The rate of brain death and organ donation in patients resuscitated from cardiac arrest: a systematic review and meta-analysis

Blood-brain barrier disruption and neuroinflammation in the hippocampus of a cardiac arrest porcine model: Single-cell RNA sequencing analysis

JOURNAL/nrgr/04.03/01300535-202602000-00043/figure1/v/2025-05-05T160104Z/r/image-tiff Global brain ischemia and neurological deficit are consequences of cardiac arrest that lead to high mortality. Despite advancements in resuscitation science, our limited understanding of the cellular and molecular mechanisms underlying post-cardiac arrest brain injury have hindered the development of effective neuroprotective strategies. Previous studies primarily focused on neuronal death, potentially overlooking the contributions of non-neuronal cells and intercellular communication to the pathophysiology of cardiac arrest-induced brain injury. To address these gaps, we hypothesized that single-cell transcriptomic analysis could uncover previously unidentified cellular subpopulations, altered cell communication networks, and novel molecular mechanisms involved in post-cardiac arrest brain injury. In this study, we performed a single-cell transcriptomic analysis of the hippocampus from pigs with ventricular fibrillation-induced cardiac arrest at 6 and 24 hours following the return of spontaneous circulation, and from sham control pigs. Sequencing results revealed changes in the proportions of different cell types, suggesting post-arrest disruption in the blood-brain barrier and infiltration of neutrophils. These results were validated through western blotting, quantitative reverse transcription-polymerase chain reaction, and immunofluorescence staining. We also identified and validated a unique subcluster of activated microglia with high expression of S100A8, which increased over time following cardiac arrest. This subcluster simultaneously exhibited significant M1/M2 polarization and expressed key functional genes related to chemokines and interleukins. Additionally, we revealed the post-cardiac arrest dysfunction of oligodendrocytes and the differentiation of oligodendrocyte precursor cells into oligodendrocytes. Cell communication analysis identified enhanced post-cardiac arrest communication between neutrophils and microglia that was mediated by neutrophil-derived resistin, driving pro-inflammatory microglial polarization. Our findings provide a comprehensive single-cell map of the post-cardiac arrest hippocampus, offering potential novel targets for neuroprotection and repair following cardiac arrest.

Elevated glycocalyx shedding components as the early predictors of unfavorable outcomes in patients after cardiac arrest: A single-center observational study

OBJECTIVE

To assess the association of serum glycocalyx shedding components (Heparan sulfate, HS; Hyaluronic acid, HA; Syndecan-1, Sdc-1) with outcomes after CA.

METHODS

Patients who were comatose for >24 h after CA in the intensive care unit (ICU) of the Affiliated Hospital of Xuzhou Medical University from 9/2021 to 04/2023 were enrolled. Serum samples were collected 24 h after CA to measure the concentrations of glycocalyx shedding components. The outcomes were the 30-day Cerebral Performance Categories (CPC) scale and 30-day mortality. The association of glycocalyx shedding with outcomes was examined by regression analysis. The area under the curve was used to evaluate the value of glycocalyx shedding for predicting outcomes. Sensitivity analysis and subgroup analysis were conducted.

RESULTS

111 patients were enrolled. The unfavorable group (CPC 3-5, n = 69) had significantly higher serum concentrations of HA and Sdc-1 than the favorable group (CPC 1-2, n = 42) (HA:149.7 ng/ml vs. 824.8 ng/ml, P < 0.001; Sdc-1: 303.8 ng/L vs. 447.0 ng/L, P = 0.026)but not HS. Elevated serum HA concentrations was an independent risk factor for unfavorable 30-day neurological function (OR = 2.485, 95 % CI = 1.656-3.729). For the 30-day mortality, the nonsurvivor group (n = 53) had significantly higher serum concentrations of HA, HS and Sdc-1 (HA: 177.3 ng/ml vs. 1106.7 ng/ml, P < 0.001; HS: 2403.7 ng/ml vs. 3383.3 ng/ml P = 0.030; Sdc-1: 352.1 ng/L vs. 487.8 ng/L, P = 0.005) than the survivor group (n = 58). However, only elevated serum HA and Sdc-1 concentrations are independent risk factors for 30-day mortality (HA: HR = 2.321, 95 % CI = 1.776-3.035; Sdc-1: HR = 1.702, 95 % CI = 1.038-2.792).

CONCLUSIONS

Elevated serum HA at 24 h after CA is an independent risk factor for 30-day unfavorable neurological function or mortality and elevated serum Sdc-1 concentrations is an independent risk factor for 30-day mortality. Our results suggested the potential value of serum glycocalyx shedding components as predictors for the outcomes in post-CA patients.

Histopathological patterns of hypoxic-ischemic encephalopathy after cardiac arrest: A retrospective brain autopsy study of 319 patients

PURPOSE

Understanding the pathophysiology of hypoxic-ischemic encephalopathy (HIE) provides important knowledge for the interpretation of neuroprognostic investigations after cardiac arrest (CA). One important aspect are the patterns of regional severity of selective neuronal death within the brain.

METHODS

In a monocentric, retrospective study, we included CA patients with initially successful resuscitation, who had received brain autopsies after death. We quantified selective eosinophilic neuronal death (SEND) in cerebral neocortex, hippocampus, basal ganglia, cerebellum, and brainstem. Using a previously established classification, we dichotomized HIE severity in SEND 0-1 (<30%, reflecting no or mild HIE) versus SEND 2-4 (≥30%, reflecting moderate to severe HIE). We analyzed histopathological HIE patterns and analyzed inter-regional and inter-neocortical correlation of SEND.

RESULTS

Of 319 patients, the mean SEND was 1.8 in hippocampus, 1.4 in neocortex, and 0.9 in brainstem. Typical histopathological HIE patterns were: (I) No or mild SEND in all brain regions, (II) predominant SEND in hippocampus with no or mild SEND in other brain regions, (III) severe SEND in neocortex, but not in brainstem, and (IV) severe SEND in the brainstem with neocortical HIE. In 7(9.7%) of 72 patients with histopathology from two different neocortical regions, the SEND differed by more than 30%. Among 154 patients with a SEND greater than 30% in at least one brain region, 14(9.1%) had predominant SEND in cerebellum, and 4(2.6%) predominant SEND in basal ganglia.

CONCLUSIONS

CA causes typical histopathological HIE patterns, with the hippocampus being more susceptible to SEND, than the cerebral neocortex, and the brainstem being the most resistant brain region. The neocortical distribution of SEND is mostly homogeneous; however, a relevant subgroup shows substantial neocortical HIE heterogeneity. Further studies are required to provide a more granular histopathological analysis of infrequent HIE patterns and their implications for neuroprognostication.

Association of emergency intensive care unit occupancy due to brain-dead organ donors with ambulance diversion

Our study aims to explore how intensive care unit (ICU) occupancy by brain-dead organ donors affects emergency ambulance diversions. In this retrospective, single-center study at an emergency ICU (EICU), brain-dead organ donors were managed until organ procurement. We classified each day between August 1, 2021, and July 31, 2023, as either an exposure day (any day with a brain-dead organ donor in the EICU from admission to organ procurement) or a control day (all other days). The study compared these days and used multiple logistic regression analysis to assess the impact of EICU occupancy by brain-dead organ donors on ambulance diversions. Over two years, 6,058 emergency patients were transported by ambulance, with 1327 admitted to the EICU, including 13 brain-dead organ donors. Brain-dead donors had longer EICU stays (17 vs. 2 days, P < 0.001). With 168 exposure and 562 control days, EICU occupancy was higher on exposure days (75% vs. 67%, P = 0.003), leading to more ambulance diversions. Logistic regression showed exposure days significantly increased ambulance diversions, with an odds ratio of 1.79 (95% CIs 1.10-2.88). This study shows that managing brain-dead organ donors in the EICU leads to longer stays and higher occupancy, resulting in more frequent ambulance diversions. These findings highlight the critical need for policies that optimize ICU resource allocation while maintaining the infrastructure necessary to support organ donation programs and ensuring continued care for brain-dead donors, who play an essential role in addressing the organ shortage crisis.

Association of targeted temperature management on progression to brain death after severe anoxic brain injury following cardiac arrest: an observational study

OBJECTIVE

Targeted temperature management (TTM), through its physiological effects on intracranial pressure, may impede the progression to brain death (BD) in severe anoxic brain injury post-cardiac arrest (CA). We examined the potential association between the use of TTM and the occurrence of BD after CA.

DESIGN

Monocentric, retrospective study.

SETTING

Intensive care unit, Versailles Hospital, France.

PARTICIPANTS

Comatose survivors of CA who died from BD or postanoxic encephalopathy (PAE) after 24 hours.

