CaRdiac Arrest Survival Score (CRASS) - A tool to predict good neurological outcome after out-of-hospital cardiac arrest

External validation of three scores for predicting prehospital return of spontaneous circulation in out-of-hospital cardiac arrest

BACKGROUND

Although three established models for predicting the return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) exist, combinational external validation of these models remains limited. This study aimed to externally validate and compare the performance of three predictive models-RACA, P-ROSC, and UB-ROSC-and provide evidence to guide the selection and application of predictive models for prehospital ROSC in diverse settings.

METHODS

A retrospective validation was conducted using the National Taiwan University Hospital Hsinchu and Yunlin Branch Out-of-Hospital Cardiac Arrest Research Databases. Patients with EMS-treated OHCAs admitted to the hospital between January 2016 and July 2023 were recruited. The primary outcome was prehospital ROSC. Model performance was evaluated using discrimination, calibration, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic odds ratio. Calibration and density distribution plots were generated.

RESULTS

All three models demonstrated moderate-to-high discrimination with AUROCs of 0.758 (RACA), 0.755 (P-ROSC), and 0.747 (UB-ROSC). The RACA score exhibited better calibration across the risk deciles, whereas the P-ROSC and UB-ROSC scores tended to overestimate the probabilities at higher predicted risk levels. The P-ROSC score required fewer variables and showed the best separation between prehospital and non-prehospital ROSC cases. Optimal cut-off values for the RACA, P-ROSC, and UB-ROSC scores were 0.45, 41, and - 13, respectively, with corresponding sensitivities of 62 %, 56 %, and 71 % and specificities of 78 %, 82 %, and 69 %. All models achieved high NPVs (>96 %), but PPVs remained low (16-21 %).

CONCLUSIONS

The P-ROSC, which requires fewer variables, has emerged as the most practical model for Taiwanese populations. However, the choice of the model should be guided by the availability of variables, regional EMS characteristics, and trends in prehospital ROSC rates.

Association between the Clinical Frailty Scale and Neurological Outcomes in Out-of-Hospital Cardiac Arrest: A Retrospective Study

Background

Frailty is a physical condition characterized by increased vulnerability to external stressors. This study investigated the impact of premorbid frailty, as measured by the Clinical Frailty Scale (CFS), on neurological prognosis in patients with out-of-hospital cardiac arrest (OHCA).

Methods

This is a single-center retrospective study. Data from 2006 to 2020 were analyzed for 595 adult OHCA patients admitted to the intensive care unit of National Taiwan University Hospital following resuscitation. Variables included demographics, medical history, resuscitation details, post-resuscitation data, and frailty assessments based on CFS. The primary outcome was favorable neurological performance, defined as a cerebral performance category (CPC) score of 2 or less at discharge.

Results

In total, 523 of the 595 patients were included in the analysis. Among these, 224 survived, and 173 exhibited favorable neurological outcomes. Patients with favorable outcomes had significantly lower CFS scores than those with poor outcomes (3.2 ± 1.5 vs. 4.5 ± 1.8, p < 0.0001). The proportion of favorable neurological outcomes declined as CFS scores increased. Multivariate logistic regression analysis identified several factors independently associated with worse neurological outcomes: CFS >4 (odds ratio (OR): 0.301, 95% confidence interval (CI): 0.163-0.540), age >70 years (OR: 0.969, 95% CI: 0.953-0.986), history of malignancy (OR: 0.421, 95% CI: 0.209-0.813), epinephrine >2 mg during resuscitation (OR: 0.776, 95% CI: 0.712-0.840), and arterial blood gas pH <7.1 (OR: 28.396, 95% CI: 6.487-129.350). The model demonstrated good performance, with an area under the curve (AUC) value of 0.853. No significant relationships were observed between CFS and other variables.

Conclusions

CFS values ≤4 were independently associated with favorable neurological outcomes following OHCA.

External validation and comparative performance of the SLANT score for neuroprognostication in out-of-hospital cardiac arrest survivors undergoing targeted temperature management: insights from an Asian cohort

BACKGROUND

Neurological outcomes after out-of-hospital cardiac arrest (OHCA) depend on multiple factors, including the patient's baseline condition and post-arrest management. The SLANT, developed specifically for OHCA survivors treated with targeted temperature management (TTM), requires further validation, particularly in Asian populations.

METHODS

This multicenter retrospective cohort study analyzed data from 2016 to 2023, examining demographics, pre-arrest conditions, resuscitation events, and laboratory biomarkers following TTM. The primary outcome was defined as a poor neurological outcome at hospital discharge. Model performance was assessed using the area under the receiver operating characteristic curve. Multivariate logistic regression analysis was used to analyze the included variables.

RESULTS

A total of 448 eligible adult patients were included, of whom 77.9% experienced poor neurological outcomes at discharge. The performance of the current cohort was comparable to that of the original SLANT cohort, achieving an area under the curve of 0.797 (95% confidence interval: 0.746-0.849). All five factors of the SLANT score remained statistically significant in predicting poor neurological outcomes. At a cutoff of ≥ 6.5, the SLANT score demonstrated a specificity of 53.5% and positive predictive value (PPV) of 86.9%. Increasing the cutoff value to 8.5 improved the specificity to 66.7% and the PPV to 89.6%.

CONCLUSION

The SLANT showed high PPV for predicting poor neurological outcomes at discharge in patients with OHCA undergoing TTM across a multicenter Asian cohort. Combining the score with other neurological assessments is recommended for improved neuroprognostication.

Ferritin Levels on Hospital Admission Predict Hypoxic-Ischemic Encephalopathy in Patients After Out-of-Hospital Cardiac Arrest: A Prospective Observational Single-Center Study

AIM

Out-of-hospital cardiac arrest (OHCA) is a major health concern in Western societies. Poor outcome after OHCA is determined by the extent of hypoxic-ischemic encephalopathy (HIE). Dysregulation of iron metabolism has prognostic relevance in patients with ischemic stroke and sepsis. The aim of this study was to determine whether serum iron parameters help to estimate outcomes after OHCA.

METHODS

In this prospective single-center study, 70 adult OHCA patients were analyzed. Serum ferritin, iron, transferrin (TRF), and TRF saturation (TRFS) were measured in blood samples drawn on day 0 (admission), day 2, day 4, and 6 months after the return of spontaneous circulation (ROSC). The association of 4 iron parameters with in-hospital mortality, neurological outcome (cerebral performance category [CPC]), and HIE was investigated by receiver operating characteristics and multivariate regression analyses.

RESULTS

OHCA subjects displayed significantly increased serum ferritin levels on day 0 and lowered iron, TRF, and TRFS on days 2 and 4 after ROSC, as compared to concentrations measured at a 6-month follow-up. Iron parameters were not associated with in-hospital mortality or neurological outcomes according to the CPC. Ferritin on admission was an independent predictor of features of HIE on cranial computed tomography and death due to HIE.

CONCLUSION

OHCA is associated with alterations in iron metabolism that persist for several days after ROSC. Ferritin on admission can help to predict HIE.

Mild therapeutic hypothermia after cardiac arrest - effect on survival with good neurological outcome outside of randomised controlled trials: A registry-based analysis

BACKGROUND

For nearly 20 years, in international guidelines, mild therapeutic hypothermia (MTH) was an important component of postresuscitation care. However, recent randomised controlled trials have questioned its benefits. At present, international guidelines only recommend actively preventing fever, but there are ongoing discussions about whether the majority of cardiac arrest patients could benefit from MTH treatment.

OBJECTIVE

The aim of this study was to compare the outcome of adult patients treated with and without MTH after cardiac arrest.

DESIGN

Observational cohort study.

SETTING

German Resuscitation Registry covering more than 31 million inhabitants of Germany and Austria.

PATIENTS

All adult patients between 2006 and 2022 with out-of-hospital or in-hospital cardiac arrest and comatose on admission.

MAIN OUTCOME MEASURES

Primary endpoint: hospital discharge with good neurological outcome [cerebral performance categories (CPC) 1 or 2]. Secondary endpoint: hospital discharge. We used a multivariate binary logistic regression analysis to identify the effects on outcome of all known influencing variables.

RESULTS

We analysed 33 933 patients (10 034 treated with MTH, 23 899 without MTH). The multivariate regression model revealed that MTH was an independent predictor of CPC 1/2 survival and of hospital discharge with odds ratio (95% confidence intervals) of 1.60 (1.49 to 1.72), P < 0.001 and 1.89 (1.76 to 2.02), P < 0.001, respectively.

CONCLUSION

Our data indicate the existence of a positive association between MTH and a favourable neurological outcome after cardiac arrest. It therefore seems premature to refrain from giving MTH treatment for the entire spectrum of patients after cardiac arrest. Further prospective studies are needed.

