Hydrogen gas with extracorporeal cardiopulmonary resuscitation improves survival after prolonged cardiac arrest in rats

BACKGROUND

Despite the benefits of extracorporeal cardiopulmonary resuscitation (ECPR) in cohorts of selected patients with cardiac arrest (CA), extracorporeal membrane oxygenation (ECMO) includes an artificial oxygenation membrane and circuits that contact the circulating blood and induce excessive oxidative stress and inflammatory responses, resulting in coagulopathy and endothelial cell damage. There is currently no pharmacological treatment that has been proven to improve outcomes after CA/ECPR. We aimed to test the hypothesis that administration of hydrogen gas (H₂) combined with ECPR could improve outcomes after CA/ECPR in rats.

METHODS

Rats were subjected to 20 min of asphyxial CA and were resuscitated by ECPR. Mechanical ventilation (MV) was initiated at the beginning of ECPR. Animals were randomly assigned to the placebo or H₂ gas treatment groups. The supplement gas was administered with O₂ through the ECMO membrane and MV. Survival time, electroencephalography (EEG), brain functional status, and brain tissue oxygenation were measured. Changes in the plasma levels of syndecan-1 (a marker of endothelial damage), multiple cytokines, chemokines, and metabolites were also evaluated.

RESULTS

The survival rate at 4 h was 77.8% (7 out of 9) in the H₂ group and 22.2% (2 out of 9) in the placebo group. The Kaplan-Meier analysis showed that H₂ significantly improved the 4 h-survival endpoint (log-rank P = 0.025 vs. placebo). All animals treated with H₂ regained EEG activity, whereas no recovery was observed in animals treated with placebo. H₂ therapy markedly improved intra-resuscitation brain tissue oxygenation and prevented an increase in central venous pressure after ECPR. H₂ attenuated an increase in syndecan-1 levels and enhanced an increase in interleukin-10, vascular endothelial growth factor, and leptin levels after ECPR. Metabolomics analysis identified significant changes at 2 h after CA/ECPR between the two groups, particularly in D-glutamine and D-glutamate metabolism.

CONCLUSIONS

H₂ therapy improved mortality in highly lethal CA rats rescued by ECPR and helped recover brain electrical activity. The underlying mechanism might be linked to protective effects against endothelial damage. Further studies are warranted to elucidate the mechanisms responsible for the beneficial effects of H₂ on ischemia-reperfusion injury in critically ill patients who require ECMO support.

Reliability of prognostic biomarkers after prehospital extracorporeal cardiopulmonary resuscitation with target temperature management

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) performed at the emergency scene in out-of-hospital cardiac arrest (OHCA) can minimize low-flow time. Target temperature management (TTM) after cardiac arrest can improve neurological outcome. A combination of ECPR and TTM, both implemented as soon as possible on scene, appears to have promising results in OHCA. To date, it is still unknown whether the implementation of TTM and ECPR on scene affects the time course and value of neurological biomarkers.

Methods

69 ECPR patients were examined in this study. Blood samples were collected between 1 and 72 h after ECPR and analyzed for S100, neuron-specific enolase (NSE), lactate, D-dimers and interleukin 6 (IL6). Cerebral performance category (CPC) scores were used to assess neurological outcome after ECPR upon hospital discharge. Resuscitation data were extracted from the Regensburg extracorporeal membrane oxygenation database and all data were analyzed by a statistician. The data were analyzed using non-parametric methods. Diagnostic accuracy of biomarkers was determined by area under the curve (AUC) analysis. Results were compared to the relevant literature.

Results

Non-hypoxic origin of cardiac arrest, manual chest compression until ECPR, a short low-flow time until ECPR initiation, low body mass index (BMI) and only a minimal need of extra-corporeal membrane oxygenation support were associated with a good neurological outcome after ECPR. Survivors with good neurological outcome had significantly lower lactate, IL6, D-dimer, and NSE values and demonstrated a rapid decrease in the initial S100 value compared to non-survivors.

Conclusions

A short low-flow time until ECPR initiation is important for a good neurological outcome. Hypoxia-induced cardiac arrest has a high mortality rate even when ECPR and TTM are performed at the emergency scene. ECPR patients with a higher BMI had a worse neurological outcome than patients with a normal BMI. The prognostic biomarkers S100, NSE, lactate, D-dimers and IL6 were reliable indicators of neurological outcome when ECPR and TTM were performed at the emergency scene.

Near-fatal Panton-Valentine leukocidin-positive Staphylococcus aureus pneumonia, shock and complicated extracorporeal membrane oxygenation cannulation: A case report

BACKGROUND

Panton-Valentine leukocidin (PVL) is an exotoxin secreted by Staphylococcus aureus (S. aureus), responsible for skin and soft tissue infections. As a cause of severe necrotising pneumonia, it is associated with a high mortality rate. A rare entity, the epidemiology of PVL S. aureus (PVL-SA) pneumonia as a complication of influenza coinfection, particularly in young adults, is incompletely understood.