MAIN OUTCOME MEASURES

PAE deaths corresponded to withdrawal of life-sustaining therapy (WLST) due to irreversible postanoxic coma or vegetative state according to prognostication guidelines. BD corresponded to the cessation of cerebral vascularisation secondary to intracranial hypertension. The diagnosis of BD was definite by clinical diagnosis of deep coma according to the Glasgow Coma Scale 3, loss of all brainstem reflexes and the demonstration of apnoea during a hypercapnia test. A cerebral omputed tomography (CT) scan or two isoelectric and unreactive electroencephalograms were used to confirm BD. To identify the independent association between TTM and BD, we conducted a multivariable logistic regression analysis.

RESULTS

Out of 256 patients included between 2005 and 2021, 54.3% received TTM for at least 24 hours, and 56 patients (21.9%) died from BD. In the multivariable analysis, TTM for 24 hours or more was not associated with a decrease in BD (Odds Ratio 1.08, 95% CI 0.51 to 2.32). Factors associated with BD included a total duration of no-flow plus low-flow exceeding 30 min, CA due to neurological causes or hanging and a high arterial partial pressure of carbon dioxide between days 1 and 2 after admission.

CONCLUSIONS

This exploratory analysis of post-CA patients with severe anoxic brain injury did not find an association between TTM ≥24 hours and a reduction in BD. Further studies are needed to identify specific subgroups of post-CA patients for whom TTM may be especially futile or even harmful.

Organ Utilization From Donors Following Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review of Graft and Recipient Outcome

BACKGROUND

The global shortage of solid organs for transplantation is exacerbated by high demand, resulting in organ deficits and steadily growing waiting lists. Diverse strategies have been established to address this issue and enhance organ availability, including the use of organs from individuals who have undergone extracorporeal cardiopulmonary resuscitation (eCPR). The main aim of this work was to examine the outcomes for both graft and recipients of solid organ transplantations sourced from donors who underwent eCPR.

METHODS

We performed a systematic literature review using a combination of the terms related to extracorporeal life support and organ donation. Using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, PubMed and Scopus databases were searched up to February 2024.

RESULTS

From 1764 considered publications, 13 studies comprising 130 donors and 322 organ donations were finally analyzed. On average, included patients were 36 y old, and the extracorporeal life support was used for 4 d. Kidneys were the most often transplanted organs (68%; 220/322), followed by liver (22%; 72/322) and heart (5%; 15/322); with a very good short-term graft survival rate (95% for kidneys, 92% for lungs, 88% for liver, and 73% for heart). Four studies with 230 grafts reported functional outcomes at the 1-y follow-up, with graft losses reported for 4 hearts (36%), 8 livers (17%), and 7 kidneys (4%).

CONCLUSIONS

Following eCPR, organs can be successfully used with very high graft and recipient survival. In terms of meeting demand, the use of organs from patients after eCPR might be a suitable method for expanding the organ donation pool.

Optic Nerve Sheath Diameter in Predicting the Neurological Outcomes of Cardiac Arrest Survivors: A Systematic Review and Meta-analysis

Introduction

Previous studies have investigated different methods for estimating neurological outcomes after cardiac arrest. However, there is still much uncertainty about using optic nerve sheath diameter (ONSD) measurement as an indirect method for predicting neurological outcomes following cardiac arrest. In this meta-analysis, we aimed to investigate the value of ONSD for predicting the neurological outcomes of cardiac arrest survivors.

Methods

We comprehensively performed a systematic search in three main electronic databases, including Scopus, Medline, and Web of Science Cochrane, from inception to August 2024. Based on the heterogeneity evaluation results, fixed or random effects models were used to estimate the pooled diagnostic parameters. Meta-regressions were performed for subgroup analysis.

Results

The pooled sensitivity and specificity of ONSD for predicting the neurological outcomes were 0.56 (95% CI, 0.35-0.74) and 0.92 (95% CI, 0.85-0.96), respectively. Meta-regression revealed that as the cutoff level of ONSD increases, the sensitivity significantly decreases (P < 0.01), while the specificity significantly increases (P = 0.01). Furthermore, meta-regression analysis revealed that ONSD measurement using CT scans is significantly associated with lower sensitivity and higher specificity compared to ultrasound (P = 0.009 and P = 0.01).

Conclusion

Our meta-analysis showed that ONSD has low sensitivity and high specificity for predicting neurological outcomes in survivors of cardiac arrest. However, since the cut-off values and methods of ONSD measurement affect its predictive performance, further studies will be required to standardize these factors to achieve optimal predictive parameters.

The dynamics of organ donation in Palestine: legal, religious, and socioeconomic perspectives in a complex political and economic landscape

Background

Organ donation in Palestine is influenced by a unique blend of legal, religious, and socioeconomic factors compounded by the region's political and economic instability. Despite the increasing need for organ transplantation, public hesitation and misconceptions hinder participation. This study aimed to explore these dynamics, identify barriers, and provide insights into improving organ donation practices in Palestine.

Methods

A quantitative survey was conducted among 639 Palestinian adults residing on the West Bank. The survey assessed participants' attitudes, awareness, and perceptions of organ donation across three domains: religious/psychological, medical, and legal. The data were analyzed using chi-square tests and three-way ANOVA to explore differences in attitudes based on demographic factors such as sex, academic level, and place of residence.

Results

The study revealed significant variability in public attitudes toward organ donation, with 43.4% willing to donate organs after death but 30% still opposed. Religious and psychological awareness significantly influenced participants' attitudes, with 40.35% agreeing that organ donation aligns with their beliefs. Medical awareness was higher, with 48.8% feeling informed about the process. Legal awareness was moderate, with 44.85% understanding of the legal framework. The analysis showed no significant demographic differences in attitudes toward organ donation.

Conclusion

Public awareness, religious beliefs, and socioeconomic conditions play crucial roles in shaping organ donation attitudes in Palestine. This study highlights the need for targeted educational campaigns that integrate religious perspectives and raise awareness about the legal and medical aspects of organ donation. Strengthening legal frameworks and healthcare infrastructure will be key to improving organ donation rates and ensuring ethical practices in the region.

Solid organ transplantation originating from uncontrolled donation after circulatory death in Europe: a narrative review

Human organ transplantation has begun in the 1960s with donation after circulatory death. At that time this was named non heart beating donation, later donation after cardiac death and nowadays it is named donation after circulatory death. Currently, we are facing a significant shortage of transplant organs in Europe and worldwide. To increase the graft acceptance from donation after controlled or uncontrolled circulatory death, preceding regional normothermic perfusion by an extracorporeal circulation before organ procurement or ex-situ machine perfusion are frequently implemented in clinical practice as organ assessment and reconditioning techniques. Due to these advancements more organs can be potentially transplanted, even after out-of-hospital cardiac arrest (OHCA). First line actors like emergency physicians and pre-hospital paramedics must be aware of such programs to recognize and refer patients for donation in OHCA situations. This review provides an overview of organs transplanted from uncontrolled donation after circulatory death (uDCD) and emphasize the role of the emergency physician in the organ donation cascade. Outcome of uDCD has a lower effectiveness than donation after brain death (DBD) and controlled donation after circulatory death (cDCD) for short term graft survival. However, observational studies illustrate that long term outcome from uDCD is comparable to graft outcome from cDCD and DBD. We summarize the studies reporting the procured organ rate and functional outcome of organs originated from uDCD. European databases indicate a high incidence of OHCA, where resuscitation efforts are initiated but the rate of return of spontaneous circulation (ROSC) remains limited. These patients represent a substantial potential pool of organ donors for uDCD programs. However, these programs tend to overestimate the number of potential donors. While organ procurement from uDCD has yielded favorable outcomes, further research is required to accurately assess the associated costs and benefits and to establish clear donor selection guidelines. Furthermore, the use of new technologies like extracorporeal Cardiopulmonary Resuscitation (E-CPR) for organ donation should be investigated from both medical and economical perspectives. Emergency departments must also explore the feasibility of implementing these programs.

Optimizing brain protection after cardiac arrest: advanced strategies and best practices

Cardiac arrest (CA) is associated with high incidence and mortality rates. Among patients who survive the acute phase, brain injury stands out as a primary cause of death or disability. Effective intensive care management, including targeted temperature management, seizure treatment and maintenance of normal physiological parameters, plays a crucial role in improving survival and neurological outcomes. Current guidelines advocate for neuroprotective strategies to mitigate secondary brain injury following CA, although certain treatments remain subjects of debate. Clinical examination and neuroimaging studies, both invasive and non-invasive neuromonitoring methods and serum biomarkers are valuable tools for predicting outcomes in comatose resuscitated patients. Neuromonitoring, in particular, provides vital insights for identifying complications, personalizing treatment approaches and forecasting prognosis in patients with brain injury post-CA. In this review, we offer an overview of advanced strategies and best practices aimed at optimizing brain protection after CA.

Temporal trends in organ donation among cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation

AIMS

This study explores the evolution of organ donation from patients treated with extracorporeal-cardiopulmonary-resuscitation (ECPR) for refractory out-of-hospital-cardiac-arrest (OHCA) and evaluates the public health benefits of a mature ECPR program.