Prediction of neurologic outcome after out-of-hospital cardiac arrest: An interpretable approach with machine learning

Out-of-hospital cardiac arrest (OHCA) is a critical condition with low survival rates. In patients with a return of spontaneous circulation, brain injury is a leading cause of death. In this study, we propose an interpretable machine learning approach for predicting neurologic outcome after OHCA, using information available at the time of hospital admission.

METHODS

The study population were 55 615 OHCA cases registered in the Swedish Cardiopulmonary Resuscitation Registry between 2010 and 2020. The dataset was split to training and validation sets (for model development) and test set (for evaluation of the final model). We used an XGBoost algorithm with stratified, repeated 10-fold cross-validation along with Optuna framework for hyperparameters tuning. The final model was trained on 10 features selected based on the importance scores and evaluated on the test set in terms of discrimination, calibration and bias-variance tradeoff. We used SHapley Additive exPlanations to address the 'black-box' model and align with eXplainable artificial intelligence.

RESULTS

The final model achieved: area under the receiver operating characteristic value 0.964 (95% confidence interval (CI) [0.960-0.968]), sensitivity 0.606 (95% CI [0.573-0.634]), specificity 0.975 (95% CI [0.972-0.978]), positive predictive value (PPV) 0.664 (95% CI [0.625-0.696]), negative predictive value (NPV) 0.969 (95% CI [0.966-0.972]), macro F1 0.803 (95% CI [0.788-0.816]), and showed a very good calibration. SHAP features with the highest impact on the model's output were:'ROSC on arrival to hospital', 'Initial rhythm asystole' and 'Conscious on arrival to hospital'.

CONCLUSIONS

The XGBoost machine learning model with 10 features available at the time of hospital admission showed good performance for predicting neurologic outcome after OHCA, with no apparent signs of overfitting.

The German Resuscitation Registry - Epidemiological data for out-of-hospital and in-hospital cardiac arrest

Introduction

The German Resuscitation Registry was started in 2007 and collects data on out-of-hospital as well as in-hospital cardiac arrest and resuscitation. It has collected more than 400.000 datasets till today.

Methods

The German Resuscitation Registry (GRR) is a voluntary quality improvement tool and research tool for out-of-hospital and in-hospital resuscitation as well as in-hospital emergency treatment. It collects data for initial treatment, in-hospital care as well as long-term outcome in an online database. For risk stratification two scores have been developed, published, and implemented. The participants are getting annual and monthly or quarterly reports in addition to the standardized online, 24/7 available analyzing options. An annual public report is published as well. We are reporting on the OHCA annual report of 2022.

Results

In 2022 the incidence of CPR started or continued by EMS was 77.6/100.000 inhabitants/year. The mean age was 70.2 years and 66.7% were male bystanders who started CPR in 51.3%. The average response time for the first EMS vehicle to arrive on scene was 6:55 min.In 57.9% of the cases, they had a presumed cardiac cause. The primary outcome, return-of-spontaneous circulation (ROSC) was achieved in 42.1%.

Discussion

With its more than 450.000 included datasets, the GRR is an established tool for quality improvement and research in Germany and internationally. The results for the incidence of OHCA and outcome from 2022 are compared to EuReCa TWO data ranging in the upper third of European countries. Furthermore, the GRR has contributed to increasing knowledge of OHCA by conducting and publishing research e.g. on epidemiology, airway management, and medication of OHCA.

Ongoing CPR with an onboard physician

Introduction

Recent data are not available on ongoing CPR for emergency services with an onboard physician. The aim of the present study was to identify factors associated with the decision to transport patients to hospital with ongoing CPR and examine their survival to hospital discharge with good neurological status.

Methods

An observational study based on a registry of out-of-hospital cardiac arrests attended to by emergency services with an onboard physician. All OHCA cases occurring between the 1st of January and the 31st of December 2022 were included. Patients receiving ongoing CPR during transport to the hospital were compared with patients pronounced dead at the scene following arrival of the care team. The dependent variable was ongoing CPR during transport to the hospital. The main characteristics and the neurological status of patients surviving to discharge were described.

Results

A total of 9321 cases were included, of which 350 (3.7%) were transported to hospital with ongoing CPR. Such patients were young (59.9 ± 20.1 years vs 64.6 ± 16.9 years; p < 0.001; 95%CI: 0.98 [0.98; 0.99]) with arrest taking place outside of the home (151 [44.5%] vs 4045 [68.01%]; p < 0.001; 95%CI: 0.41 [0.31; 0.54]) and being witnessed by EMS (126 [36.0%] vs 667 [11.0%]; p < 0.001; 95%CI: 4.31 [3.19; 5.80]), whilst initial rhythm differed from asystole (164 [47.6%] vs 4325 [73.0%]; p < 0.01; 95%CI: 0.44 [0.33; 0.60]) and a mechanical device was more often employed during resuscitation and transport to hospital (199 [56.9%] vs 2050 [33.8%]; p < 0.001; 95%CI: 2.75 [2.10; 3.59]). Seven patients (2%) were discharged alive from hospital, five with ad integrum neurological recovery (CPC1) and two with minimally impaired neurological function (CPC2).

Conclusions

The strategy of ongoing CPR is uncommon in EMS with an onboard physician. Despite their limited efficacy, the availability of mechanical chest compression devices, together with the possibility of specific hospital treatments, mainly ICP and ECMO, opens up the possibility of this approach with determined patients.

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Mortality after cardiac arrest in children less than 2 years: relevant factors

BACKGROUND

There are only scant studies of predicting outcomes of pediatric resuscitation due to lack of population-based data. This study aimed to determine variable factors that may impact the survival of resuscitated children aged under 24 months.

METHODS

This is a retrospective study of 66 children under 24 months. Cardiopulmonary resuscitation (CPR) with pediatric advanced life support guideline was performed uniformly for all children. Linear regression analysis with variable factors was conducted to determine impacts on mortality.

RESULT

Factors with statistically significant increases in mortality were the number of administered epinephrine (p value < 0.001), total CPR duration (p value < 0.001), in-hospital CPR duration of out-hospital cardiac arrest (p value < 0.001), and changes in cardiac rhythm (p value < 0.040). However, there is no statistically significant association between patient outcomes and remaining factors such as age, sex, underlying disease, etiology, time between last normal to CPR, initial CPR location, initial cardiac rhythm, venous access time, or inotropic usage.

CONCLUSION

More than 10 times of epinephrine administration and CPR duration longer than 30 minutes were associated with a higher mortality rate, while each epinephrine administration and prolonged CPR time increased mortality.

IMPACT STATEMENT

This study analyzed various factors influencing mortality after cardiac arrest in patients under 24 months. Increased number of administered epinephrine and prolonged cardiopulmonary resuscitation duration do not increase survival rate in patients under 24 months. In patients with electrocardiogram rhythm changes during CPR, mortality increased when the rhythm changed into asystole in comparison to no changes occurring in the rhythm.

Gender-related differences in adults concerning frequency, survival and treatment quality after out-of-hospital cardiac arrest (OHCA): An observational cohort study from the German resuscitation registry

BACKGROUND

In Germany approximately 20,500 women and 41,000 men were resuscitated after out-of-hospital cardiac arrest (OHCA) each year. We are currently experiencing a discussion about the possible undersupply of women in healthcare. The aim of the present study was to examine the prevalence of OHCA in Germany, as well as the outcome and quality of resuscitation care for both women and men.

METHODS

We present a cohort study from the German Resuscitation Registry (2006-2022). The quality of care was assessed for both EMS and hospital care based on risk-adjusted survival rates with the endpoints: "hospital admission with return of spontaneous circulation" (ROSCadmission) for all patients and "discharge with favourable neurological recovery" (CPC1/2discharge) for all admitted patients. Risk adjustment was performed using logistic regression analysis (LRA). If sex was significantly associated with survival, a matched-pairs-analysis (MPA) followed to explore the frequency of guideline adherence.

RESULTS

58,798 patients aged ≥ 18 years with OHCA and resuscitation were included (men = 65.2%, women = 34.8%). In the prehospital phase the male gender was associated with lower ROSCadmission-rate (LRA: OR = 0.79, CI = 0.759-0.822). A total of 27,910 patients were admitted. During hospital care, men demonstrated a better prognosis (OR = 1.10; CI = 1.015-1.191). MPA revealed a more intensive therapy for men both during EMS and hospital care. Looking at the complete chain of survival, LRA revealed no difference for men and women concerning CPC1/2discharge (n = 58,798; OR = 0.95; CI = 0.888-1.024).

CONCLUSION

In Germany, 80% more men than women experience OHCA. The prognosis for CPC1/2discharge remains low (men = 10.5%, women = 7.1%), but comparable after risk adjustment. There is evidence of undersupply of care for women during hospital treatment, which could be associated with a worse prognosis. Further investigations are required to clarify these findings.

