ObjectiveTo systematically review the early clinical prediction value of machine learning (ML) for cardiac arrest (CA).MethodsPubMed, EMbase, WanFang Data and CNKI databases were electronically searched to retrieve all ML studies on predicting CA from January 2015 to February 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. The value of each model was evaluated based on the area under receiver operating characteristic curve (AUC) and accuracy.ResultsA total of 38 studies were included. In terms of data sources, 13 studies were based on public database, and other studies retrospectively collected clinical data, in which 21 directly predicted CA, 3 predicted CA-related arrhythmias, and 9 predicted sudden cardiac death. A total of 51 models had been adopted, among which the most popular ML methods included artificial neural network (n=11), followed by random forest (n=9) and support vector machine (n=5). The most frequently used input feature was electrocardiogram parameters (n=20), followed by age (n=12) and heart rate variability (n=10). Six studies compared the ML models with other traditional statistical models and the results showed that the AUC value of ML was generally higher than that in traditional statistical models.ConclusionsThe available evidence suggests that ML can accurately predict the occurrence of CA, and the performance is significantly superior to traditional statistical model in certain cases.
ObjectiveTo compare the effects of different airway management strategies on outcomes of patients with out-of-hospital cardiac arrest (OHCA).MethodsWe searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and WanFang Data for relevant studies comparing the influence of different airway management strategies on outcomes of OHCA patients. The deadline was up to 31st May, 2019. Grading of Recommendations Assessment, Development and Evaluation system 3.6 was used for quality assessment, and RevMan 5.3 software was used for meta-analysis. Odds ratio (OR) and 95% confidence interval (CI) were used to conduct the comparison. Results A total of 20 studies were finally enrolled, including 880 567 OHCA patients. Compared with supraglottic airway (SGA), bag-valve mask (BVM) improved the rate of survival to discharge of OHCA patients [OR=1.45, 95%CI (1.01, 2.08), P=0.04], while the rate of return of spontaneous circulation (ROSC) was not improved (P>0.05); in the subgroup analysis, BVM and SGA had similar effect on the rate of ROSC and the rate of survival to discharge in Asian countries (P>0.05), while BVM performed better than SGA in the two rates in European and American countries. BVM and endotracheal intubation (ETI) had similar effect on the two rates (P>0.05). In Asian countries, ETI performed better than BVM in the rate of ROSC [OR=0.63, 95%CI (0.49, 0.81), P=0.000 3], and there was no statistically significant difference in the rate of survival to discharge between ETI and BVM (P>0.05); while in European andAmerican countries, BVM performed better than ETI in the rate of survival to discharge [OR=3.10, 95%CI (2.69, 3.56), P<0.000 01], and there was no statistically significant difference in the rate of ROSC between ETI and BVM (P>0.05). Compared with SGA, ETI improved the rate of ROSC [OR=0.68, 95%CI (0.62, 0.76), P<0.000 01] and the rate of survival to discharge [OR=0.89, 95%CI (0.81, 0.98), P=0.02]. In Asian countries, ETI performed better than SGA in the two rates (P<0.05); while in European and American countries and New Zealand, ETI performed better than SGA in the rate of ROSC (P<0.05), but there was no statistically significant difference in the rate of survival to discharge (P>0.05). Conclusions Different airway management strategies have differente effects on OHCA patients. The optimal airway management strategy when rescuing OHCA patients might be selected based on local emergency medical service system conditions.
ObjectiveTo systematically review the efficacy and safety of intravascular cooling versus surface cooling for induced mild hypothermia on the prognosis of patients with cardiac arrest (CA) after resuscitation.MethodsPubMed, EMbase, The Cochrane Library, CNKI and WanFang Data databases were electronically searched to collect cohort studies and randomized controlled trials (RCTs) about the efficacy and safety of intravascular cooling versus surface cooling for CA patients after resuscitation from inception to July 2019. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 13.0 software.ResultsA total of 9 cohort studies and 3 RCTs involving 2 104 patients were included. The results of meta-analysis showed that: the rate of good neurological function was significantly higher (OR=1.45, 95%CI 1.18 to 1.78, P<0.001) and the induction time was significantly shorter (SMD=−1.35, 95%CI −2.34 to −0.36, P=0.008) in the intravascular cooling group, but there was no statistical difference in mortality between two groups (OR=0.84, 95%CI 0.70 to 1.00, P=0.053). In terms of complications related to mild hypothermia, the rate of excessive hypothermia (OR=0.27, 95%CI 0.18 to 0.41, P<0.001) and arrhythmia (OR=0.60, 95%CI 0.40 to 0.89, P=0.012) was significantly lower in the patients treated with intravascular cooling, but the incidence of coagulopathy was higher (OR=1.61, 95%CI 1.05 to 2.49, P=0.03). There was no statistical difference in the incidence of pneumonia between two groups (OR=1.20, 95%CI 0.94 to 1.53, P=0.147).ConclusionCurrent evidence shows that intravascular cooling has significant neurological protection for patients with CA compared with surface cooling since it can decrease the induction time and the rate of excessive hypothermia and arrhythmia, but it may have a negative effect on the coagulation function. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to verify the above conclusion.