METHODS

This retrospective, single-center study included OHCA patients (2016-2023) who had mostly initial shockable rhythms and were treated with ECPR. Organ donation rates from non-survivors through these years were analyzed. The public health benefit of ECPR was determined by the ratio of the sum of survivors with Cerebral Performance Category 1-2 and non-survivors who donated at least 1 solid organ, to the total ECPR patients. Temporal trends were analyzed yearly using linear regression.

RESULTS

Out of 419 ECPR patients presenting with refractory OHCA over the study period, 116 survived neurologically intact (27.7%). Among non-survivors (n = 303), families of 41 (13.5%) consented to organ donation (median age 51 years, 75.6% male) and organs from 38 patients were harvested, leading to 74 organ transplants to 73 recipients. The transplanted organs included 43 kidneys (58.1%), 27 livers (36.5%), 3 lungs (4%), and 1 heart (1.4%), averaging 2.4 ± 0.9 accepted organs/donor. The number of organ donors and successful transplants correlated positively with the years since the ECPR program's initiation (ptrend = 0.009, ptrend = 0.01). Overall, 189 patients (116 survivors, 73 organ recipients) benefited from ECPR, achieving organ-failure-free survival. The cumulative public health benefit of ECPR, considering the 116 survivors and 38 donors was 36.8%.

CONCLUSION

The public health benefits of an established ECPR program extend beyond individual ECPR patient survival, forming a new, previously under-recognized source of transplant donors.

Potential organ donors during two years at the second largest hospital in Norway

BACKGROUND

Western Norway has the lowest number of actual deceased organ donors per million inhabitants in Norway. We wished to find the total number of potential donors and donor organs during 2 years at Haukeland University Hospital, the largest hospital in the region, and evaluate where and why potential donors were lost.

METHODS

We evaluated all patients who died at Haukeland University Hospital in 2018-19. We checked if intensive care patients, filling the criteria as organ donors after brain death, became donors, and the reasons why potential donors were lost. We also estimated the number of potential donors after circulatory death. We checked if patients transferred from the intensive care units and patients never admitted to intensive care were potential donors. Location, gender, age, and possible number of organs were registered.

RESULTS

Of 1453 in-hospital deaths, 20 brain-dead patients became actual donors. One brain-dead and two other potential donors, one of them discharged to a bed ward, were not evaluated at the intensive care units. Relatives refused in five patients. Three fulfilled the Norwegian criteria from 2021 as organ donors after circulatory death. Ten potential donors after brain death were never admitted to intensive care and died on neurological or neurosurgical wards. If all potential organ donors were realised, the number of donors would double. The number of transplanted organs would increase less, as organs used per donor would drop from 3.50 to 2.90.

CONCLUSION

Our study cannot explain the low number of donors in our region compared with the rest of Norway. If all potential donations were implemented, the number of actual donors would double. Patients dying outside the intensive care units represent the largest potential source for extra donors, maximally increasing the number of donors by 42%, high-quality livers 44% and kidneys 18%. Introducing organ donation after circulatory death may increase the number of donors by 15% and the number of high-quality livers and kidneys by 12%.

Brain death/death by neurologic criteria: What you need to know

ABSTRACT

Since the beginning of time, man has been intrigued with the question of when a person is considered dead. Traditionally, death has been considered the cessation of all cardiorespiratory function. At the end of the last century a new definition was introduced into the lexicon surrounding death in addition to cessation of cardiac and respiratory function: Brain Death/Death by Neurologic Criteria (BD/DNC). There are medical, legal, ethical, and even theological controversies that surround this diagnosis. In addition, there is no small amount of confusion among medical practitioners regarding the diagnosis of BD/DNC. For families enduring the devastating development of BD/DNC in their loved one, it is the duty of the principal caregiver to provide a transparent presentation of the clinical situation and clear definitive explanation of what constitutes BD/DNC. In this report, we present a historical outline of the development of BD/DNC as a clinical entity, specifically how one goes about making a determination of BD/DNC, what steps are taken once a diagnosis of BD/DNC is made, a brief discussion of some of the ethical/moral issues surrounding this diagnosis, and finally the caregiver approach to the family of a patient who had been declared with BD/DNC. It is our humble hope that with a greater understanding of the myriad of complicated issues surrounding the diagnosis of BD/DNC that the bedside caregiver can provide needed closure for both the patient and the family enduring this critical time in their life.

Assessing feasibility of proposed extracorporeal cardiopulmonary resuscitation programmes for out-of-hospital cardiac arrest in Scotland via geospatial modelling

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) can improve survival for refractory out-of-hospital cardiac arrest (OHCA). We sought to assess the feasibility of a proposed ECPR programme in Scotland, considering both in-hospital and pre-hospital implementation scenarios.

METHODS

We included treated OHCAs in Scotland aged 16-70 between August 2018 and March 2022. We defined those clinically eligible for ECPR as patients where the initial rhythm was ventricular fibrillation, ventricular tachycardia, or pulseless electrical activity, and where pre-hospital return of spontaneous circulation was not achieved. We computed the call-to-ECPR access time interval as the amount of time from emergency medical service (EMS) call reception to either arrival at an ECPR-ready hospital or arrival of a pre-hospital ECPR crew. We determined the number of patients that had access to ECPR within 45 min, and estimated the number of additional survivors as a result.

RESULTS

A total of 6,639 OHCAs were included in the geospatial modelling, 1,406 of which were eligible for ECPR. Depending on the implementation scenario, 52.9-112.6 (13.8-29.4%) OHCAs per year had a call-to-ECPR access time within 45 min, with pre-hospital implementation scenarios having greater and earlier access to ECPR for OHCA patients. We further estimated that an ECPR programme in Scotland would yield 11.8-28.2 additional survivors per year, with the pre-hospital implementation scenarios yielding higher numbers.

CONCLUSION

An ECPR programme for OHCA in Scotland could provide access to ECPR to a modest number of eligible OHCA patients, with pre-hospital ECPR implementation scenarios yielding higher access to ECPR and higher numbers of additional survivors.

Organ donation after extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest in a metropolitan cardiac arrest centre in Milan, Italy

INTRODUCTION

Extracorporeal cardiopulmonary resuscitation (ECPR) may improve survival in refractory out-of-hospital cardiac arrest (OHCA) but also expand the donor pool as these patients often become eligible for organ donation. Our aim is to describe the impact of organ donation in OHCA patients treated with ECPR in a high-volume cardiac arrest centre.

METHODS

Rate of organ donation (primary outcome), organs harvested, a composite of patient survival with favourable neurological outcome or donation of ≥1 solid organ (ECPR benefit), and the potential total number of individuals benefiting from ECPR (survivors with favourable neurological outcome and potential recipients of one solid organ) were analysed among all-rhythms refractory OHCA patients treated with ECPR between January 2013-November 2022 at San Raffaele Hospital in Milan, Italy.

RESULTS

Among 307 adults with refractory OHCA treated with ECPR (95% witnessed, 66% shockable, low-flow 70 [IQR 58-81] minutes), 256 (83%) died during hospital stay, 33% from brain death. Donation of at least one solid organ occurred in 58 (19%) patients, 53 (17%) after determination of brain death and 5 (1.6%) after determination of circulatory death, contributing a total of 167 solid organs (3.0 [IQR 2.5-4.0] organs/donor). Overall, 196 individuals (29 survivors with favourable neurological outcome and 167 potential recipients of 1 solid organ) possibly benefited from ECPR. ECPR benefit composite outcome was achieved in 87 (28%) patients. Solid organ donation decreased from 19% to 16% in patients with low-flow <60 min and to 11% with low-flow <60 min and initial shockable rhythm.

CONCLUSIONS

When ECPR fails in patients with refractory OHCA, organ donation after brain or circulatory death can help a significant number of patients awaiting transplantation, enhancing the overall benefit of ECPR. ECPR selection criteria may affect the number of potential organ donors.

Clinical Factors Associated With Mode of Death Following Cardiac Arrest

BACKGROUND

Death after resuscitation from cardiac arrest is common. Although associated factors have been identified, knowledge about their relationship with specific modes of death is limited.

OBJECTIVE

To identify clinical factors associated with specific modes of death following cardiac arrest.

METHODS

This study involved a retrospective medical record review of patients admitted to a single health care center from January 2015 to March 2020 after resuscitation from cardiac arrest who died during their index hospitalization. Mode of death was categorized as either brain death, withdrawal of life-sustaining therapies due to neurologic causes, death due to medical causes, or withdrawal of life-sustaining therapies due to patient preference. Clinical characteristics across modes of death were compared.

