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.

Acute lung injury and recovery in patients with refractory VT/VF cardiac arrest treated with prolonged CPR and veno-arterial extracorporeal membrane oxygenation

AIM

Describe the lung injury patterns among patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest (VT/VF OHCA) supported with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) facilitated resuscitation.

METHODS

In this retrospective single-center cohort study including VT/VF OHCA patients supported with VA ECMO, we compared OHCA characteristics, post-arrest computed tomography (CT) scans, ventilator parameters, and other lung-related pathology between survivors, patients who developed brain death, and those with other causes of death.

RESULTS

Among 138 patients, 48/138 (34.8%) survived, 31/138 (22.4%) developed brain death, and 59/138 (42.7%) died of other causes. Successful extubation was achieved in 39/138 (28%) with a median time to extubation of 8.0 days (6.0, 11.0) in those who survived. Tracheostomy was required in 15/48 (31.3%) survivors. Chest CT obtained on all patients showed lung injury in at least one lung area in 124/135 (91.8%) patients, predominantly in the dependent posterior areas. There was no association between the number of affected areas and survival. Lung compliance was low on admission [26 (19,33) ml/cmH₂0], improved throughout hospitalization (p = 0.03), and recovered faster in survivors compared to those who died (p < 0.001). VA-ECMO allowed the use of lung-protective ventilation while maintaining normalized PaO₂ and PaCO₂. Patients treated with V-A ECMO and either IABP or Impella had lower pulmonary compliance and more affected areas on their CT compared to those treated with V-A ECMO alone.

CONCLUSIONS

Lung injury is common among patients with refractory VT/VF OHCA requiring V-A ECMO, but imaging severity is not associated with survival. Reductions in lung compliance accompany post-arrest lung injury while compliance recovery is associated with survival.

Extracorporeal cardiopulmonary resuscitation (eCPR) and cerebral perfusion: A narrative review

Extracorporeal cardiopulmonary resuscitation (eCPR) is emerging as an effective, lifesaving resuscitation strategy for select patients with prolonged or refractory cardiac arrest. Currently, a paucity of evidence-based recommendations is available to guide clinical management of eCPR patients. Despite promising results from initial clinical trials, neurological injury remains a significant cause of morbidity and mortality. Neuropathology associated with utilization of an extracorporeal circuit may interact significantly with the consequences of a prolonged low-flow state that typically precedes eCPR. In this narrative review, we explore current gaps in knowledge about cerebral perfusion over the course of cardiac arrest and resuscitation with a focus on patients treated with eCPR. We found no studies which investigated regional cerebral blood flow or cerebral autoregulation in human cohorts specific to eCPR. Studies which assessed cerebral perfusion in clinical eCPR were small and limited to near-infrared spectroscopy. Furthermore, no studies prospectively or retrospectively evaluated the relationship between epinephrine and neurological outcomes in eCPR patients. In summary, the field currently lacks a comprehensive understanding of how regional cerebral perfusion and cerebral autoregulation are temporally modified by factors such as pre-eCPR low-flow duration, vasopressors, and circuit flow rate. Elucidating these critical relationships may inform future strategies aimed at improving neurological outcomes in patients treated with lifesaving eCPR.

The neuro-prognostic value of the ion shift index in cardiac arrest patients following extracorporeal cardiopulmonary resuscitation

BACKGROUND

The ion shift index (ISI) as a prognostic indicator that can show the severity of hypoxic-ischemic injury. We aimed to evaluate the performance of the ISI in predicting unfavorable neurological outcomes at hospital discharge in cardiac arrest (CA) patients following extracorporeal cardiopulmonary resuscitation (ECPR) and to compare its performance to other prognostic predictors.

METHODS

This was a retrospective observational study including adult CA patients treated with ECPR between January 2018 and December 2022 in a tertiary hospital. Data regarding clinical characteristics and laboratory parameters were collected from medical records. The ISI was determined based on the first available serum electrolyte levels after ECPR. The primary outcome was unfavorable neurological status at hospital discharge, defined as Cerebral Performance Categories 3-5. Comparisons of the characteristics between the two groups were made using the χ2 test for categorical variables and the t-test or non-parametric Mann-Whitney U-test for continuous variables, as appropriate. Correlation analysis was performed using Spearman's rank correlation coefficient. A two-tailed P-value <0.05 was considered statistically significant.

