Factors for modifying the termination of resuscitation rule in out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest in Bahrain: National retrospective cohort study

Aim

There is limited research on Out-of-hospital cardiac arrest (OHCA) in the Gulf Cooperation Council (GCC) and especially in Bahrain. This is the first study to describe the incidence, characteristics, and outcomes of OHCA in Bahrain.

Methods

This was a retrospective national observational study on OHCA patients in Bahrain using the Utstein framework for resuscitation. Data was collected between 1st July 2022 to 30th June 2023 from the electronic medical records of the only three governmental hospitals emergency departments (EDs) and National Ambulance (NA).

Results

The annual incidence of OHCA attended by (Emergency Medical Services) EMS was nearly 21 per 100,000 population. The majority were males (n = 228, 68.8 %) with median age of 65 years (IQR=49-78). Most OHCA cases were witnessed (n = 265, 81 %), with (n = 247, 76 %) happened at home/residence. Rates for bystander CPR was low (n = 122, 36.8 %) and bystander automated external defibrillator (AED) was not performed in any of the cases. The OHCA cases transported by the NA was (n = 314, 94.8 %), with median response time of 9 min (IQR=7-12). However, only (n = 20, 6.0 %) were witnessed by EMS, and (n = 7, 2.1 %) received EMS defibrillation for shockable rhythms. First monitored rhythms included shockable rhythm in (n = 28, 8.5 %) versus non-shockable rhythm in (n = 303, 91.5 %). In the EDs, return of spontaneous circulation was achieved in (n = 60, 18.1 %) cases. But survival rate to hospital discharge at 30-day was (n = 4, 1.2 %) and survival rate to hospital discharge with good neurological outcomes was (n = 0, 0 %). Conclusion: In Bahrain the estimated annual incidence of OHCA is 21 individuals per 100,000 population, with a very low survival rate. Solutions should focus on community-level CPR and AED training, evaluating OHCA care provided by EMS, and establishing OHCA registry.

A Simple Scoring System for Identifying Favorable Neurologic Outcomes Among Out-of-Hospital Cardiac Arrest Patients With Asystole

STUDY OBJECTIVE

Asystole is the most common initial rhythm in out-of-hospital cardiac arrest (OHCA) but indicates a low likelihood of neurologic recovery. This study aimed to develop a novel scoring system to be easily applied at the time of emergency department arrival for identifying favorable neurologic outcomes in OHCA survivors with an asystole rhythm.

METHODS

This study is a secondary analysis based on a previously collected nationwide database, targeting nontraumatic adult OHCA patients aged ≥18 years with an asystole rhythm who achieved return of spontaneous circulation (ROSC) between January 2016 and December 2020. The primary outcome was a favorable neurologic outcome defined as Cerebral Performance Categories scores of 1 or 2 at hospital discharge. A prediction model was developed through multivariable logistic regression analysis in a derivation cohort in the form of a scoring system (WBC-ASystole). The performance and calibration of the model were tested using an internal validation cohort.

RESULTS

Among 19,803 OHCA patients with survival to hospital admission, 6,322 had asystole, and 285 (4.5%) achieved good neurologic outcomes. Factors associated with favorable outcomes included age, witness arrest, bystander cardiopulmonary resuscitation, time from call to hospital arrival, and out-of-hospital ROSC achievement. The WBC-ASystole score, totaling 11 points, exhibited a predictive performance with an area under the receiver operating characteristic curve of 0.80 (95% confidence interval [CI] 0.76 to 0.83) and 0.79 (95% CI 0.74 to 0.83) in the derivation and validation cohorts, respectively. After categorizing patients into 3 groups based on probability for good neurologic outcomes, the sensitivity and specificity were as follows: 0.98 (95% CI 0.97 to 0.99) and 0.09 (95% CI 0.09 to 0.10) for the very low predicted probability group (WBC-ASystole ≤2), 0.85 (95% CI 0.82 to 0.89) and 0.54 (95% CI 0.53 to 0.55) for the low predicted probability group (WBC-ASystole 3 to 4), and 0.36 (95% CI 0.34 to 0.39) and 0.93 (95% CI 0.92 to 0.93) for fair predicted probability group (WBC-ASystole≥5), respectively.

CONCLUSIONS

Although external validation studies must be performed, among OHCA patients with asystole, the WBC-ASystole scoring system may identify those patients who are likely to have a favorable neurologic outcome.

Potential kidney donors among patients with out-of-hospital cardiac arrest and a termination of resuscitation rule

IMPORTANCE

Uncontrolled donation after circulatory determination of death (uDCD) has been developed and can serve as a source of kidneys for transplantation, especially when considering patients that meet extended criteria donation (ECD).