The treatment of organ function damage secondary to return of spontaneous circulation in patients with cardiac arrest is an important part of advanced life support. The incidence of lung injury secondary to return of spontaneous circulation in patients with cardiac arrest is as high as 79%. Understanding the characteristics and related mechanisms of lung injury secondary to return of spontaneous circulation in patients with cardiac arrest, and early identification and treatment of lung injury secondary to return of spontaneous circulation are crucial to the clinical treatment of patients with cardiac arrest. Therefore, this article reviews the research progress on the characteristics, risk factors, mechanisms and treatment of lung injury secondary to return of spontaneous circulation in patients with cardiac arrest, in order to provide a reference for the research and clinical diagnosis and treatment of lung injury secondary to return of spontaneous circulation in patients with cardiac arrest.
Currently, cardiac arrest has become a major public health problem, which has a high incidence rate and a high mortality rate in humans. With the continuous advancement of cardiopulmonary resuscitation techniques, the overall prognosis of cardiac arrest victims is gradually improved. However, cardiac arrest events under special circumstances are still serious threats to human health. This article reviews the progress of epidemiology, pathogenesis, treatment characteristics, and key points of cardiopulmonary resuscitation in those special cardiac arrest events associated with trauma, poisoning, drowning and pregnancy.
Objective To systematically review risk prediction models of in-hospital cardiac arrest in patients with cardiovascular disease, and to provide references for related clinical practice and scientific research for medical professionals in China. Methods Databases including CBM, CNKI, WanFang Data, PubMed, ScienceDirect, Web of Science, The Cochrane Library, Wiley Online Journals and Scopus were searched to collect studies on risk prediction models for in-hospital cardiac arrest in patients with cardiovascular disease from January 2010 to July 2022. Two researchers independently screened the literature, extracted data, and evaluated the risk of bias of the included studies. Results A total of 5 studies (4 of which were retrospective studies) were included. Study populations encompassed mainly patients with acute coronary syndrome. Two models were modeled using decision trees. The area under the receiver operating characteristic curve or C statistic of the five models ranged from 0.720 to 0.896, and only one model was verified externally and for time. The most common risk factors and immediate onset factors of in-hospital cardiac arrest in patients with cardiovascular disease included in the prediction model were age, diabetes, Killip class, and cardiac troponin. There were many problems in analysis fields, such as insufficient sample size (n=4), improper handling of variables (n=4), no methodology for dealing with missing data (n=3), and incomplete evaluation of model performance (n=5). Conclusion The prediction efficiency of risk prediction models for in-hospital cardiac arrest in patients with cardiovascular disease was good; however, the model quality could be improved. Additionally, the methodology needs to be improved in terms of data sources, selection and measurement of predictors, handling of missing data, and model evaluations. External validation of existing models is required to better guide clinical practice.
American Heart Association issued American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care in October 2020. A sixth link, recovery, has been added to both the adult out-of-hospital cardiac arrest chain and in-hospital cardiac arrest chain in this version of the guidelines to emphasize the importance of recovery and survivorship for resuscitation outcomes. Analogous chains of survival have also been developed for adult out-of-hospital cardiac arrest and in-hospital cardiac arrest. The major new and updated recommendations involve the early initiation of cardiopulmonary resuscitation by lay rescuers, early administration of epinephrine, real-time audiovisual feedback, physiologic monitoring of cardiopulmonary resuscitation quality, double sequential defibrillation not supported, intravenous access preferred over intraosseous, post-cardiac arrest care and neuroprognostication, care and support during recovery, debriefings for rescuers, and cardiac arrest in pregnancy. This present review aims to interpret these updates by reviewing the literature and comparing the recommendations in these guidelines with previous ones.
Objective To describe the clinical profiles of cardiac arrest due to fatal pulmonary embolism (FPE), and review the literature on FPE diagnosis and treatment. Methods The clinical profiles of two cases with cardiac arrest for FPE were presented. A systematic search of Medline (1950 - 2014) and EMbase (1980-2014) was conducted to identify studies that investigated the use of thrombolytic medications to treat cardiac arrest for FPE. Results The fatal event of two patients occurred after surgery. Both of them survived with cardiopulmonary resuscitation and administration of thrombolysis and anticoagulation, but one of them had major bleeding during anticoagulation. Six articles were found involving 72473 cases of cardiac arrest due to pulmonary embolism (PE) or unstable massive PE. The thrombolytic agents were recombinant tissue plasminogen activator or streptokinase, but the administration and dose of thrombolytic agents were unclear. Overall, administration of thrombolytics can shorten the time to return of spontaneous circulation and improve the survival rate. There was, however, an increased risk of bleeding events following administration of thrombolytics. Conclusions Because of the high mortality of cardiac arrest for FPE, the clinician should correctly identify patients with a high likelihood of FPE. Early use of thrombolytics is very important and can potentially improve patient outcomes.