CASE SUMMARY

An adolescent girl presented with haemoptysis and respiratory distress, deteriorated rapidly, with acute respiratory distress syndrome (ARDS) and profound shock requiring extensive, prolonged resuscitation, emergency critical care and venovenous extracorporeal membrane oxygenation (ECMO). Cardiac arrest and a rare complication of ECMO cannulation necessitated intra-procedure extracorporeal cardiopulmonary resuscitation, i.e., venoarterial ECMO. Coordinated infectious disease, microbiology and Public Health England engagement identified causative agents as PVL-SA and influenza A/H3N2 from bronchial aspirates within hours. Despite further complications of critical illness, the patient made an excellent recovery with normal cognitive function. The coordinated approach of numerous multidisciplinary specialists, nursing staff, infection control, specialist cardiorespiratory support, hospital services, both adult and paediatric and Public Health are testimony to what can be achieved to save life against expectation, against the odds. The case serves as a reminder of the deadly nature of PVL-SA when associated with influenza and describes a rare complication of ECMO cannulation.

CONCLUSION

PVL-SA can cause severe ARDS and profound shock, with influenza infection. A timely coordinated multispecialty approach can be lifesaving.

How effective is extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest? A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has gained increasing as a promising but resource-intensive intervention for out-of-hospital cardiac arrest (OHCA). There is little data to quantify the impact of this intervention and the patients likely to benefit from its use. We conducted a meta-analysis of the literature to assess the survival benefit associated with ECPR for OHCA.

METHODS

We searched PubMed, Embase, and Scopus databases to identify relevant observational studies and randomized control trials. We used the Newcastle-Ottawa Scale and Cochrane risk-of-bias tool to assess studies' quality. We performed random-effects meta-analysis for the primary outcome of survival to hospital discharge and used meta-regressions to assess heterogeneity.

RESULTS

We identified 1287 articles, reviewed the full text of 209 and included 44 in our meta-analysis. Our analysis included 3097 patients with OHCA. Patients' mean age was 52, 79% were male, and 60% had primary ventricular fibrillation/ventricular tachycardia arrest. We identified a survival-to-discharge rate of 24%; 18% survived with favorable neurologic function. 30- and 90-days survival rates were both around 18%. The majority of included articles were high quality studies.

CONCLUSIONS

Extracorporeal cardiopulmonary resuscitation is a promising but resource-intensive intervention that may increase rates of survival to hospital discharge among patients who experience OHCA.

Pediatric extracorporeal cardiopulmonary resuscitation: single-center study

Background/aim

Extracorporeal cardiopulmonary resuscitation (ECPR) is defined as the venoarterial extracorporeal membrane oxygenation (VA-ECMO) support in a patient who experienced a sudden pulseless condition attributable to cessation of cardiac mechanical activity and circulation. We aimed to evaluate the clinical outcomes of our ECPR experience in a pediatric patient population.

Materials and methods

Between September 2014 and November 2017, 15 children were supported with ECPR following in-hospital cardiac arrest (IHCA) in our hospitals. VA-ECMO setting was established for all patients. Pediatric cerebral performance category (PCPC) scales and long-term neurological prognosis of the survivors were assessed.

Results

The median age of the study population was 60 (4–156) months. The median weight was 18 (4.8–145) kg, height was 115 (63–172) cm, and body surface area was 0.73 (0.27–2.49) m². The cause of cardiac arrest was a cardiac and circulatory failure in 12 patients (80%) and noncardiac causes in 20%. Dysrhythmia was present in 46%, septic shock in 13%, bleeding in 6%, low cardiac output syndrome in 13%, and airway disease in 6% of the study population. Median low-flow time was 95 (range 20–320) min. Central VA-ECMO cannulation was placed in only 2 (13.3%) cases. However, the return of spontaneous circulation (ROSC) was obtained in 10 (66.6%) patients, and 5 (50%) of them survived. Overall, 5 patients were discharged from the hospital. Finally, survival following ECPR was 33.3%, and all survivors were neurologically intact at hospital-discharge.

Conclusion

ECPR can be a life-saving therapeutic strategy using a promising technology in the pediatric IHCA population. Early initiation and a well-coordinated, skilled, and dedicated ECMO team are the mainstay for better survival rates.

