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.

Actual Cost of Extracorporeal Cardiopulmonary Resuscitation: A Time-Driven Activity-Based Costing Study.

OBJECTIVES: To determine the actual cost and drivers of the cost of an extracorporeal cardiopulmonary resuscitation (E-CPR) care cycle. PERSPECTIVE: A time-driven activity-based costing study conducted from a healthcare provider perspective. SETTING: A quaternary care ICU providing around-the-clock E-CPR service for out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) in Australia. METHODS: The E-CPR care cycle was defined as the time from initiating E-CPR to hospital discharge or death of the patient. Detailed process maps with discrete steps and probabilistic decision nodes accounting for the complex trajectories of E-CPR patients were developed. Data about clinical and nonclinical resources and timing of activities was collected multiple times for each process . Total direct costs were calculated using the time estimates and unit costs per resource for all clinical and nonclinical resources. The total direct costs were combined with indirect costs to obtain the total cost of E-CPR. RESULTS: From 10 E-CPR care cycles observed during the study period, a minimum of 3 observations were obtained per process. The E-CPR care cycle's mean (95% CI) cost was $75,014 ($66,209-83,222). Initiation of extracorporeal membrane oxygenation (ECMO) and ECMO management constituted 18% of costs. The ICU management (35%) and surgical costs (20%) were the primary cost determinants. IHCA had a higher mean (95% CI) cost than OHCA ($87,940 [75,372-100,570] vs. 62,595 [53,994-71,890], p < 0.01), mainly because of the increased survival and ICU length of stay of patients with IHCA. The mean cost for each E-CPR survivor was $129,503 ($112,422-147,224). CONCLUSIONS: Significant costs are associated with E-CPR for refractory cardiac arrest. The cost of E-CPR for IHCA was higher compared with the cost of E-CPR for OHCA. The major determinants of the E-CPR costs were ICU and surgical costs. These data can inform the cost-effectiveness analysis of E-CPR in the future.

Extracorporeal cardiopulmonary resuscitation versus standard treatment for refractory out-of-hospital cardiac arrest: a Bayesian meta-analysis.

BACKGROUND: The outcomes of several randomized trials on extracorporeal cardiopulmonary resuscitation (ECPR) in patients with refractory out-of-hospital cardiac arrest were examined using frequentist methods, resulting in a dichotomous interpretation of results based on p-values rather than in the probability of clinically relevant treatment effects. To determine such a probability of a clinically relevant ECPR-based treatment effect on neurological outcomes, the authors of these trials performed a Bayesian meta-analysis of the totality of randomized ECPR evidence. METHODS: A systematic search was applied to three electronic databases. Randomized trials that compared ECPR-based treatment with conventional CPR for refractory out-of-hospital cardiac arrest were included. The study was preregistered in INPLASY (INPLASY2023120060). The primary Bayesian hierarchical meta-analysis estimated the difference in 6-month neurologically favorable survival in patients with all rhythms, and a secondary analysis assessed this difference in patients with shockable rhythms (Bayesian hierarchical random-effects model). Primary Bayesian analyses were performed under vague priors. Outcomes were formulated as estimated median relative risks, mean absolute risk differences, and numbers needed to treat with corresponding 95% credible intervals (CrIs). The posterior probabilities of various clinically relevant absolute risk difference thresholds were estimated. RESULTS: Three randomized trials were included in the analysis (ECPR, n = 209 patients; conventional CPR, n = 211 patients). The estimated median relative risk of ECPR for 6-month neurologically favorable survival was 1.47 (95%CrI 0.73-3.32) with a mean absolute risk difference of 8.7% (- 5.0; 42.7%) in patients with all rhythms, and the median relative risk was 1.54 (95%CrI 0.79-3.71) with a mean absolute risk difference of 10.8% (95%CrI - 4.2; 73.9%) in patients with shockable rhythms. The posterior probabilities of an absolute risk difference > 0% and > 5% were 91.0% and 71.1% in patients with all rhythms and 92.4% and 75.8% in patients with shockable rhythms, respectively. CONCLUSION: The current Bayesian meta-analysis found a 71.1% and 75.8% posterior probability of a clinically relevant ECPR-based treatment effect on 6-month neurologically favorable survival in patients with all rhythms and shockable rhythms. These results must be interpreted within the context of the reported credible intervals and varying designs of the randomized trials. REGISTRATION: INPLASY (INPLASY2023120060, December 14th, 2023, https://doi.org/10.37766/inplasy2023.12.0060 ).