RESULTS

Among the 122 patients involved, 46 (37.7%) had out-of-hospital CA, and 88 had unfavorable neurological outcomes. The ISI was significantly higher in the unfavorable outcome group than in the favorable outcome group (3.74 [3.15-4.57] vs. 2.69 [2.51-3.07], P<0.001). A higher ISI level was independently related to unfavorable outcome (odds ratio=6.529, 95% confidence interval 2.239-19.044, P=0.001). An ISI level >3.12 predicted unfavorable outcomes with a sensitivity and specificity of 74.6% and 85.2%, respectively (P<0.001). The prognostic performance of ISI (area under the curve [AUC]=0.887) was similar to that of other predictors, such as gray-to-white matter ratio (AUC=0.850, P=0.433) and neuron-specific enolase (AUC=0.925, P=0.394).

CONCLUSION

ISI may be used as a prognostic biomarker to predict neurological outcomes in CA patients following ECPR.

Improving access to extracorporeal membrane oxygenation for out of hospital cardiac arrest: pre-hospital ECPR and alternate delivery strategies

BACKGROUND

The use of extracorporeal membrane oxygenation (ECPR) in refractory out-of-hospital cardiac arrest (OHCA) patients is usually implemented in-hospital. As survival in ECPR patients is critically time-dependent, alternative models in ECPR delivery could improve equity of access.

OBJECTIVES

To identify the best strategy of ECPR delivery to provide optimal patient access, to examine the time-sensitivity of ECPR on predicted survival and to model potential survival benefits from different delivery strategies of ECPR.

METHODS

We used transport accessibility frameworks supported by comprehensive travel time data, population density data and empirical cardiac arrest time points to quantify the patient catchment areas of the existing in-hospital ECPR service and two alternative ECPR strategies: rendezvous strategy and pre-hospital ECPR in Sydney, Australia. Published survival rates at different time points to ECMO flow were applied to predict the potential survival benefit.

RESULTS

With an in-hospital ECPR strategy for refractory OHCA, five hospitals in Sydney (Australia) had an effective catchment of 811,091 potential patients. This increases to 2,175,096 under a rendezvous strategy and 3,851,727 under the optimal pre-hospital strategy. Assuming earlier provision of ECMO flow, expected survival for eligible arrests will increase by nearly 6% with the rendezvous strategy and approximately 26% with pre-hospital ECPR when compared to the existing in-hospital strategy.

CONCLUSION

In-hospital ECPR provides the least equitable access to ECPR. Rendezvous and pre-hospital ECPR models substantially increased the catchment of eligible OHCA patients. Traffic and spatial modelling may provide a mechanism to design appropriate ECPR service delivery strategies and should be tested through clinical trials.

Characteristics of pediatric non-cardiac eCPR programs in United States and Canadian hospitals: A cross-sectional survey

OBJECTIVE

To characterize practices surrounding pediatric eCPR in the U.S. and Canada.

METHODS

Cross-sectional survey of U.S. and Canadian hospitals with non-cardiac eCPR programs. Variables included hospital and surgical group demographics, eCPR inclusion/exclusion criteria, cannulation approaches, and outcomes (survival to decannulation and survival to discharge).

RESULTS

Surveys were completed by 40 hospitals in the United States (37) and Canada (3) among an estimated 49 programs (82% response rate). Respondents tended to work in >200 bed free-standing children's hospitals (27, 68%). Pediatric general surgeons respond to activations in 32 (80%) cases, with a median group size of 7 (IQR 5,9.5); 8 (20%) responding institutions take in-house call and 63% have a formal back-up system for eCPR. Dedicated simulation programs were reported by 22 (55%) respondents. Annual eCPR activations average approximately 6/year; approximately 39% of patients survived to decannulation, with 35% surviving to discharge. Cannulations occurred in a variety of settings and were mostly done through the neck at the purview of cannulating surgeon/proceduralist. Exclusion criteria used by hospitals included pre-hospital arrest (21, 53%), COVID+ (5, 13%), prolonged CPR (18, 45%), lethal chromosomal anomalies (15, 38%) and terminal underlying disease (14, 35%).

CONCLUSIONS

While there are some similarities regarding inclusion/exclusion criteria, cannulation location and modality and follow-up in pediatric eCPR, these are not standard across multiple institutions. Survival to discharge after eCPR is modest but data on cost and long-term neurologic sequela are lacking. Codification of indications and surgical approaches may help clarify the utility and success of eCPR.

Knowledge gaps and research priorities in adult veno-arterial extracorporeal membrane oxygenation: a scoping review

PURPOSE

This scoping review aims to identify and describe knowledge gaps and research priorities in veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

An expert panel was recruited consisting of eight international experts from different backgrounds. First, a list of priority topics was made. Second, the panel developed structured questions using population, intervention, comparison and outcomes (PICO) format. All PICOs were scored and prioritized. For every selected PICO, a structured literature search was performed.

