Cardiac arrest, stony heart, and cardiopulmonary resuscitation: An updated revisit

The post-resuscitation period is recognized as the main predictor of cardiopul-monary resuscitation(CPR)outcomes.The first description of post-resuscitation syndrome and stony heart was published over 50 years ago.Major manifestations may include but are not limited to,persistent precipitating pathology,systemic ischemia/reperfusion response,post-cardiac arrest brain injury,and finally,post-cardiac arrest myocardial dysfunction(PAMD)after successful resuscitation.Why do some patients initially survive successful resuscitation,and others do not?Also,why does the myocardium response vary after resuscitation?These ques-tions have kept scientists busy for several decades since the first successful resuscitation was described.By modifying the conventional modalities of resu-scitation together with new promising agents,rescuers will be able to salvage the jeopardized post-resuscitation myocardium and prevent its progression to a dismal,stony heart.Community awareness and staff education are crucial for shortening the resuscitation time and improving short-and long-term outcomes.Awareness of these components before and early after the restoration of circulation will enhance the resuscitation outcomes.This review extensively addresses the underlying pathophysiology,management,and outcomes of post-resuscitation syndrome.The pattern,management,and outcome of PAMD and post-cardiac arrest shock are different based on many factors,including in-hospital cardiac arrest vs out-of-hospital cardiac arrest(OHCA),witnessed vs unwitnessed cardiac arrest,the underlying cause of arrest,the duration,and protocol used for CPR.Although restoring spontaneous circulation is a vital sign,it should not be the end of the game or lone primary outcome;it calls for better understanding and aggressive multi-disciplinary interventions and care.The development of stony heart post-CPR and OHCA remain the main challenges in emergency and critical care medicine.

Glucose metabolic reprogramming-related parameters for the prediction of 28-day neurological prognosis and all-cause mortality in patients after cardiac arrest:a prospective single-center observational study

BACKGROUND:We aimed to observe the dynamic changes in glucose metabolic reprogrammingrelated parameters and their ability to predict neurological prognosis and all-cause mortality in cardiac arrest patients after the restoration of spontaneous circulation(ROSC).METHODS:Adult cardiac arrest patients after ROSC who were admitted to the emergency or cardiac intensive care unit of the First Aflliated Hospital of Dalian Medical University from August 1,2017,to May 30,2021,were enrolled.According to 28-day survival,the patients were divided into a non-survival group(n=82) and a survival group(n=38).Healthy adult volunteers(n=40) of similar ages and sexes were selected as controls.The serum levels of glucose metabolic reprogrammingrelated parameters(lactate dehydrogenase [LDH],lactate and pyruvate),neuron-specific enolase(NSE) and interleukin 6(IL-6) were measured on days 1,3,and 7 after ROSC.The Acute Physiology and Chronic Health Evaluation II(APACHE II) score and Sequential Organ Failure Assessment(SOFA) score were calculated.The Cerebral Performance Category(CPC) score was recorded on day 28 after ROSC.RESULTS:Following ROSC,the serum LDH(607.0 U/L vs.286.5 U/L),lactate(5.0 mmol/L vs.2.0 mmol/L),pyruvate(178.0 μmol/L vs.70.9 μmol/L),and lactate/pyruvate ratio(34.1 vs.22.1) significantly increased and were higher in the non-survivors than in the survivors on admission(all P<0.05).Moreover,the serum LDH,pyruvate,IL-6,APACHE II score,and SOFA score on days 1,3 and 7 after ROSC were significantly associated with 28-day poor neurological prognosis and 28-day all-cause mortality(all P<0.05).The serum LDH concentration on day 1 after ROSC had an area under the receiver operating characteristic curve(AUC) of 0.904 [95% confidence interval [95% CI]:0.851–0.957]) with 96.8% specificity for predicting 28-day neurological prognosis and an AUC of 0.950(95% CI:0.911–0.989) with 94.7% specificity for predicting 28-day all-cause mortality,which was the highest among the glucose metabolic reprogramming-related parameters tested.CONCLUSION:Serum parameters related to glucose metabolic reprogramming were significantly increased after ROSC.Increased serum LDH and pyruvate levels,and lactate/pyruvate ratio may be associated with 28-day poor neurological prognosis and all-cause mortality after ROSC,and the predictive eflcacy of LDH during the first week was superior to others.

