Field termination-of-resuscitation rule for refractory out-of-hospital cardiac arrests in Japan

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.

Resuscitation (un-)wanted: Does anyone care? A retrospective real data analysis

BACKGROUND AND OBJECTIVES

In case of out-of-hospital cardiac arrest (OHCA) personnel of the emergency medical services (EMS) are regularly confronted with advanced directives (AD) and do-not-attempt-resuscitation (DNACPR) orders. The authors conducted a retrospective analysis of EMS operation protocols to examine the prevalence of DNACPR in case of OHCA and the influence of a presented DNACPR on CPR-duration, performed Advanced-Life-Support (ALS) measures and decision making.

MATERIALS AND METHODS

Retrospective analysis of prehospital medical documentation of all resuscitation incidents in a German county with 250,000 inhabitants from 1 January 2016 to 31 December 2022. Combined with data from the structured CPR team-feedback database patients characteristics, measures and course of the CPR were analysed. Statistic testing with significance level p < 0.05.

RESULTS

In total n = 1,474 CPR events were analysed. Patients with DNACPR vs. no DNACPR: n = 263 (17.8%) vs. n = 1,211 (82.2%). Age: 80.0 ± 10.3 years vs. 68.0 ± 13.9 years; p < 0.001. Patients with ASA-status III/IV: n = 214 (81.3%) vs. n = 616 (50.9%); p < 0.001. Initial layperson-CPR: n = 148 (56.3%) vs. n = 647 (55.7%); p = 0.40. Airway management: n = 185 (70.3%) vs. n = 1,069 (88.3%); p < 0.001. With DNACPR CPR-duration initiated layperson-CPR vs. no layperson-CPR: 19:14 min (10:43-25:55 min) vs. 12:40 min (06:35-20:03 min); p < 0.001.

CONCLUSION

In case of CPR EMS-personnel are often confronted with DNACPR-orders. Patients are older and have more previous diseases than patients without DNACPR. Initiated layperson-CPR might lead to misinterpretation of patients will with impact on CPR-duration and unwanted measures. Awareness of this issue should be created through measures such as training programs in particular to train staff in the interpretation and legal admissibility of ADs.

Termination of Cardiopulmonary Resuscitation in Mountain Rescue: A Scoping Review and ICAR MedCom 2023 Recommendations

Lugnet, Viktor, Miles McDonough, Les Gordon, Mercedes Galindez, Nicolas Mena Reyes, Alison Sheets, Ken Zafren, and Peter Paal. Termination of cardiopulmonary resuscitation in mountain rescue: a scoping review and ICAR MedCom 2023 recommendations. High Alt Med Biol. 24:274-286, 2023. Background: In 2012, the International Commission for Mountain Emergency Medicine (ICAR MedCom) published recommendations for termination of cardiopulmonary resuscitation (CPR) in mountain rescue. New developments have necessitated an update. This is the 2023 update for termination of CPR in mountain rescue. Methods: For this scoping review, we searched the PubMed and Cochrane libraries, updated the recommendations, and obtained consensus approval within the writing group and the ICAR MedCom. Results: We screened a total of 9,102 articles, of which 120 articles met the inclusion criteria. We developed 17 recommendations graded according to the strength of recommendation and level of evidence. Conclusions: Most of the recommendations from 2012 are still valid. We made minor changes regarding the safety of rescuers and responses to primary or traumatic cardiac arrest. The criteria for termination of CPR remain unchanged. The principal changes include updated recommendations for mechanical chest compression, point of care ultrasound (POCUS), extracorporeal life support (ECLS) for hypothermia, the effects of water temperature in drowning, and the use of burial times in avalanche rescue.

Prognostic predictors in patients with cardiopulmonary arrest: A novel equation for evaluating the 30-day mortality

BACKGROUND

Early prediction of outcomes after cardiopulmonary arrest (CPA) is important for considering the best support. Our purpose was to evaluate predictors of the 30-day mortality in patients with CPA after return of spontaneous circulation (ROSC) and to assess an equation for calculating the 30-day mortality using clinical parameters.