RESULTS

After an initial list of 49 topics, eight were scored as high-priority. For most of these selected topics, current literature is limited to observational studies, mainly consisting of retrospective cohorts. Only for ECPR and anticoagulation, randomized controlled trials (RCTs) have been performed or are ongoing. Per topic, a summary of the literature is stated including recommendations for further research.

CONCLUSIONS

This scoping review identifies and presents an overview of knowledge gaps and research priorities in VA-ECMO. Current literature is mostly limited to observational studies, although with increasing attention for this patient population, more RCTs are finishing or ongoing. Translational research, from preclinical trials to high-quality or randomized controlled trials, is important to improve the standard practices in this critically ill patient population. Take-home message This scoping review identifies and presents an overview of research gaps and priorities in VA-ECMO. Translational research, from preclinical trials to high-quality or randomized controlled trials, is important to improve the standard practices in this critically ill patient population.

Eligibility of out-of-hospital cardiac arrest patients for extracorporeal cardiopulmonary resuscitation in the United States: A geographic information system model

BACKGROUND

Recent evidence suggest that extracorporeal cardiopulmonary resuscitation (ECPR) may improve survival rates for nontraumatic out-of-hospital cardiac arrest (OHCA). Eligibility criteria for ECPR are often based on patient age, clinical variables, and facility capabilities. Expanding access to ECPR across the U.S. requires a better understanding of how these factors interact with transport time to ECPR centers.

METHODS

We constructed a Geographic Information System (GIS) model to estimate the number of ECPR candidates in the U.S. We utilized a Resuscitation Outcome Consortium (ROC) database to model time-dependent rates of ECPR eligibility and the Cardiac Arrest Registry to Enhance Survival (CARES) registry to determine the total number of OHCA patients who meet pre-specified ECPR criteria within designated transportation times. The combined model was used to estimate the total number of ECPR candidates.

RESULTS

There were 588,203 OHCA patients in the CARES registry from 2013 to 2020. After applying clinical eligibility criteria, 22,104 (3.76%) OHCA patients were deemed eligible for ECPR. The rate of ROSC increased with longer resuscitation time, which resulted in fewer ECPR candidates. The proportion of OHCA patients eligible for ECPR increased with older age cutoffs. Only 1.68% (9,889/588,203) of OHCA patients in the U.S. were eligible for ECPR based on a 45-minute transportation time to an ECMO-ready center model.

CONCLUSIONS

Less than 2% of OHCA patients are eligible for ECPR in the U.S. GIS models can identify the impact of clinical criteria, transportation time, and hospital capabilities on ECPR eligibility to inform future implementation strategies.

Extracorporeal versus conventional cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a secondary analysis of the Prague OHCA trial

BACKGROUND

Survival rates in refractory out-of-hospital cardiac arrest (OHCA) remain low with conventional advanced cardiac life support (ACLS). Extracorporeal life support (ECLS) implantation during ongoing resuscitation, a method called extracorporeal cardiopulmonary resuscitation (ECPR), may increase survival. This study examined whether ECPR is associated with improved outcomes.

METHODS

Prague OHCA trial enrolled adults with a witnessed refractory OHCA of presumed cardiac origin. In this secondary analysis, the effect of ECPR on 180-day survival using Kaplan-Meier estimates and Cox proportional hazard model was examined.

RESULTS

Among 256 patients (median age 58 years, 83% male) with median duration of resuscitation 52.5 min (36.5-68), 83 (32%) patients achieved prehospital ROSC during ongoing conventional ACLS prehospitally, 81 (32%) patients did not achieve prehospital ROSC with prolonged conventional ACLS, and 92 (36%) patients did not achieve prehospital ROSC and received ECPR. The overall 180-day survival was 51/83 (61.5%) in patients with prehospital ROSC, 1/81 (1.2%) in patients without prehospital ROSC treated with conventional ACLS and 22/92 (23.9%) in patients without prehospital ROSC treated with ECPR (log-rank p < 0.001). After adjustment for covariates (age, sex, initial rhythm, prehospital ROSC status, time of emergency medical service arrival, resuscitation time, place of cardiac arrest, percutaneous coronary intervention status), ECPR was associated with a lower risk of 180-day death (HR 0.21, 95% CI 0.14-0.31; P < 0.001).