RESULTS

The analysis included 731 patients. Death due to medical causes was the most common mode of death. Compared with the other groups of patients, those with brain death were younger, had fewer comorbidities, were more likely to have experienced unwitnessed and longer cardiac arrest, and had more severe acidosis and hyperglycemia on presentation. Patients who died owing to medical causes or withdrawal of life-sustaining therapies due to patient preference were older and had more comorbidities, fewer unfavorable cardiac arrest characteristics, and fewer days between cardiac arrest and death.

CONCLUSIONS

Significant associations were found between several clinical characteristics and specific mode of death following cardiac arrest. Decision-making regarding withdrawal of care after resuscitation from cardiac arrest should be based on a multimodal approach that takes account of a variety of personal and clinical factors.

Emergent Management of Hypoxic-Ischemic Brain Injury

OBJECTIVE

This article outlines interventions used to improve outcomes for patients with hypoxic-ischemic brain injury after cardiac arrest.

LATEST DEVELOPMENTS

Emergent management of patients after cardiac arrest requires prevention and treatment of primary and secondary brain injury. Primary brain injury is minimized by excellent initial resuscitative efforts. Secondary brain injury prevention requires the detection and correction of many pathophysiologic processes that may develop in the hours to days after the initial arrest. Key physiologic parameters important to secondary brain injury prevention include optimization of mean arterial pressure, cerebral perfusion, oxygenation and ventilation, intracranial pressure, temperature, and cortical hyperexcitability. This article outlines recent data regarding the treatment and prevention of secondary brain injury. Different patients likely benefit from different treatment strategies, so an individualized approach to treatment and prevention of secondary brain injury is advisable. Clinicians must use multimodal sources of data to prognosticate outcomes after cardiac arrest while recognizing that all prognostic tools have shortcomings.

ESSENTIAL POINTS

Neurologists should be involved in the postarrest care of patients with hypoxic-ischemic brain injury to improve their outcomes. Postarrest care requires nuanced and patient-centered approaches to the prevention and treatment of primary and secondary brain injury and neuroprognostication.

Organ donation after extracorporeal cardiopulmonary resuscitation: a nationwide retrospective cohort study

BACKGROUND

Limited data are available on organ donation practices and recipient outcomes, particularly when comparing donors who experienced cardiac arrest and received extracorporeal cardiopulmonary resuscitation (ECPR) followed by veno-arterial extracorporeal membrane oxygenation (ECMO) decannulation, versus those who experienced cardiac arrest without receiving ECPR. This study aims to explore organ donation practices and outcomes post-ECPR to enhance our understanding of the donation potential after cardiac arrest.

METHODS

We conducted a nationwide retrospective cohort study using data from the Japan Organ Transplant Network database, covering all deceased organ donors between July 17, 2010, and August 31, 2022. We included donors who experienced at least one episode of cardiac arrest. During the study period, patients undergoing ECMO treatment were not eligible for a legal diagnosis of brain death. We compared the timeframes associated with each donor's management and the long-term graft outcomes of recipients between ECPR and non-ECPR groups.

RESULTS

Among 370 brain death donors with an episode of cardiac arrest, 26 (7.0%) received ECPR and 344 (93.0%) did not; the majority were due to out-of-hospital cardiac arrests. The median duration of veno-arterial ECMO support after ECPR was 3 days. Patients in the ECPR group had significantly longer intervals from admission to organ procurement compared to those not receiving ECPR (13 vs. 9 days, P = 0.005). Lung graft survival rates were significantly lower in the ECPR group (log-rank test P = 0.009), with no significant differences in other organ graft survival rates. Of 160 circulatory death donors with an episode of cardiac arrest, 27 (16.9%) received ECPR and 133 (83.1%) did not. Time intervals from admission to organ procurement following circulatory death and graft survival showed no significant differences between ECPR and non-ECPR groups. The number of organs donated was similar between the ECPR and non-ECPR groups, regardless of brain or circulatory death.

CONCLUSIONS

This nationwide study reveals that lung graft survival was lower in recipients from ECPR-treated donors, highlighting the need for targeted research and protocol adjustments in post-ECPR organ donation.

Survival, but not the severity of hypoxic-ischemic encephalopathy, is associated with higher mean arterial blood pressure after cardiac arrest: a retrospective cohort study

Background

This study investigates the association between the mean arterial blood pressure (MAP), vasopressor requirement, and severity of hypoxic-ischemic encephalopathy (HIE) after cardiac arrest (CA).

Methods

Between 2008 and 2017, we retrospectively analyzed the MAP 200 h after CA and quantified the vasopressor requirements using the cumulative vasopressor index (CVI). Through a postmortem brain autopsy in non-survivors, the severity of the HIE was histopathologically dichotomized into no/mild and severe HIE. In survivors, we dichotomized the severity of HIE into no/mild cerebral performance category (CPC) 1 and severe HIE (CPC 4). We investigated the regain of consciousness, causes of death, and 5-day survival as hemodynamic confounders.

Results

Among the 350 non-survivors, 117 had histopathologically severe HIE while 233 had no/mild HIE, without differences observed in the MAP (73.1 vs. 72.0 mmHg, pgroup = 0.639). Compared to the non-survivors, 211 patients with CPC 1 and 57 patients with CPC 4 had higher MAP values that showed significant, but clinically non-relevant, MAP differences (81.2 vs. 82.3 mmHg, pgroup < 0.001). The no/mild HIE non-survivors (n = 54), who regained consciousness before death, had higher MAP values compared to those with no/mild HIE (n = 179), who remained persistently comatose (74.7 vs. 69.3 mmHg, pgroup < 0.001). The no/mild HIE non-survivors, who regained consciousness, required fewer vasopressors (CVI 2.1 vs. 3.6, pgroup < 0.001). Independent of the severity of HIE, the survivors were weaned faster from vasopressors (CVI 1.0).

Conclusions

Although a higher MAP was associated with survival in CA patients treated with a vasopressor-supported MAP target above 65 mmHg, the severity of HIE was not. Awakening from coma was associated with less vasopressor requirements. Our results provide no evidence for a MAP target above the current guideline recommendations that can decrease the severity of HIE.

Blood-brain barrier permeability for the first 24 hours in hypoxic-ischemic brain injury following cardiac arrest

BACKGROUND

This study aimed to explore the changes in blood-brain barrier (BBB) permeability and intracranial pressure (ICP) for the first 24 h after the return of spontaneous circulation (ROSC) and their association with injury severity of cardiac arrest.

METHODS

This prospective study analysed the BBB permeability assessed using the albumin quotient (Qa) and ICP every 2 h for the first 24 h after ROSC. The injury severity of cardiac arrest was assessed using Pittsburgh Cardiac Arrest Category (PCAC) scores. The primary outcome was the time course of changes in the BBB permeability and ICP for the first 24 h after ROSC and their association with injury severity (PCAC scores of 1-4).

RESULTS

Qa and ICP were measured 274 and 197 times, respectively, in 32 enrolled patients. Overall, the BBB permeability increased progressively over time after ROSC, and then it increased significantly at 18 h after ROSC compared with the baseline. In contrast, the ICP revealed non-significant changes for the first 24 h after ROSC. The Qa in the PCAC 2 group was < 0.01, indicating normal or mild BBB disruption at all time points, whereas the PCAC 3 and 4 groups showed a significant increase in BBB permeability at 14 and 22 h, and 12 and 14 h after ROSC, respectively.

CONCLUSION

BBB permeability increased progressively over time for the first 24 h after ROSC despite post-resuscitation care, whereas ICP did not change over time. BBB permeability has an individual pattern when stratified by injury severity.

A Comprehensive Review and Practical Guide of the Applications of Evoked Potentials in Neuroprognostication After Cardiac Arrest

Cardiorespiratory arrest is a very common cause of morbidity and mortality nowadays, and many therapeutic strategies, such as induced coma or targeted temperature management, are used to reduce patient sequelae. However, these procedures can alter a patient's neurological status, making it difficult to obtain useful clinical information for the reliable estimation of neurological prognosis. Therefore, complementary investigations are conducted in the early stages after a cardiac arrest to clarify functional prognosis in comatose cardiac arrest survivors in the first few hours or days. Current practice relies on a multimodal approach, which shows its greatest potential in predicting poor functional prognosis, whereas the data and tools to identify patients with good functional prognosis remain relatively limited in comparison. Therefore, there is considerable interest in investigating alternative biological parameters and advanced imaging technique studies. Among these, somatosensory evoked potentials (SSEPs) remain one of the simplest and most reliable tools. In this article, we discuss the technical principles, advantages, limitations, and prognostic implications of SSEPs in detail. We will also review other types of evoked potentials that can provide useful information but are less commonly used in clinical practice (e.g., visual evoked potentials; short-, medium-, and long-latency auditory evoked potentials; and event-related evoked potentials, such as mismatch negativity or P300).