Effects of pre-existing type 1 diabetes mellitus on survival outcome following out-of-hospital cardiac arrest: a registry-based observational study in Sweden.

BACKGROUND: It has been estimated that 80% of cases of out-of-hospital cardiac arrest (OHCA) are due to cardiac causes. It is well-documented that diabetes is a risk factor for conditions associated with sudden cardiac arrest. Type 1 diabetes (T1D) displays a threefold to fivefold increased risk of cardiovascular disease and death compared with the general population. OBJECTIVE: This study aims to assess the characteristics and survival outcomes of individuals with and without T1D who experienced an OHCA. Design: A registry-based nationwide observational study with two cohorts, patients with T1D and patients without T1D. Setting: All emergency medical services and hospitals in Sweden were included in the study. PARTICIPANTS: Using the Swedish Cardiopulmonary Resuscitation Registry, we enrolled 54 568 cases of OHCA where cardiopulmonary resuscitation was attempted between 2010 and 2020. Among them, 448 patients with T1D were identified using International Classification of Diseases-code: E10. METHODS: Survival analysis was performed using Kaplan-Meier and logistic regression. Multiple regression was adjusted for age, sex, cause of arrest, prevalence of T1D and time to cardiopulmonary resuscitation. MAIN OUTCOME MEASURES: The outcomes were discharge status (alive vs dead), 30 days survival and neurological outcome at discharge. RESULTS: There were no significant differences in patients discharged alive with T1D 37.3% versus, 46% among cases without T1D. There was also no difference in neurological outcome. Kaplan-Meier curves yielded no significant difference in long-term survival. Multiple regression showed no significant association with survival after accounting for covariates, OR 0.99 (95% CI 0.96 to 1.02), p value=0.7. Baseline characteristics indicate that patients with T1D were 5 years younger at OHCA occurrence and had proportionally fewer cases of heart disease as the cause of arrest (57.6% vs 62.7%). CONCLUSION: We conclude, with the current sample size, that there is no statistically significant difference in long-term or short-term survival between patients with and without T1D following OHCA.

End-tidal Carbon Dioxide Trajectory-based Prognostication of Out-of-hospital Cardiac Arrest.

Background: During cardiopulmonary resuscitation (CPR), end-tidal carbon dioxide (EtCO2) is primarily determined by pulmonary blood flow, thereby reflecting the blood flow generated by CPR. We aimed to develop an EtCO2 trajectory-based prediction model for prognostication at specific time points during CPR in patients with out-of-hospital cardiac arrest (OHCA). Methods: We screened patients receiving CPR between 2015-2021 from a prospectively collected database of a tertiary-care medical center. The primary outcome was survival to hospital discharge. We used group-based trajectory modeling to identify the EtCO2 trajectories. Multivariable logistic regression analysis was used for model development and internally validated using bootstrapping. We assessed performance of the model using the area under the receiver operating characteristic curve (AUC). Results: The primary analysis included 542 patients with a median age of 68.0 years. Three distinct EtCO2 trajectories were identified in patients resuscitated for 20 minutes (min): low (average EtCO2 10.0 millimeters of mercury [mm Hg]; intermediate (average EtCO2 26.5 mm Hg); and high (average EtCO2: 51.5 mm Hg). Twenty-min EtCO2 trajectory was fitted as an ordinal variable (low, intermediate, and high) and positively associated with survival (odds ratio 2.25, 95% confidence interval [CI] 1.07-4.74). When the 20-min EtCO2 trajectory was combined with other variables, including arrest location and arrest rhythms, the AUC of the 20-min prediction model for survival was 0.89 (95% CI 0.86-0.92). All predictors in the 20-min model remained statistically significant after bootstrapping. Conclusion: Time-specific EtCO2 trajectory was a significant predictor of OHCA outcomes, which could be combined with other baseline variables for intra-arrest prognostication. For this purpose, the 20-min survival model achieved excellent discriminative performance in predicting survival to hospital discharge.