CONCLUSIONS

In this secondary analysis of the randomized refractory OHCA trial, ECPR was associated with improved 180-day survival in patients without prehospital ROSC.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01511666, Registered 19 January 2012.

Refractory Anaphylactic Shock Requiring Emergent Venoarterial Extracorporeal Membrane Oxygenation in the Emergency Department: A Case Report

Venoarterial extracorporeal membrane oxygenation is a viable salvage intervention for patients who experience cardiopulmonary arrest or profound shock from any cause. Acute anaphylactic shock is a rare cause of cardiac arrest. We present a case of a 35-year-old male who experienced cardiac arrest owing to anaphylactic shock while receiving general anesthesia for a routine outpatient surgical procedure. Traditional advanced cardiac life support therapies were provided by paramedics en route to the emergency department of a suburban, community-based hospital. Maximal medical management including endotracheal intubation, intravenous steroids, intravenous crystalloid fluid administration, intravenous vasoactive medications, and high-quality cardiopulmonary resuscitation was provided. Although return of spontaneous circulation was achieved, profound cardiogenic shock persisted. Venoarterial extracorporeal membrane oxygenation was initiated by the emergency department provider and nursing team. The patient survived, was neurologically intact, had full recovery, and was discharged home several days later. We have extensive experience with venoarterial extracorporeal membrane oxygenation, and this case exemplifies the value of an established emergency department extracorporeal membrane oxygenation program in managing all causes of cardiac arrest or refractory shock.

Cases of prolonged cardiac arrest with preserved gasping successfully resuscitated with ECPR

Longer cardiopulmonary resuscitation (CPR) time is associated with worsened neurological outcomes in out-of-hospital cardiac arrest (OHCA). Gasping during CPR is a favorable neurological predictor for OHCA. Recently, the efficacy of extracorporeal cardiopulmonary resuscitation (ECPR) in refractory cardiac arrest has been reported. However, the significance of gasping in refractory cardiac arrest patients with long CPR durations treated with ECPR is still unclear. We report two cases of cardiac arrest with gasping that were successfully resuscitated by ECPR, despite extremely long low-flow times. In case 1, a 58-year-old man presented with cardiac arrest and ventricular fibrillation (VF). Gasping was observed when the patient arrived at the hospital. ECPR was initiated 82 min after cardiac arrest. The patient was diagnosed with hypertrophic cardiomyopathy. ECMO was withdrawn on day 4, and the patient was discharged without neurological impairment. In case 2, a 49-year-old man experienced cardiac arrest with VF, and his gasping was preserved during transportation. On arrival, VF persisted, and gasping was observed; therefore, ECMO was initiated 93 min after cardiac arrest. He was diagnosed with acute myocardial infarction. ECMO was withdrawn on day 4 and he was discharged from the hospital without any neurological impairment. Resuscitation and ECPR should not be abandoned in case of preserved gasping, even when the low-flow time is extremely long.

Association between stress hyperglycemia on admission and unfavorable neurological outcome in OHCA patients receiving ECPR

BACKGROUND

Stress hyperglycemia is a normal response to stress and has been associated with outcomes in out-of-hospital cardiac arrest (OHCA) patients. However, this association remained unknown in OHCA patients receiving extracorporeal cardiopulmonary resuscitation (ECPR). This study aimed to examine the association between degree of stress hyperglycemia on admission and neurological outcomes at discharge in OHCA patients receiving ECPR.

PATIENTS AND METHODS

This was a retrospective cohort study of adult OHCA patients receiving ECPR between 2011 and 2021. Patients were classified into three groups: absence of stress hyperglycemia (blood glucose level on admission < 200 mg/dL), moderate stress hyperglycemia (200-299 mg/dL), and severe stress hyperglycemia (≥ 300 mg/dL). The primary outcome was unfavorable neurological outcome (Cerebral Performance Category: 3-5) at discharge.

RESULTS

This study included 160 patients; unfavorable neurological outcomes totaled 79.4% (n = 127). There were 23, 52, and 85 patients in the absence, moderate, and severe stress hyperglycemia groups, respectively. Of each group, unfavorable neurological outcomes constituted 91.3%, 71.2%, and 81.2%, respectively. Multivariable analysis showed that, compared with moderate stress hyperglycemia, absence of stress hyperglycemia on admission was significantly associated with unfavorable neurological outcome at discharge (odds ratio [OR], 4.70; 95% confidence interval [CI], 1.07-33.35; p = 0.039).

CONCLUSION

Compared with moderate stress hyperglycemia on admission, absence of stress hyperglycemia showed significant association with unfavorable neurological outcome at discharge in OHCA patients receiving ECPR.