Ethics of ECPR research

The design of emergency medicine trials can raise several ethical concerns - risks may be greater, and randomisation may have to occur before consent. Research in emergency medicine is thus an illuminating context to explore the interplay between risk and randomisation, and the consequences for consent. Using a currently running trial, we describe possible concerns, considerations, and solutions to reconcile the conflicting interests of scientific inquiry, ethical principles, and clinical reality in emergency medicine research.

Modeling severe functional impairment or death following ECPR in pediatric cardiac patients: Planning for an interventional trial

AIM

We aimed to characterize extracorporeal CPR (ECPR) outcomes in our center and to model prediction of severe functional impairment or death at discharge.

METHODS

All ECPR events between 2011 and 2019 were reviewed. The primary outcome measure was severe functional impairment or death at discharge (Functional Status Score [FSS] ≥ 16). Organ dysfunction was graded using the Pediatric Logistic Organ Dysfunction Score-2, neuroimaging using the modified Alberta Stroke Program Early Computed Tomography Score. Multivariable logistic regression was used to model FSS ≥ 16 at discharge.

RESULTS

Of the 214 patients who underwent ECPR, 182 (median age 148 days, IQR 14-827) had an in-hospital cardiac arrest and congenital heart disease and were included in the analysis. Of the 110 patients who underwent neuroimaging, 52 (47%) had hypoxic-ischemic injury and 45 (41%) had hemorrhage. In-hospital mortality was 52% at discharge. Of these, 87% died from the withdrawal of life-sustaining therapies; severe neurologic injury was a contributing factor in the decision to withdraw life-sustaining therapies in 50%. The median FSS among survivors was 8 (IQR 6-8), and only one survivor had severe functional impairment. At 6 months, mortality was 57%, and the median FSS among survivors was 6 (IQR 6-8, n = 79). Predictive models identified FSS at admission, single ventricle physiology, extracorporeal membrane oxygenation (ECMO) duration, mean PELOD-2, and worst mASPECTS (or DWI-ASPECTS) as independent predictors of FSS ≥ 16 (AUC = 0.931) and at 6 months (AUC = 0.924).

CONCLUSION

Mortality and functional impairment following ECPR in children remain high. It is possible to model severe functional impairment or death at discharge with high accuracy using daily post-ECPR data up to 28 days. This represents a prognostically valuable tool and may identify endpoints for future interventional trials.

Impact of age on the outcomes of extracorporeal cardiopulmonary resuscitation: analysis using inverse probability of treatment weighting

OBJECTIVES

Patient selection is crucial to improving the outcomes of extracorporeal cardiopulmonary resuscitation (ECPR). However, ECPR's efficacy with older patients remains unknown.

METHODS

We reviewed patients who underwent extracorporeal membrane oxygenation (ECMO) for refractory cardiac arrest from January 2006 to December 2018. Exclusion criteria were age <18 years, cannulation failure and ECMO applied at another hospital. We divided patients into 2 groups with an age cut-off of 66 years, using the Contal and O'Quigley method for overall survival. We performed inverse probability of treatment weighting (IPTW) between the 2 groups and set the primary outcome as overall survival.

RESULTS

We included 318 patients in our study (≤66 years, n = 199; >66 years, n = 119). Before IPTW, we observed that the older group had a higher frequency of diabetes, hypertension, and myocardial infarction. In the young group, more patients had out-of-hospital cardiac arrest as compared with the older group. The hospital mortality rate was 55% (48.7% in the young group, 65.5% in the older group; P = 0.004). In the multivariable analysis after IPTW, the older group showed worse outcomes in overall survival [hazard ratio (HR) = 2.02; 95% confidence interval (CI), 1.50-2.70; P < 0.001] and neurological outcomes at discharge (odds ratio = 2.95; 95% CI, 1.69-5.14; P = <0.001). ECMO insertion during catheterization (HR = 0.57; 95% CI, 0.36-0.90; P = 0.015) and recovery of spontaneous circulation before pump-on (HR = 0.67; 95% CI, 0.50-0.89; P = 0.007) were positive predictors, but initial asystole rhythm, non-cardiac cause (HR = 2.39; 95% CI, 1.59-3.61; P < 0.001), out-of-hospital cardiac arrest (HR = 1.86; 95% CI, 1.24-2.79; P = 0.003) and prolonged cardiopulmonary resuscitation to pump-on time (HR = 1.01; 95% CI, 1.01-1.02; P < 0.001) were negative predictors for overall survival.

CONCLUSIONS

Older patients who had ECPR had significantly worse survival and neurological outcomes. For patients older than age 66 years, more careful patient selection is critically important for improving the efficacy of ECPR.

Outcomes associated with delayed enteral feeding after cardiac arrest treated with veno-arterial extracorporeal membrane oxygenation and targeted temperature management

INTRODUCTION

While early enteral nutrition is generally preferred in critically ill patients, the optimal timing of feeding among refractory cardiac arrest patients is unknown. We examined the association between timing of enteral nutrition and patient survival and safety outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) who were treated with extracorporeal cardiopulmonary resuscitation (ECPR).