Simple approach to quantify hypoxic-ischemic brain injury severity from computed tomography imaging files after cardiac arrest

BACKGROUND

Grey-white ratio (GWR) can estimate severity of cytotoxic cerebral edema secondary to hypoxic-ischemic brain injury after cardiac arrest and predict progression to death by neurologic criteria (DNC). Current approaches to calculating GWR are not standardized and have variable interrater reliability. We tested if measures of variance of brain density on early computed tomographic (CT) imaging after cardiac arrest could predict DNC.

METHODS

We performed a retrospective cohort study, identifying post-arrest patients treated between 2011 and 2020 at our single center. We extracted demographic data from our registry and Digital Imaging and Communication in Medicine (DICOM) files for each patient's first brain CT. We analyzed slices 15-20 of each DICOM, corresponding to the level of the basal ganglia while accommodating differences in patient anatomy. We extracted pixel arrays and converted the radiodensities to Hounsfield units (HU). To focus on brain tissue densities, we excluded HU > 60 and < 10. We calculated the variance of each patient's HU distribution and the difference between the means of a two-group Gaussian finite mixture model. We compared these novel metrics to existing measures of cerebral edema, then randomly divided our data into 80% training and 20% test sets and used logistic regression to predict DNC.

RESULTS

Of 1,133 included subjects, 457 (40%) were female, mean (standard deviation) age was 58 (16) years, and 115 (10%) progressed to DNC. CTs were obtained a median [interquartile range] of 4.2 [2.8-5.7] hours post-arrest. Our novel measures correlated weakly with GWR. HU variance, but not difference between mixture model means, differed significantly between subjects with and without sulcal or cistern effacement. GWR outperformed our novel measures in predicting progression to DNC with an area under the receiver operating characteristic curve (AUC) of 0.82, compared to HU variance (AUC = 0.73) and the difference between mixture model means (AUC = 0.56).

CONCLUSION

There are differences in the distribution of HU on post-arrest CT in patients with qualitative measures of cerebral edema. Current methods to quantify cerebral edema outperform simple measures of attenuation variance on early brain CT. Further analyses could investigate if these measures of variance, or other distributional characteristics of brain density, have improved predictive performance on brain CTs obtained later in the clinical course or derived from discrete regions of anatomical interest.

2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Cardiac arrest is common and deadly, affecting up to 700 000 people in the United States annually. Advanced cardiac life support measures are commonly used to improve outcomes. This "2023 American Heart Association Focused Update on Adult Advanced Cardiovascular Life Support" summarizes the most recent published evidence for and recommendations on the use of medications, temperature management, percutaneous coronary angiography, extracorporeal cardiopulmonary resuscitation, and seizure management in this population. We discuss the lack of data in recent cardiac arrest literature that limits our ability to evaluate diversity, equity, and inclusion in this population. Last, we consider how the cardiac arrest population may make up an important pool of organ donors for those awaiting organ transplantation.

A review of pre-hospital extracorporeal cardiopulmonary resuscitation and its potential application in the North East of England

Patients in the UK who suffer an out-of-hospital cardiac arrest are treated with cardiopulmonary resuscitation in the pre-hospital environment. Current survival outcomes are low in out-of-hospital cardiac arrest. Extracorporeal cardiopulmonary resuscitation is a technique which is offered to patients in specialised centres which provides better blood flow and oxygen delivery than conventional chest compressions. Shortening the interval between cardiac arrest and restoration of circulation is associated with improved outcomes in extracorporeal cardiopulmonary resuscitation. Delivering extracorporeal cardiopulmonary resuscitation in the pre-hospital environment can shorten this interval, improving outcomes in out-of-hospital cardiac arrest. This article will review recently published studies and summarise studies currently being undertaken in pre-hospital extracorporeal cardiopulmonary resuscitation. It will also discuss the potential application of a pre-hospital extracorporeal cardiopulmonary resuscitation programme in the North East of England.

Cumulative dose of epinephrine and mode of death after non-shockable out-of-hospital cardiac arrest: a registry-based study

BACKGROUND

Epinephrine increases the chances of return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA), especially when the initial rhythm is non-shockable. However, this drug could also worsen the post-resuscitation syndrome (PRS). We assessed the association between epinephrine use during cardiopulmonary resuscitation (CPR) and subsequent intensive care unit (ICU) mortality in patients with ROSC after non-shockable OHCA.

METHODS

We used data prospectively collected in the Sudden Death Expertise Center (SDEC) registry (capturing OHCA data located in the Greater Paris area, France) between May 2011 and December 2021. All adults with ROSC after medical, cardiac and non-cardiac causes, non-shockable OHCA admitted to an ICU were included. The mode of death in the ICU was categorized as cardiocirculatory, neurological, or other.

RESULTS

Of the 2,792 patients analyzed, there were 242 (8.7%) survivors at hospital discharge, 1,004 (35.9%) deaths from cardiocirculatory causes, 1,233 (44.2%) deaths from neurological causes, and 313 (11.2%) deaths from other etiologies. The cardiocirculatory death group received more epinephrine (4.6 ± 3.8 mg versus 1.7 ± 2.8 mg, 3.2 ± 2.6 mg, and 3.5 ± 3.6 mg for survivors, neurological deaths, and other deaths, respectively; p < 0.001). The proportion of cardiocirculatory death increased linearly (R2 = 0.92, p < 0.001) with cumulative epinephrine doses during CPR (17.7% in subjects who did not receive epinephrine and 62.5% in those who received > 10 mg). In multivariable analysis, a cumulative dose of epinephrine was strongly associated with cardiocirculatory death (adjusted odds ratio of 3.45, 95% CI [2.01-5.92] for 1 mg of epinephrine; 12.28, 95% CI [7.52-20.06] for 2-5 mg; and 23.71, 95% CI [11.02-50.97] for > 5 mg; reference 0 mg; population reference: alive at hospital discharge), even after adjustment on duration of resuscitation. The other modes of death (neurological and other causes) were also associated with epinephrine use, but to a lesser extent.

CONCLUSIONS

In non-shockable OHCA with ROSC, the dose of epinephrine used during CPR is strongly associated with early cardiocirculatory death. Further clinical studies aimed at limiting the dose of epinephrine during CPR seem warranted. Moreover, strategies for the prevention and management of PRS should take this dose of epinephrine into consideration for future trials.

Extracorporeal cardiopulmonary resuscitation-based approach to refractory out-of-hospital cardiac arrest: A focus on organ donation, a secondary analysis of a Prague OHCA randomized study

BACKGROUND

Refractory out-of-hospital cardiac arrest (OHCA) has a poor outcome. In patients, who cannot be rescued despite using advanced techniques like extracorporeal cardiopulmonary resuscitation (ECPR), organ donation may be considered. This study aims to evaluate, in refractory OHCA, how ECPR versus a standard-based approach allows organ donorship.

METHODS

The Prague OHCA trial randomized adults with a witnessed refractory OHCA of presumed cardiac origin to either an ECPR-based or standard approach. Patients who died of brain death or those who died of primary circulatory reasons and were not candidates for cardiac transplantation or durable ventricle assist device were evaluated as potential organ donors by a transplant center. In this post-hoc analysis, the effect on organ donation rates and one-year organ survival in recipients was examined.

RESULTS

Out of 256 enrolled patients, 75 (29%) died prehospitally or within 1 hour after admission and 107 (42%) during the hospital stay. From a total of 24 considered donors, 21 and 3 (p = 0.01) were recruited from the ECPR vs standard approach arm, respectively. Fifteen brain-dead and none cardiac-dead subjects were ultimately accepted, 13 from the ECPR and two from the standard strategy group. A total of 36 organs were harvested. The organs were successfully transplanted into 34 recipients. All transplanted organs were fully functional, and none of the recipients died due to graft failure within the one-year period post-transplant.

CONCLUSION

The ECPR-based approach in the refractory OHCA trial is associated with increased organ donorship and an excellent outcome of transplanted organs.

TRIAL REGISTRATION

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

Development and validation of a novel score to predict brain death after out-of-hospital cardiac arrest

BACKGROUND AND OBJECTIVES

Brain death (BD) occurs in 9-24% of successfully resuscitated out-of-hospital cardiac arrests (OHCA). To predict BD after OHCA, we developed a novel brain death risk (BDR) score.

METHODS

We identified independent predictors of BD after OHCA in a retrospective, single academic center cohort between 2011 and 2021. The BDR score ranges from 0 to 7 points and includes: non-shockable rhythm (1 point), drug overdose as etiology of arrest (1 point), evidence of grey-white differentiation loss or sulcal effacement on head computed tomography (CT) radiology report within 24 hours of arrest (2 points), Full-Outline-Of-UnResponsiveness (FOUR) score of 0 (2 points), FOUR score 1-5 (1 point), and age <45 years (1 point). We internally validated the BDR score using k-fold cross validation (k = 8) and externally validated the score at an independent academic center. The main outcome was BD.