METHODS

We retrospectively analyzed the data of 194 consecutive patients with CPA and ROSC in a derivation study (2015-2022). We compared clinical parameters between the survived (n = 78) and dead (n = 116) patients. We derived an equation for estimated probability of death based on clinical parameters, using multivariate logistic regression analysis. The reliability of the equation was validated in 80 additional patients with CPA.

RESULTS

The 30-day mortality was associated with sex, witnessed cardiac arrest, bystander cardiopulmonary resuscitation (CPR), CPA due to acute myocardial infarction, pupil diameter, Glasgow Coma Scale score (GCS), presence of light reflex, arterial or venous pH, lactate levels, initial ventricular fibrillation (VF), CPA time, and age. The derived logistic regression equation was as follows: Estimated probability of death = 1 / (1 + e-x), x = (0.25 × bystander CPR) + (0.44 × pupil diameter) - (0.14 × GCS) + (0.09 × lactate) - (1.87 × initial VF) + (0.07 × CPA time) + (0.05 × age) - 7.03. The cut-off value for estimated probability of death calculated by this equation was 54.5 %, yielding a sensitivity, specificity, and accuracy of 86.2 %, 80.8 %, and 84.5 %, respectively. In the validation model, these values were 81.8 %, 85.7 %, and 82.5 %, respectively.

CONCLUSIONS

The 30-day mortality may be calculated after ROSC in patients with CPA using simple clinical parameters. This equation may facilitate further best support for patients with CPA.

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.

Termination of resuscitation in out-of-hospital cardiac arrest in women and men: An ESCAPE-NET project

AIM

Women have less favorable resuscitation characteristics than men. We investigated whether the Advanced Life Support Termination of Resuscitation rule (ALS-TOR) performs equally in women and men. Additionally, we studied whether adding or removing criteria from the ALS-TOR improved classification into survivors and non-survivors.

METHODS

We analyzed 6,931 female and 14,548 male out-of-hospital cardiac arrest (OHCA) patients from Dutch and Swedish registries, and validated in 10,772 female and 21,808 male Danish OHCA patients. Performance measures were calculated for ALS-TOR in relation to 30-day survival. Recursive partitioning analysis was performed with the ALS-TOR criteria, as well as age, comorbidities, and additional resuscitation characteristics (e.g. initial rhythm, OHCA location). Finally, we explored if we could reduce the number of ALS-TOR criteria without loss of prognostic value.

RESULTS

The ALS-TOR had a specificity and positive predictive value (PPV) of ≥99% in both women and men (e.g. PPV 99.9 in men). Classification by recursive partitioning analysis showed a high sensitivity but a PPV below 99%, thereby exceeding the acceptable miss rate of 1%. A combination of no return of spontaneous circulation (ROSC) before transport to the hospital and unwitnessed OHCA resulted in nearly equal specificity and PPV, higher sensitivity, and a lower transport rate to the hospital than the ALS-TOR.

CONCLUSION

For both women and men, the ALS-TOR has high specificity and low miss rate for predicting 30-day OHCA survival. We could not improve the classification with additional characteristics. Employing a simplified version may decrease the number of futile transports to the hospital.

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.

Out of hospital cardiac arrest in Western Sydney-an analysis of outcomes and estimation of future eCPR eligibility

Background

Refractory out of hospital cardiac arrest (OHCA) is associated with extremely poor outcomes. However, in selected patients extracorporeal cardiopulmonary resuscitation (eCPR) may be an effective rescue therapy, allowing time treat reversible causes. The primary goal was to estimate the potential future caseload of eCPR at historically 'low-volume' extracorporeal membrane oxygenation (ECMO) centres.

Methods

A 3-year observational study of OHCA presenting to the Emergency Department (ED of an urban referral centre without historical protocolised use of eCPR. Demographics and standard Utstein outcomes are reported. Further, an a priori analysis of each case for potential eCPR eligibility was conducted. A current eCPR selection criteria (from the 2-CHEER study) was used to determine eligibly.