METHODS

We performed a retrospective analysis of 142 consecutive patients presenting with OHCA due to ventricular fibrillation or ventricular tachycardia treated with ECPR and targeted temperature management (TTM). Neurologically favorable survival and clinical outcomes were compared between patients who received early enteral nutrition (<48 h after admission to the intensive care unit) and patients receiving delayed enteral nutrition (initiated >48 h after admission).

RESULTS

Enteral nutrition was initiated in 90/142 (63%) patients. Early enteral nutrition was provided in 34/90 (38%) while delayed nutrition occurred in 56/90 (62%). In adjusted analysis including patients who received nutrition, delayed enteral feeding was associated with increased odds of neurologically favorable survival (29 vs 54%, CI 1.04-7.25, p = 0.04). There were no significant differences in the incidence of pneumonia (18 vs 27%, p = 0.16), gastrointestinal bleeding (5.9 vs 3.6%, p = 0.42), intestinal ischemia (5.9 vs 5.4%, p = 0.90), ileus (12 vs 11%, p = 0.98), or need for tracheostomy (15 vs 20%, p = 0.81) between early and late feeding groups.

CONCLUSION

In patients with refractory OHCA treated with ECPR and TTM, delayed enteral nutrition was associated with improved neurologically favorable survival. Adverse events related to enteral feeding were not associated with timing of feeding initiation.

A qualitative exploratory case series of patient and family experiences with ECPR for out-of-hospital cardiac arrest

Objective

There is currently no existing data examining the opinions of patients and families after treatment with extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA). We sought to interview family members and patients to learn from their experiences and satisfaction with treatment.

Methods

We contacted family members and survivors for all cases treated with ECPR for refractory OHCA at St. Paul’s Hospital between January 2014 and July 2018. We performed semi-structured interviews with participants, specifically within the topics of: information sharing (including impressions of an ECPR informational pamphlet), prognostication, organ donation, and perceived value of ECPR. Due to low participant enrolment, we described all interviews in a narrative approach.

Results

Within the study period, there were 23 OHCAs treated with ECPR; two survivors and three family members agreed to participate. Participants were satisfied with the treatment provided, including information sharing and prognostication. There were mixed opinions about the best method of information-sharing (verbal vs written), as well as the timing of organ donation conversations. All participants believed ECPR for OHCA to be of high value.

Conclusion

Patient’s conveyed satisfaction with ECPR treatment, with mixed views on the best information sharing strategy. Further study is needed to define the optimal methods and timing for discussions of organ donation, especially for treatments of with a relatively low likelihood success.

Association between age and neurological outcomes in out-of-hospital cardiac arrest patients resuscitated with extracorporeal cardiopulmonary resuscitation: a nationwide multicentre observational study

AIMS

Little is known about the difference in outcomes between young and old patients who received extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA). Therefore, we aimed to investigate the differences in outcomes between those aged ≥75 years and <75 years who experienced OHCA and were resuscitated with ECPR.

METHODS AND RESULTS

We performed a secondary analysis of a nationwide prospective cohort study using the Japanese Association for Acute Medicine OHCA registry. We identified patients aged ≥18 years with OHCA who received ECPR. The patients were classified into three age groups (18-59 years, 60-74 years, and ≥75 years). The primary outcome was a 1-month neurological outcome. To examine the association between age and 1-month neurological outcome, we performed logistic regression analyses fitted with generalized estimating equations. From 2014 to 2017, we identified 875 OHCA patients aged ≥18 years who received ECPR. The proportion of patients who survived with favourable neurological outcome in the patients aged 18-59 years, 60-74 years, and ≥75 years were 15% (64/434), 8.9% (29/326), and 1.7% (2/115), respectively. In the multivariable analysis, compared with the age of 18-59 years, the proportions of favourable neurological outcomes were significantly lower in patients aged 60-74 years [adjusted odds ratio (OR), 0.44; 95% confidence interval (CI), 0.32-0.61] and those aged ≥75 years (adjusted OR, 0.26; 95% CI, 0.11-0.59).

CONCLUSION

Advanced age (age ≥75 years in particular) was significantly associated with poor neurological outcomes in patients with OHCA who received ECPR.

[Training module extracorporeal life support (ECLS): consensus statement of the DIVI, DGTHG, DGfK, DGAI, DGIIN, DGF, GRC and DGK]

Mechanical circulatory support using extracorporeal life support systems (ECLS) has significantly increased in recent years. These critically ill patients pose special challenges to the multiprofessional treatment team and require comprehensive, interdisciplinary and interprofessional concepts. For this reason, to ensure the best possible patient care a standardized ECLS training module has been created at national specialist society level, taking emergency and intensive care management into account.