A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study

BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest patients.This study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysmogram(POP)parameters can be used to identify unsustained ROSC.METHODS:We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014.Patients’general information,ETCO_(2),and POP parameters were collected and statistically analyzed.RESULTS:The included 105 ROSC episodes(from 80 cardiac arrest patients)comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes.The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group(29.2%vs.9.4%,P<0.05).The logistic regression analysis showed that the difference between after and before ROSC in ETCO_(2)(ΔETCO_(2))and the difference between after and before ROCS in area under the curve of POP(ΔAUCp)were independently associated with sustained ROSC(odds ratio[OR]=0.931,95%confi dence interval[95%CI]0.881-0.984,P=0.011 and OR=0.998,95%CI 0.997-0.999,P<0.001).The area under the receiver operating characteristic curve ofΔETCO_(2),ΔAUCp,and the combination of both to predict unsustained ROSC were 0.752(95%CI 0.660-0.844),0.883(95%CI 0.818-0.948),and 0.902(95%CI 0.842-0.962),respectively.CONCLUSION:Patients with unsustained ROSC have a poor prognosis.The combination ofΔETCO_(2) andΔAUCp showed signifi cant predictive value for unsustained ROSC.

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

Approach to traumatic cardiac arrest in the emergency department: a narrative literature review for emergency providers

BACKGROUND:Traumatic cardiac arrest(TCA)is a major contributor to mortality and morbidity in all age groups and poses a significant burden on the healthcare system.Although there have been advances in treatment modalities,survival rates for TCA patients remain low.This narrative literature review critically examines the indications and eff ectiveness of current therapeutic approaches in treating TCA.METHODS:We performed a literature search in the PubMed and Scopus databases for studies published before December 31,2022.The search was refi ned by combining search terms,examining relevant study references,and restricting publications to the English language.Following the search,943 articles were retrieved,and two independent reviewers conducted a screening process.RESULTS:A review of various studies on pre-and intra-arrest prognostic factors showed that survival rates were higher when patients had an initial shockable rhythm.There were conflicting results regarding other prognostic factors,such as witnessed arrest,bystander cardiopulmonary resuscitation(CPR),and the use of prehospital or in-hospital epinephrine.Emergency thoracotomy was found to result in more favorable outcomes in cases of penetrating trauma than in those with blunt trauma.Resuscitative endovascular balloon occlusion of the aorta(REBOA)provides an advantage to emergency thoracotomy in terms of occupational safety for the operator as an alternative in managing hemorrhagic shock.When implemented in the setting of aortic occlusion,emergency thoracotomy and REBOA resulted in comparable mortality rates.Veno-venous extracorporeal life support(V-V ECLS)and veno-arterial extracorporeal life support(V-A ECLS)are viable options for treating respiratory failure and cardiogenic shock,respectively.In the context of traumatic injuries,V-V ECLS has been associated with higher rates of survival to discharge than V-A ECLS.CONCLUSION:TCA remains a signifi cant challenge for emergency medical services due to its high morbidity and mortality rates.Pre-and intra-arrest prognostic factors can help identify patients who are likely to benefit from aggressive and resource-intensive resuscitation measures.Further research is needed to enhance guidelines for the clinical use of established and emerging therapeutic approaches that can help optimize treatment effi cacy and ameliorate survival outcomes.

Recovering from prolonged cardiac arrest induced by electric shock:A case report

BACKGROUND Cardiac arrest(CA)induced by electric shock is a rare occurrence,particularly in cases of prolonged CA.Currently,there is limited literature on similar incidents,and we present a relevant case report.CASE SUMMARY A 27-year-old Asian male man,experiencing respiratory CA due to electric shock,was successfully restored to sinus rhythm after 50 min of cardiopulmonary resuscitation and 8 electrical defibrillation sessions.In the subsequent stages,the patient received multiple organ function protection measures,leading to a successful recovery and eventual discharge from the hospital.CONCLUSION Prolonging resuscitation time can enhance the chances of survival for patients,this study provide valuable insights into the management of electric shock-induced CA.