RESULTS

The development cohort included 362OHCA patients, of whom 18% (N = 58) experienced BD. Internal validation provided an area under the receiving operator characteristic curve (AUC) (95% CI) of 0.931 (0.905-0.957). In the validation cohort, 19.8% (N = 17) experienced BD. The AUC (95% CI) was 0.849 (0.765-0.933). In both cohorts, a BDR score >4 was the optimal cut off (sensitivity 0.903 and 0.882, specificity 0.830 and 0.652, in the development and validation cohorts respectively).

DISCUSSION

The BDR score identifies those at highest risk for BD after OHCA. Our data suggest that a BDR score >4 is the optimal cut off.

Organ Donation After Out-of-Hospital Cardiac Arrest: A Scientific Statement From the International Liaison Committee on Resuscitation

AIM OF THE REVIEW

Improving rates of organ donation among patients with out-of-hospital cardiac arrest who do not survive is an opportunity to save countless lives. The objectives of this scientific statement were to do the following: define the opportunity for organ donation among patients with out-of-hospital cardiac arrest; identify challenges and opportunities associated with organ donation by patients with cardiac arrest; identify strategies, including a generic protocol for organ donation after cardiac arrest, to increase the rate and consistency of organ donation from this population; and provide rationale for including organ donation as a key clinical outcome for all future cardiac arrest clinical trials and registries.

METHODS

The scope of this International Liaison Committee on Resuscitation scientific statement was approved by the International Liaison Committee on Resuscitation board and the American Heart Association, posted on ILCOR.org for public comment, and then assigned by section to primary and secondary authors. A unique literature search was completed and updated for each section.

RESULTS

There are a number of defining pathways for patients with out-of-hospital cardiac arrest to become organ donors; however, modifications in the Maastricht classification system need to be made to correctly identify these donors and to report outcomes with consistency. Suggested modifications to the minimum data set for reporting cardiac arrests will increase reporting of organ donation as an important resuscitation outcome. There are a number of challenges with implementing uncontrolled donation after cardiac death protocols, and the greatest impediment is the lack of legislation in most countries to mandate organ donation as the default option. Extracorporeal cardiopulmonary resuscitation has the potential to increase organ donation rates, but more research is needed to derive neuroprognostication rules to guide clinical decision-making about when to stop extracorporeal cardiopulmonary resuscitation and to evaluate cost-effectiveness.

CONCLUSIONS

All health systems should develop, implement, and evaluate protocols designed to optimize organ donation opportunities for patients who have an out-of-hospital cardiac arrest and failed attempts at resuscitation.

Kidneys recovered from brain dead cardiac arrest patients resuscitated with ECPR show similar one-year graft survival compared to other donors

INTRODUCTION

Among patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) as a second line of treatment for refractory out-of-hospital cardiac arrest (OHCA), some may develop brain death and become eligible for organ donation. The objective of this study was to evaluate long-term outcomes of kidney grafts recovered from these patients.

MATERIAL AND METHODS

We conducted a retrospective monocentric observational study between January 1, 2011, and December 31, 2017. We exclusively included patients eligible for planned donation after brainstem death and from whom at least one organ graft was retrieved and transplanted. We compared two groups of brain dead patients: those treated with ECPR for refractory OHCA (ECPR group) and a diverse group of patients who did not receive ECPR, from which only 5/23 (22%) had OHCA (control group). The primary outcome was one-year kidney graft survival.

RESULTS

We included 45 patients, 23 in the control group and 22 in the ECPR group. Although patients in the ECPR group were younger and had a lower prevalence of chronic renal disease (p = 0.01), their kidney function was more severely impaired upon admission in the ICU. A total of 68 kidney grafts were retrieved, transplanted, and studied, 34 in each study group. There was no significant difference between the two groups in terms of one-year kidney graft survival (p = 0.52).

CONCLUSION

Organ transplantation from patients treated with ECPR after refractory OHCA showed one-year kidney graft survival rates comparable to those of patients not treated with ECPR.

Organ Donation After Out-of-Hospital Cardiac Arrest: A Scientific Statement From the International Liaison Committee on Resuscitation

AIM OF THE REVIEW

Improving rates of organ donation among patients with out-of-hospital cardiac arrest who do not survive is an opportunity to save countless lives. The objectives of this scientific statement were to do the following: define the opportunity for organ donation among patients with out-of-hospital cardiac arrest; identify challenges and opportunities associated with organ donation by patients with cardiac arrest; identify strategies, including a generic protocol for organ donation after cardiac arrest, to increase the rate and consistency of organ donation from this population; and provide rationale for including organ donation as a key clinical outcome for all future cardiac arrest clinical trials and registries.

METHODS

The scope of this International Liaison Committee on Resuscitation scientific statement was approved by the International Liaison Committee on Resuscitation board and the American Heart Association, posted on ILCOR.org for public comment, and then assigned by section to primary and secondary authors. A unique literature search was completed and updated for each section.

RESULTS

There are a number of defining pathways for patients with out-of-hospital cardiac arrest to become organ donors; however, modifications in the Maastricht classification system need to be made to correctly identify these donors and to report outcomes with consistency. Suggested modifications to the minimum data set for reporting cardiac arrests will increase reporting of organ donation as an important resuscitation outcome. There are a number of challenges with implementing uncontrolled donation after cardiac death protocols, and the greatest impediment is the lack of legislation in most countries to mandate organ donation as the default option. Extracorporeal cardiopulmonary resuscitation has the potential to increase organ donation rates, but more research is needed to derive neuroprognostication rules to guide clinical decision-making about when to stop extracorporeal cardiopulmonary resuscitation and to evaluate cost-effectiveness.

CONCLUSIONS

All health systems should develop, implement, and evaluate protocols designed to optimise organ donation opportunities for patients who have an out-of-hospital cardiac arrest and failed attempts at resuscitation.

Paucity of neuroprognostic testing after cardiac arrest in the United States

BACKGROUND

Withdrawal of life-sustaining therapies for perceived poor neurological prognosis is the most common cause of death for patients hospitalized after resuscitation from cardiac arrest. Accurate neuroprognostication is challenging and high stakes, so guidelines recommend multimodality testing. We quantified the frequency and timing with which guideline recommended diagnostics were acquired prior to in-hospital death after cardiac arrest.

METHODS

We performed a retrospective cohort study using the Optum® deidentified Electronic Health Record dataset for 2010 to 2021. We included in-hospital decedents admitted after resuscitation from non-traumatic cardiac arrest. We quantified the number of decedents who underwent head computed tomographic imaging, electroencephalography, somatosensory evoked potentials, brain magnetic resonance imaging, or evaluation by a neurologist, as well as the timing of these tests.

RESULTS

Of 34,585 included patients, median age was 66 [interquartile range 53 - 79] years and 13,609 (39%) were female. Median hospital length of stay was 0 days [0-1] days, and only 16% of deaths occurred on or after day three. Only 3,245 patients (9%) had at least one neurodiagnostic test acquired and only 1,708 (5%) were evaluated by a neurologist. The most common neurological diagnostic test to be obtained was CT imaging, acquired in 3,004 (9%) of the overall cohort. Only 852 patients (2%) of patients had at least two diagnostic modalities obtained.

DISCUSSION

In this retrospective cohort, we found few patients hospitalized after out-of-hospital cardiac arrest underwent guideline-recommended prognostic testing. If validated in prospective cohorts with more granular clinical information, better guideline adherence and more frequent use of multimodality neuroprognostication offer an opportunity to improve quality of post-arrest care.

Guidelines for Neuroprognostication in Comatose Adult Survivors of Cardiac Arrest

BACKGROUND

Among cardiac arrest survivors, about half remain comatose 72 h following return of spontaneous circulation (ROSC). Prognostication of poor neurological outcome in this population may result in withdrawal of life-sustaining therapy and death. The objective of this article is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling surrogates of comatose cardiac arrest survivors.

METHODS

A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, which included clinical variables and prediction models, were selected based on clinical relevance and the presence of an appropriate body of evidence. The Population, Intervention, Comparator, Outcome, Timing, Setting (PICOTS) question was framed as follows: "When counseling surrogates of comatose adult survivors of cardiac arrest, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of poor functional outcome assessed at 3 months or later?" Additional full-text screening criteria were used to exclude small and lower-quality studies. Following construction of the evidence profile and summary of findings, recommendations were based on four GRADE criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. In addition, good practice recommendations addressed essential principles of neuroprognostication that could not be framed in PICOTS format.

RESULTS

Eleven candidate clinical variables and three prediction models were selected based on clinical relevance and the presence of an appropriate body of literature. A total of 72 articles met our eligibility criteria to guide recommendations. Good practice recommendations include waiting 72 h following ROSC/rewarming prior to neuroprognostication, avoiding sedation or other confounders, the use of multimodal assessment, and an extended period of observation for awakening in patients with an indeterminate prognosis, if consistent with goals of care. The bilateral absence of pupillary light response > 72 h from ROSC and the bilateral absence of N20 response on somatosensory evoked potential testing were identified as reliable predictors. Computed tomography or magnetic resonance imaging of the brain > 48 h from ROSC and electroencephalography > 72 h from ROSC were identified as moderately reliable predictors.

