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.

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.

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.

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.

A meta-analysis of the success rates of heartbeat restoration within the platinum 10min among outpatients suffering from sudden cardiac arrest in China

Background:The optimal time to save a person who has had a sudden cardiac arrest is within the first few minutes of the incident.Early compression and early defibrillation should be performed at this time.Timeliness is the key to successful CPR; as such,Prof.He proposed the 'platinum 10 min' system to study early CPR issues.This paper systematically evaluates the success rates of heartbeat restoration within the 'platinum 10min' among patients suffering from sudden cardiac arrest.Methods:The clinical data of outpatients suffering from a cardiac arrest were retrieved from the China Knowledge Network(January 1975-January 2015),the Chongqing VIP database(January 1989-January 2015),and the Wanfang database(January 1990-January 2015).The success of the cardiopulmonary resuscitation(CPR) performed at different times after the patients had cardiac arrests was analyzed.Two researchers screened the literature and extracted the data independently.A meta-analysis was conducted using Stata 12.0.A total of 57 papers met the inclusion criteria,including 29,269 patients.Of these patients,1,776 had their heartbeats successfully restored.The results showed high heterogeneity(χ~2=3428.85,P<0.01,I2=98.4%).The meta-analysis was conducted using a random-effects model.The combined effect size was 0.171(0.144-0.199).Results:1) The success rate of heartbeat restoration did not differ among the four emergency treatment methods that patients received:the methods described in the 2000 Guidelines for CPR and Emergency Cardiovascular Care,that described in the 2005 version,2010 version,and another CPR method.2) The patients were divided into five groups based on the time when CPR was performed:the ?1min group,the 1-5min group,the 5-10 min group,the 10-15 min group and the >15min group.The CPR success rates of these five groups were 0.247(0.15-0.344),0.353(0.250-0.456),0.136(0.109-0.163),0.058(0.041-0.075),and 0.011(0.004-0.019),respectively.The CPR success rates did not differ between the patients in the ?1min group and the 1-5min group.This success rate was higher for the patients in the 1-5min group than those in the 10-15 min group,those in the 10-15 min group,and those in the >15min group.The CPR success rate was higher for the patients in the 5-10 min group than those in the 10-15 min group and those in the >15min group.The CPR success rate was higher for the patients in the 10-15 min group than those in the >15min group.In addition,the patients were divided into two groups based on whether CPR was performed within the first 10 min after the cardiac arrest occurred:the ?10min group and the >10min group.The CPR success rate was higher for the patients in the ?10min group [0.189(0.161-0.218)] than those in the >10min group [0.044(0.032-0.056)].3) Differences were not found between the CPR success rates among the patients in the telephone guidance group [0.167(0.016-0.351)] and those in the ?1min,1-5min,5-10 min,10-15 min,and >15min groups.4) The CPR success rates did not differ among in the patients in the witness + public group [0.329(0.221-0.436)],those in the ?1min group,and those in the 1-5min group.However,this success rate was higher in the patients in the witness + public group than those in the 5-10 min,10-15 min,and >15min groups.Conclusion:The success rate of heartbeat restoration did not differ among patients receiving CPR based on different guidelines.The success rate of CPR lies in its timeliness.The participation of the general population is the cornerstone of improving CPR.Providing complete emergency treatment equipment and perfecting comprehensive measures can improve the success rate of CPR among patients within the platinum 10 min.CPR research in China must be improved.

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.

Renal Doppler and Novel Biomarkers to Assess Acute Kidney Injury in a Swine Model of Ventricular Fibrillation Cardiac Arrest

Background： Majority of the research on cardiac arrest （CA） have focused on post-CA brain injury and myocardial dysfunction, the renal dysfunction and acute kidney injury （AKI） in other critical illnesses after CA have not been well described. This study was designed to assess AKI with renal Doppler and novel AK1 biomarkers in a swine model of ventricular fibrillation cardiac arrest （VFCA）. Methods： Thirty healthy piglets were divided into VFCA group （17 = 22） and Sham group （n = 8） in a blinded manner. Mean arterial pressure, heart rate. and cardiac output were recorded continuously. Cardiac arrest （CA） was induced by programmed electric stimulation in the VFCA group, and then cardiopulmonary resuscitation was performed. Twenty piglets returned of spontaneous circulation （ROSC） and received intensive care. Blood and urine samples were collected for AKI biomarkers testing, and Color Doppler flow imaging was performed at baseline, 6 h, 12 h, and 24 11. respectively after ROSC. At ROSC 24 h, the animals were sacrificed and a semi-quantitative evaluation of pathologic kidney injury was performed. Results： In the VFCA group, corrected resistive index （cRl） increased from 0.47 ± 0.03 to 0.64 ± 0.06, and pulsatility index （PI） decreased from 0.82 ± 0.03 to 0.68 ± 0.04 after ROSC. Cystatin C （CysC） in both serum and urine samples increased at ROSC 6 h, but neutrophil gelatinase-associated lipocalin （NGAL） in serum increased to 5.34 ± 1.68 ng/ml at ROSC 6 h, and then decreased to 3.16 ± 0.69 ng/ml at ROSC 24 h while CysC increasing constantly. According to the renal histopathology, 18 of 20 animals suffered from kidney injury. The grade of renal injury was highly correlated with RI, cRI, NGAL, and CysC. Linear regression equation was established： Grade of renal injury = 0.002× serum CysC ＋ 6.489 × PI ＋ 4.544 × cRI - 8.358 （r^2 = 0.698, F = 18.506, P 〈 0.001）. Conclusions： AKI is common in post-CA syndrome. Renal Doppler and novel AKI biomarkers in serum and urine are of significant importance as early predictors of post-CA AKI.