OBJECTIVE

This study assessed the theorical size and characteristics of the potential pool of kidney transplants from uDCD with standard criteria donation (SCD) and ECD among patients who meet Termination of Resuscitation (TOR) criteria following Out of Hospital Cardiac Arrest (OHCA).

METHODS AND PARTICIPANTS

This study focused on adult patients experiencing unexpected OHCA, who were prospectively enrolled in the Parisian registry from May 16th, 2011, to December 31st, 2020.

RESULTS

During the study period, EMS attempted resuscitation for 19,976 OHCA patients, of which 64.5% (12,890) had no return of spontaneous circulation. Among them, 47.4% (9,461) had TOR criteria, representing no chance of survival, and from them, 8.8% (1,764) met SCD criteria and could be potential organ donors and 33.6% (6,720) met ECD for kidney donors. The mean potential number per year of uDCD candidates with SCD and ECD remain stable respectively around 98 (±10.8) and 672 (±103.8) cases per year. Elderly patients (≥65 y.o.) represented 61.2% (n = 5,763/9,461) of patients who met TOR and 100% (5763/5763) of patients who could have matched both ECD criteria and TOR.

CONCLUSION AND RELEVANCE

Implementing uDCD program including SCD and ECD for kidney transplantation among OHCA cases quickly identified by the TOR, holds significant potential to substantially broaden the pool of organ donors. These programs could offer a viable solution to address the pressing burden of kidney shortage, particularly benefiting elderly recipients who may otherwise face prolonged waiting times and limited access to suitable organs.

Termination of Resuscitation Rules and Survival Among Patients With Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

Importance

Termination of resuscitation (TOR) rules may help guide prehospital decisions to stop resuscitation, with potential effects on patient outcomes and health resource use. Rules with high sensitivity risk increasing inappropriate transport of nonsurvivors, while rules without excellent specificity risk missed survivors. Further examination of the performance of TOR rules in estimating survival of out-of-hospital cardiac arrest (OHCA) is needed.

Objective

To determine whether TOR rules can accurately identify patients who will not survive an OHCA.

Data Sources

For this systematic review and meta-analysis, the MEDLINE, Embase, CINAHL, Cochrane Library, and Web of Science databases were searched from database inception up to January 11, 2024. There were no restrictions on language, publication date, or time frame of the study.

Study Selection

Two reviewers independently screened records, first by title and abstract and then by full text. Randomized clinical trials, case-control studies, cohort studies, cross-sectional studies, retrospective analyses, and modeling studies were included. Systematic reviews and meta-analyses were reviewed to identify primary studies. Studies predicting outcomes other than death, in-hospital studies, animal studies, and non-peer-reviewed studies were excluded.

Data Extraction and Synthesis

Data were extracted by one reviewer and checked by a second. Two reviewers assessed risk of bias using the Revised Quality Assessment Tool for Diagnostic Accuracy Studies. Cochrane Screening and Diagnostic Tests Methods Group recommendations were followed when conducting a bivariate random-effects meta-analysis. This review followed the Preferred Reporting Items for a Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) statement and is registered with the International Prospective Register of Systematic Reviews (CRD42019131010).

Main Outcomes and Measures

Sensitivity and specificity tables with 95% CIs and bivariate summary receiver operating characteristic (SROC) curves were produced. Estimates of effects at different prevalence levels were calculated. These estimates were used to evaluate the practical implications of TOR rule use at different prevalence levels.

Results

This review included 43 nonrandomized studies published between 1993 and 2023, addressing 29 TOR rules and involving 1 125 587 cases. Fifteen studies reported the derivation of 20 TOR rules. Thirty-three studies reported external data validations of 17 TOR rules. Seven TOR rules had data to facilitate meta-analysis. One clinical study was identified. The universal termination of resuscitation rule had the best performance, with pooled sensitivity of 0.62 (95% CI, 0.54-0.71), pooled specificity of 0.88 (95% CI, 0.82-0.94), and a diagnostic odds ratio of 20.45 (95% CI, 13.15-31.83).

Conclusions and Relevance

In this review, there was insufficient robust evidence to support widespread implementation of TOR rules in clinical practice. These findings suggest that adoption of TOR rules may lead to missed survivors and increased resource utilization.

A Machine Learning Prediction Model for Non-cardiogenic Out-of-hospital Cardiac Arrest with Initial Non-shockable Rhythm

Objectives

The purpose of this study was to develop and validate a machine learning prediction model for the prognosis of non-cardiogenic out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm.