CONCLUSIONS

These guidelines provide recommendations on the reliability of predictors of poor outcome in the context of counseling surrogates of comatose survivors of cardiac arrest and suggest broad principles of neuroprognostication. Few predictors were considered reliable or moderately reliable based on the available body of evidence.

Neuroprognostication in the Post Cardiac Arrest Patient: A Canadian Cardiovascular Society Position Statement

Cardiac arrest (CA) is associated with a low rate of survival with favourable neurologic recovery. The most common mechanism of death after successful resuscitation from CA is withdrawal of life-sustaining measures on the basis of perceived poor neurologic prognosis due to underlying hypoxic-ischemic brain injury. Neuroprognostication is an important component of the care pathway for CA patients admitted to hospital but is complex, challenging, and often guided by limited evidence. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to evaluate the evidence underlying factors or diagnostic modalities available to determine prognosis, recommendations were generated in the following domains: (1) circumstances immediately after CA; (2) focused neurologic exam; (3) myoclonus and seizures; (4) serum biomarkers; (5) neuroimaging; (6) neurophysiologic testing; and (7) multimodal neuroprognostication. This position statement aims to serve as a practical guide to enhance in-hospital care of CA patients and emphasizes the adoption of a systematic, multimodal approach to neuroprognostication. It also highlights evidence gaps.

Efficacy of acupuncture for cardiopulmonary cerebral resuscitation: A systematic review and meta-analysis

Background

Cerebral resuscitation is one of the main therapeutic aims in the treatment of cardiac arrest (CA) patients who experience a return of spontaneous circulation (ROSC). However, the therapeutic effects of current treatments are not ideal. The purpose of this study was to evaluate the efficacy of neurological function of acupuncture combined with conventional cardiopulmonary cerebral resuscitationthe (CPCR) for patients after ROSC.

Methods

Seven electronic databases and other related websites were searched to identify studies on acupuncture combined with conventional CPCR for patients after ROSC. R software was used to conduct a meta-analysis, and the outcomes that could not be pooled were analyzed using a descriptive analysis.

Results

Seven RCTs involving 411 participants who had experienced ROSC were eligible for inclusion. The main acupoints were Neiguan (PC6), Shuigou (DU26), Baihui (DU20), Yongquan (KI1), and Sanyinjiao (SP6). Compared to conventional CPCR, acupuncture combined with conventional CPCR led to significantly higher Glasgow Coma Scale (GCS) scores on day 3 (mean difference (MD)=0.89, 95% CI: 0.43, 1.35, I² = 0%), day 5 (MD = 1.21, 95% CI: 0.27, 2.15; I² = 0%), and day 7 (MD = 1.92, 95% CI: 1.35, 2.50; I² = 0%).

Conclusion

Acupuncture-assisted conventional CPCR may have a potential role in improving neurological function in CA patients after ROSC, but the certainty of evidence is very low and more high-quality studies are required.

Protocol registration

This review was registered at the International Prospective Registry of Systematic Reviews (PROSPERO): CRD42021262262.

Donors brain-dead after successful resuscitation of cardiac arrest: Early outcome and postoperative complications of lung recipients

BACKGROUND

The outcomes of lung transplantation (LT) recipients who received a graft from a brain-dead donor after successful resuscitation from cardiac arrest (CA donors) have been poorly described. This study compared the one-year survival of LT recipients depending on the CA status of the donor.

METHODS

This prospective observational single-centre study analysed all consecutive patients who underwent LT at Bichat Claude Bernard Hospital, Paris, between January 2016 and December 2020. All donors who experienced CA prior to organ donation, regardless of rhythm or duration, were considered CA donors. The postoperative complications and outcomes of LT recipients were analysed. The one-year survival was compared using Kaplan-Meier curves and log-rank tests. Independent risk factors for one-year mortality were assessed using multivariate analysis (p < 0.05 was considered significant). The Paris North Hospitals Institutional Review Board approved the study.

RESULTS

A total of 236 LT recipients were analysed and 66 (28%) received a graft from a CA donor. The median durations of no/low flow were 4 [0-10]/20 [15-30] minutes, respectively. Shockable and non-shockable rhythms were observed in 11 (17%) and 47 (72%) of the CA donors, respectively. The characteristics of the grafts and early postoperative complications were not different in the CA and non-CA groups. Receiving a graft from a CA donor was not an independent risk factor for recipient one-year mortality.

CONCLUSION

Receiving a graft from a CA donor did not worsen the outcome of LT recipients. Acceptation of these grafts must be systematically considered to increase the pool of available grafts.

The impact of different targeted temperatures on out-of-hospital cardiac arrest outcomes in patients receiving extracorporeal membrane oxygenation: a nationwide cohort study

BACKGROUND

Targeted temperature management (TTM) is recommended in the management of out-of-hospital cardiac arrest (OHCA) when coma persists after the return of spontaneous circulation. In the setting of extracorporeal membrane oxygenation (ECMO) for OHCA patients, TTM is associated with good neurological outcomes and is recommended in the Extracorporeal Life Support Organization guidelines. However, the optimal targeted temperature for these patients has not yet been adequately investigated. This study aimed to compare the impact of different targeted temperatures on the outcomes in OHCA patients receiving ECMO.

METHODS

This was a retrospective analysis of data from the Japanese Association for Acute Medicine (JAAM)-OHCA Registry, a multicentre nationwide prospective database in Japan in which 103 institutions providing emergency care participated. OHCA patients aged ≥ 18 years who required ECMO with TTM between June 2014 and December 2019 were included in our analysis. The primary outcome was 30-day survival with favourable neurological outcomes, defined as a Glasgow-Pittsburgh cerebral performance category score of 1 or 2. Patients were divided into two groups according to their targeted temperature: normothermic TTM (n-TTM) (35-36 °C) and hypothermic TTM (h-TTM) (32-34 °C). We compared the outcomes between the two targeted temperature groups using multivariable logistic regression and inverse probability weighting (IPW).

RESULTS

A total of 890 adult OHCA patients who received ECMO and TTM were eligible for our analysis. Of these patients, 249 (28%) and 641 (72%) were treated with n-TTM and h-TTM, respectively. The proportions of patients with 30-day favourable neurological outcomes were 16.5% (41/249) and 15.9% (102/641), in the n-TTM and h-TTM groups, respectively. No difference in neurological outcomes was observed in the multiple regression analysis [adjusted odds ratio 0.91, 95% confidence interval (CI) 0.58-1.43], and the result was constant in the IPW (odds ratio 1.01, 95% CI 0.67-1.54).

CONCLUSION

No difference was observed between n-TTM and h-TTM in OHCA patients receiving TTM with ECMO. The current understanding that changes to the targeted temperature have little impact on the outcome of patients may remain true regardless of ECMO use.

Risk factors for development of cerebral edema following cardiac arrest

BACKGROUND

Cerebral edema following cardiac arrest is a well-known complication of resuscitation and portends a poor outcome. We identified predictors of post-cardiac arrest cerebral edema and tested the association of cerebral edema with discharge outcome.

METHODS

We performed a retrospective chart review including patients admitted at a single center between January 2015-March 2020 following resuscitation from in-hospital and out-of-hospital cardiac arrest who had head computed tomography imaging. Our primary outcome was moderate-to-severe cerebral edema, which we defined as loss of grey-white differentiation with effacement of the basal and ambient cisterns and radiographic evidence of uncal herniation. We used logistic regression to test associations of demographic information, clinical predictors and comorbidities with moderate-severe cerebral edema.

RESULTS

We identified 727 patients who met the inclusion criteria, of whom 102 had moderate-to-severe cerebral edema. We identified six independent predictors of moderate-to-severe cerebral edema: younger age, prolonged arrest duration, pulseless electrical activity/asystole as initial rhythm, unwitnessed cardiac arrest, hyperglycemia on admission, and lower Glasgow coma score on presentation. Of patients with moderate-to-severe cerebral edema, 2% survived to discharge, 56% had withdrawal of life-sustaining therapies and 42% progressed to death by neurological criteria.

CONCLUSIONS

Our study identified several risk factors associated with the development of cerebral edema following cardiac arrest. Further studies are needed to determine the benefits of early interventions in these high-risk patients.

Cardiovascular mechanism of donor brain death and heart recipient survival

BACKGROUND

Heart donation after donor brain death from cardiac arrest despite successful resuscitation may be associated with worse recipient outcomes due to potential graft ischemia or underlying rhythmic/structural defects. However, selected grafts from such donors often have normal cardiac function and anatomy. We investigated whether a cardiovascular mechanism of donor brain death (CV-DBD) was associated with worse recipient outcomes.