Association of intentional cooling, achieved temperature and hypothermia duration with in-hospital mortality in patients treated with extracorporeal cardiopulmonary resuscitation: An analysis of the ELSO Registry

AIM

To investigate whether intentional cooling, achieved temperature and hypothermia duration were associated with in-hospital death in patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest.

METHODS

This is a retrospective analysis of the Extracorporeal Life Support Organization Registry. Patients 18-79 years of age who received ECPR between 2010 and 2019 were included. We compared outcomes for intentional cooling versus no intentional cooling. Then, among those who completed intentional cooling, we compared the outcomes between i) achieved temperature ≤34℃, 34-36℃, and >36℃, and ii) duration ≤36℃ for <12 hours, 12-48 hours, and ≥48 hours. The primary outcome was in-hospital mortality within 90 days. Cox proportional hazard models were generated with adjustment for covariates.

RESULTS

Among 4,214 ECPR patients, 1,511 patients were included in the final analysis. After multivariable adjustment, there was no significant difference in in-hospital mortality between patients with intentional cooling and no intentional cooling (hazard ratio [HR], 1.06 [95% CI 0.92-1.21]; p=0.395). In the 609 patients who completed intentional cooling, temperature at 34-36℃ had a significantly lower adjusted HR for in-hospital mortality compared with >36℃ (HR, 0.73 [0.55-0.96]; p=0.025). Moreover, temperature ≤36℃ for 12-48 hours had a significantly lower adjusted HR for in-hospital mortality compared with ≤36℃ for <12 hours (HR, 0.69 [0.53-0.90]; p=0.005).

CONCLUSION

Intentional cooling was not associated with lower in-hospital mortality in ECPR patients. However, among patients with intentional cooling, achieving temperature of 34-36℃ for 12-48 hours was associated with lower in-hospital mortality.

Eligibility of extracorporeal cardiopulmonary resuscitation on in-hospital cardiac arrests in Sweden: a national registry study

AIMS

Extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest (CA) is used in selected cases. The incidence of ECPR-eligible patients is not known. The aim of this study was to identify the ECPR-eligible patients among in-hospital CAs (IHCA) in Sweden and to estimate the potential gain in survival and neurological outcome, if ECPR was to be used.

METHODS AND RESULTS

Data between 1 January 2015 and 30 August 2019 were extracted from the Swedish Cardiac Arrest Register (SCAR). Two arbitrary groups were defined, based on restrictive or liberal inclusion criteria. In both groups, logistic regression was used to determine survival and cerebral performance category (CPC) for conventional cardiopulmonary resuscitation (cCPR). When ECPR was assumed to be possible, it was considered equivalent to return of spontaneous circulation, and the previous logistic regression model was applied to define outcome for comparison of conventional CPR and ECPR. The assumption in the model was a minimum of 15 min of refractory CA and 5 min of cannulation. A total of 9209 witnessed IHCA was extracted from SCAR. Depending on strictness of inclusion, an average of 32-64 patients/year remains in refractory after 20 min of cCPR, theoretically eligible for ECPR. If optimal conditions for ECPR are assumed and potential negative side effects disregarded of, the estimated potential benefit of survival of ECPR in Sweden would be 10-19 (0.09-0.19/100 000) patients/year, when a 30% success rate is expected. The benefit of ECPR on survival and CPC scoring was found to be detrimental over time and minimal at 60 min of cCPR.

CONCLUSION

The number of ECPR-eligible patients among IHCA in Sweden is dependent on selection criteria and predicted to be low. There is an estimated potential benefit of ECPR, on survival and neurological outcome if initiated within 60 min of the IHCA.

The association between time to extracorporeal cardiopulmonary resuscitation and outcome in patients with out-of-hospital cardiac arrest

AIMS

Extracorporeal cardiopulmonary resuscitation (ECPR) is considered for potentially reversible out-of-hospital cardiac arrest (OHCA). However, the association between time to ECPR and outcome has not been well established.