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.

Extracorporeal Membrane Oxygenation Improving Survival and Alleviating Kidney Injury in a Swine Model of Cardiac Arrest Compared to Conventional Cardiopulmonary Resuscitation

Background： Acute kidney injury （AKI） frequently occurs in cardiopulmonary resuscitation patients. Studies comparing the effects of extracorporeal membrane oxygenation （ECMO） with conventional cardiopuhnonary resuscitation （CCPR） on AKI were rare. This study aimed to compare the effects of ECMO with those of CCPR on survival rate and AKI and explore the underlying mechanisms in a swine model of cardiac arrest （CA）. Methods： Sixteen male pigs were treated with ventricular fibrillation to establish CA model and then underwent CCPR （CCPR group, n = 8） or ECMO during cardiopulmonary resuscitation （ECPR group, n = 8）. The study endpoints were 6 h after return of spontaneous circulation （ROSC） or death. Serum and urine samples were collected at baseline and during the 6 h after ROSC. The biomarkers of AKI were detected by enzyme-linked immunosorbent assay. The apoptosis of renal tubular epithelial cells was discovered by transmission electron microscope （TEM） and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Apoptosis-related genes were detected by immune-staining and Western blotting. Data were compared by Student＇s t-test. Results： All pigs in ECPR group were successfully resuscitated with a higher 6-h survival rate （8/8） compared to CCPR group （6/8）. The expressions ofAKl biomarkers including neutrophil gelatinase-associated lipocalin （NGAL）, tissue inhibitor ofmetalloproteinase2 （TIMP2）, insulin-like growth factor-binding protein 7 （IGFBP7）, liver fatty acid-binding protein （LFABP）, and kidney injury molecule l （Kim-1） were all increased along with the time after ROSC in both groups and lower in ECPR group compared with CCPR group. Especially, products of urinary T1MP and IGFBP levels （TIMP＊IGFBP） were significantly lower at ROSC4 （0.58 ± 0.10 ng^2/ml^2 vs. 1.18 ± 0.38 ng^2/ml^2, t = 4.33, P =0.003） and ROSC6 （1.79 ±0.45 ng2^/ml^2 vs. 3.00 ±0.44 ng^2/ml^2, t = 5.49, P 〈 0.001）; urinary LFABP was significantly lower at ROSC6 （0.74 ± 0.06 pg/ml vs. 0.85 4±0.11 pg/ml, t = 2.41, P = 0.033）; and urinary Kim-1 was significantly lower at ROSC4 （0.66 ± 0.09 pg/ml vs. 0.83 ± 0.06 pg/ml, t = 3.99, P = 0.002） and ROSC6 （0.73 ± 0.12 pg/ml vs. 0.89 ± 0.08 pg/ml, t = 2.82, P = 0.016）. Under light microscope and TEM, the morphological injures in renal tissues were found to be improved in ECPR group. Moreover, apoptosis was also alleviated in ECPR group. Conclusions： Compared with CCPR, ECMO improves survival rate and alleviates AKI in a swine model of CA. The mechanism of which might be via downregulating AKI biomarkers and apoptosis in kidney.

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.

Mild hypothermia in improving multiple organ dysfunction after cardiac arrest

BACKGROUND： Resuscitation after cardiac arrest （CA） with a whole-body ischemia–reperfusion injury causes brain injury and multiple organ dysfunction （MODS）. This study aimed to determine whether mild systemic hypothermia could decrease multiple organ dysfunctions after resuscitation from cardiac arrest.METHODS： The patients who had been resuscitated after cardiac arrest were reviewed. During the resuscitation they had been assigned to undergo therapeutic hypothermia （target temperature, 32°C to 34°C, measured in the rectum） over a period of 24 to 36 hours or to receive standard treatment with normothermia. Markers of different organ injury were evaluated for the ？ rst 72 hours after recovery of spontaneous circulation （ROSC）.RESULTS： At 72 hours after ROSC, 23 patients in the hypothermia group for whom data were available had favorable neurologic, myocardial, hepatic and pulmonic outcomes as compared with 26 patients in the normothermia group. The values of renal function were not signi？ cantly different between the two groups. However, blood coagulation function was badly injured in the hypothermia group.CONCLUSION： In the patients who have been successfully resuscitated after cardiac arrest, therapeutic mild hypothermia can alleviate dysfunction after resuscitation from cardiac arrest.