Results

In the study window 248 eligible cardiac arrest cases were included in the OHCA registry. 30-day survival was 23.4% (n = 58). The mean age of survivors was 55.4 years. 17 (6.8%) cases were deemed true refractory arrests and fulfilled the 2-CHEER eligibility criteria. The majority of these cases presented within “office hours” and no case obtained a return of spontaneous circulation standard advanced life support.

Conclusions

In this contemporary OHCA registry a significant number of refractory cases were deemed potential eCPR candidates reflecting a need for future interdisciplinary work to support delivery of this therapy.

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.

Short-term outcome and characteristics of critical care for nontrauma patients in the emergency department

BACKGROUND

Emergency medical care for critically ill nontrauma patients (CINT) varies between different emergency departments (ED) and healthcare systems, while resuscitation of trauma patients is always performed within the ED. In many ED CINT are treated and stabilized while in many German smaller hospitals CINT are transferred directly to the intensive care unit (ICU) without performing critical care measures in the ED. Little is known about the resuscitation room management of CINT regarding patient characteristics and outcome although bigger hospitals perform ED resuscitation of CINT in routine care. Against this background we conducted this retrospective analysis of CINT treated by an ED resuscitation room concept in a German 756 bed teaching hospital.

METHODS

The collective of CINT treated within the ED resuscitation room (1 October 2018 to 31 March 2019) was analyzed after ethical approval. After each resuscitation room operation, the team leader filled out a standardized paper-based questionnaire and qualified the patient as a resuscitation room patient this way. Only patients who underwent invasive procedures and were admitted to ICU or died in the ED were included. Patient characteristics, performed critical care measures, short-term outcomes and the comparison of admission characteristics between survivors and non-survivors were evaluated. Additionally, the accordance of ED admission diagnoses and discharge diagnoses were analyzed.

RESULTS

Overall, 243 of 19,854 ED patients (1.22%) were treated in the resuscitation room. After exclusion of trauma patients, 193 (0.97%) CINT were included. Overall mortality was 29% (n = 56), 24‑h mortality was 13% (n = 25). Patient characteristics (vital signs, blood gas analysis) differed significantly between survivors and nonsurvivors except for respiratory rate and pain scale. An excerpt of conducted resuscitation room measures was as follows: arterial line n = 78 (40%); noninvasive ventilation n = 60 (31%); endotracheal intubation n = 56 (29%); cardiopulmonary resuscitation n = 19 (10%), central venous line n = 8 (4%). The number of conducted measures differed between survivors and nonsurvivors (median and interquartile range, IQR): 4 (IQR 2) vs. 4 (IQR 3) p = 0.0453. The length of ED stay was 148.2 ± 202.7 min until the patient was admitted to an ICU or died within the ED. ED admission diagnoses matched with hospital discharge diagnoses in 78%.

CONCLUSION

The observed mortality was high and was comparable to patient collectives with septic shock. Nonsurvivors showed significantly more impaired vital parameters and blood gas analysis parameters. Vital parameters together with blood gas analysis might enable ED risk stratification of CINT. Resuscitation room management enables immediate stabilization and diagnostic work-up of CINT even when no ICU bed is available. Furthermore, optimal allocation to specialized ICUs can probably be enabled more accurately after a first diagnostic work-up; however, although a first diagnostic work-up including laboratory tests and computed tomography in many cases was performed, ED admission and hospital discharge diagnoses matched only in 78%.

Prognostic value of transient conduction disturbance in out-of-hospital cardiac arrest

Aim

A retrospective observational study to verify the impact of electrocardiograms (ECGs) following out‐of‐hospital cardiac arrest (OHCA) on mortality.

Methods

We retrospectively studied 101 OHCA patients who achieved a return of spontaneous circulation (ROSC) and survived for ≥3 h. Among them, 50 patients (66 ± 17 years; 22 male) were evaluated using 12‐lead ECGs repeatedly and were included in the final analysis: immediately after ROSC (initial ECG) and after the initial evaluation in the emergency department (second ECG). Transient conduction disturbance (transient CD) was defined as a narrowing in QRS duration from the initial to second ECG of ≥18 ms. Multivariate Cox regression analyses were carried out to predict 90‐day mortality following OHCA.