METHODS AND RESULTS

Between June 2014 and December 2017, we enrolled 34 754 OHCA patients in a multicentre, prospective fashion [Japanese Association for Acute Medicine (JAAM)-OHCA registry]. After the application of exclusion criteria, 695 OHCA patients who underwent ECPR for cardiac causes were eligible for this study. We investigated the association between the call-to-ECPR interval and favourable neurological outcome (cerebral performance category 1 or 2) at 30 days. Seventy-seven patients (11%) had a favourable neurological outcome at 30 days. The call-to-ECPR intervals in these patients were significantly shorter than in those with an unfavourable neurological outcome [49 (41-58) vs. 58 (48-68) min, respectively, P < 0.001]. A longer call-to-ECPR interval was associated with a smaller proportion of patients undergoing percutaneous coronary intervention (PCI) (P = 0.034) or target temperature management (TTM) (P < 0.001). Stepwise multivariable logistic regression analysis revealed that the call-to-ECPR interval was an independent predictor of favourable neurological outcome [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.94-0.99, P = 0.001], as were age, male gender, initial shockable rhythm, transient return of spontaneous circulation in the prehospital setting, arterial pH at hospital arrival, PCI (OR 2.30, 95% CI 1.14-4.66, P = 0.019), and TTM (OR 2.28, 95% CI 1.13-4.62, P = 0.019).

CONCLUSION

A shorter call-to-ECPR interval and implementation of PCI and TTM predicted a favourable neurological outcome at 30 days in OHCA patients who underwent ECPR for cardiac causes.

A novel extracorporeal cardiopulmonary resuscitation strategy using a hybrid emergency room for patients with pulseless electrical activity

BACKGROUND

Whether extracorporeal cardiopulmonary resuscitation (ECPR) is indicated for patients with pulseless electrical activity (PEA) remains unclear. Pulmonary embolism with PEA is a good candidate for ECPR; however, PEA can sometimes include an aortic disease and intracranial haemorrhage, with extremely poor neurological outcomes, and can thus not be used as a suitable candidate. We began employing an ECPR strategy that utilised a hybrid emergency room (ER) to perform computed tomography (CT) before extracorporeal membrane oxygenation (ECMO) induction from January 2020. Therefore, the present study aimed to evaluate the effectiveness of this ECPR strategy.

METHODS

Medical records of patients who transferred to our hybrid ER and required ECPR for PEA between January 2020 and November 2021 were reviewed.

RESULTS

Twelve consecutive patients (median age, 67 [range, 57-73] years) with PEA requiring ECPR were identified in our hybrid ER. Among these patients, nine were diagnosed using an initial CT scan (intracranial haemorrhage (3); cardiac tamponade due to aortic dissection (3); aortic rupture (2); and cardiac rupture (1)), and unnecessary ECMO was avoided. The remaining three patients underwent ECPR, and two of them survived with favourable neurological outcomes. Patients not indicated for ECPR were excluded before ECMO induction.

CONCLUSION

Our ECPR strategy that involved the utilisation of a hybrid ER may be useful for the exclusion of patients with PEA not indicated for ECPR and decision making.

Serum proteome alterations during conventional and extracorporeal resuscitation in pigs

Background

Only a small number of patients survive an out-of-hospital cardiac arrest (CA) and can be discharged from hospital alive with a large percentage of these patients retaining neurological impairments. In recent years, extracorporeal cardiopulmonary resuscitation (ECPR) has emerged as a beneficial strategy to optimize cardiac arrest treatment. However, ECPR is still associated with various complications. To reduce these problems, a profound understanding of the underlying mechanisms is required. This study aims to investigate the effects of CA, conventional cardiopulmonary resuscitation (CPR) and ECPR using a whole-body reperfusion protocol (controlled and automated reperfusion of the whole body—CARL) on the serum proteome profiles in a pig model of refractory CA.

Methods

N = 7 pigs underwent 5 min of untreated CA followed by 30 min CPR and 120 min perfusion with CARL. Blood samples for proteomic analysis were drawn at baseline, after CPR and at the end of the CARL period. Following albumin-depletion, proteomic analysis was performed using liquid chromatography–tandem mass spectrometry.

Results

N = 21 serum samples were measured resulting in the identification and quantification of 308–360 proteins per sample and 388 unique proteins in total. The three serum proteome profiles at the investigated time points clustered individually and segregated almost completely when considering a 90% confidence interval. Differential expression analysis showed significant abundance changes in 27 proteins between baseline and after CPR and in 9 proteins after CARL compared to CPR. Significant findings were further validated through a co-abundance cluster analysis corroborating the observed abundance changes.

Conclusions

The presented data highlight the impact of systemic ischemia and reperfusion on the entire serum proteome during resuscitation with a special focus on changes regarding haemolysis, coagulation, inflammation, and cell-death processes. Generally, the observed changes contribute to post-ischemic complications. Better understanding of the underlying mechanisms during CA and resuscitation may help to limit these complications and improve therapeutic options.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03441-4.