Impact of Bystander Cardiopulmonary Resuscitation on Out-of-Hospital Cardiac Arrest Outcome in Vietnam.

Introduction: Patients experiencing an out-of-hospital cardiac arrest (OHCA) frequently do not receive bystander cardiopulmonary resuscitation (CPR), especially in low- and middle-income countries (LMIC). In this study we sought to determine the prevalence of OHCA patients in Vietnam who received bystander CPR and its effects on survival outcomes. Methods: We performed a multicenter, retrospective observational study of patients (≥18 years) presenting with OHCA at three major hospitals in an LMIC from February 2014-December 2018. We collected data on the hospital and patient characteristics, the cardiac arrest events, the emergency medical services (EMS) system, the therapy methods, and the outcomes and compared these data, before and after pairwise 1:1 propensity score matching, between patients who received bystander CPR and those who did not. Upon admission, we assessed factors associated with good neurological survival at hospital discharge in univariable and multivariable logistic models. Results: Of 521 patients, 388 (74.5%) were men, and the mean age was 56.7 years (SD 17.3). Although most cardiac arrests (68.7%, 358/521) occurred at home and 78.8% (410/520) were witnessed, a low proportion (22.1%, 115/521) of these patients received bystander CPR. Only half of the patients were brought by EMS (8.1%, 42/521) or private ambulance (42.8%, 223/521), 50.8% (133/262) of whom had resuscitation attempts. Before matching, there was a significant difference in good neurological survival between patients who received bystander CPR (12.2%, 14/115) and patients who did not (4.7%, 19/406; P < .001). After matching, good neurological survival was absent in all OHCA patients who did not receive CPR from a bystander. The multivariable analysis showed that bystander CPR (adjusted odds ratio: 3.624; 95% confidence interval 1.629-8.063) was an independent predictor of good neurological survival. Conclusion: In our study, only 22.1% of total OHCA patients received bystander CPR, which contributed significantly to a low rate of good neurological survival in Vietnam. To improve the chances of survival with good neurological functions of OHCA patients, more people should be trained to perform bystander CPR and teach others as well. A standard program for emergency first-aid training is necessary for this purpose.

Normal value of neuron-specific enolase for predicting good neurological outcomes in comatose out-of-hospital cardiac arrest survivors.

Research on prognostic factors for good outcomes in out-of-hospital cardiac arrest (OHCA) survivors is lacking. We assessed whether normal levels of normal neuron-specific enolase (NSE) value would be useful for predicting good neurological outcomes in comatose OHCA survivors treated with targeted temperature management (TTM). This registry-based observational study with consecutive adult (≥18 years) OHCA survivors with TTM who underwent NSE measurement 48 hours after cardiac arrest was conducted from October 2015 to November 2022. Normal NSE values defined as the upper limit of the normal range by the manufacturer (NSE <16.3 µg/L) and guideline-suggested (NSE < 60 µg/L) were examined for good neurologic outcomes, defined as Cerebral Performance Categories ≤2, at 6 months post-survival. Among 226 OHCA survivors with TTM, 200 patients who underwent NSE measurement were enrolled. The manufacturer-suggested normal NSE values (<16.3 µg/L) had a specificity of 99.17% for good neurological outcomes with a very low sensitivity of 12.66%. NSE <60 µg/L predicted good outcomes with a sensitivity of 87.34% and specificity of 72.73%. However, excluding 14 poor-outcome patients who died from multi-organ dysfunction excluding hypoxic brain injury, the sensitivity and specificity of normal NSE values were 12.66% and 99.07% of NSE < 16.3 µg/L, and 87.34% and 82.24% of NSE < 60 µg/L. The manufacturer-suggested normal NSE had high specificity with low sensitivity, but the guideline-suggested normal NSE value had a comparatively low specificity for good outcome prediction in OHCA survivors. Our data demonstrate normal NSE levels can be useful as a tool for multimodal appropriation of good outcome prediction.

