hospital cardiac arrest (OHCA).MethodsWe performed a comprehensive search of the...