Extracorporeal cardiopulmonary resuscitation in adult patients with out-of-hospital cardiac arrest: a retrospective large cohort multicenter study in Japan

BACKGROUND

The prevalence of extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA) has been increasing rapidly worldwide. However, guidelines or clinical studies do not provide sufficient data on ECPR practice. The aim of this study was to provide real-world data on ECPR for patients with OHCA, including details of complications.

METHODS

We did a retrospective database analysis of observational multicenter cohort study in Japan. Adult patients with OHCA of presumed cardiac etiology who received ECPR between 2013 and 2018 were included. The primary outcome was favorable neurological outcome at hospital discharge, defined as a cerebral performance category of 1 or 2.

RESULTS

A total of 1644 patients with OHCA were included in this study. The patient age was 18-93 years (median: 60 years). Shockable rhythm in the initial cardiac rhythm at the scene was 69.4%. The median estimated low flow time was 55 min (interquartile range: 45-66 min). Favorable neurological outcome at hospital discharge was observed in 14.1% of patients, and the rate of survival to hospital discharge was 27.2%. The proportions of favorable neurological outcome at hospital discharge in terms of shockable rhythm, pulseless electrical activity, and asystole were 16.7%, 9.2%, and 3.9%, respectively. Complications were observed during ECPR in 32.7% of patients, and the most common complication was bleeding, with the rates of cannulation site bleeding and other types of hemorrhage at 16.4% and 8.5%, respectively.

CONCLUSIONS

In this large cohort, data on the ECPR of 1644 patients with OHCA show that the proportion of favorable neurological outcomes at hospital discharge was 14.1%, survival rate at hospital discharge was 27.2%, and complications were observed during ECPR in 32.7%.

The association of modifiable mechanical ventilation settings, blood gas changes and survival on extracorporeal membrane oxygenation for cardiac arrest

RESEARCH QUESTION

Given the relative independence of ventilator settings from gas exchange and plasticity of blood gas values during extracorporeal cardiopulmonary resuscitation (ECPR), do mechanical ventilation parameters and blood gas values influence survival?

METHODS

Observational cohort study of 7488 adult patients with ECPR from the Extracorporeal Life Support Organization (ELSO) Registry. We performed case-mix adjustment for severity of illness and patient type using generalized estimating equation logistic regression to determine factors associated with hospital survival accounting for clustering by center, standardizing variables by 1 standard deviation (SD) of their values. We examined non-linear relationships between ventilatory and blood gas values with hospital survival.

RESULTS

Hospital survival was decreased with higher PaO2 on ECMO (OR 0.69, per 1SD increase [95% CI 0.64, 0.74]; p < 0.001) and with any relative changes in PaCO2 (pre-arrest to on-ECMO) in a non-linear fashion. Survival was worsened with any peak inspiratory pressure >20 cmH20 (OR 0.69, per 1SD [0.64, 0.75]; p < 0.001) and above 40% fraction of inspired oxygen (OR 0.75, per 1SD [0.69, 0.82]; p < 0.001), and with higher dynamic driving pressure (OR 0.72, per 1 SD increase [0.65, 0.79]; <0.001). Ventilation settings and blood gas values varied widely across hospitals, but were not associated with annual hospital ECPR case volume.

CONCLUSION

Lower ventilatory pressures, avoidance of hyperoxia, and relatively unchanged CO2 (pre- to on-ECMO) were all associated with survival in patients after ECPR, yet varied across hospitals. Our findings represent potential targets for prospective trials for this rapidly growing therapy to test if these associations have causality.

Extracorporeal Cardiopulmonary Resuscitation Guided by End-Tidal Carbon Dioxide-a Porcine Model

Extracorporeal membrane cardiopulmonary resuscitation (ECPR) during cardiopulmonary resuscitation (CPR) for selected cases and end-tidal carbon dioxide (ETCO₂) could be used to guide initiation of ECPR. Ventricular fibrillation was induced in 12 pigs and CPR was performed until ETCO₂ fell below 10 mmHg; then, ECPR was performed. Animals were divided into group short (G_Short) and group long (G_Long), according to time of CPR. Carotid blood flow was higher (p = 0.02) and mean arterial blood pressure lower in G_Long during CPR (p < 0.05). B-Lactate was lower and pH higher in G_Short (p < 0.01). In microdialysis lactate-pyruvate ratio, glycerol and glutamate increased in both groups during CPR, but considerably in G_Long (p < 0.01). No difference could be seen in histopathology of the brain or kidney post-ECPR. No apparent histological differences of tissue damage in brains or levels of S100B in plasma were detected between groups. This might suggest that ETCO₂ could be used as a marker for brain injury following ECPR.