Prognostic factors associated with favourable functional outcome among adult patients requiring extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR), has demonstrated promise in the management of refractory out-of-hospital cardiac arrest (OHCA). However, evidence from observational studies and clinical trials are conflicting and the factors influencing outcome have not been well established.

METHODS

We conducted a systematic review and meta-analysis summarizing the association between pre-ECPR prognostic factors and likelihood of good functional outcome among adult patients requiring ECPR for OHCA. We searched Medline and Embase databases from inception to February 28, 2023 and screened studies with two independent reviewers. We performed meta-analyses of unadjusted and adjusted odds ratios, adjusted hazard ratios and mean differences separately. We assessed risk of bias using the QUIPS tool and certainty of evidence using the GRADE approach.

FINDINGS

We included 29 observational and randomized studies involving 7,397 patients. Factors with moderate or high certainty of association with increased survival with favourable functional outcome include pre-arrest patient factors, such as younger age (odds ratio (OR) 2.13, 95% CI 1.52 to 2.99) and female sex (OR 1.37, 95% CI 1.11 to 1.70), as well as intra-arrest factors, such as shockable rhythm (OR 2.79, 95% CI 2.04 to 3.80), witnessed arrest (OR 1.68 (95% CI 1.16 to 2.42), bystander CPR (OR 1.55, 95% CI 1.19 to 2.01), return of spontaneous circulation (OR 2.81, 95% CI 2.19 to 3.61) and shorter time to cannulation (OR 1.14, 95% CI 1.17 to 1.69 per 10 minutes).

INTERPRETATION

The findings of this review confirm several clinical concepts wellestablished in the cardiac arrest literature and their applicability to the patient for whom ECPR is considered - that is, the impact of pre-existing patient factors, the benefit of timely and effective CPR, as well as the prognostic importance of minimizing low-flow time. We advocate for the thoughtful consideration of these prognostic factors as part of a risk stratification framework when evaluating a patient's potential candidacy for ECPR.

Out-of-hospital cardiac arrest treated with prehospital double sequential external defibrillation during eCPR in refractory VF - a case report

BACKGROUND

Double sequential external defibrillation (DSED) has demonstrated increased survival with good neurological outcome in a recent randomized controlled trial. DSED has not been studied in patients with extracorporeal cardiopulmonary resuscitation (eCPR).

CASE

We present the first case of prehospital eCPR with ongoing refractory ventricular fibrillation (VF), terminated by DSED. After six shocks, return of spontaneous circulation was initially achieved; however, the patient went into recurrent VF. ECPR was performed prehospital, with VF still refractory after three more shocks. DSED successfully terminated VF and showed a further increase in etCO2 and near-infrared spectroscopy cerebral oximetry values.

CONCLUSION

DSED can be a sufficient strategy for patients in refractory VF while on eCPR and should be evaluated in further studies.

Bayesian network predicted variables for good neurological outcomes in patients with out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is linked to a poor prognosis and remains a public health concern. Several studies have predicted good neurological outcomes of OHCA. In this study, we used the Bayesian network to identify variables closely associated with good neurological survival outcomes in patients with OHCA. This was a retrospective observational study using the Japan Association for Acute Medicine OHCA registry. Fifteen explanatory variables were used, and the outcome was one-month survival with Glasgow-Pittsburgh cerebral performance category (CPC) 1-2. The 2014-2018 dataset was used as training data. The variables selected were identified and a sensitivity analysis was performed. The 2019 dataset was used for the validation analysis. Four variables were identified, including the motor response component of the Glasgow Coma Scale (GCS M), initial rhythm, age, and absence of epinephrine. Estimated probabilities were increased in the following order: GCS M score: 2-6; epinephrine: non-administered; initial rhythm: spontaneous rhythm and shockable; and age: <58 and 59-70 years. The validation showed a sensitivity of 75.4% and a specificity of 95.4%. We identified GCS M score of 2-6, initial rhythm (spontaneous rhythm and shockable), younger age, and absence of epinephrine as variables associated with one-month survival with CPC 1-2. These variables may help clinicians in the decision-making process while treating patients with OHCA.

Prehospital predicting factors using a decision tree model for patients with witnessed out-of-hospital cardiac arrest and an initial shockable rhythm

The effect of prehospital factors on favorable neurological outcomes remains unclear in patients with witnessed out-of-hospital cardiac arrest (OHCA) and a shockable rhythm. We developed a decision tree model for these patients by using prehospital factors. Using a nationwide OHCA registry database between 2005 and 2020, we retrospectively analyzed a cohort of 1,930,273 patients, of whom 86,495 with witnessed OHCA and an initial shockable rhythm were included. The primary endpoint was defined as favorable neurological survival (cerebral performance category score of 1 or 2 at 1 month). A decision tree model was developed from randomly selected 77,845 patients (development cohort) and validated in 8650 patients (validation cohort). In the development cohort, the presence of prehospital return of spontaneous circulation was the best predictor of favorable neurological survival, followed by the absence of adrenaline administration and age. The patients were categorized into 9 groups with probabilities of favorable neurological survival ranging from 5.7 to 70.8% (areas under the receiver operating characteristic curve of 0.851 and 0.844 in the development and validation cohorts, respectively). Our model is potentially helpful in stratifying the probability of favorable neurological survival in patients with witnessed OHCA and an initial shockable rhythm.

Resuscitation of older adults in Norway; a comparison of survival and outcome after out-of-hospital cardiac arrest in healthcare institutions and at home

BACKGROUND

Perceptions about expected outcome after out-of-hospital cardiac arrest (OHCA) influence treatment decisions, and there is a need for updated evidence about outcomes for the elderly.

METHOD

We conducted a cross-sectional study of cases reported to the Norwegian Cardiac Arrest Registry from 2015 through 2021 of patients 60 years and older, suffering cardiac arrest in healthcare institutions or at home. We examined reasons for emergency medical service (EMS) withholding or withdrawing resuscitation. We compared survival and neurological outcome for EMS-treated patients and explored factors associated with survival using multivariate logistic regression.

RESULT

We included 12,191 cases and the EMS started resuscitation in 10,340 (85%). The incidence per capita of OHCA the EMS were alerted to was 267/100,000 in healthcare institutions and 134/100,000 at home. Resuscitation was most frequently withdrawn due to medical history (n = 1251). In healthcare institutions, 72 of 1503 (4.8%) patients survived to 30 days compared to 752 of 8837 (8.5%) at home (P <.001). We found survivors in all age cohorts both in healthcare institutions and at home, and most of the 824 survivors had a good neurological outcome with a Cerebral Performance Category ≤2 (88%).

CONCLUSION

Medical history was the most frequent reason for EMS not to start or continue resuscitation, indicating a need for a discussion about, and documentation of, advance directives in this age group. When EMS attempted resuscitation, most survivors had a good neurological outcome, both in healthcare institutions and at home.

Triglyceride-glucose index is associated with the occurrence and prognosis of cardiac arrest: a multicenter retrospective observational study

BACKGROUND

Triglyceride-glucose (TyG) index is an efficient indicator of insulin resistance and is proven to be a valuable marker in several cardiovascular diseases. However, the relationship between TyG index and cardiac arrest (CA) remains unclear. The present study aimed to investigate the association of the TyG index with the occurrence and clinical outcomes of CA.

METHODS

In this retrospective, multicenter, observational study, critically ill patients, including patients post-CA, were identified from the eICU Collaborative Research Database and evaluated. The TyG index for each patient was calculated using values of triglycerides and glucose recorded within 24 h of intensive care unit (ICU) admission. In-hospital mortality and ICU mortality were the primary clinical outcomes. Logistic regression, restricted cubic spline (RCS), and correlation analyses were performed to explore the relationship between the TyG index and clinical outcomes. Propensity score matching (PSM), overlap weighting (OW), and inverse probability of treatment weighting (IPTW) were adopted to balance the baseline characteristics of patients and minimize selection bias to confirm the robustness of the results. Subgroup analysis based on different modifiers was also performed.

RESULTS

Overall, 24,689 critically ill patients, including 1021 patients post-CA, were enrolled. The TyG index was significantly higher in patients post-CA than in those without CA (9.20 (8.72-9.69) vs. 8.89 (8.45-9.41)), and the TyG index had a moderate discrimination ability to identify patients with CA from the overall population (area under the curve = 0.625). Multivariate logistic regression indicated that the TyG index was an independent risk factor for in-hospital mortality (OR = 1.28, 95% CI: 1.03-1.58) and ICU mortality (OR = 1.27, 95% CI: 1.02-1.58) in patients post-CA. RCS curves revealed that an increased TyG index was linearly related to higher risks of in-hospital and ICU mortality (P for nonlinear: 0.225 and 0.271, respectively). Even after adjusting by PSM, IPTW, and OW, the TyG index remained a risk factor for in-hospital mortality and ICU mortality in patients experiencing CA, which was independent of age, BMI, sex, etc. Correlation analyses revealed that TyG index was negatively correlated with the neurological status of patients post-CA.