[Training module extracorporeal life support (ECLS): consensus statement of the DIVI, DGTHG, DGfK, DGAI, DGIIN, DGF, GRC and DGK]

Mechanical circulatory support using extracorporeal life support systems (ECLS) has significantly increased in recent years. These critically ill patients pose special challenges to the multiprofessional treatment team and require comprehensive, interdisciplinary and interprofessional concepts. For this reason, to ensure the best possible patient care a standardized ECLS training module has been created at national specialist society level, taking emergency and intensive care management into account.

Impact of pulse pressure on clinical outcome in extracorporeal cardiopulmonary resuscitation (eCPR) patients

BACKGROUND

Hemodynamic response to successful extracorporeal cardiopulmonary resuscitation (eCPR) is not uniform. Pulse pressure (PP) as a correlate for myocardial damage or recovery from it, might be a valuable tool to estimate the outcome of these patients.

METHODS

We report retrospective data of a single-centre registry of eCPR patients, treated at the Interdisciplinary Medical Intensive Care Unit at the Medical Centre, University of Freiburg, Germany, between 01/2017 and 01/2020. The association between PP of the first 10 days after eCPR and hospital survival was investigated. Moreover, patients were divided into three groups according to their PP [low (0-9 mmHg), mid (10-29 mmHg) and high (≥ 30 mmHg)] at each time point.

RESULTS

One hundred forty-three patients (age 63 years, 74.1% male, 40% OHCA, average low flow time 49 min) were analysed. Overall hospital survival rate was 28%. A low PP both early after eCPR (after 1, 3, 6 and 12 h) and after day 1 to day 8 was associated with reduced hospital survival. At each time point (1 h to day 5) the classification of patients into a low, mid and high PP group was able to categorize the patients for a low (5-20%), moderate (20-40%) and high (50-70%) survival rate. A multivariable analysis showed that the mean PP of the first 24 h was an independent predictor for survival (p = 0.008).

CONCLUSION

In this analysis, PP occurred to be a valuable parameter to estimate survival and maybe support clinical decision making in the further course of patients after eCPR.

Prognostic value of signs of life throughout cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest

PURPOSE

Prognostication of refractory out-of-hospital cardiac arrest (OHCA) is essential for selecting the population that may benefit from extracorporeal cardiopulmonary resuscitation (ECPR). We aimed to examine the prognostic value of signs of life before or throughout conventional CPR for individuals undergoing ECPR for refractory OHCA.

METHODS

Pooling the original data from three cohort studies, we estimated the prevalence of signs of life, for individuals with refractory OHCA resuscitated with ECPR. We performed multivariable logistic regression to examine the independent associations between the occurrence of signs of life and 30-day survival with a CPC score ≤ 2.

RESULTS

The analytical sample consisted of 434 ECPR recipients. The prevalence of any sign of life was 61%, including pupillary light reaction (48%), gasping (32%), or increased level of consciousness (13%). Thirty-day survival with favorable neurological outcome was 15% (63/434). In multivariable analysis, the adjusted odds ratios of 30-day survival with favorable neurological outcome were 7.35 (95% confidence interval [CI], 2.71-19.97), 5.86 (95% CI, 2.28-15.06), 4.79 (95% CI, 2.16-10.63), and 1.75 (95% CI, 0.95-3.21) for any sign of life, pupillary light reaction, increased level of consciousness, and gasping, respectively.

CONCLUSION

The assessment of signs of life before or throughout CPR substantially improves the accuracy of a multivariable prognostic model in predicting 30-day survival with favorable neurological outcome. The lack of any sign of life might obviate the provision of ECPR for patients without shockable cardiac rhythm.

Outcome in refractory out-of-hospital cardiac arrest before and after implementation of an ECPR protocol

AIM

To compare the outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) fulfilling the criteria for extracorporeal cardiopulmonary resuscitation (ECPR) before and after implementation of an ECPR protocol, whether the patient received ECPR or not.

METHODS

We compared cardiac arrest registry data before (2014-2015) and after (2016-2019) implementation of the ECPR protocol. The ECPR criteria were presumed cardiac origin, witnessed arrest with ventricular fibrillation, bystander CPR, age 18-65, advanced life support (ALS) within 15 min and ALS > 10 min without return of spontaneous circulation (ROSC). The primary outcome was 30-day survival; the secondary outcomes were sustained ROSC, neurological outcome and the proportion of patients transported with ongoing ALS.