Results

Among 50 OHCA patients, 30 patients survived for 90 days. Thirty patients had initial ventricular fibrillation rhythm. Median emergency medical services response time and low‐flow duration were 8 and 21 min, respectively. Multivariate analysis showed that the transient CD and low‐flow duration were significant predictors of all‐cause mortality (hazard ratio 16.55, 1.06; P = 0.001, 0.022, respectively).

Conclusion

Transient CD is a powerful predictor of 90‐day mortality in patients who survived 3 h after ROSC from OHCA.

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.

The Sequential Organ Failure Assessment (SOFA) score predicts mortality and neurological outcome in patients with post-cardiac arrest syndrome

BACKGROUND

Patients experiencing out-of-hospital cardiac arrest (OHCA) and subsequent post-cardiac arrest syndrome are often compromised by multi-organ failure. The Sequential Organ Failure Assessment (SOFA) score has been used to predict clinical outcome of patients requiring intensive care for multi-organ failure. Thus, the assessment of SOFA score is recommended as a criterion for sepsis. Although post-cardiac arrest patients frequently develop sepsis-like status in ICU, there are limited reports evaluating the SOFA score in post-cardiac arrest patients. We investigated the predictive value of the SOFA score in survival and neurological outcomes in patients with post-cardiac arrest syndrome.

METHODS

A total of 231 cardiovascular arrest patients achieving return of spontaneous circulation (ROSC) were finally extracted from the institutional consecutive database comprised of 1218 OHCA patients transferred to the institution between January 2015 and July 2018. The SOFA score was calculated on admission and after 48h. Predictors of survival and neurological outcome defined as having cerebral-performance-category (CPC) 1 or 2 at 30 days were determined.

RESULTS

SOFA score was lower in survived patients (5.0 vs 10.0, p<0.001) and those with favorable neurological outcome (5.0 vs 8.0, p<0.001) as compared with the counterparts. The SOFA score on admission was an independent predictor of survival (OR 0.68, 95% confidence interval [CI] 0.59-0.78; p<0.001) and favorable neurological performance (OR 0.79; 95% CI 0.69-0.90; p<0.001) at 30 days. Furthermore, a change in SOFA score (48-0h) was predictive of favorable 30-day neurological outcome (OR 0.71, 95% CI 0.60-0.85; p<0.001).

CONCLUSIONS

Evaluation of the SOFA score in the ICU is useful to predict survival and neurological outcome in post-cardiac arrest patients.

Diagnostic performance of the basic and advanced life support termination of resuscitation rules: A systematic review and diagnostic meta-analysis

AIM

To minimize termination of resuscitation (TOR) in potential survivors, the desired positive predictive value (PPV) for mortality and specificity of universal TOR-rules are ≥99%. In lack of a quantitative summary of the collective evidence, we performed a diagnostic meta-analysis to provide an overall estimate of the performance of the basic and advanced life support (BLS and ALS) termination rules.

DATA SOURCES

We searched PubMed/EMBASE/Web-of-Science/CINAHL and Cochrane (until September 2019) for studies on either or both TOR-rules in non-traumatic, adult cardiac arrest. PRISMA-DTA-guidelines were followed.

RESULTS

There were 19 studies: 16 reported on the BLS-rule (205.073 patients, TOR-advice in 57%), 11 on the ALS-rule (161.850 patients, TOR-advice in 24%). Pooled specificities were 0.95 (0.89-0.98) and 0.98 (0.95-1.00) respectively, with a PPV of 0.99 (0.99-1.00) and 1.00 (0.99-1.00). Specificities were significantly lower in non-Western than Western regions: 0.84 (0.73-0.92) vs. 0.99 (0.97-0.99), p < 0.001 for the BLS rule. For the ALS-rule, specificities were 0.94 (0.87-0.97) vs. 1.00 (0.99-1.00), p < 0.001. For non-Western regions, 16 (BLS) or 6 (ALS) out of 100 potential survivors met the TOR-criteria. Meta-regression demonstrated decreasing performance in settings with lower rates of in-field shocks.