CONCLUSION

Elevated TyG index is significantly associated with the occurrence of CA and higher mortality risk in patients post-CA. Our findings extend the landscape of TyG index in cardiovascular diseases, which requires further prospective cohort study.

Developments in Post-Resuscitation Care for Out-of-Hospital Cardiac Arrests in Adults-A Narrative Review

This review focuses on current developments in post-resuscitation care for adults with an out-of-hospital cardiac arrest (OHCA). As the incidence of OHCA is high and with a low percentage of survival, it remains a challenge to treat those who survive the initial phase and regain spontaneous circulation. Early titration of oxygen in the out-of-hospital phase is not associated with increased survival and should be avoided. Once the patient is admitted, the oxygen fraction can be reduced. To maintain an adequate blood pressure and urine output, noradrenaline is the preferred agent over adrenaline. A higher blood pressure target is not associated with higher rates of good neurological survival. Early neuro-prognostication remains a challenge, and prognostication bundles should be used. Established bundles could be extended by novel biomarkers and methods in the upcoming years. Whole blood transcriptome analysis has shown to reliably predict neurological survival in two feasibility studies. This needs further investigation in larger cohorts.

A novel cardiac arrest severity score for the early prediction of hypoxic-ischemic brain injury and in-hospital death

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) outcomes are unsatisfactory despite postcardiac arrest care. Early prediction of prognoses might help stratify patients and provide tailored therapy. In this study, we derived and validated a novel scoring system to predict hypoxic-ischemic brain injury (HIBI) and in-hospital death (IHD).

METHODS

We retrospectively analyzed Korean Hypothermia Network prospective registry data collected from in Korea between 2015 and 2018. Patients without neuroprognostication data were excluded, and the remaining patients were randomly divided into derivation and validation cohorts. HIBI was defined when at least one prognostication predicted a poor outcome. IHD meant all deaths regardless of cause. In the derivation cohort, stepwise multivariate logistic regression was conducted for the HIBI and IHD scores, and model performance was assessed. We then classified the patients into four categories and analyzed the associations between the categories and cerebral performance categories (CPCs) at hospital discharge. Finally, we validated our models in an internal validation cohort.

RESULTS

Among 1373 patients, 240 were excluded, and 1133 were randomized into the derivation (n = 754) and validation cohorts (n = 379). In the derivation cohort, 7 and 8 predictors were selected for HIBI (0-8) and IHD scores (0-11), respectively, and the area under the curves (AUC) were 0.85 (95% CI 0.82-0.87) and 0.80 (95% CI 0.77-0.82), respectively. Applying optimum cutoff values of ≥6 points for HIBI and ≥7 points for IHD, the patients were classified as follows: HIBI (-)/IHD (-), Category 1 (n = 424); HIBI (-)/IHD (+), Category 2 (n = 100); HIBI (+)/IHD (-), Category 3 (n = 21); and HIBI (+)/IHD (+), Category 4 (n = 209). The CPCs at discharge were significantly different in each category (p < 0.001). In the validation cohort, the model showed moderate discrimination (AUC 0.83, 95% CI 0.79-0.87 for HIBI and AUC 0.77, 95% CI 0.72-0.81 for IHD) with good calibration. Each category of the validation cohort showed a significant difference in discharge outcomes (p < 0.001) and a similar trend to the derivation cohort.

CONCLUSIONS

We presented a novel approach for assessing illness severity after OHCA. Although external prospective studies are warranted, risk stratification for HIBI and IHD could help provide OHCA patients with appropriate treatment.

Wiederbelebungsmaßnahmen bei leblosen Pflegeheimbewohnern durchführen oder unterlassen?

Ziel der Arbeit Entscheidungen über Reanimationsversuche (RV) müssen die Chancen auf Überleben gegen die Aussichten auf zusätzliches Leid abwägen. Für Pflegeheimbewohner soll die Basis dieser Abwägung auf Grundlage der im Deutschen Reanimationsregister verfügbaren Endpunkte verbreitert werden.

Methodik Retrospektive Auswertung prähospitaler RV der Jahre 2012 bis 2019.

Ergebnisse Eingeschlossen wurden 2510 Datensätze. Das Durchschnittsalter betrug 83,7 (±7,5) Jahre, 1497 (59,6%) waren weiblich. Es erfolgten 98 (3,9%) Lebendentlassungen; davon 61 (2,4%) mit neurologisch gutem Outcome. Im Krankenhaus verstarben 791 (31,5%); 561 (22,4%) innerhalb 24 Stunden. Am Einsatzort verstarben 1621 (64,6%). Diese und weitere Endpunkte wurden stratifiziert als Spektrum dargestellt und Subgruppen nach Alter, Pre Emergency Status und Einsatzsituationen gebildet.

Schlussfolgerung Für die Entscheidungsfindung scheinen neben den prähospitalen Einsatzsituationen besonders Patientencharakteristika relevant zu sein.

Effect of video laryngoscopy for non-trauma out-of-hospital cardiac arrest on clinical outcome: A registry-based analysis

AIM

Videolaryngoscopy (VL) is a promising tool to provide a safe airway during cardiopulmonary resuscitation (CPR) and to ensure early reoxygenation. Using data from the German Resuscitation Registry, we investigated the outcome of non-traumatic out-of-hospital cardiac arrest (OHCA) patients treated with VL versus direct laryngoscopy (DL) for airway management.

METHODS

We analysed retrospective data of 14,387 patients from 1 January 2018 until 31 December 2021 (VL group, n = 2201; DL group, n = 12186). Primary endpoint was discharge with cerebral performance categories one and two (CPC1/2). Secondary endpoints were the rate of return of spontaneous circulation (ROSC), hospital admission, hospital admission with ongoing cardiopulmonary resuscitation, 30-day survival/ hospital discharge and airway management complications. We used multivariate binary logistic regression analysis to identify the effects on outcome of known influencing variables and of VL vs DL.

RESULTS

The multivariate regression model revealed that VL was an independent predictor of CPC1/2 survival (OR = 1.34, 95% CI = 1.12-1.61, p = 0.002) and of hospital discharge/30-day survival (OR = 1.26, 95% CI = 1.08-1.47, p = 0,004).

CONCLUSION

VL for endotracheal intubation (ETI) at OHCA was associated with better neurological outcome in patients with ROSC. Therefore, the use of VL for OHCA offers a promising perspective. Further prospective studies are required.

External validation of the TiPS65 score for predicting good neurological outcomes in patients with out-of-hospital cardiac arrest treated with extracorporeal cardiopulmonary resuscitation

AIM

Estimating prognosis of patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) is essential for selecting candidates. The TiPS65 score can predict neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) treated with ECPR. We aimed to perform an external validation of this score.

METHODS

Data from the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry, a multicentred, nationwide, prospectively registered database, were analysed. All adult patients with OHCA and shockable rhythm and treated with ECPR between January 2018 to December 2019 were included. In the TiPS65 score, age, call-to-hospital arrival time, initial cardiac rhythm at hospital arrival, and initial pH value were used as predictors. The primary outcome was 30-day survival with favourable neurological outcomes (Cerebral Performance Category 1 or 2). Discrimination, using the C-statistic, and predictive performances of each score, such as sensitivity and specificity, were investigated.

RESULTS

Of 590 included patients (517 [81.6%] men; median [interquartile range] age, 60 [50-69] years), 64 (10.8%) reported favourable neurological outcomes. The C-statistic of the TiPS65 score was 0.729 (95% confidence interval (CI): 0.672-0.786). When the cut-off of TiPS65 score was set to >1, the sensitivity and specificity were 0.906 (95%CI: 0.807-0.965) and 0.430 (95%CI: 0.387-0.473), respectively; conversely, when the cut-off was set to >3, they were 0.172 (95%CI: 0.089-0.287) and 0.971 (95%CI: 0.953-0.984), respectively.

CONCLUSIONS

The TiPS65 score shows reasonable discrimination and predictive performances. This score can be supportive in the decision-making process for the selection of eligible patients for ECPR in clinical settings.

Outcome differences between PARAMEDIC2 and the German Resuscitation Registry: a secondary analysis of a randomized controlled trial compared with registry data

BACKGROUND AND IMPORTANCE

There has been much discussion of the results of the PARAMEDIC2 trial, as resuscitation outcome rates are considerably lower in this trial than in country-level registries on out-of-hospital cardiac arrest (OHCA). Here, we developed a statistical framework to investigate this gap and to examine possible sources for observed discrepancies in outcome rates.