Five-year prognosis of patients with acute myocardial infarction and out-of-hospital cardiac arrest.

OBJECTIVES: This study aimed to assess the mortality and prognosis of acute myocardial infarction (AMI) patients with out-of-hospital cardiac arrest (OHCA) initially admitted to Department of Anesthesiology and Intensive Care in comparison with patients initially admitted to Cardiac Centre (CC). BACKGROUND: Global acute coronary syndrome (ACS) registries often omit patients with OHCA initially admitted to anaesthesiology and intensive care units. This exclusion may lead to underestimated mortality rates in patients following acute MI worldwide. METHODS: A retrospective analysis was conducted in patients admitted in 2014 to the (Department of Anesthesiology and Intensive Care) at a single center, J.A. Reiman Teaching Hospital in Presov, Slovakia. Survival rates were evaluated in-hospital, at 30 days, and annually over a five-year period. Patients with STEMI and NSTEMI were analyzed separately, particularly during the early in-hospital phase. RESULTS: In the OHCA group, 52% of STEMI patients experienced in-hospital mortality, whereas the CC group reported only 3% mortality. The total hospital mortality for STEMI patients was 6.69%. Among NSTEMI patients in the OHCA group, in-hospital mortality reached 50%, compared to 4.33% in the CC group. The total center mortality for all NSTEMI patients was 6.09%. CONCLUSION: Although the short-term prognosis for MI patients with OHCA is unfavorable, with a 30-day mortality rate of 54.9%, for those who survive the initial 30 days following cardiac arrest and are successfully discharged from the hospital, the long-term prognosis aligns with MI patients without OHCA. In light of these findings, the inclusion of all patients with MI (from both OHCA and CC groups) in global ACS registries could significantly raise in-hospital and 30-day mortality rates (Tab. 3, Fig. 4, Ref. 21).

Association between sub-phenotypes identified using latent class analysis and neurological outcomes in patients with out-of-hospital cardiac arrest in Japan.

BACKGROUND: In patients who experience out-of-hospital cardiac arrest (OHCA), it is important to assess the association of sub-phenotypes identified by latent class analysis (LCA) using pre-hospital prognostic factors and factors measurable immediately after hospital arrival with neurological outcomes at 30 days, which would aid in making treatment decisions. METHODS: This study retrospectively analyzed data obtained from the Japanese OHCA registry between June 2014 and December 2019. The registry included a complete set of data on adult patients with OHCA, which was used in the LCA. The association between the sub-phenotypes and 30-day survival with favorable neurological outcomes was investigated. Furthermore, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by multivariate logistic regression analysis using in-hospital data as covariates. RESULTS: A total of, 22,261 adult patients who experienced OHCA were classified into three sub-phenotypes. The factor with the highest discriminative power upon patient's arrival was Glasgow Coma Scale followed by partial pressure of oxygen. Thirty-day survival with favorable neurological outcome as the primary outcome was evident in 66.0% participants in Group 1, 5.2% in Group 2, and 0.5% in Group 3. The 30-day survival rates were 80.6%, 11.8%, and 1.3% in groups 1, 2, and 3, respectively. Logistic regression analysis revealed that the ORs (95% CI) for 30-day survival with favorable neurological outcomes were 137.1 (99.4-192.2) for Group 1 and 4.59 (3.46-6.23) for Group 2 in comparison to Group 3. For 30-day survival, the ORs (95%CI) were 161.7 (124.2-212.1) for Group 1 and 5.78 (4.78-7.04) for Group 2, compared to Group 3. CONCLUSIONS: This study identified three sub-phenotypes based on the prognostic factors available immediately after hospital arrival that could predict neurological outcomes and be useful in determining the treatment strategy of patients experiencing OHCA upon their arrival at the hospital.