CONCLUSIONS

Despite an overall high PPV, this meta-analysis highlights a clinically important variation in diagnostic performance of the BLS and ALS TOR-rules. Lower specificity and PPV were seen in non-Western regions, and populations with lower rates of in-field defibrillation. Improved insight in the varying diagnostic performance is highly needed, and local validation of the rules is warranted to prevent in-field termination of potential survivors.

Effectiveness of dispatcher instructions-dependent or independent bystander cardiopulmonary resuscitation on neurological survival among patients with out-of-hospital cardiac arrest

BACKGROUND

We evaluated the association between survival and bystandercardiopulmonary resuscitation (CPR) with or without dispatcher instructions (DI) considering the time from emergency call receipt by the dispatch center to emergency medical services (EMS) personnel's contact with the patient (i.e. time to EMS arrival).

METHODS

This prospective study conducted in Osaka City, Japan, from 2009 to 2015 included patients with medical cause-related out-of-hospital cardiac arrest who were ≥18 years old. The primary outcome was one-month favorable neurological survival. Using multiple logistic regression models, the adjusted odds ratios (AOR) of independent and DI-dependent CPR for the primary outcome were compared with no CPR. Adjustments were made for patients' age, sex, activities of daily living before the cardiac arrest, year of cardiac arrest, location, presence or absence of witnesses, etiology of cardiac arrest, and the time from EMS contact with the patient to patient's arrival at the hospital. The effective estimated "time to EMS arrival" was also calculated.

RESULTS

For analyses 10,925 individuals were eligible. Independent CPR had a significantly higher one-month favorable neurological survival than no CPR whereas there was no significant difference between DI-dependent CPR and no CPR (AOR, 1.90 [1.47-2.46] and 1.16 [0.91-1.47], respectively). The estimated "time to EMS arrival" for a one-month favorable neurological survival after independent CPR was ≤13min.

CONCLUSIONS

Bystander CPR that did not need DI was associated with significantly higher one-month favorable neurological survival than no CPR, with an effective estimated "time to EMS arrival" of ≤13min.

Public location and survival from out-of-hospital cardiac arrest in the public-access defibrillation era in Japan

BACKGROUND

The use of public-access automated external defibrillators (AEDs) has become common in Japan. To provide a strategy for appropriate public-access AED deployment, we assessed public-access defibrillation (PAD) by laypersons and the outcomes following out-of-hospital cardiac arrest (OHCA) among adult patients by location of arrest.

METHODS

From a nationwide, prospective, population-based registry of patients after OHCA in Japan, we enrolled adult patients with bystander-witnessed OHCA of medical origin in public locations between 2013 and 2015. The primary outcome measure was one-month favorable neurological outcome defined by cerebral performance category 1 or 2. Factors associated with favorable neurological outcome after ventricular fibrillation (VF) were assessed by multivariable logistic regression analysis.

RESULTS

A total of 20,970 adult bystander-witnessed OHCAs of medical origin occurred in public locations. Of those, the proportions of PAD by location were: 13.1% (757/5761) in public areas, 15.9% (333/2089) at workplaces, 26.0% (544/2095) in recreation/sports areas, 36.1% (112/310) in educational institutions, and 5.8% (241/4151) on streets/highways. In a multivariable analysis of VF arrests, both bystander cardiopulmonary resuscitation [adjusted odds ratio (AOR), 1.78; 95% confidence interval (CI), 1.54-2.07] and PAD (AOR, 2.33; 95% CI, 2.05-2.66), and emergency medical service (EMS) response time (AOR, 0.89; 95% CI, 0.87-0.90) were associated with improved outcomes. Earlier PAD initiated by bystanders before EMS arrival was also associated with better outcomes after OHCA.

CONCLUSIONS

In Japan, where public-access AEDs are well-disseminated, the PAD program worked effectively for adult OHCA of medical origin occurring in public locations. Notably, the proportions of PAD differed substantially according to specific public locations.