RESULTS

There were 1086 and 3135 patients in the pre- and post-implementation sample; 48 (4%) and 100 (3%) met the ECPR criteria, respectively. Of these, 21 (44%) vs. 37 (37%) were alive after 30 days, p = 0.4, and 30 (63%) vs. 50 (50%) achieved sustained ROSC, p = 0.2. All survivors in the pre-implementation sample had cerebral performance category 1-2 vs. 30 (81%) in the post-implementation sample, p = 0.03. Of the patients fulfilling the ECPR criteria, 7 (15%) and 26 (26%), p = 0.1, were transported with ongoing ALS in the pre- and post-implementation sample, respectively.

CONCLUSIONS

There were no differences in 30-day survival or prehospital ROSC in patients with refractory OHCA before and after initiation of an ECPR protocol.

A review of ECMO for cardiac arrest

Cardiac arrest is an important public health concern, affecting an estimated 356,500 people in the out-of-hospital setting and 209,000 people in the in-hospital setting each year. The causes of cardiac arrest include acute coronary syndromes, pulmonary embolism, dyskalemia, respiratory failure, hypovolemia, sepsis, and poisoning among many others. In order to tackle the enormous issue of high mortality among sufferers of cardiac arrest, ongoing research has been seeking improved treatment protocols and novel therapies. One of the mechanical devices that has been increasingly utilized for cardiac arrest is venoarterial extracorporeal membrane oxygenation (VA-ECMO). Presently there is only one published randomized controlled trial examining the use of VA-ECMO as part of cardiopulmonary resuscitation (CPR), a process referred to as extracorporeal cardiopulmonary resuscitation (ECPR). Recently there has been significant progress in providing ECPR for refractory cardiac arrest patients. This narrative review seeks to outline the use of ECPR for both in-hospital and out-of-hospital cardiac arrest, as well as provide information on the expected outcomes associated with its use.

Long-term neurologically intact survival after extracorporeal cardiopulmonary resuscitation for in-hospital or out-of-hospital cardiac arrest: A systematic review and meta-analysis

Background

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as extracorporeal cardiopulmonary resuscitation (ECPR) to support further resuscitation efforts in patients with cardiac arrest, yet its clinical effectiveness remains uncertain.

Objectives

This study reviews the role of ECPR in contemporary resuscitation care compared to no ECPR and/or standard care, e.g. conventional CPR, and quantitatively summarize the rates of long-term neurologically intact survival after adult in-hospital cardiac arrest (IHCA) or out-of-hospital cardiac arrest (OHCA).

Methods

We searched the following databases on January 31 st, 2020: CENTRAL, MEDLINE, Embase, and Web of Science. We followed PRISMA guidelines and used PICO format to summarize the research questions. Risk of bias was assessed using the ROBINS-I tool. Pooled risk ratios (RRs) for each outcome of interest were calculated. Quality of evidence was evaluated according to GRADE guidelines.

Results

Six cohort studies were included, totaling 1750 patients. Of these, 530 (30.3%) received the intervention, and 91 (17.2%) survived with long-term neurologically intact survival. ECPR compared to no ECPR is likely associated with improved long-term neurologically intact survival after cardiac arrest in any setting (risk ratio [RR] 3.11, 95% confidence interval [CI] 2.06–4.69; p < 0.00001) (GRADE: Very low quality). Similar results were found for long-term neurologically intact survival after IHCA (RR 3.21, 95% CI 1.74–5.94; p < 0.0002) (GRADE: Very low quality) and OHCA (RR 3.11, 95% CI 1.50–6.47; p < 0.002) (GRADE: Very low quality). Long-term time frames for neurologically intact survival (three months to two years) were combined into a single category, defined a priori as a Glasgow-Pittsburgh cerebral performance category (CPC) of 1 or 2.

Conclusions

VA-ECMO used as ECPR is likely associated with improved long-term neurologically intact survival after cardiac arrest. Future evidence from randomized trials is very likely to have an important impact on the estimated effect of this intervention and will further define optimal clinical practice. Review registration: PROSPERO CRD42020171945.

The Minnesota mobile extracorporeal cardiopulmonary resuscitation consortium for treatment of out-of-hospital refractory ventricular fibrillation: Program description, performance, and outcomes

BACKGROUND

We describe implementation, evaluate performance, and report outcomes from the first program serving an entire metropolitan area designed to rapidly deliver extracorporeal membrane oxygenation (ECMO)-facilitated resuscitation to patients with refractory ventricular fibrillation/ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA).