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.

Electrocardiographic changes during induced therapeutic hypothermia in comatose survivors after cardiac arrest

AIM: To assess the safety of therapeutic hypothermia(TH) concerning arrhythmias we analyzed serial electrocardiograms(ECG) during TH.METHODS: All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34℃. TH was obtained with cool fluid infusion or a specific intravascular device. Twelvelead ECG before,during,and after TH,as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period,47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG,recorded at 25 mm/s and 10 mm/m V. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm,RR,PR,QT and corrected QT(QTc by Bazett formula,measured in lead v2) intervals,QRS duration,presence of Osborn's J wave and U wave,as well as ST segment displacement and T wave amplitude in leads Ⅱ,v2 and v5.RESULTS: Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming(P < 0.0005,both). There was a nonsignificant prolongation of the PR interval during TH and a significant decrease with rewarming(P = 0.041). QRS duration significantly prolonged(P = 0.041) with TH and shortened back(P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms(P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms(P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia(19.1%),followed by severe bradycardia or paced rhythm(10.6%),accelerated nodal rhythm(8.5%) and atrial fibrillation(6.4%). No life threatening arrhythmias(sustained ventricular tachycardia,polymorphic ventricular tachycardia or ventricular fibrillation) occurred during TH. CONCLUSION: A 38.3% of patients had cardiac arrhythmias during TH but without life-threatening arrhythmias. A concern may rise when inducing TH to patients with long QT syndrome.

Characteristics and outcomes of out-of-hospital cardiac arrest in Zhejiang Province

China has undergone tremendous economic growth,but there still remains much room for improvement inemergency medical service （EMS） system.[1] The EMSin China comprises of three parts： the pre-hospitalemergency service, the emergency department, andthe intensive care unit. Not much is known about theexact numbers of out-of-hospital cardiac arrest （OHCA）across the whole of China, though there are reports fromspecifi c provinces.

Active compression-decompression cardiopulmonary resuscitation(CPR) versus standard CPR for cardiac arrest patients:a meta-analysis

BACKGROUND:Active compression-decompression cardiopulmonary resuscitation(ACDCPR) has been popular in the treatment of patients with cardiac arrest(CA).However,the effect of ACD-CPR versus conventional standard CPR(S-CRP) is contriversial.This study was to analyze the efficacy and safety of ACD-CPR versus S-CRP in treating CA patients.METHODS:Randomized or quasi-randomized controlled trials published from January 1990 to March 2011 were searched with the phrase "active compression-decompression cardiopulmonary resuscitation and cardiac arrest" in PubMed,EmBASE,and China Biomedical Document Databases.The Cochrane Library was searched for papers of meta-analysis.Restoration of spontaneous circulation(ROSC) rate,survival rate to hospital admission,survival rate at 24 hours,and survival rate to hospital discharge were considered primary outcomes,and complications after CPR were viewed as secondary outcomes.Included studies were critically appraised and estimates of effects were calculated according to the model of fixed or random effects.Inconsistency across the studies was evaluated using the I2 statistic method.Sensitivity analysis was made to determine statistical heterogeneity.RESULTS:Thirteen studies met the criteria for this meta-analysis.The studies included 396 adult CA patients treated by ACD-CPR and 391 patients by S-CRP.Totally 234 CA patients were found out hospitals,while the other 333 CA patients were in hospitals.Two studies were evaluated with high-quality methodology and the rest 11 studies were of poor quality.ROSC rate,survival rate at 24 hours and survival rate to hospital discharge with favorable neurological function indicated that ACD-CPR is superior to S-CRP,with relative risk(RR) values of 1.39(95%CI 0.99-1.97),1.94(95%CI 1.45-2.59) and 2.80(95%CI 1.60-5.24).No significant differences were found in survival rate to hospital admission and survival rate to hospital discharge for ACD-CPR versus S-CRP with RR values of 1.06(95%CI 0.76-1.60) and 1.00(95%CI 0.73-1.38).CONCLUSION:Quality controlled studies confirmed the superiority of ACD-CPR to S-CRP in terms of ROSC rate and survival rate at 24 hours.Compared with S-CRP,ACD-CPR could not improve survival rate to hospital admission or survival rate to hospital discharge.