Correction:Establishment of a prediction model for prehospital return of spontaneous circulation in out-of-hospital patients with cardiac arrest

This is an erratum to an already published paper named“Establishment of a prediction model for prehospital return of spontaneous circulation in out-ofhospital patients with cardiac arrest”.We found errors in the affiliated institution of the authors.We apologize for our unintentional mistake.Please note,these changes do not affect our results.

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

BACKGROUND:The ion shift index(ISI) as a prognostic indicator that can show the severity of hypoxic-ischemic injury.We aimed to evaluate the performance of the ISI in predicting unfavorable neurological outcomes at hospital discharge in cardiac arrest(CA) patients following extracorporeal cardiopulmonary resuscitation(ECPR) and to compare its performance to other prognostic predictors.METHODS:This was a retrospective observational study including adult CA patients treated with ECPR between January 2018 and December 2022 in a tertiary hospital.Data regarding clinical characteristics and laboratory parameters were collected from medical records.The ISI was determined based on the first available serum electrolyte levels after ECPR.The primary outcome was unfavorable neurological status at hospital discharge,defined as Cerebral Performance Categories 3–5.Comparisons of the characteristics between the two groups were made using the χ2 test for categorical variables and the t-test or non-parametric Mann-Whitney U-test for continuous variables,as appropriate.Correlation analysis was performed using Spearman’s rank correlation coeficient.A two-tailed P-value <0.05 was considered statistically significant.RESULTS:Among the 122 patients involved,46(37.7%) had out-of-hospital CA,and 88 had unfavorable neurological outcomes.The ISI was significantly higher in the unfavorable outcome group than in the favorable outcome group(3.74 [3.15–4.57] vs.2.69 [2.51–3.07],P<0.001).A higher ISI level was independently related to unfavorable outcome(odds ratio=6.529,95% confidence interval 2.239–19.044,P=0.001).An ISI level >3.12 predicted unfavorable outcomes with a sensitivity and specificity of 74.6% and 85.2%,respectively(P<0.001).The prognostic performance of ISI(area under the curve [AUC]=0.887) was similar to that of other predictors,such as gray-to-white matter ratio(AUC=0.850,P=0.433) and neuronspecific enolase(AUC=0.925,P=0.394).CONCLUSION:ISI may be used as a prognostic biomarker to predict neurological outcomes in CA patients following ECPR.

Establishment of a prediction model for prehospital return of spontaneous circulation in out-of-hospital patients with cardiac arrest

BACKGROUND Out-of-hospital cardiac arrest(OHCA)is a leading cause of death worldwide.AIM To explore factors influencing prehospital return of spontaneous circulation(P-ROSC)in patients with OHCA and develop a nomogram prediction model.METHODS Clinical data of patients with OHCA in Shenzhen,China,from January 2012 to December 2019 were retrospectively analyzed.Least absolute shrinkage and selection operator(LASSO)regression and multivariate logistic regression were applied to select the optimal factors predicting P-ROSC in patients with OHCA.A nomogram prediction model was established based on these influencing factors.Discrimination and calibration were assessed using receiver operating charac-teristic(ROC)and calibration curves.Decision curve analysis(DCA)was used to evaluate the model’s clinical utility.RESULTS Among the included 2685 patients with OHCA,the P-ROSC incidence was 5.8%.LASSO and multivariate logistic regression analyses showed that age,bystander cardiopulmonary resuscitation(CPR),initial rhythm,CPR duration,ventilation mode,and pathogenesis were independent factors influencing P-ROSC in these patients.The area under the ROC was 0.963.The calibration plot demonstrated that the predicted P-ROSC model was concordant with the actual P-ROSC.The good clinical usability of the prediction model was confirmed using DCA.CONCLUSION The nomogram prediction model could effectively predict the probability of P-ROSC in patients with OHCA.