Sex Disparities in Resuscitation Quality Following Out of Hospital Cardiac Arrest.

BACKGROUND: Women are known to be disadvantaged compared with men in the early links of the Chain of Survival, receiving fewer bystander interventions. We aimed to describe sex-based disparities in emergency medical service resuscitation quality and processes of care for out-of-hospital cardiac arrest. METHODS AND RESULTS: We conducted a retrospective analysis of patients who were nontraumatic with out-of-hospital cardiac arrest aged ≥16 years where resuscitation was attempted between March 2019 and June 2023. We investigated 18 routinely captured performance metrics and performed adjusted logistic and quantile regression analyses to assess sex-based differences in these metrics. During the study period, 10 161 patients with out-of-hospital cardiac arrest met the eligibility criteria, of whom 3216 (32%) were women. There were no clinically relevant sex-based differences observed in regard to external cardiac compressions; however, women were 34% less likely to achieve a systolic blood pressure >100 mm Hg on arrival at the hospital (adjusted odds ratio [AOR], 0.66 [95% CI, 0.47-0.92]). Furthermore, women had a longer time to 12-lead ECG acquisition after return of spontaneous circulation (median adjusted difference, 1.00 minute [95% CI, 0.38-1.62]) and 33% reduced odds of being transported to a 24-hour percutaneous coronary intervention-capable facility (AOR, 0.67 [95% CI, 0.49-0.91]). Resuscitation was also terminated sooner for women compared with men (median adjusted difference, -4.82 minutes [95% CI, -6.77 to -2.87]). CONCLUSIONS: Although external cardiac compression quality did not vary by sex, significant sex-based disparities were seen in emergency medical services processes of care following out-of-hospital cardiac arrest. Further investigation is required to elucidate the underlying causes of these differences and examine their influence on patient outcomes.

The Incidence and Outcomes of Out-of-Hospital Cardiac Arrest During the COVID-19 Pandemic in South Korea: Multicenter Registry Study.

BACKGROUND: The COVID-19 pandemic has profoundly affected out-of-hospital cardiac arrest (OHCA) and disrupted the chain of survival. Even after the end of the pandemic, the risk of new variants and surges persists. Analyzing the characteristics of OHCA during the pandemic is important to prepare for the next pandemic and to avoid repeated negative outcomes. However, previous studies have yielded somewhat varied results, depending on the health care system or the specific characteristics of social structures. OBJECTIVE: We aimed to investigate and compare the incidence, outcomes, and characteristics of OHCA during the prepandemic and pandemic periods using data from a nationwide multicenter OHCA registry. METHODS: We conducted a multicenter, retrospective, observational study using data from the Korean Cardiac Arrest Resuscitation Consortium (KoCARC) registry. This study included adult patients with OHCA in South Korea across 3 distinct 1-year periods: the prepandemic period (from January to December 2019), early phase pandemic period (from July 2020 to June 2021), and late phase pandemic period (from July 2021 to June 2022). We extracted and contrasted the characteristics of patients with OHCA, prehospital time factors, and outcomes for the patients across these 3 periods. The primary outcomes were survival to hospital admission and survival to hospital discharge. The secondary outcome was good neurological outcome. RESULTS: From the 3 designated periods, a total of 9031 adult patients with OHCA were eligible for analysis (prepandemic: n=2728; early pandemic: n=2954; and late pandemic: n=3349). Witnessed arrest (P<.001) and arrest at home or residence (P=.001) were significantly more frequent during the pandemic period than during the prepandemic period, and automated external defibrillator use by bystanders was lower in the early phase of the pandemic than during other periods. As the pandemic advanced, the rates of the first monitored shockable rhythm (P=.10) and prehospital endotracheal intubation (P<.001) decreased significantly. Time from cardiac arrest cognition to emergency department arrival increased sequentially (prepandemic: 33 min; early pandemic: 35 min; and late pandemic: 36 min; P<.001). Both survival and neurological outcomes worsened as the pandemic progressed, with survival to discharge showing the largest statistical difference (prepandemic: 385/2728, 14.1%; early pandemic: 355/2954, 12%; and late pandemic: 392/3349, 11.7%; P=.01). Additionally, none of the outcomes differed significantly between the early and late phase pandemic periods (all P>.05). CONCLUSIONS: During the pandemic, especially amid community COVID-19 surges, the incidence of OHCA increased while survival rates and good neurological outcome at discharge decreased. Prehospital OHCA factors, which are directly related to OHCA prognosis, were adversely affected by the pandemic. Ongoing discussions are needed to maintain the chain of survival in the event of a new pandemic. TRIAL REGISTRATION: ClinicalTrials.gov NCT03222999; https://classic.clinicaltrials.gov/ct2/show/NCT03222999.