Design

Data were obtained from a nationwide OHCA registry in Japan. Overall, 222,056 patients with OHCA and an initial non-shockable rhythm were identified from the registry in 2016 and 2017. Patients aged <18 years and OHCA caused by cardiogenic origin, cancer, and external factors were excluded. Finally, 58,854 participants were included.

Methods

Patients were classified into the training dataset (n=29,304, data from 2016) and the test dataset (n=29,550, data from 2017). The training dataset was used to train and develop the machine learning model, and the test dataset was used for internal validation. We selected XGBoost as the machine learning classifier. The primary outcome was the poor prognosis defined as cerebral performance category of 3-5 at 1 month. Eleven prehospital variables were selected as outcome predictors.

Results

In validation, the machine learning model predicted the primary outcome with an accuracy of 90.8% [95% confidence interval (CI): 90.5-91.2], a sensitivity of 91.4% [CI: 90.7-91.4], a specificity of 74.1% [CI: 69.2-78.6], and an area under the receiver operating characteristic value of 0.89 [0.87-0.92]. The important features for model development were the prehospital return of spontaneous circulation, prehospital adrenaline administration, and initial electrical rhythm.

Conclusions

We developed a favorable machine learning model to predict the prognosis of non-cardiogenic OHCA with an initial non-shockable rhythm in the early stage of resuscitation.

Association between the number of prehospital defibrillation attempts and a sustained return of spontaneous circulation: a retrospective, multicentre, registry-based study

BACKGROUND

Currently, there is no consensus on the number of defibrillation attempts that should be made before transfer to a hospital in patients with out-of-hospital cardiac arrest (OHCA). This study aimed to evaluate the association between the number of defibrillations and a sustained prehospital return of spontaneous circulation (ROSC).

METHODS

A retrospective analysis of a multicentre, prospectively collected, registry-based study in Republic of Korea was conducted for OHCA patients with prehospital defibrillation. The primary outcome was sustained prehospital ROSC, and the secondary outcome was a good neurological outcome at hospital discharge, defined as Cerebral Performance Category score 1 or 2. Cumulative incidence of sustained prehospital ROSC and good neurological outcome according to number of defibrillations were examined. Multivariable logistic regression analysis was used to examine whether the number of defibrillations was independently associated with the outcomes.

RESULTS

Excluding 172 patients with missing data, a total of 1983 OHCA patients who received prehospital defibrillation were included. The median time from arrest to first defibrillation was 10 (IQR 7-15) min. The numbers of patients with sustained prehospital ROSC and good neurological outcome were 738 (37%) and 549 (28%), respectively. Sustained ROSC rates decreased as the number of defibrillation attempts increased from the first to the sixth (16%, 9%, 5%, 3%, 2% and 1%, respectively). The cumulative sustained ROSC rate, and good neurological outcome rate from initial defibrillation to sixth defibrillation were 16%, 25%, 30%, 34%, 36%, 36% and 11%, 18%, 22%, 25%, 26%, 27%, respectively. With adjustment for clinical characteristics and time to defibrillation, a higher number of defibrillations was independently associated with a lower chance of a sustained ROSC (OR 0.81, 95% CI 0.76 to 0.86) and a lower chance of good neurological outcome (OR 0.86, 95% CI 0.80 to 0.92).

CONCLUSIONS

We observed no significant increase in ROSC after five defibrillations, and no absolute increase in ROSC after seven defibrillations. These data provide a starting point for determination of the optimal defibrillation strategy prior to consideration for prehospital extracorporeal cardiopulmonary resuscitation (ECPR) or conveyance to a hospital with an ECPR capability.

TRIAL REGISTRATION NUMBER

NCT03222999.

Pre-arrest comorbidity burden and the future risk of out-of-hospital cardiac arrest in Korean adults

OBJECTIVE

To investigate the impact of pre-arrest comorbidities on future out-of-hospital cardiac arrest (OHCA) development using a nationwide dataset.

METHODS

This population-based, matched case-control study used the national health insurance claims data relevant to OHCA in South Korea from January 2009 to December 2018. Case patients were randomly matched to controls by age, sex and date of cardiac arrest. Controls were defined as patients who did not experience OHCA based on claim codes in national health screening data. The comorbidity burden was assessed using the Charlson Comorbidity Index (CCI).