DESIGN

Summary data from the PARAMEDIC2 trial were used as available in the publication of this study. We developed a modelling framework based on logistic regression to compare data from this randomized controlled trial and registry data from the German Resuscitation Registry (GRR), where we considered 26 019 patients treated with epinephrine for OHCA in the GRR. To account and adjust for differences in patient characteristics and baseline variables predictive for outcomes after OHCA between the GRR cohort and the PARAMEDIC2 study sample, we included all available variables determined at the arrival of EMS personnel in the modelling framework: age, sex, initial cardiac rhythm, cause of cardiac arrest, witness of cardiac arrest, CPR performed by a bystander, and the interval between emergency call and arrival of the ambulance at the scene (baseline model). In order to find possible explanations for the discrepancies in outcome between PARAMEDIC2 and GRR, in a second (baseline plus treatment) model, we additionally included all available variables related to the interventions of the EMS personnel (type of airway management, type of vascular access, and time to administration of epinephrine).

MAIN RESULTS

A patient cohort with baseline variables as in the PARAMEDIC2 trial would have survived to hospital discharge in 7.7% and survived with favourable neurological outcome in 5.0% in an EMS and health care system as in Germany, compared with 3.2 and 2.2%, respectively, in the Epinephrine group of the trial. Adding treatment-related variables to our logistic regression model, the rate of survival to discharge would decrease from 7.7 (for baseline variables only) to 5.6% and the rate of survival with favourable neurological outcome from 5.0 to 3.4%.

CONCLUSION

Our framework helps in the medical interpretation of the PARAMEDIC2 trial and the transferability of the trial's results for other EMS systems. Significantly higher rates of survival and favourable neurological outcome than reported in this trial could be possible in other EMS and health care systems.

End-tidal carbon dioxide (ETCO2) at intubation and its increase after 10 minutes resuscitation predicts survival with good neurological outcome in out-of-hospital cardiac arrest patients

AIM

To evaluate whether end-tidal carbon dioxide (ETCO2) value at intubation and its early increase (10 min) after intubation predict both the survival to hospital admission and the survival at hospital discharge, including good neurological outcome (CPC 1-2), in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

All consecutive OHCA patients of any etiology between 2015 and 2018 in Pavia Province (Italy) and Ticino Region (Switzerland) were considered. Patients died before ambulance arrival, with a "do-not-resuscitate" order, without ETCO2 value or with incomplete data were excluded.

RESULTS

The study population consisted of 668 patients. An ETCO2 value at intubation > 20 mmHg and its increase 10 min after intubation were independent predictors (after correction for known predictors of OHCA outcome) of survival to hospital admission and survival at hospital discharge. Relative to hospital discharge with good neurological outcome, ETCO2 at intubation and its 10-min change were confirmed predictors both individually and in a bivariable analysis (OR 1.83, 95 %CI 1.02-3.3; p = 0.04 and OR 3.9, 95 %CI 1.97-7.74; p < 0.001, respectively). This was confirmed also when accounting for gender, age, etiology and location. After further adjustment for bystander and CPR status, presenting rhythm and EMS arrival time, the ETCO2 change remained an independent predictor.

CONCLUSIONS

ETCO2 value > 20 mmHg at intubation and its increase during resuscitation improve the prediction of survival at hospital discharge with good neurological outcome of OHCA patients. ETCO2 increase during resuscitation is a more powerful predictor than ETCO2 at intubation. A larger prospective study to confirm this finding appears warranted.

Scoring Systems to Predict Survival or Neurological Recovery after Out-of-hospital Cardiac Arrest

Numerous prediction scores have been developed to better inform clinical decision-making following out-of-hospital cardiac arrest (OHCA), however, there is no consensus among clinicians over which score to use. The aim of this review was to identify and compare scoring systems to predict survival and neurological recovery in patients with OHCA. A structured literature search of the MEDLINE database was carried out from inception to December 2021. Studies developing or validating scoring systems to predict outcome following OHCA were selected. Relevant data were extracted and synthesised for narrative review. In total, 16 scoring systems were identified: one predicting the probability of return of spontaneous circulation, six predicting survival to hospital discharge and nine predicting neurological outcome. NULL-PLEASE and CAST are recommended as the best scores to predict mortality and neurological outcome, respectively, due to the extent of external validation, ease of use and high predictive value of the variables. Whether use of these scores can lead to more cost-effective service delivery remains unclear.

Survival after traumatic cardiac arrest is possible—a comparison of German patient-registries

Background

Out-of-hospital cardiac arrest (OHCA) due to trauma is rare, and survival in this group is infrequent. Over the last decades, several new procedures have been implemented to increase survival, and a “Special circumstances chapter” was included in the European Resuscitation Council (ERC) guidelines in 2015. This article analysed outcomes after traumatic cardiac arrest in Germany using data from the German Resuscitation Registry (GRR) and the TraumaRegister DGU® (TR-DGU) of the German Trauma Society. 

Methods

In this study, data from patients with OHCA between 01.01.2014 and 31.12.2019 secondary to major trauma and where cardiopulmonary resuscitation (CPR) was started were eligible for inclusion. Endpoints were return of spontaneous circulation (ROSC), hospital admission with ROSC and survival to hospital discharge.

Results

1.049 patients were eligible for inclusion. ROSC was achieved in 28.7% of the patients, 240 patients (22.9%) were admitted to hospital with ROSC and 147 (14.0%) with ongoing CPR. 643 (67.8%) patients were declared dead on scene. Of all patients resuscitated after traumatic OHCA, 27.3% (259) died in hospital. The overall mortality was 95.0% and 5.0% survived to hospital discharge (47). In a multivariate logistic regression analysis; age, sex, injury severity score (ISS), head injury, found in cardiac arrest, shock on admission, blood transfusion, CPR in emergency room (ER), emergency surgery and initial electrocardiogram (ECG), were independent predictors of mortality.

Conclusion

Traumatic cardiac arrest was an infrequent event with low overall survival. The mortality has remained unchanged over the last decades in Germany. Additional efforts are necessary to identify reversible cardiac arrest causes and provide targeted trauma resuscitation on scene.

Trial registration

DRKS, DRKS-ID DRKS00027944. Retrospectively registered 03/02/2022.

External validation of the Survival After ROSC in Cardiac Arrest (SARICA) score for predicting survival after return of spontaneous circulation using multinational pan-asian cohorts

Aim

Accurate and timely prognostication of patients with out-of-hospital cardiac arrest (OHCA) who attain return of spontaneous circulation (ROSC) is crucial in clinical decision-making, resource allocation, and communication with family. A clinical decision tool, Survival After ROSC in Cardiac Arrest (SARICA), was recently developed, showing excellent performance on internal validation. We aimed to externally validate SARICA in multinational cohorts within the Pan-Asian Resuscitation Outcomes Study.

Materials and methods

This was an international, retrospective cohort study of patients who attained ROSC after OHCA in the Asia Pacific between January 2009 and August 2018. Pediatric (age <18 years) and traumatic arrests were excluded. The SARICA score was calculated for each patient. The primary outcome was survival. We used receiver operating characteristics (ROC) analysis to calculate the model performance of the SARICA score in predicting survival. A calibration belt plot was used to assess calibration.

Results

Out of 207,450 cases of OHCA, 24,897 cases from Taiwan, Japan and South Korea were eligible for inclusion. Of this validation cohort, 30.4% survived. The median SARICA score was 4. Area under the ROC curve (AUC) was 0.759 (95% confidence interval, CI 0.753–0.766) for the total population. A higher AUC was observed in subgroups that received bystander CPR (AUC 0.791, 95% CI 0.782–0.801) and of presumed cardiac etiology (AUC 0.790, 95% CI 0.782–0.797). The model was well-calibrated.

Conclusion

This external validation study of SARICA demonstrated high model performance in a multinational Pan-Asian cohort. Further modification and validation in other populations can be performed to assess its readiness for clinical translation.

A retrospective study of mortality for perioperative cardiac arrests toward a personalized treatment

Perioperative cardiac arrest (POCA) is associated with a high mortality rate. This work aimed to study its prognostic factors for risk mitigation by means of care management and planning. A database of 380,919 surgeries was reviewed, and 150 POCAs were curated. The main outcome was mortality prior to hospital discharge. Patient demographic, medical history, and clinical characteristics (anesthesia and surgery) were the main features. Six machine learning (ML) algorithms, including LR, SVC, RF, GBM, AdaBoost, and VotingClassifier, were explored. The last algorithm was an ensemble of the first five algorithms. k-fold cross-validation and bootstrapping minimized the prediction bias and variance, respectively. Explainers (SHAP and LIME) were used to interpret the predictions. The ensemble provided the most accurate and robust predictions (AUC = 0.90 [95% CI, 0.78-0.98]) across various age groups. The risk factors were identified by order of importance. Surprisingly, the comorbidity of hypertension was found to have a protective effect on survival, which was reported by a recent study for the first time to our knowledge. The validated ensemble classifier in aid of the explainers improved the predictive differentiation, thereby deepening our understanding of POCA prognostication. It offers a holistic model-based approach for personalized anesthesia and surgical treatment.