Establishment of a Rat Model of Capillary Leakage Syndrome Induced by Cardiopulmonary Resuscitation After Cardiac Arrest

Objective:Cardiopulmonary resuscitation(CPR)after cardiac arrest(CA)is one of the main causes of capillary leakage syndrome(CLS).This study aimed to establish a stable CLS model following the CA and cardiopulmonary resuscitation(CA-CPR)model in Sprague-Dawley(SD)rats.Methods:We conducted a prospective,randomized,animal model study.All adult male SD rats were randomly divided into a normal group(group N),a sham operation group(group S),and a cardiopulmonary resuscitation group(group T).The SD rats of the three groups were all inserted with 24-G needles through their left femoral arteries and right femoral veins.In group S and group T,the endotracheal tube was intubated.In group T,CA induced by asphyxia(AACA)was caused by vecuronium bromide with the endotracheal tube obstructed for 8 min,and the rats were resuscitated with manual chest compression and mechanical ventilation.Preresuscitation and postresuscitation measurements,including basic vital signs(BVS),blood gas analysis(BG),routine complete blood count(CBC),wet-to-dry ratio of tissues(W/D),and the HE staining results after 6 h were evaluated.Results:In group T,the success rate of the CA-CPR model was 60%(18/30),and CLS occurred in 26.6%(8/30)of the rats.There were no significant differences in the baseline characteristics,including BVS,BG,and CBC,among the three groups(P>0.05).Compared with pre-asphyxia,there were significant differences in BVS,CBC,and BG,including temperature,oxygen saturation(SpO_(2)),mean arterial pressure(MAP),central venous pressure(CVP),white blood cell count(WBC),hemoglobin,hematocrit,pH,pCO_(2),pO_(2),SO_(2),lactate(Lac),base excess(BE),and Na+(P<0.05)after the return of spontaneous circulation(ROSC)in group T.At 6 h after ROSC in group T and at 6 h after surgery in groups N and S,there were significant differences in temperature,heart rate(HR),respiratory rate(RR),SpO_(2),MAP,CVP,WBC,pH,pCO_(2),Na+,and K+among the three groups(P<0.05).Compared with the other two groups,the rats in group T showed a significantly increased W/D weight ratio(P<0.05).The HE-stained sections showed consistent severe lesions in the lung,small intestine,and brain tissues of the rats at 6 h after ROSC following AACA.Conclusion:The CA-CPR model in SD rats induced by asphyxia could reproduce CLS with good stability and reproducibility.

Eff ect of post-rewarming fever after targeted temperature management in cardiac arrest patients: a systematic review and meta-analysis

BACKGROUND:Targeted temperature management(TTM),as a therapeutic temperature control strategy for cardiac arrest(CA),is recommended by guidelines.However,the relationship between postrewarming fever(PRF)and the prognosis of CA patients is unclear.Therefore,we aim to summarize the studies regarding the infl uence of PRF on patients with CA.METHODS:EMBASE,PubMed,and Cochrane Central databases were searched from inception to March 13,2022.Randomized clinical trials(RCTs)and cohort studies on PRF in CA patients were included.According to the heterogeneity,the meta-analysis was performed using a random eff ects model or fi xed eff ects model to calculate the pooled odds ratios(ORs)and corresponding 95%confi dence intervals(CIs).The outcome data were unfavorable neurological outcome and mortality.RESULTS:The meta-analysis included 11 observational studies involving 3,246 patients.The results of the meta-analysis show that PRF(body temperature>38.0℃)has no eff ect on the neurological outcome of CA patients(OR 0.71,95%CI 0.43–1.17,I282%)and has a signifi cant relationship with lower mortality(OR 0.63;95%CI 0.49–0.80,I239%).However,PRF with a stricter defi nition(body temperature>38.5℃)was associated with worse neurological outcome(OR 1.44,95%CI 1.08–1.92,I245%)and higher mortality(OR 1.71,95%CI 1.25–2.35,I247%).CONCLUSION:This study suggests that PRF>38.0℃ may not affect the neurological outcome and have a lower mortality in CA patients who completed TTM.However,PRF>38.5℃ is a potential prognostic factor for worse outcomes in CA patients.