Since the outbreak of the coronavirus disease 2019, the incidence and mortality of cardiac arrest have increased significantly worldwide, and the management of cardiac arrest is facing new challenges. The European Resuscitation Council issued the 2021 European Resuscitation Council Guidelines in March 2021 to update the important parts of cardiopulmonary resuscitation and added recommendations for the management of cardiopulmonary resuscitation during the coronavirus disease 2019 epidemic. This article will compare the difference between this guideline and the 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care and integrate some key points, review literature and then summarize the latest research progress in cardiopulmonary resuscitation since the outbreak of the coronavirus disease 2019 epidemic. The content mainly involves cardiopulmonary resuscitation during the coronavirus disease 2019 epidemic, early prevention, early recognition, application of new technologies, airway management, extracorporeal cardiopulmonary resuscitation and post-resuscitation treatment.
ObjectiveTo investigate the effects of esophageal cooling (EC) on lung injury and systemic inflammatory response after cardiopulmonary resuscitation in swine.MethodsThirty-two domestic male white pigs were randomly divided into sham group (S group, n=5), normothermia group (NT group, n=9), surface cooling group (SC group, n=9), and EC group (n=9). The animals in the S group only experienced the animal preparation. The animal model was established by 8 min of ventricular fibrillation and then 5 min of cardiopulmonary resuscitation in the other three groups. A normal temperature of (38.0±0.5)℃ was maintained by surface blanket throughout the experiment in the S and NT groups. At 5 min after resuscitation, therapeutic hypothermia was implemented via surface blanket or EC catheter to reach a target temperature of 33℃, and then maintained until 24 h post resuscitation, and followed by a rewarming rate of 1℃/h for 5 h in the SC and EC groups. At 1, 6, 12, 24 and 30 h after resuscitation, the values of extra-vascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI) were measured, and meanwhile arterial blood samples were collected to measure the values of oxygenation index (OI) and venous blood samples were collected to measure the serum levels of tumor necrosis factor-α (TNF-α) and inerleukin-6 (IL-6). At 30 h after resuscitation, the animals were euthanized, and then the lung tissue contents of TNF-α, IL-6 and malondialdehyde, and the activities of superoxide dismutase (SOD) were detected.ResultsAfter resuscitation, the induction of hypothermia was significantly faster in the EC group than that in the SC group (2.8 vs. 1.5℃/h, P<0.05), and then its maintenance and rewarming were equally achieved in the two groups. The values of ELWI and PVPI significantly decreased and the values of OI significantly increased from 6 h after resuscitation in the EC group and from 12 h after resuscitation in the SC group compared with the NT group (all P<0.05). Additionally, the values of ELWI and PVPI were significantly lower and the values of OI were significantly higher from 12 h after resuscitation in the EC group than those in the SC group [ELWI: (13.4±3.1) vs. (16.8±2.7) mL/kg at 12 h, (12.4±3.0) vs. (16.0±3.6) mL/kg at 24 h, (11.1±2.4) vs. (13.9±1.9) mL/kg at 30 h; PVPI: 3.7±0.9 vs. 5.0±1.1 at 12 h, 3.4±0.8 vs. 4.6±1.0 at 24 h, 3.1±0.7 vs. 4.2±0.7 at 30 h; OI: (470±41) vs. (417±42) mm Hg (1 mm Hg=0.133 kPa) at 12 h, (462±39) vs. (407±36) mm Hg at 24 h, (438±60) vs. (380±33) mm Hg at 30 h; all P<0.05]. The serum levels of TNF-α and IL-6 significantly decreased from 6 h after resuscitation in the SC and EC groups compared with the NT group (all P<0.05). Additionally, the serum levels of IL-6 from 6 h after resuscitation and the serum levels of TNF-α from 12 h after resuscitation were significantly lower in the EC group than those in the SC group [IL-6: (299±23) vs. (329±30) pg/mL at 6 h, (336±35) vs. (375±30) pg/mL at 12 h, (297±29) vs. (339±36) pg/mL at 24 h, (255±20) vs. (297±33) pg/mL at 30 h; TNF-α: (519±46) vs. (572±49) pg/mL at 12 h, (477±77) vs. (570±64) pg/mL at 24 h, (436±49) vs. (509±51) pg/mL at 30 h; all P<0.05]. The contents of TNF-α, IL-6, and malondialdehyde significantly decreased and the activities of SOD significantly increased in the SC and EC groups compared with the NT group (all P<0.05). Additionally, lung inflammation and oxidative stress were further significantly alleviated in the EC group compared with the SC group [TNF-α: (557±155) vs. (782±154) pg/mg prot; IL-6: (616±134) vs. (868±143) pg/mg prot; malondialdehyde: (4.95±1.53) vs. (7.53±1.77) nmol/mg prot; SOD: (3.18±0.74) vs. (2.14±1.00) U/mg prot; all P<0.05].ConclusionTherapeutic hypothermia could be rapidly induced by EC after resuscitation, and further significantly alleviated post-resuscitation lung injury and systemic inflammatory response compared with conventional surface cooling.