Effect of timing of advanced life support on out-of-hospital cardiac arrests at home.

AIM: In cases of out-of-hospital cardiac arrests (OHCA) occurring at home, Japanese emergency medical services personnel decide whether to provide treatment on the scene or during transport based on their judgment. This study aimed to evaluate the association between the timing of advanced life support (ALS) (i.e., endotracheal intubation [ETI] or adrenaline administration) for OHCA at home and prognosis. METHOD: This retrospective cohort study used data from the Japan Utstein Registry and emergency transport data collected from patients who underwent pre-hospital ETI (n = 6806) and received adrenaline (n = 22,636) between 2016 and 2019. The timing of ETI or adrenaline administration was determined as "on the scene" or "in the ambulance." Multiple logistic regression analysis was used to estimate the association among the timing of ALS implementation, pre-hospital return of spontaneous circulation (ROSC), and survival at 1 month. RESULT: ETI on the scene was significantly positively associated with pre-hospital ROSC (adjusted odds ratio [AOR], 1.81; 95% confidence interval [CI], 1.57-2.09) and survival at 1 month (AOR, 1.81; 95% CI, 1.47-2.23). Adrenaline administration on the scene was significantly positively associated with pre-hospital ROSC (AOR, 2.51; 95% CI, 2.33-2.70) and survival at 1 month (AOR, 2.13; 95% CI, 1.89-2.40). CONCLUSION: Our analysis suggests performing ALS on the scene was associated with pre-hospital ROSC and survival at 1 month. Further efforts are needed to increase the rate of ALS implementation on the scene by emergency life-saving technicians.

A metabolic profile of xenon and metabolite associations with 6-month mortality after out-of-hospital cardiac arrest: A post-hoc study of the randomised Xe-Hypotheca trial.

PURPOSE: Out-of-hospital cardiac arrest (OHCA) carries a relatively poor prognosis and requires multimodal prognostication to guide clinical decisions. Identification of previously unrecognized metabolic routes associated with patient outcome may contribute to future biomarker discovery. In OHCA, inhaled xenon elicits neuro- and cardioprotection. However, the metabolic effects remain unknown. MATERIALS AND METHODS: In this post-hoc study of the randomised, 2-group, single-blind, phase 2 Xe-Hypotheca trial, 110 OHCA survivors were randomised 1:1 to receive targeted temperature management (TTM) at 33°C with or without inhaled xenon during 24 h. Blood samples for nuclear magnetic resonance spectroscopy metabolic profiling were drawn upon admission, at 24 and 72 h. RESULTS: At 24 h, increased lactate, adjusted hazard-ratio 2.25, 95% CI [1.53; 3.30], p<0.001, and decreased branched-chain amino acids (BCAA) leucine 0.64 [0.5; 0.82], p = 0.007, and valine 0.37 [0.22; 0.63], p = 0.003, associated with 6-month mortality. At 72 h, increased lactate 2.77 [1.76; 4.36], p<0.001, and alanine 2.43 [1.56; 3.78], p = 0.001, and decreased small HDL cholesterol ester content (S-HDL-CE) 0.36 [0.19; 0.68], p = 0.021, associated with mortality. No difference was observed between xenon and control groups. CONCLUSIONS: In OHCA patients receiving TTM with or without xenon, high lactate and alanine and decreased BCAAs and S-HDL-CE associated with increased mortality. It remains to be established whether current observations on BCAAs, and possibly alanine and lactate, could reflect neural damage via their roles in the metabolism of the neurotransmitter glutamate. Xenon did not significantly alter the measured metabolic profile, a potentially beneficial attribute in the context of compromised ICU patients. TRIAL REGISTRATION: Trial Registry number: ClinicalTrials.gov Identifier: NCT00879892.