Modified Glucose-insulin-potassium Therapy for Hemorrhage-induced Traumatic Cardiac Arrest in Rabbits

Objective Resuscitation with whole blood is known to be better than that with saline in attaining the return of spontaneous circulation(ROSC)and improving the short-term survival rate for hemorrhage-induced traumatic cardiac arrest(HiTCA).However,the resuscitation with whole blood alone fails to address the pathophysiological abnormalities,including hyperglycemia,hyperkalemia and coagulopathy,after HiTCA.The present study aimed to determine whether the modified glucose-insulin-potassium(GIK)therapy can ameliorate the above-mentioned pathophysiological abnormalities,enhance the ROSC,improve the function of key organs,and reduce the mortality after HiTCA.Methods HiTCA was induced in rabbits(n=36)by controlled hemorrhage.Following arrest,the rabbits were randomly divided into three groups(n=12 each):group A(no resuscitation),group B(resuscitation with whole blood),and group C(resuscitation with whole blood plus GIK).The GIK therapy was administered based on the actual concentration of glucose and potassium.The ROSC rate and survival rate were obtained.Hemodynamical and biochemical changes were detected.Thromboelastography(TEG)was used to measure coagulation parameters,and enzyme-linked immunosorbent assay to detect parameters related to inflammation,coagulation and the function of brain.Results All animals in groups B and C attained ROSC.Two rabbits died 24–48 h after HiTCA in group B,while no rabbits died in group C.The GIK therapy significantly reduced the levels of blood glucose,potassium,and biological markers for inflammatory reaction,and improved the heart,kidney,liver and brain function in group C when compared to group B.Furthermore,the R values of TEG were significantly lower in group C than in group B,and the maximum amplitude of TEG was slightly lower in group B than in group C,with no significant difference found.Conclusion Resuscitation with whole blood and modified GIK therapy combined can ameliorate the pathophysiological disorders,including hyperglycemia,hyperkalemia and coagulopathy,and may improve the function of key organs after HiTCA.

Cardiac arrest secondary to pulmonary embolism treated with extracorporeal cardiopulmonary resuscitation:Six case reports

BACKGROUND Massive pulmonary embolism(PE)results in extremely high mortality rates.Veno-arterial extracorporeal membrane oxygenation(VA-ECMO)can provide circulatory and oxygenation support and rescue patients with massive PE.However,there are relatively few studies of extracorporeal cardiopulmonary resuscitation(ECPR)in patients with cardiac arrest(CA)secondary to PE.The aim of the present study is to investigate the clinical use of ECPR in conjunction with heparin anticoagulation in patients with CA secondary to PE.CASE SUMMARY We report the cases of six patients with CA secondary to PE treated with ECPR in the intensive care unit of our hospital between June 2020 and June 2022.All six patients experienced witnessed CA whilst in hospital.They had acute onset of severe respiratory distress,hypoxia,and shock rapidly followed by CA and were immediately given cardiopulmonary resuscitation and adjunctive VA-ECMO therapy.During hospitalization,pulmonary artery computed tomography angiography was performed to confirm the diagnosis of PE.Through anticoagulation management,mechanical ventilation,fluid management,and antibiotic treatment,five patients were successfully weaned from ECMO(83.33%),four patients survived for 30 d after discharge(66.67%),and two patients had good neurological outcomes(33.33%).CONCLUSION For patients with CA secondary to massive PE,ECPR in conjunction with heparin anticoagulation may improve outcomes.

Meta-analysis of the success rate of heartbeat recovery in patients with prehospital cardiac arrest in the past 40 years in China