METHODS

This observational cohort study analyzed consecutive patients prospectively enrolled in the Minnesota Mobile Resuscitation Consortium's ECMO-facilitated resuscitation program. Entry criteria included: 1) adults (aged 18-75), 2) VF/VT OHCA, 3) no return of spontaneous circulation following 3 shocks, 4) automated cardiopulmonary resuscitation with a Lund University Cardiac Arrest System (LUCAS™), and 5) estimated transfer time of < 30 min. The primary endpoint was functionally favorable survival to hospital discharge with Cerebral Performance Category (CPC) 1 or 2. Secondary endpoints included 3-month functionally favorable survival, program benchmarks, ECMO cannulation rate, and safety. Essential program components included emergency medical services, 3 community ECMO Initiation Hospitals with emergency department ECMO cannulation sites and 24/7 cardiac catheterization laboratories, a 24/7 mobile ECMO cannulation team, and a single, centralized ECMO intensive care unit.

FINDINGS

From December 1, 2019 to April 1, 2020, 63 consecutive patients were transported and 58 (97%) met criteria and were treated by the mobile ECMO service. Mean age was 57 ± 1.8 years; 46/58 (79%) were male. Program benchmarks were variably met, 100% of patients were successfully cannulated, and no safety issues were identified. Of the 58 patients, 25/58 (43% [CI:31-56%]) were both discharged from the hospital and alive at 3 months with CPC 1 or 2.

INTERPRETATION

This first, community-wide ECMO-facilitated resuscitation program in the US demonstrated 100% successful cannulation, 43% functionally favorable survival rates at hospital discharge and 3 months, as well as safety. The program provides a potential model of this approach for other communities.

FUNDING

The Helmsley Charitable Trust.

Cost-effectiveness of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A multi-centre prospective cohort study

AIM

Extracorporeal cardiopulmonary resuscitation (ECPR) is an evolving resuscitative method for refractory cardiopulmonary arrests. However, considering the substantial healthcare costs and resources involved, there is an urgent need for a full economic evaluation. We therefore assessed the cost-effectiveness of ECPR for refractory ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT).

METHODS

We developed a decision model to estimate lifetime costs and outcomes for out-of-hospital cardiac arrest patients with VF/pVT who received either ECPR or conventional cardiopulmonary resuscitation. Quality-adjusted life-years (QALY) was used as the main outcome measure. This model was a combination of a decision tree model for the acute phase based on a prospective observational study (SAVE-J study), together with a Markov model for long-term follow-up periods extrapolated from published data. To evaluate the robustness of this model, we conducted a comprehensive deterministic sensitivity analysis (DSA) and a probabilistic sensitivity analysis (PSA).

RESULTS

ECPR was cost-effective, with an incremental cost of ¥3,521,189 (Є30,227), an incremental effectiveness of 1.34 QALY, and an incremental cost-effectiveness ratio of ¥2,619,692 (Є22,489) per QALY gained. DSA revealed that the present model was most sensitive to probability of Cerebral Performance Category 1 after ECPR (¥2,153,977/QALY to ¥3,186,475/QALY), patient age (¥2,170,112/QALY to ¥3,334,252/QALY), and long-term medical cost for modified Rankin Scale 0 (¥2,280,352/QALY to ¥2,855,330/QALY). PSA indicated ECPR to be cost-effective and below the willingness-to-pay threshold of ¥5,000,000 with an 86.7 % possibility.

CONCLUSIONS

ECPR was an economically acceptable resuscitative strategy, and the results of the present study were robust even when considering the uncertainty of all parameters.

Out-of-hospital cardiac arrest patients with an initial non-shockable rhythm could be candidates for extracorporeal cardiopulmonary resuscitation: a retrospective study

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) is a promising treatment for refractory out-of-hospital cardiac arrest (OHCA). Most studies evaluating the effectiveness of ECPR include patients with an initial shockable rhythm. However, the effectiveness of ECPR for patients with an initial non-shockable rhythm remains unknown. This retrospective single-center study aimed to evaluate the effectiveness of ECPR for patients with an initial non-shockable rhythm, with reference to the outcomes of OHCA patients with an initial shockable rhythm.

Methods

Adult OHCA patients treated with ECPR at our center during 2011–2018 were included in the study. Patients were classified into the initial shockable rhythm group and the non-shockable rhythm group. The primary outcome was the cerebral performance category (CPC) scale score at hospital discharge. A CPC score of 1 or 2 was defined as a good outcome.

Results

In total, 186 patients were eligible. Among them, 124 had an initial shockable rhythm and 62 had an initial non-shockable rhythm. Among all patients, 158 (85%) were male, with a median age of 59 (interquartile range [IQR], 48–65) years, and the median low flow time was 41 (IQR, 33–48) min. Collapse was witnessed in 169 (91%) patients, and 36 (19%) achieved return of spontaneous circulation (ROSC) transiently. Proportion of female patients, presence of bystander cardiopulmonary resuscitation, and collapse after the arrival of emergency medical service personnel were significantly higher in the non-shockable rhythm group. The rate of good outcomes at hospital discharge was not significantly different between the shockable and non-shockable groups (19% vs. 16%, p = 0.69). Initial shockable rhythm was not significantly associated with good outcome after controlling for potential confounders (adjusted odds ratio 1.58, 95% confidence interval: 0.66–3.81, p = 0.31). In the non-shockable group, patients with good outcomes had a higher rate of transient ROSC, and pulmonary embolism was the leading etiology.