Neurological prognosis prediction upon arrival at the hospital after out-of-hospital cardiac arrest: R-EDByUS score.

AIM: To develop a new scoring model for patients with cardiogenic out-of-hospital cardiac arrest (OHCA) to facilitate neurological prognosis prediction upon hospital arrival by using prehospital resuscitation features alone. METHODS: Between 2005 and 2019, we enrolled 942,891 adult patients with OHCA of presumed cardiac aetiology from the All-Japan Utstein Registry. Scoring models applied prehospital resuscitation features a priori from the variables the American College of Cardiology algorithm including age, duration to return of spontaneous circulation (ROSC) or hospital arrival, no bystander cardiopulmonary resuscitation (CPR), unwitnessed arrest, and nonshockable rhythm (R-EDByUS score) to predict unfavorable neurological outcomes defined as Cerebral Performance Category 3, 4, or 5 at 1 month. We created nomograms as a "Regression-based model," and created a "Simplified model" in which points were assigned by category for predicting unfavorable neurological outcomes for both the prehospital ROSC cohort (67,064 patients) and the ongoing CPR cohort (875,827 patients). For internal validation, bootstrap optimism-corrected estimates of predictive performance were calculated. RESULTS: A total of 46,971 (70.0%) and 870,991 (99.4%) patients in the prehospital ROSC and ongoing CPR cohorts, respectively, had unfavorable neurological outcomes. In the prehospital ROSC cohort, the C-statistics of the Regression-based and Simplified models were 0.851 and 0.842, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. In the ongoing CPR cohort, the C-statistics of the Regression-based and Simplified models were 0.872 and 0.865, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. CONCLUSIONS: The R-EDByUS score accurately predicted the neurological prognosis of cardiogenic OHCA upon hospital arrival.

Impact of Blood Pressure Targets in Patients With Heart Failure Undergoing Postresuscitation Care: A Subgroup Analysis From a Randomized Controlled Trial.

BACKGROUND: To assess the effect of targeting higher or lower blood pressure during postresucitation intensive care among comatose patients with out-of-hospital cardiac arrest with a history of heart failure. METHODS: The BOX trial (Blood Pressure and Oxygenation Targets After Out-of-Hospital Cardiac Arrest) was a randomized, controlled, double-blinded, multicenter study comparing titration of vasopressors toward a mean arterial pressure (MAP) of 63 versus 77 mm Hg during postresuscitation intensive care. Patients with a history of heart failure were included in this substudy. Pulmonary artery catheters were inserted shortly after admission. History of heart failure was assessed through chart review of all included patients. The primary outcome was cardiac index during the first 72 hours. Secondary outcomes were left ventricular ejection fraction, heart rate, stroke volume, renal replacement therapy and all-cause mortality at 365 days. RESULTS: A total of 134 patients (17% of the BOX cohort) had a history of heart failure (patients with left ventricular ejection fraction, ≤40%: 103 [77%]) of which 71 (53%) were allocated to a MAP of 77 mm Hg. Cardiac index at intensive care unit arrival was 1.77±0.11 L/min·m-2 in the MAP63-group and 1.78±0.17 L/min·m-2 in the MAP77, P=0.92. During the next 72 hours, the mean difference was 0.15 (95% CI, -0.04 to 0.35) L/min·m-2; Pgroup=0.22. Left ventricular ejection fraction and stroke volume was similar between the groups. Patients allocated to MAP77 had significantly elevated heart rate (mean difference 6 [1-12] beats/min, Pgroup=0.03). Vasopressor usage was also significantly increased (P=0.006). At 365 days, 69 (51%) of the patients had died. The adjusted hazard ratio for 365 day mortality was 1.38 (0.84-2.27), P=0.20 and adjusted odds ratio for renal replacement therapy was 2.73 (0.84-8.89; P=0.09). CONCLUSIONS: In resuscitated patients with out-of-hospital cardiac arrest with a history of heart failure, allocation to a higher blood pressure target resulted in significantly increased heart rate in the higher blood pressure-target group. However, no certain differences was found for cardiac index, left ventricular ejection fraction or stroke volume. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03141099.

Impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest outcomes in Japan.

This study investigates the impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest (OHCA) outcomes in Japan, aiming to address a critical research gap. Analyzing data from the All-Japan Utstein registry covering pediatric OHCA cases from 2018 to 2021, the study observed no significant changes in one-month survival, neurological outcomes, or overall performance when comparing the pre-pandemic (2018-2019) and pandemic (2020-2021) periods among 6765 cases. However, a notable reduction in pre-hospital return of spontaneous circulation (ROSC) during the pandemic (15.1-13.1%, p = .020) was identified. Bystander-initiated chest compressions and rescue breaths declined (71.1-65.8%, 22.3-13.0%, respectively; both p < .001), while bystander-initiated automated external defibrillator (AED) use increased (3.7-4.9%, p = .029). Multivariate logistic regression analyses identified factors associated with reduced pre-hospital ROSC during the pandemic. Post-pandemic, there was no noticeable change in the one-month survival rate. The lack of significant change in survival may be attributed to the negative effects of reduced chest compressions and ventilation being offset by the positive impact of widespread AED availability in Japan. These findings underscore the importance of innovative tools and systems for safe bystander cardiopulmonary resuscitation during a pandemic, providing insights to optimize pediatric OHCA care.

Mortality after paediatric emergency calls for patients with or without pre-existing comorbidity: a nationwide population based cohort study.

BACKGROUND: Life-threatening conditions are infrequent in children. Current literature in paediatric prehospital research is centred around trauma and paediatric out-of-hospital cardiac arrests (POHCA). The aims of this study were to (1) outline the distribution of trauma, POHCA or other medical symptoms among survivors and non-survivors after paediatric emergency calls, and (2) to investigate these clinical presentations' association with mortality in children with and without pre-existing comorbidity, respectively. METHODS: Nationwide population-based cohort study including ground and helicopter emergency medical services in Denmark for six consecutive years (2016-2021). The study included all calls to the emergency number 1-1-2 regarding children ≤ 15 years (N = 121,230). Interhospital transfers were excluded, and 1,143 patients were lost to follow-up. Cox regressions were performed with trauma or medical symptoms as exposure and 7-day mortality as the outcome, stratified by 'Comorbidity', 'Severe chronic comorbidity' and 'None' based on previous healthcare visits. RESULTS: Mortality analysis included 76,956 unique patients (median age 5 (1-12) years). Annual all-cause mortality rate was 7 per 100,000 children ≤ 15 years. For non-survivors without any pre-existing comorbidity (n = 121), reasons for emergency calls were trauma 18.2%, POHCA 46.3% or other medical symptoms 28.9%, whereas the distribution among the 134 non-survivors with any comorbidity was 7.5%, 27.6% and 55.2%, respectively. Compared to trauma patients, age- and sex-adjusted hazard ratio for patients with calls regarding medical symptoms besides POHCA was 0.8 [0.4;1.3] for patients without comorbidity, 1.1 [0.5;2.2] for patients with comorbidity and 6.1 [0.8;44.7] for patients with severe chronic comorbidity. CONCLUSION: In both non-survivors with and without comorbidity, a considerable proportion of emergency calls had been made because of various medical symptoms, not because of trauma or POHCA. This outline of diagnoses and mortality following paediatric emergency calls can be used for directing paediatric in-service training in emergency medical services.