Background:Systematic evaluation of the successful heartbeat recovery rate(HRR)in patients during the platinum ten minutes after cardiac arrest.Methods:The databases of CNKI(January 1979–March 2019),Chongqing VIP(January 1989–March 2019),Wanfang(January 1990–March 2019)and Web of Science(January 1900-May 2020)were searched.To collect the clinical data of patients with cardiac arrest before hospitalization and analyze the cardiopulmonary resuscitation(CPR)at different times.Literature selection and data extraction were carried out by two researchers independently,and the meta package of R software(version 3.61)was used for analysis.Results:A total of 116 papers met the inclusion criteria,including 37,181 patients.Of these patients,3367 had their heartbeats successfully restored.The results showed a high degree of heterogeneity(χ2=6999.21,P<0.01,I2=97.6%).The meta-analysis was conducted using a random-effects model.The combined effect size was 0.199(0.157–0.250).(1)According to the five CPR groups(International Cardiopulmonary Resuscitation Guide 2000,2005,2010,2015 and other versions),the HRR of other versions[0.264(0.176–0.375)]was higher than the International Cardiopulmonary Resuscitation 2005 edition[0.121(0.092–0.158)].(2)The rescue time was divided into the 0 to≤5 min group,the 5 to≤10 min group,the 10 to≤15 min group,and the>15 min group.The HRR were 0.417(0.341–0.496),0.143(0.104–0.193),0.049(0.034–0.069),and 0.022(0.009–0.051),respectively.The HRR was higher in the 0 to≤5 min group than in the 5 to≤10 min group,the 10 to≤15 min group and the>15 min group.There was no difference between the 10 to≤15 min group and the>15 min group.(3)When the groups were stratified with the cutoff of 10 min,the≤10 min group HRR[0.250(0.202–0.306)]was higher than the>10 min group rate[0.041(0.029–0.057)].(4)The HRR of the telephone guidance group was[0.273(0.227–0.325)]lower than that of the 0 to≤5 min group[0.429(0.347–0.516)]but higher than that of the 5 to≤10 min group,the 10 to≤15 min group,and the>15 min group.(5)The HRR of the witness group[0.325(0.216–0.458)]was not different from that of the 0 to≤5 min group,but it was higher than those of the 5 to≤10 min group,the 10 to≤15 min group and the>15 min group.(6)There was no significant difference HRR between the witnessed group,the telephone guidance group and the≤10 min group.Conclusions:(1)The HRR is time-sensitive,and early rescue can improve it.(2)CPR performed within the platinum ten minutes must be executed by the public,and other forces are auxiliary.(3)The concept of peri-cardiac arrest period(PCAP)should be established and improved to guide CPR.

Intrahospital Dissemination of Automatic External Defibrillators Decrease Time to Defibrillation of In-Hospital Cardiac Arrests

Background: Survival rates for in-hospital cardiac (IHCA) arrest are low. Early defibrillation is vital and international guidelines, which requests defibrillation within three minutes. Can dissemination of automatic external defibrillators (AED) at hospital wards shorten time to defibrillation compared to standard care, calling for medical emergency team (MET)? Material & Methods: Forty-eight (48) units at S?dersjukhuset, Sweden, were included in the study. They were divided into the intervention group (24 units equipped with AEDs) and the standard care group (24 units with no AEDs). Intervention group staff were trained in CPR to use AEDs and standard care group staff were trained in just CPR. Data were gathered from patient records, AEDs and the Swedish National Registry of Cardiopulmonary Resuscitation (NRCR). Results: 126 IHCA patients were included, 47 in the standard care group, 79 in the intervention group. AEDs in the intervention group were connected to a defibrillator and it was ready to shock before arrival of MET in 83.5% of all cases. AEDs were ready to be used on average 96 seconds (14-427 s) before arrival of MET. Seven (15%) patients were defibrillated in the control group and Twenty (25%) in the intervention group. Defibrillation within three minutes occurred in 67% in the intervention group (11/17), compared with none (0/7) in the control group (p = 0.02). Conclusion: A systematic implementation of AEDs in hospital wards decrease time to defibrillation compared to a standard MET response system. Larger studies are needed to evaluate the impact on the outcome.