RESULTS

A total of 191 370 OHCA patients were matched to 347 568 controls. The mean CCI in the case group was 3.76, which was significantly higher than that in the control group (1.75, p<0.001). Overall, OHCA was 1.35 (95% CI 1.34 to 1.35) times more likely to occur with every 1 point increase in the CCI. All other comorbidities constituting the CCI were associated with the OHCA risk (p<0.001). Patients with CCI ≥3 presented an OR of 3.71 (95% CI 3.67 to 3.76) for the risk of OHCA occurrence. This association was more pronounced in patients aged <70 years than in those aged ≥70 years (OR (95% CI) 16.07 (15.48 to 16.68) vs 6.50 (6.33 to 6.68)).

CONCLUSION

A high burden of pre-arrest comorbidity was associated with a higher risk of OHCA development, which was more pronounced in patients with less advanced age.

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.

Ion Shift Index at the Immediate Post-Cardiac Arrest Period as an Early Prognostic Marker in Out-of-Hospital Cardiac Arrest Survivors

The ion shift index (ISI) is a suggested marker to reflect the magnitude of ischemic damage. This study aimed to investigate the prognostic value of the ISI for predicting poor neurological outcomes at 6 months in comatose out-of-hospital cardiac arrest (OHCA) survivors by comparing it with the OHCA and Cardiac Arrest Hospital Prognosis (CAHP) scores. This observational registry-based cohort study included adult comatose OHCA survivors admitted to a tertiary care hospital in Korea between 2015 and 2021. The ISI was calculated using the serum electrolyte levels obtained within one hour of resuscitation. The primary outcome was poor neurological function (Cerebral Performance Category score of 3−5) at 6 months. Of the 250 OHCA survivors, 164 (65.6%) had poor neurological outcomes. These patients had a higher median ISI than those with good neurological outcomes (4.95 vs. 3.26, p < 0.001). ISI (adjusted odds ratio, 2.107; 95% confidence interval, 1.350−3.288, p = 0.001) was associated with poor neurological outcomes. The prognostic performance of ISI (area under the curve [AUC], 0.859) was similar to that of the OHCA score (AUC, 0.858; p = 0.968) and the CAHP score (AUC, 0.894; p = 0.183). ISI would be a prognostic biomarker for comatose OHCA survivors that is available during the immediate post-cardiac arrest period.

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

Background

In 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.

Methods

We 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.

Results

Recursive 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.

Conclusion

The 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03999-x.

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

BACKGROUND

Resuscitation 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).

METHODS

A 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.

RESULTS

Among 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.

CONCLUSIONS

Both 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.

National survey of do not attempt resuscitation decisions on out-of-hospital cardiac arrest in China

BACKGROUND

To investigate and understand the determinants of decisions not to attempt resuscitation following out-of-hospital cardiac arrest, to contribute to establishing rules that are appropriate to China.

METHODS

We recruited participants through directors of emergency medical services across China. A 28-question web survey was available between February 5 and March 6, 2021 that targeted demographic information and views on emergency work and cardiopulmonary resuscitation. Each question was assigned a value between 1 and 7 based on the level of importance from low to high. T-tests, one-way analysis of variance, and Kruskal-Wallis H-tests were used to compare continuous variables. Binary logistic regression analysis was used to identify factors influencing when people considered it suitable to initiate cardiopulmonary resuscitation.

RESULTS

The study involved 4289 participants from 31 provinces, autonomous regions and municipalities in mainland China, of whom 52.8% were male. The top three reasons for not attempting cardiopulmonary resuscitation were decomposition/hypostasis/rigor mortis (6.39 ± 1.44 points), massive injury (4.57 ± 2.08 points) and family members' preference (4.35 ± 1.98 points). In total, 2761 (64.4%) thought emergency services should not attempt cardiopulmonary resuscitation when cardiac arrest had happened more than 30 min before, and there had been no bystander cardiopulmonary resuscitation. Gender (OR 1.233, p = 0.002), religion (OR 1.147, p = 0.046), level (OR 0.903, p = 0.028) or classification of city (OR 0.920, p = 0.049), years of work experience (OR 0.884, p = 0.004), and major (OR 1.032, p = 0.044) all influenced how long after cardiac arrest was considered suitable for initiating cardiopulmonary resuscitation.

CONCLUSIONS

Chinese emergency physicians have different perceptions of when not to attempt resuscitation to those practicing elsewhere. The existing guidelines for resuscitation are not suitable for China, and China-specific guidelines need to be established.

Impact of dispatcher-assisted cardiopulmonary resuscitation on performance of termination of resuscitation criteria

BACKGROUND

Current Advanced Life Support Termination of Resuscitation (TOR) guidelines suggest when to cease cardiopulmonary resuscitation (CPR). With the significant increase of Dispatch-Assisted CPR (DA-CPR) programs, the impact of DA-CPR on the TOR criteria performance is not clear.