Mechanical chest compression devices under special circumstances

AIM

According to the current resuscitation guidelines, the use of mechanical chest compression devices could be considered under special circumstances like transport with ongoing resuscitation or long-term resuscitation. The aim of this study was to investigate whether survival is improved using mechanical devices under such circumstances.

METHODS

Out-of-hospital cardiac arrests from all high-quality data centres of the German Resuscitation Registry from 2007 to 2020 were investigated. The use of mechanical devices was compared separately for transport with ongoing resuscitation, prolonged resuscitation (>45 min), and resuscitation with fibrinolytic agents applied. Baseline characteristics, 30-day survival/discharged alive, and neurological function at discharge were analysed descriptively; and 30-day survival/discharged alive was additionally analysed using multivariate logistic regression.

RESULTS

Overall, patients who were treated with a mechanical device tended to be younger and were significantly more likely to have a witnessed cardiac arrest and a shockable initial rhythm. During the study period, 4,851 patients were transported to hospital with ongoing resuscitation (devices used in 44.2%). The 30-day survival was equal (odds ratio, OR: 1.13, 95%-CI: 0.79-1.60). In 3,920 cases, a resuscitation duration > 45 min was documented (9.5% with device). When a device was used, 30-day survival was significantly increased (OR 2.33, 95%-CI: 1.30-4.15). Fibrinolytic agents were used in 2,106 patients (22.2% with device). Here, 30-day survival was significantly worse with a device (OR: 0.52, 95%-CI: 0.30-0.91).

CONCLUSION

Mechanical devices are not associated with better survival when used during transport, but rescuer safety could still be an important argument for their use. Devices are associated with better survival in prolonged resuscitation, but worse survival when a fibrinolytic was used.

Higher chance of survival in patients with out-of-hospital cardiac arrest attributed to poisoning

AIM OF THE STUDY

Description and comparison of cohort characteristics and outcome of adult patients with out-of-hospital cardiac arrest (OHCA) attributed to poisoning (P-OHCA) versus patients with OHCA attributed to other medical causes (NP-OHCA).

METHODS

We included all patients who received cardiopulmonary resuscitation after OHCA between January 2011 and December 2020 from German emergency medical services with good data quality in the German Resuscitation Registry.

EXCLUSION CRITERIA

patients < 18 years of age or OHCA attributed to trauma, drowning, intracranial bleeding or exsanguination.

RESULTS

Patients with P-OHCA (n = 574) were significantly younger compared to NP-OHCA (n = 40,146) (median age of 43 (35-54) years vs. 73 (62-82) years; p < 0.001). Cardiac arrest in P-OHCA patients was significantly less often witnessed by bystanders (41.8 % vs. 66.2 %, p < 0.001). Asystole was the predominant initial rhythm in P-OHCA patients (73.5% vs. 53.7%, p < 0.001) while ventricular fibrillation (VF) and pulseless electrical activity (PEA) were less common (9.2% vs. 25.1% and 16.2 % vs. 20.5%, p < 0.001). P-OHCA had a higher chance of survival with good neurological outcome at hospital discharge (15.2 vs. 8.8 % p < 0.001) and poisoning was an independent protective prognostic factor in multivariate analysis (OR 2.47, 95%-CI [1.71-3.57]). P-OHCA patients with initial PEA survival with good neurological outcome was comparable to initial VF (34.3 % vs. 37.7%).

CONCLUSION

Patients in the P-OHCA group had a significantly higher chance of survival with good neurological outcome and PEA as initial rhythm was as favourable as initial VF. Therefore, in P-OHCA patients resuscitation efforts should be extended.

Importance of reporting survival as incidence: a cross-sectional comparative study on out-of-hospital cardiac arrest registry data from Germany and Norway

OBJECTIVES

Health registries are a unique source of information about current practice and can describe disease burden in a population. We aimed to understand similarities and differences in the German Resuscitation Registry (GRR) and the Norwegian Cardiac Arrest Registry (NorCAR) and compare incidence and survival for patients resuscitated after out-of-hospital cardiac arrest.

DESIGN

A cross-sectional comparative analysis reporting incidence and outcome on a population level.

SETTING

We included data from the cardiac arrest registries in Germany and Norway.

PARTICIPANTS

Patients resuscitated between 1 January 2015 and 31 December 2019 were included, resulting in 29 222 cases from GRR and 16 406 cases from NorCAR. From GRR, only emergency medical services (EMS) reporting survival information for patients admitted to the hospital were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

This study focused on the EMS systems, the registries and the patients included in both registries. The results compare the total incidence, incidence of patients resuscitated by EMS, and the incidence of survival.

RESULTS

We found an incidence of 68 per 100 000 inhabitants in GRR and 63 in NorCAR. The incidence of patients treated by EMS was 67 in GRR and 53 in NorCAR. The incidence of patients arriving at a hospital was higher in GRR (24.3) than in NorCAR (15.1), but survival was similar (8 in GRR and 7.8 in NorCAR).

CONCLUSION

GRR is a voluntary registry, and in-hospital information is not reported for all cases. NorCAR has mandatory reporting from all EMS and hospitals. EMS in Germany starts treatment on more patients and bring a higher number to hospital, but we found no difference in the incidence of survival. This study has improved our knowledge of both registries and highlighted the importance of reporting survival as incidence when comparing registries.

Initial Blood pH, Lactate and Base Deficit Add No Value to Peri-Arrest Factors in Prognostication of Neurological Outcome After Out-of-Hospital Cardiac Arrest

Background: In cardiac arrest survivors, metabolic parameters [pH value, lactate concentration, and base deficit (BD)] are routinely added to peri-arrest factors (including age, sex, bystander cardiopulmonary resuscitation, shockable first rhythm, resuscitation duration, adrenaline dose) to enhance early outcome prediction. However, the additional value of this strategy remains unclear.

Methods: We used our resuscitation database to screen all patients ≥18 years who had suffered in- or out-of-hospital cardiac arrest (IHCA, OHCA) between January 1st, 2005 and May 1st, 2019. Patients with incomplete data, without return of spontaneous circulation or treatment with sodium bicarbonate were excluded. To analyse the added value of metabolic parameters to prognosticate neurological function, we built three models using logistic regression. These models included: (1) Peri-arrest factors only, (2) peri-arrest factors plus metabolic parameters and (3) metabolic parameters only. Receiver operating characteristics curves regarding 30-day good neurological function (Cerebral Performance Category 1-2) were analysed.

Results: A total of 2,317 patients (OHCA: n = 1842) were included. In patients with OHCA, model 1 and 2 had comparable predictive value. Model 3 was inferior compared to model 1. In IHCA patients, model 2 performed best, whereas both metabolic (model 3) and peri-arrest factors (model 1) demonstrated similar power. PH, lactate and BD had interchangeable areas under the curve in both IHCA and OHCA.

Conclusion: Although metabolic parameters may play a role in IHCA, no additional value in the prediction of good neurological outcome could be found in patients with OHCA. This highlights the importance of accurate anamnesis especially in patients with OHCA.

Predicting Survived Events in Nontraumatic Out-of-Hospital Cardiac Arrest: A Comparison Study on Machine Learning and Regression Models

BACKGROUND

Prediction of early outcomes of nontraumatic out-of-hospital cardiac arrest (OHCA) by emergency physicians is inaccurate.

OBJECTIVE

Our aim was to develop and validate practical machine learning (ML)-based models to predict early outcomes of nontraumatic OHCA for use in the emergency department (ED). We compared their discrimination and calibration performances with the traditional logistic regression (LR) approach.

METHODS

Between October 1, 2017 and March 31, 2020, prehospital resuscitation was performed on 17,166 OHCA patients. There were 8157 patients 18 years or older with nontraumatic OHCA who received continued resuscitation in the ED included for analysis. Eleven demographic and resuscitation predictor variables were extracted to predict survived events, defined as any sustained return of spontaneous circulation until in-hospital transfer of care. Prediction models based on random forest (RF), multilayer perceptron (MLP), and LR were created with hyperparameter optimization. Model performances on internal and external validation were compared using discrimination and calibration statistics.

RESULTS

The three models showed similar discrimination performances with c-statistics values of 0.712 (95% confidence interval [CI] 0.711-0.713) for LR, 0.714 (95% CI 0.712-0.717) for RF, and 0.712 (95% CI 0.710-0.713) for MLP models on external validation. For calibration, MLP model had a better performance (slope of calibration regression line = 1.10, intercept = -0.09) than LR (slope = 1.17, intercept = -0.11) and RF (slope = 1.16, intercept= -0.10).

CONCLUSIONS

Two practical ML-based and one regression-based clinical prediction models of nontraumatic OHCA for survived events were developed and validated. The ML-based models did not outperform LR in discrimination, but the MLP model showed a better calibration performance.