Cardiac arrest after graft reperfusion during liver transplantation

BACKGROUND: Cardiac arrest ( CA) during orthotopic liver transplantation (OLT) is rare but it threatens the lives of patients. The cause of perioperitive CA is not fully understood. We reported the occurrence of CA in 5 patients after unclamping of the vena cava and investigated the relationship between CA and associated variables. METHODS: Five patients with CA after graft reperfusion during OLT in our unit from November 1996 to September 2003 were retrospectively reviewed. Analyzed data included donor and recipient demographic data, and recipient operative and postoperative events. RESULTS: Five (2.1%) of 240 patients undergoing OLT experienced CA 5 minutes after graft reperfusion. Two patients died of resuscitation failure. Hyperkalemia and metabolic acidosis after revascularization were observed in some patients. The five patients had hypothermia and hypocalce-mia, and one had pulmonary embolism. CONCLUSIONS: CA is one of the syndromes after reperfusion. Many factors such as hyperkalemia, acidosis or pulmonary embolism combined with hypothermia and hy-pocalcemia during the operation seem to contribute to the occurrence of CA.

Application of Positron Emission Tomography in the Detection of Myocardial Metabolism in Pig Ventricular Fibrillation and Asphyxiation Cardiac Arrest Models after Resuscitation

Objective To study the application of positron emission tomography （PET） in detection of myocardia metabolism in pig ventricular fibrillation and asphyxiation cardiac arrest models after resuscitation. Methods Thirty-two healthy miniature pigs were randomized into a ventricular fibrillation cardiac arrest （VFCA） group （n=16） and an asphyxiation cardiac arrest （ACA） group （n=16）. Cardiac arrest （CA） was induced by programmed electric stimulation or endotracheal tube clamping followed by cardiopulmonary resuscitation （CPR） and defibrillation. At four hours and 24 h after spontaneous circulation was achieved, myocardial metabolism was assessed by PET. 18F-FDG myocardial uptake in PET was analyzed and the maximum standardized uptake value （SUVmax） was measured. Results Spontaneous circulation was 200% and 62.5% in VFCA group and ACA group, respectively. PET demonstrated that the myocardial metabolism injuries was more severe and widespread after ACA than after VFCA. The SUVrnax was higher in VFCA group than in ACA group （P〈0.01）. In VFCA group, SUVmax at 24 h after spontaneous circulation increased to the level of baseline. Conclusion ACA causes more severe cardiac metabol associated with less successful resuscitation. Myocardial sm injuries than VFCA. Myocardial dysfunction is stunning does occur with VFCA but not with ACA.

Global research trends in cardiac arrest research:a visual analysis of the literature based on CiteSpace

BACKGROUND:The high morbidity,high mortality and low survival rate of cardiac arrest(CA)cause a heavy global burden.We aimed to analyze the changes in scientific output related to CA over the past two decades.METHODS:We analyzed the scientific output related to CA from 2000 to 2020 via the Web of Science.The data were analyzed using CiteSpace software.RESULTS:In total,28,312 articles relating to CA were identified in the Web of Science.The volume of scientific research output in the field of global CA research was mainly distributed in the Americas,Europe and Asia,covering a wide range.Of the 28,312 articles,the research content of the highly cited literature mainly focused on CA,mild hypothermia treatment,and prognosis of CA patients.CONCLUSION:Various scientific methods were applied to reveal scientific productivity,collaboration,and research hotspots in the CA research field.Cardiopulmonary resuscitation(CPR),extracorporeal membrane oxygenation(ECMO),survival and target temperature management are research hotspots.Future research on CA will continue to focus on its treatment and prognosis to improve the survival rate of CA patients.

Comparison of extracorporeal and conventional cardiopulmonary resuscitation:A meta-analysis of 2 260 patients with cardiac arrest

BACKGROUND: This meta-analysis aimed to determine whether extracorporeal cardiopulmonary resuscitation(ECPR), compared with conventional cardiopulmonary resuscitation(CCPR), improves outcomes in adult patients with cardiac arrest(CA).DATA RESOURCES: Pub Med, EMBASE, Web of Science, and China Biological Medicine Database were searched for relevant articles. The baseline information and outcome data(survival, good neurological outcome at discharge, at 3–6 months, and at 1 year after CA) were collected and extracted by two authors. Pooled risk ratios(RRs) and 95% confidence intervals(CIs) were calculated using Review Manager 5.3.RESULTS: In six studies 2 260 patients were enrolled to study the survival rate to discharge and longterm neurological outcome published since 2000. A signi? cant effect of ECPR was observed on survival rate to discharge compared to CCPR in CA patients(RR 2.37, 95%CI 1.63–3.45, P<0.001), and patients who underwent ECPR had a better long-term neurological outcome than those who received CCPR(RR 2.79, 95%CI 1.96–3.97, P<0.001). In subgroup analysis, there was a significant difference in survival to discharge favoring ECPR over CCPR group in OHCA patients(RR 2.69, 95%CI 1.48–4.91, P=0.001). However, no signi? cant difference was found in IHCA patients(RR 1.84, 95%CI 0.91–3.73, P=0.09).CONCLUSION: ECPR showed a bene? cial effect on survival rate to discharge and long-term neurological outcome over CCPR in adult patients with CA.