METHODS

We queried the United Network for Organ Sharing (UNOS) database for first-time, single-organ, adult (age 18+) heart transplant recipients and their associated donors between January 2005 and March 2021. Recipients were stratified by donor status (CV-DBD vs. non-CV-DBD). We performed multivariable Cox proportional hazards modeling to ascertain whether receiving a CV-DBD graft was independently associated with mortality.

RESULTS

Of 35,833 included recipients, 2,702 (7.5%) received CV-DBD grafts. The associated donors were significantly more likely to be female, older, and have a history of diabetes, hypertension, and substance use (all p < .001). On unadjusted Kaplan-Meier analysis, CV-DBD recipients had a significantly reduced median survival than non-CV-DBD recipients (12.0 vs. 13.1 years, log-rank p = .04). However, after adjusting for donor/recipient age, recipient comorbidities, annualized center volume, and transplantation era, CV-DBD organ status was not associated with recipient mortality (hazard ratio: 1.05, 95% confidence interval: 0.96-1.13, p = .28).

CONCLUSION

In this analysis of over 35,000 heart transplants, CV-DBD status was not associated with adjusted recipient survival. Donor brain death due to cardiac arrest should not be an absolute contraindication to heart donation, although graft function should be carefully assessed before transplantation.

Ion Shift Index at the Immediate Post-Cardiac Arrest Period as an Early Prognostic Marker in Out-of-Hospital Cardiac Arrest Survivors

The ion shift index (ISI) is a suggested marker to reflect the magnitude of ischemic damage. This study aimed to investigate the prognostic value of the ISI for predicting poor neurological outcomes at 6 months in comatose out-of-hospital cardiac arrest (OHCA) survivors by comparing it with the OHCA and Cardiac Arrest Hospital Prognosis (CAHP) scores. This observational registry-based cohort study included adult comatose OHCA survivors admitted to a tertiary care hospital in Korea between 2015 and 2021. The ISI was calculated using the serum electrolyte levels obtained within one hour of resuscitation. The primary outcome was poor neurological function (Cerebral Performance Category score of 3−5) at 6 months. Of the 250 OHCA survivors, 164 (65.6%) had poor neurological outcomes. These patients had a higher median ISI than those with good neurological outcomes (4.95 vs. 3.26, p < 0.001). ISI (adjusted odds ratio, 2.107; 95% confidence interval, 1.350−3.288, p = 0.001) was associated with poor neurological outcomes. The prognostic performance of ISI (area under the curve [AUC], 0.859) was similar to that of the OHCA score (AUC, 0.858; p = 0.968) and the CAHP score (AUC, 0.894; p = 0.183). ISI would be a prognostic biomarker for comatose OHCA survivors that is available during the immediate post-cardiac arrest period.

Early risk stratification for progression to death by neurological criteria following out-of-hospital cardiac arrest

BACKGROUND

Some patients resuscitated from out-of-hospital cardiac arrest (OHCA) progress to death by neurological criteria (DNC). We hypothesized that initial brain imaging, electroencephalography (EEG), and arrest characteristics predict progression to DNC.

METHODS

We identified comatose OHCA patients from January 2010 to February 2020 treated at a single quaternary care facility in Western Pennsylvania. We abstracted demographics and arrest characteristics; Pittsburgh Cardiac Arrest Category, initial motor exam and pupillary light reflex; initial brain computed tomography (CT) grey-to-white ratio (GWR), sulcal or basal cistern effacement; initial EEG background and suppression ratio. We used two modeling approaches: fast and frugal tree (FFT) analysis to create an interpretable clinical risk stratification tool and ridge regression for comparison. We used bootstrapping to randomly partition cases into 80% training and 20% test sets and evaluated test set sensitivity and specificity.

RESULTS

We included 1,569 patients, of whom 147 (9%) had diagnosed DNC. Across bootstrap samples, >99% of FFTs included three predictors: sulcal effacement, and in cases without sulcal effacement, the combination of EEG background suppression and GWR ≤ 1.23. This tree had mean sensitivity and specificity of 87% and 81%. Ridge regression with all available predictors had mean sensitivity 91 % and mean specificity 83%. Subjects falsely predicted as likely to progress to DNC generally died of rearrest or withdrawal of life sustaining therapies due to poor neurological prognosis. Two of these cases awakened from coma during the index hospitalization.

CONCLUSIONS

Sulcal effacement on presenting brain CT or EEG suppression with GWR ≤ 1.23 predict progression to DNC after OHCA.

One and Done Epinephrine in Out-of-Hospital Cardiac Arrest? Outcomes in a Multiagency United States Study

BACKGROUND

Cardiac arrest guidelines recommend epinephrine every 3-5 minutes during cardiac arrest resuscitation. However, it is unclear if multiple epinephrine doses are associated with improved outcomes. The objective of this study was to determine if a single-dose epinephrine protocol was associated with improved survival compared to traditional multidose protocols.

METHODS

We conducted a pre-post study across five North Carolina EMS agencies from 11/1/2016 to 10/29/2019. Patients ≥18 years old with attempted resuscitation for non-traumatic prehospital cardiac arrest were included. Data were collected 1 year before and after implementation of the single-dose epinephrine protocol. Prior to implementation, all agencies used a multidose epinephrine protocol. The Cardiac Arrest Registry to Enhance Survival (CARES) was used to obtain patient outcomes. Study outcomes were survival to hospital discharge (primary) and return of spontaneous circulation (ROSC). Analysis was by intention to treat. Outcomes were compared pre- vs. post-implementation using generalized estimating equations to account for clustering within EMS agencies. Adjusted analyses included age, sex, race, shockable vs. non-shockable rhythm, witnessed arrest, automatic external defibrillator availability, EMS response interval, and bystander cardiopulmonary resuscitation.

RESULTS

During the study period there were 1,690 encounters (899 pre- and 791 post-implementation). The population was 74.7% white, 61.1% male, and had a median age of 65 (IQR 53-76) years. Survival to hospital discharge was similar pre- vs. post-implementation [13.6% (122/899) vs. 15.4% (122/791); OR 1.19, 95%CI 0.89-1.59]. However, ROSC was more common post-implementation [42.3% (380/899) vs. 32.5% (257/791); OR 0.66, 95%CI 0.54-0.81]. After adjusting for covariates, the single-dose protocol was associated with similar survival to discharge rates (aOR 0.88, 95%CI 0.77-1.29), but with decreased ROSC rates (aOR 0.58, 95%CI 0.47-0.72).

CONCLUSION

A prehospital single-dose epinephrine protocol was associated with similar survival to hospital discharge, but decreased ROSC rates compared to the traditional multidose epinephrine protocol.

Exclusive color-coded duplex sonography of extracranial vessels reliably confirms brain death: A prospective study

Background

Transcranial color-coded duplex sonography (TCCD) can be used as an ancillary test for determining irreversible loss of brain function (ILBF) when demonstration of cerebral circulatory arrest (CCA) is required. However, visualization of the intracranial vessels by TCCD is often difficult, or even impossible, in this patient cohort due to elevated intracranial pressure, an insufficient transtemporal bone window, or warped anatomical conditions. Since extracranial color-coded duplex sonography (ECCD) can be performed without restriction in the aforementioned situations, we investigated the feasibility of omitting TCCD altogether, such that the ILBF examination would be simplified, without compromising on its reliability.

Methods

A total of 122 patients were prospectively examined by two experienced neurointensivists for the presence of ILBF from 01/2019-12/2021. Inclusion criteria were (i) the presence of a severe cerebral lesion on cranial CT or MRI, and (ii) brainstem areflexia. Upon standardized clinical examination, 9 patients were excluded due to incomplete brainstem areflexia, and a further 22 due to the presence of factors with a potentially confounding influence on apnea testing, EEG or sonography. A total of 91 patients were enrolled and underwent needle-EEG recording for >30 min (= gold standard), as well as ECCD and TCCD. The sonographer was blinded to the EEG result.

Results

All patients whose ECCD result was consistent with ILBF had this diagnosis confirmed by EEG (n = 77; specificity: 1). Both ECCD and EEG were not consistent with ILBF in a further 12 patients. In the remaining two patients, ECCD detected reperfusion due to long-lasting cerebral hypoxia; however, ILBF was ultimately confirmed by EEG (sensitivity: 0.975). This yielded a positive predictive value (PPV) of one and a negative predictive value of 0.857 for the validity of ECCD in ILBF confirmation. TCCD was not possible/inconclusive in 31 patients (34%).

Conclusions

The use of ECCD for the confirmation of ILBF is associated with high levels of specificity and a high positive predictive value when compared to needle-electrode EEG. This makes ECCD a potential alternative to the ancillary tests currently used in this setting, but confirmation in a multi-center trial is warranted.

Trial registration

https://www.drks.de, DRKS00017803.