Favorable prognosis by extracorporeal cardiopulmonary resuscitation for subsequent shockable rhythm patients

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) patients who convert from an initial non-shockable rhythm to a subsequent shockable rhythm reportedly have a better prognosis for survival than those without rhythm conversion. We evaluated the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for OHCA patients with a subsequent shockable rhythm.

METHODS

This study was conducted using the Japanese Association of Acute Medicine OHCA registry. We included OHCA patients with a subsequent shockable rhythm from June 2014 to December 2017. The included patients were divided into those with and without ECPR. The primary outcome was 30-day survival. Logistic regression analysis and propensity score matching were performed to compare the outcomes between patients with and without ECPR.

RESULTS

A total of 2,102 patients were analyzed, consisting of 162 with ECPR and 1,940 without ECPR. Before propensity score matching, 24 (14.8%) patients with ECPR and 61 (3.1%) patients without ECPR survived for 30 days; ECPR was associated with increased survival (P < 0.05; odds ratio [OR], 5.35; 95% confidence interval [CI], 3.09-9.02). After propensity score matching, 22/149 (14.8%) patients with ECPR and 10/149 (6.7%) patients without ECPR survived for 30 days; ECPR was associated with increased survival (P < 0.05; OR, 2.40; 95% CI, 1.04-5.91).

CONCLUSIONS

ECPR was associated with increased survival among OHCA patients with a subsequent shockable rhythm.

Extracorporeal cardiopulmonary resuscitation in adults: evidence and implications

Rates of survival with functional recovery for both in-hospital and out-of-hospital cardiac arrest are notably low. Extracorporeal cardiopulmonary resuscitation (ECPR) is emerging as a modality to improve prognosis by augmenting perfusion to vital end-organs by utilizing extracorporeal membrane oxygenation (ECMO) during conventional CPR and stabilizing the patient for interventions aimed at reversing the aetiology of the arrest. Implementing this emergent procedure requires a substantial investment in resources, and even the most successful ECPR programs may nonetheless burden healthcare systems, clinicians, patients, and their families with unsalvageable patients supported by extracorporeal devices. Non-randomized and observational studies have repeatedly shown an association between ECPR and improved survival, versus conventional CPR, for in-hospital cardiac arrest in select patient populations. Recently, randomized controlled trials suggest benefit for ECPR over standard resuscitation, as well as the feasibility of performing such trials, in out-of-hospital cardiac arrest within highly coordinated healthcare delivery systems. Application of these data to clinical practice should be done cautiously, with outcomes likely to vary by the setting and system within which ECPR is initiated. ECPR introduces important ethical challenges, including whether it should be considered an extension of CPR, at what point it becomes sustained organ replacement therapy, and how to approach patients unable to recover or be bridged to heart replacement therapy. The economic impact of ECPR varies by health system, and has the potential to outstrip resources if used indiscriminately. Ideally, studies should include economic evaluations to inform health care systems about the cost-benefits of this therapy.

Satisfactory outcome with low activated clotting time in extracorporeal membrane oxygenation

Optimal anticoagulation is critical for successful extracorporeal membrane oxygenation (ECMO) to counterbalance the activation of the coagulation system initiated by the blood-biosurface reaction and mechanical stresses. Systemic anticoagulation is achieved mainly with unfractionated heparin (UFH). Activated clotting time (ACT) is a widely used laboratory parameter to monitor anticoagulation. The therapeutic range of ACT is 180-220 s. We investigated the effect of a lower target ACT (<150 s) during ECMO on safety and outcomes and compared it with those of a conventional target ACT (180-200 s). In this single-center, retrospective study, we reviewed 72 adult patients treated with ECMO from March 2017 to October 2019. We included 43 patients after applying the exclusion criteria and divided them into the low ACT group (<150 s, n = 14, 32.6%) and conventional ACT group (≥150 s, n = 29, 67.4%). There was no difference in the successful weaning from ECMO support (50% vs. 62.1%, p = 0.452) and discharge (50% vs. 41.4%, p = 0.594) rates between the groups. One patient in the conventional ACT group had intracranial hemorrhage. There was one thromboembolic complication case with an intra-circuit thrombus. To date, anticoagulation remains a challenge during ECMO. Our results suggest that a lower target ACT does not necessarily increase the thromboembolic risk during ECMO management. Clinicians may consider anticoagulation with lower ACT target for some patients with careful assessment and close monitoring. Further prospective trials are warranted to validate these results.