Magnetic resonance imaging tracing of transplanted bone marrow mesenchymal stem cells in a rat model of cardiac arrest-induced global brain ischemia

BACKGROUND： Numerous studies have shown that magnetic resonance imaging （MRI） can detect survival and migration of super paramagnetic iron oxide-labeled stem cells in models of focal cerebral infarction. OBJECTIVE： To observe distribution of bone marrow mesenchymal stem cells （BMSCs） in a rat model of global brain ischemia following cardiac arrest and resuscitation, and to investigate the feasibility of tracing iron oxide-labeled BMSCs using non-invasive MRI. DESIGN, TIME AND SETTING： The randomized, controlled, molecular imaging study was performed at the Linbaixin Medical Research Center, Second Affiliated Hospital, Sun Yat-sen University, and the Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, China from October 2006 to February 2009. MATERIALS： A total of 40 clean, Sprague Dawley rats, aged 6 weeks and of either gender, were supplied by the Experimental Animal Center, Sun Yat-sen University, China, for isolation of BMSCs. Feridex （iron oxide）, Gyroscan Inetra 1.5T MRI system, and cardiopulmonary resuscitation device were used in this study. METHODS： A total of 30 healthy, male Sprague Dawiey rats, aged 6 months, were used to induce ventricular fibrillation using alternating current. After 8 minutes, the rats underwent 6-minute chest compression and mechanical ventilation, followed by electric defibrillation, to establish rat models of global brain ischemia due to cardiac arrest and resuscitation. A total of 24 successful models were randomly assigned to Feridex-labeled and non-labeled groups （n = 12 for each group）. At 2 hours after resuscitation, 5 ×10^8 Feridex-labeled BMSCs, with protamine sulfate as a carrier, and 5 ×10^6 non-labeled BMSCs were respectively transplanted into both groups of rats through the right carotid artery （cells were harvested in 1 mL phosphate buffered saline）. MAIN OUTCOME MEASURES： Feridex-labeled BMSCs were observed by Prussian blue staining and electron microscopy. Signal intensity, celluar viability, and proliferative capacity of BMSCs were measured using MRI, Trypan blue test, and M-IT assay, respectively. Distribution of transplanted cells was observed in rats utilizing MRI and Prussian blue staining prior to and 1, 3, 7, and 14 days after transplantation. RESULTS： Prussian blue staining displayed many blue granules in the Feridex-labeled BMSCs. High density of iron granules was observed in the cytoplasm under electron microscopy. According to MRI results, and compared with the non-labeled group, the signal intensity was decreased in the Feridex-labeled group （P 〈 0.05）. The decrease was most significant in the 50 pg/mL Feridex-labeled group （P 〈 0.01）. There were no significant differences in celluar viability and proliferation of BMSCs between the Feridex-labeled and non-labeled groups after 1 week （P 〉 0.05）. Low-signal lesions were detected in the rat hippocampus and temporal cortex at 3 days after transplantation. The low-signal lesions were still detectable at 14 days, and positively stained cells were observed in the hippocampus and temporal cortex using Prussian blue staining. There were no significant differences in signal intensity in the non-labeled group. CONCLUSION： BMSC transplantation traversed the blood-brain barrier and distributed into vulnerable zones in a rat model of cardiac arrest-induced global brain ischemia. MRI provided a non-invasive method to in vivo dynamically and spatially trace Feridex-labeled BMSCs after transplantation.