Neurologisches Ergebnis und allgemeiner Gesundheitszustand bei Langzeitüberleben nach außerklinischer kardiopulmonaler Reanimation

Fragestellung

Für Deutschland liegen nur wenige Daten zum Gesundheitszustand und Langzeitüberleben nach außerklinischer Reanimation vor. Die vorliegende Studie untersucht den allgemeinen Gesundheitszustand und das neurologische Langzeitergebnis 2,5 bis 5 Jahre nach dem Reanimationsereignis sowie den Zusammenhang zwischen Behandlungsergebnis und präklinischen Patienten- und Behandlungsfaktoren.

Methodik

Alle über einen Zeitraum von 30 Monaten (2011–2013) durch den Rettungsdienst der Stadt Bonn durchgeführten Reanimationen wurden auf Grundlage der Notarzteinsatzprotokolle und des Deutschen Reanimationsregisters retrospektiv analysiert. Der allgemeine Gesundheitszustand wurde in Anlehnung an den SF-12 erfasst und das neurologische Langzeitergebnis kategorisiert (Cerebral Performance Category [CPC]). Die vorliegenden Daten wurden einer uni- und multivariaten logistischen Regressionsanalyse unterzogen.

Ergebnis

Von insgesamt 458 Patienten überlebten 17,9 % bis zur Krankenhausentlassung, 13,8 % mehr als 2,5 Jahre und 7,7 % bis zum Stichtag der Befragung. Von den noch lebenden Patienten hatten 85,3 % ein gutes neurologisches Ergebnis (CPC ≤ 2), welches durch ein geringeres Alter, einen beobachteten Kollaps, die Durchführung einer Defibrillation und das Ausbleiben einer Vasopressorgabe begünstigt wurde (multivariate Analyse). 74,2 % der Überlebenden beschrieben ihren Gesundheitszustand als gut.

Interpretation

Insgesamt überleben langfristig nur wenige Patienten einen außerklinischen Herz-Kreislauf-Stillstand. Die überlebenden Patienten beurteilen ihren Gesundheitszustand als gut und zeigen ein gutes neurologisches Ergebnis. Dabei hängt dieses Behandlungsergebnis von denselben Parametern wie der primäre Reanimationserfolg (Überleben bis Krankenhausaufnahme) ab. Die Etablierung klinischer Instrumente zur frühen Prognoseerstellung ist wünschenswert. Hierzu sind weitere Langzeituntersuchungen größerer Patientenkollektive mit Zugriff auf Routinedaten notwendig.

Survival Following Lay Resuscitation

BACKGROUND

Resuscitation by laypersons is important in bridging the time between the occurrence of an out-of-hospital cardiac arrest (OHCA) and the arrival of emergency rescue service personnel. Depending on the reason for the cardiac arrest, however, the effectiveness of chest compressions is uncertain. The aim of this study was to explore the impact of lay resuscitation on survival following OHCA of different causes.

METHODS

The data set for analysis comprised all cases of cardiac arrest before the arrival of emergency rescue service personnel that were fully documented in the German Resuscitation Registry in the period 2007-2019. The following endpoints related to resuscitation by bystanders were evaluated-separately for each cause-descriptively and by means of multivariate logistic regression analysis: return of spontaneous circulation (ROSC), 30 days' survival/discharged alive from the hospital, and good neurological function at discharge.

RESULTS

Altogether, 40 604 cases of cardiac arrest were included. Resuscitation by laypersons was carried out in 35.1% of these cases. The rate of ROSC was statistically significantly higher after lay resuscitation for OHCA caused by cardiac events, drowning, intoxication, or central nervous system disorders (overall 48.1% versus 41.0%). For all causes-with the exception of trauma/bleeding to death and sepsis- the endpoint 30 days' survival/discharged alive was better with lay resuscitation (overall 17.0% versus 9.5%). In multivariate regression analysis, lay resuscitation was associated with improvement of the endpoint 30 days' survival/discharged alive only for OHCA caused by cardiac events (odds ratio [OR] 1.16) or intoxication (OR 1.81). For all other causes-except hypoxia-lay resuscitation tended to yield better results. Neurological function at discharge was also significantly better (overall 11.5% versus 6.1%) after lay resuscitation for OHCA of all causes except trauma/ bleeding to death, hypoxia, and sepsis.

CONCLUSION

Resuscitation by laypersons is associated with an improved result regarding the endpoint 30 days' survival/discharged alive in cases of OHCA caused by cardiac events and intoxication. These two groups account for 81% of the resuscitation patients in the study. Because there was also a tendency towards higher survival rates following OHCA of other causes (except hypoxia), laypersons should continue to be encouraged to attempt resuscitation in all cases of OHCA, whatever the cause.

Differences between manual CPR and corpuls cpr in regard to quality and outcome: study protocol of the comparing observational multi-center prospective registry study on resuscitation (COMPRESS)

Background

The effect of mechanical CPR is diversely described in the literature. Different mechanical CPR devices are available. The corpuls cpr is a new generation of piston-driven devices and was launched in 2015. The COMPRESS-trial analyzes quality of chest compression and CPR-related injuries in cases of mechanical CPR by the corpuls cpr and manual CPR.

Methods

This article describes the design and study protocol of the COMPRESS-trial. This observational multi-center study includes all patients who suffered an out-of-hospital cardiac arrest (OHCA) where CPR is attempted in four German emergency medical systems (EMS) between January 2020 and December 2022. EMS treatment, in-hospital-treatment and outcome are anonymously reported to the German Resuscitation Registry (GRR). This information is linked with data from the defibrillator, the feedback system and the mechanical CPR device for a complete dataset.

Primary endpoint is chest compression quality (complete release, compression rate, compression depth, chest compression fraction, CPR-related injuries). Secondary endpoint is survival (return of spontaneous circulation (ROSC), admission to hospital and survival to hospital discharge). The trial is sponsored by GS Elektromedizinische Geräte G. Stemple GmbH.

Discussion

This observational multi-center study will contribute to the evaluation of mechanical chest compression devices and to the efficacy and safety of the corpuls cpr.

Trial registration

DRKS, DRKS-ID DRKS00020819. Registered 31 July 2020.

Opportunities and Risks of Resuscitation Attempts in Nursing Homes

BACKGROUND

Data supporting decision-making regarding cardiopulmonary resuscitation (CPR) in German nursing homes is insufficient.

METHODS

A retrospective evaluation of pre-hospital CPR was carried out with data from the German Resuscitation Registry (Deutsches Reanimationsregister) for the years 2011-2018. Patients under age 65 were excluded, as were patients from districts in which long-term data was available for less than 60% of patients. Subgroups were analyzed based on age and certain prehospital situations; patients treated outside nursing homes were used for comparison.

RESULTS

The study group consisted of 2900 patients, whose mean age was 83.7 years (standard deviation, 7.5 years). 1766 (60.9%) were women and 1134 (39.1%) were men. 118 patients (4.0%) were discharged alive, including 64 (2.2%) with a cerebral performance category (CPC) of 1 or 2, 30 (1.0%) with an unknown CPC, and 24 (0.8%) with a CPC of 3 or 4. 902 patients (31.1%) died in the hospital, including five (0.2%) who died more than 30 days after resuscitation, 279 (9.6%) between 24 hours and 30 days, and 618 (21.3%) within 24 hours. 1880 patients (64.8%) died at the site of attempted resuscitation. In 1056 cases (36.4%), CPR was initiated before the arrival of the emergency medical services. In the "initially shockable" subgroup, 13 of 208 patients (6.3%) were discharged alive with a CPC of 1 or 2.

CONCLUSION

CPR can lead to a good neurological outcome in rare cases even when carried out in a nursing home. The large percentage of CPR attempts that were initiated only after a delay indicates that nursing home staff may often be uncertain how to proceed. Uncertainty among caregivers points to a potential for advance care planning.

Evaluation of prognostic prediction models for out-of-hospital cardiac arrest

Introduction:

Accurate prognostic prediction of out-of-hospital cardiac arrest is challenging but important for the emergency team and patient’s family members. A number of prognostic prediction models specifically designed for out-of-hospital cardiac arrest are developed and validated worldwide.

Objective:

This narrative review provides an overview of the prognostic prediction models out-of-hospital cardiac arrest patients for use in the emergency department.

Discussion:

Out-of-hospital cardiac arrest prognostic prediction models are potentially useful in clinical, administrative and research settings. Development and validation of such models require prehospital and hospital predictor and outcome variables which are best in the standardised Utstein Style. Logistic regression analysis is traditionally employed for model development but machine learning is emerging as the new tool. Examples of such models available for use in the emergency department include ROSC After Cardiac Arrest, CaRdiac Arrest Survival Score, Utstein-Based Return of Spontaneous Circulation, Out-of-Hospital Cardiac Arrest, Cardiac Arrest Hospital Prognosis and Cardiac Arrest Survival Score. The usefulness of these models awaits future studies.