METHODS

We conducted a secondary analysis of a prospectively collected registry, the Pan-Asian Resuscitation Outcomes Study. We included patients >15 years old with out-of-hospital cardiac arrest between 2014 and 2017 (after implementation of Singapore's DA-CPR program). We excluded patients with non-cardiac etiology, known do-not-resuscitate status, and healthcare provider bystanders. All cases were collected in accordance to Utstein standards. We evaluated the addition of DA-CPR to the diagnostic performance of TOR criteria using logistic regression modeling. The primary outcome was performance for predicting non-survival at 30 days. Sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

Of the 6009 cases, 319 (5.3%) were still alive at 30 days. Patients had a mean age of 67.9 (standard deviation 15.7) years and were mostly male and Chinese. Almost half of patients had no bystander CPR. The TOR criteria differentiating DA-CPR from unassisted bystander CPR has a specificity of 94% and predictive value of death of 99%, which was not significantly different from undifferentiated CPR criteria. There were differences in adjusted association with survival between unassisted and DA-CPR.

CONCLUSION

Advanced life support TOR criteria retain high specificity and predictive value of death in the context of DA-CPR. Further research should explore the differences between unassisted CPR and DA-CPR to understand differential survival outcomes.

Prediction of Neurologically Intact Survival in Cardiac Arrest Patients without Pre-Hospital Return of Spontaneous Circulation: Machine Learning Approach

Current multimodal approaches for the prognostication of out-of-hospital cardiac arrest (OHCA) are based mainly on the prediction of poor neurological outcomes; however, it is challenging to identify patients expected to have a favorable outcome, especially before the return of spontaneous circulation (ROSC). We developed and validated a machine learning-based system to predict good outcome in OHCA patients before ROSC. This prospective, multicenter, registry-based study analyzed non-traumatic OHCA data collected between October 2015 and June 2017. We used information available before ROSC as predictor variables, and the primary outcome was neurologically intact survival at discharge, defined as cerebral performance category 1 or 2. The developed models’ robustness were evaluated and compared with various score metrics to confirm their performance. The model using a voting classifier had the best performance in predicting good neurological outcome (area under the curve = 0.926). We confirmed that the six top-weighted variables predicting neurological outcomes, such as several duration variables after the instant of OHCA and several electrocardiogram variables in the voting classifier model, showed significant differences between the two neurological outcome groups. These findings demonstrate the potential utility of a machine learning model to predict good neurological outcome of OHCA patients before ROSC.

Cardiac arrest in older adult patients

PURPOSE OF REVIEW

To describe the epidemiology, prognostication, and treatment of out- and in-hospital cardiac arrest (OHCA and IHCA) in elderly patients.

RECENT FINDINGS

Elderly patients undergoing cardiac arrest (CA) challenge the appropriateness of attempting cardiopulmonary resuscitation (CPR). Current literature suggests that factors traditionally associated with survival to hospital discharge and neurologically intact survival after CA cardiac arrest in general (e.g. presenting ryhthm, bystander CPR, targeted temperature management) may not be similarly favorable in elderly patients. Alternative factors meaningful for outcome in this special population include prearrest functional status, comorbidity load, the specific age subset within the elderly population, and CA location (i.e., nursing versus private home). Age should therefore not be a standalone criterion for withholding CPR. Attempts to perform CPR in an elderly patient should instead stem from a shared decision-making process.

SUMMARY

An appropriate CPR attempt is an attempt resulting in neurologically intact survival. Appropriate CPR in elderly patients requires better risk classification. Future research should therefore focus on the associations of specific within-elderly age subgroups, comorbidities, and functional status with neurologically intact survival. Reporting must be standardized to enable such evaluation.

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

BACKGROUND

Futile 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.

METHODS

This 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.

RESULTS

In 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.

CONCLUSION

Among 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.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.

Education, Implementation, and Teams: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

For this 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, the Education, Implementation, and Teams Task Force applied the population, intervention, comparator, outcome, study design, time frame format and performed 15 systematic reviews, applying the Grading of Recommendations, Assessment, Development, and Evaluation guidance. Furthermore, 4 scoping reviews and 7 evidence updates assessed any new evidence to determine if a change in any existing treatment recommendation was required. The topics covered included training for the treatment of opioid overdose; basic life support, including automated external defibrillator training; measuring implementation and performance in communities, and cardiac arrest centers; advanced life support training, including team and leadership training and rapid response teams; measuring cardiopulmonary resuscitation performance, feedback devices, and debriefing; and the use of social media to improve cardiopulmonary resuscitation application.