Conclusions

The outcomes of patients with an initial non-shockable rhythm are comparable with those having an initial shockable rhythm. OHCA patients with an initial non-shockable rhythm could be candidates for ECPR, if they are presumed to have reversible etiology and potential for good neurological recovery.

Continuous amplitude-integrated electroencephalography for prognostication of cardiac arrest patients undergoing extracorporeal cardiopulmonary resuscitation with targeted temperature management

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has been increasingly used for adult cardiac arrest (CA) patients refractory to conventional CPR. However, data on early prognosticators of neurological outcome are lacking.

METHODS

CA patients undergoing ECPR were prospectively monitored via amplitude-integrated EEG (aEEG). Targeted temperature management (TTM) was induced using an extracorporeal membrane oxygenation system. aEEG background patterns were classified into continuous normal voltage (CNV), discontinuous normal voltage (DNV), low voltage (LV), flat trace (FT), burst suppression (BS), and status epilepticus (SE). The Cerebral Performance Category (CPC) scale scores at hospital discharge and at 6 months after discharge were assessed, as was wakefulness after TTM. Good neurological outcome was defined as a CPC score of 1 or 2.

RESULTS

Twenty-two patients were studied. Six patients who showed CNV within 24 hours after arrival, including one with initial FT and two with initial LV, regained consciousness and had good neurological outcome except for one who died of haemorrhagic complication. Patients with persistent FT or BS at any time did not regain consciousness. Regarding 19 patients in whom aEEG data were obtained within 24 hours, CNV background predicted good outcome at 6 months with 100% sensitivity, 93% specificity, 83% positive predictive values, and 100% negative predictive values. All these indices were 100% concerning wakefulness after TTM.

CONCLUSION

aEEG monitoring was feasible and practical in adult CA patients undergoing ECPR and TTM. Evolution of aEEG background within 24 hours provides early accurate information for neurological prognostication.

Extracorporeal Membrane Oxygenation in the Emergency Department

Extracorporeal membrane oxygenation (ECMO) is a mechanical way to provide oxygenation, ventilation, and perfusion to patients with severe cardiopulmonary failure. Extracorporeal cardiopulmonary resuscitation (ECPR) describes the use of ECMO during cardiac arrest. ECPR requires an organized approach to resuscitation, cannula insertion, and pump initiation. Selecting the right patients for ECPR is an important aspect of successful programs. A solid understanding of the components of the ECMO circuit is critical to troubleshooting problems. Current evidence suggests a substantial benefit of ECPR compared with traditional CPR for refractory cardiac arrest but is limited by lack of randomized trials to date.

Extracorporeal cardiopulmonary resuscitation for acute aortic dissection during cardiac arrest: A nationwide retrospective observational study

AIM

Acute aortic dissection (AAD) has been considered a contraindication for extracorporeal cardiopulmonary resuscitation (ECPR). However, studies are lacking regarding the epidemiology and effectiveness of ECPR for AAD. We aimed to examine whether ECPR for AAD during refractory cardiac arrest is effective.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018, we identified all emergently hospitalized adults who received ECPR on the day of admission and all AAD patients who received cardiopulmonary resuscitation on the day of admission. ECPR was defined as receiving both cardiopulmonary resuscitation and percutaneous extracorporeal membrane oxygenation. Outcomes were in-hospital mortality and neurological outcomes. We calculated the incremental cost-effectiveness ratio of ECPR for AAD.

RESULTS

We identified 398 AAD patients with ECPR, 9840 non-AAD patients with ECPR, and 9709 AAD patients with cardiopulmonary resuscitation but not ECPR. The incidence of AAD among the patients with ECPR on the day of admission was 3.9%. In-hospital mortality was 98% in AAD patients with ECPR, 79% in non-AAD patients with ECPR, and 98% in AAD patients with cardiopulmonary resuscitation but not ECPR. Seven AAD patients survived to discharge after ECPR; of these, six patients had good neurological outcomes at discharge. The incremental cost-effectiveness ratio of ECPR for AAD was estimated at 161,504 US dollars per quality-adjusted life year gained.

CONCLUSION

ECPR successfully improved outcomes and/or facilitated surgery for a small number of AAD patients with refractory cardiac arrest; however, the cost burden of ECPR for AAD patients may be unacceptably high.