Treatment of out-of-hospital cardiac arrest in the COVID-19 era: A 100 days experience from the Lombardy region

INTRODUCTION

An increase in the incidence of OHCA during the COVID-19 pandemic has been recently demonstrated. However, there are no data about how the COVID-19 epidemic influenced the treatment of OHCA victims.

METHODS

We performed an analysis of the Lombardia Cardiac Arrest Registry comparing all the OHCAs occurred in the Provinces of Lodi, Cremona, Pavia and Mantua (northern Italy) in the first 100 days of the epidemic with those occurred in the same period in 2019.

RESULTS

The OHCAs occurred were 694 in 2020 and 520 in 2019. Bystander cardiopulmonary resuscitation (CPR) rate was lower in 2020 (20% vs 31%, p<0.001), whilst the rate of bystander automated external defibrillator (AED) use was similar (2% vs 4%, p = 0.11). Resuscitation was attempted by EMS in 64.5% of patients in 2020 and in 72% in 2019, whereof 45% in 2020 and 64% in 2019 received ALS. At univariable analysis, the presence of suspected/confirmed COVID-19 was not a predictor of resuscitation attempt. Age, unwitnessed status, non-shockable presenting rhythm, absence of bystander CPR and EMS arrival time were independent predictors of ALS attempt. No difference regarding resuscitation duration, epinephrine and amiodarone administration, and mechanical compression device use were highlighted. The return of spontaneous circulation (ROSC) rate at hospital admission was lower in the general population in 2020 [11% vs 20%, p = 0.001], but was similar in patients with ALS initiated [19% vs 26%, p = 0.15]. Suspected/confirmed COVID-19 was not a predictor of ROSC at hospital admission.

CONCLUSION

Compared to 2019, during the 2020 COVID-19 outbreak we observed a lower attitude of laypeople to start CPR, while resuscitation attempts by BLS and ALS staff were not influenced by suspected/confirmed infection, even at univariable analysis.

Early risk stratification after resuscitation from cardiac arrest

Emergency clinicians often resuscitate cardiac arrest patients, and after acute resuscitation, clinicians face multiple decisions regarding disposition. Recent evidence suggests that out-of-hospital cardiac arrest patients with return of spontaneous circulation have higher odds of survival to hospital discharge, long-term survival, and improved functional outcomes when treated at centers that can provide advanced multidisciplinary care. For community clinicians, a high volume cardiac arrest center may be hours away. While current guidelines recommend against neurological prognostication in the first hours or days after return of spontaneous circulation, there are early findings suggestive of irrecoverable brain injury in which the patient would receive no benefit from transfer. In this Concepts article, we describe a simplified approach to quickly evaluate neurological status in cardiac arrest patients and identify findings concerning for irrecoverable brain injury. Characteristics of the arrest and resuscitation, initial neurological assessment, and brain computed tomography together can identify patients with high likelihood of irrecoverable anoxic injury. Patients who may benefit from centers with access to continuous electroencephalography are discussed. This approach can be used to identify patients who may benefit from rapid transfer to cardiac arrest centers versus those who may benefit from care close to home. Risk stratification also can provide realistic expectations for recovery to families.

Ultrasound-Guided Chest Compressions in Out-of-Hospital Cardiac Arrests

BACKGROUND

There is a significant variability in survival rates for cardiopulmonary resuscitation (CPR) in out of-hospital cardiac arrest (OHCA), and some data indicate that ultrasound improves CPR.

OBJECTIVES

We evaluated the feasibility of ultrasound for monitoring chest compressions in OHCA.

METHODS

We planned a prospective study in patients with an ultrasound-integrated CPR for OHCA. Chest compressions were performed on the intermammillary line (IML), but the position was changed according to the quality of the heart squeezing, evaluated by ultrasound. End-tidal carbon dioxide (ETCO₂) was used as the control parameter. Then we compared the area with the highest squeezing with the position of the heart in the chest computed tomography (CT) scans of 20 hospitalized patients.

RESULTS

Chest compressions were good, partial, and inadequate on the IML in 58.4%, 48.9%, and 2.8% of cases, respectively. These percentages were 75%, 25%, and 0% after these modifications: none (47.2%), increased depth (8.3%), hands moved on the lower third of the sternum (27.8%), on left parasternal line of the lower part of the sternum (13.9%), and on the center of the sternum (1 case). Accordingly, ETCO₂ improved significantly (20.37 vs. 37.10, p < 0.0001). The CT scans showed that the larger biventricular area (BVA) was under the parasternal line of the lower third of the sternum, and the mean distance IML-BVA was 5.7 cm.

CONCLUSIONS

Our study has demonstrated that CPR in OHCA can be improved using ultrasound and changing the position of the hands. This finding was connected with the ETCO₂ and confirmed by chest CT scans.

Clinical Predictive Models of Sudden Cardiac Arrest: A Survey of the Current Science and Analysis of Model Performances

Background

More than 500 000 sudden cardiac arrests (SCAs) occur annually in the United States. Clinical predictive models (CPMs) may be helpful tools to differentiate between patients who are likely to survive or have good neurologic recovery and those who are not. However, which CPMs are most reliable for discriminating between outcomes in SCA is not known.

Methods and Results

We performed a systematic review of the literature using the Tufts PACE (Predictive Analytics and Comparative Effectiveness) CPM Registry through February 1, 2020, and identified 81 unique CPMs of SCA and 62 subsequent external validation studies. Initial cardiac rhythm, age, and duration of cardiopulmonary resuscitation were the 3 most commonly used predictive variables. Only 33 of the 81 novel SCA CPMs (41%) were validated at least once. Of 81 novel SCA CPMs, 56 (69%) and 61 of 62 validation studies (98%) reported discrimination, with median c‐statistics of 0.84 and 0.81, respectively. Calibration was reported in only 29 of 62 validation studies (41.9%). For those novel models that both reported discrimination and were validated (26 models), the median percentage change in discrimination was −1.6%. We identified 3 CPMs that had undergone at least 3 external validation studies: the out‐of‐hospital cardiac arrest score (9 validations; median c‐statistic, 0.79), the cardiac arrest hospital prognosis score (6 validations; median c‐statistic, 0.83), and the good outcome following attempted resuscitation score (6 validations; median c‐statistic, 0.76).

Conclusions

Although only a small number of SCA CPMs have been rigorously validated, the ones that have been demonstrate good discrimination.

A proposal for selective resuscitation of adult cardiac arrest patients in a pandemic

Allocation of limited resources in pandemics begs for ethical guidance. The issue of ventilator allocation in pandemics has been reviewed by many medical ethicists, but as localities activate crisis standards of care, and health care workers are infected from patient exposure, the decision to pursue cardiopulmonary resuscitation (CPR) must also be examined to better balance the increased risks to healthcare personnel with the very low resuscitation rates of patients infected with coronavirus disease 2019 (COVID-19). A crisis standard of care that is equitable, transparent, and mindful of both human and physical resources will lessen the impact on society in this era of COVID-19. This paper builds on previous work of ventilator allocation in pandemic crises to propose a literature-based, justice-informed ethical framework for selecting treatment options for CPR. The pandemic affects regions differently over time, so these suggested guidelines may require adaptation to local practice variations.

Development a clinical prediction model of the neurological outcome for patients with coma and survived 24 hours after cardiopulmonary resuscitation

Background

Cardiac arrest is still a global public health problem at present. The neurological outcome is the core indicator of the prognosis of cardiac arrest. However, there is no effective means or tools to predict the neurological outcome of patients with coma and survived 24 hours after successful cardiopulmonary resuscitation (CPR).

Hypothesis

Therefore, we expect to construct a prediction model to predict the neurological outcome for patients with coma and survived 24 hours after successful CPR.

Methods

A retrospective cohort study was used to construct a prediction model of the neurological function for patients with coma and survived 24 hours after successful CPR. From January 2007 to December 2015, a total of 262 patients met the inclusion and exclusion criteria.

Results

The predictive model was developed using preselected variables by a systematic review of the literature. Finally, we get five sets of models (three sets of construction models and two sets of internal verification models) which with similar predictive value. The stepwise model, which including seven variables (age, noncardiac etiology, nonshockable rhythm, bystander CPR, total epinephrine dose, APTT, and SOFA score), was the simplest model, so we choose it as our final predictive model. The area under the ROC curve (AUC), specificity, and sensitivity of the stepwise model were respectively 0.82 (0.77, 0.87), 0.72and 0.82. The AUC, specificity, and sensitivity of the bootstrap stepwise (BS stepwise) model were respectively 0.82 (0.77, 0.87), 0.71, and 0.82.

Conclusion

This new and validated predictive model may provide individualized estimates of neurological function for patients with coma and survived 24 hours after successful CPR using readily obtained clinical risk factors. External validation studies are required further to demonstrate the model's accuracy in diverse patient populations.