Post cardiac arrest left ventricular ejection fraction associated with survival to discharge.

Background: Post cardiac arrest left ventricular ejection fraction (LVEF) is routinely assessed, but the implications of this are unknown. This study aimed to assess the association between post cardiac arrest LVEF and survival to hospital discharge. Methods: In this retrospective cohort study, all in-hospital and out of hospital cardiac arrests at our tertiary care center between January 2012 and September 2015 were included. Baseline demographics, clinical data, characteristics of the arrest, and interventions performed were collected. Earliest post cardiac arrest echocardiograms were reviewed with LVEF documented. The primary outcome was survival to discharge. Results: A total of 736 patients were included in the analysis (mean age 58 years, 44% female). 15% were out of hospital cardiac arrest (24% shockable rhythm). After adjusting for covariates, patients with LVEF < 30% had 36% lower odds of surviving to hospital discharge than those with LVEF ≥ 52% (p = 0.014). Shockable initial rhythm and targeted temperature management were associated with improved survival. Conclusion: After a cardiac arrest, an initial LVEF < 30% is associated with significantly lower odds of survival to hospital discharge.

Associated Factors of Patients' Survival in Out of Hospital Cardiac Arrest; a Cross-sectional Study.

Introduction: Chinese populations have an increasingly high prevalence of cardiac arrest. This study aimed to investigate the prehospital associated factors of survival to hospital admission and discharge among out-of-hospital cardiac arrest (OHCA) adult cases in Macao Special Administrative Region (SAR), China. Methods: Baseline characteristics as well as prehospital factors of OHCA patients were collected from publicly accessible medical records and Macao Fire Services Bureau, China. Demographic and other prehospital OHCA characteristics of patients who survived to hospital admission and discharge were analyzed using multivariate logistic regression analysis. Results: A total of 904 cases with a mean age of 74.2±17.3 (range: 18-106) years were included (78%>65 years, 62% male). Initial shockable cardiac rhythm was the strongest predictor for survival to both hospital admission (OR=3.57, 95% CI: 2.26-5.63; p<0.001) and discharge (OR=12.40, 95% CI: 5.70-26.96; p<0.001). Being male (OR=1.63, 95% CI:1.08-2.46; p =0.021) and the lower emergency medical service (EMS) response time (OR=1.62, 95% CI: 1.12-2.34; p =0.010) were also associated with a 2-fold association with survival to hospital admission. In addition, access to prehospital defibrillation (OR=4.25, 95% CI: 1.78-10.12; p <0.001) had a 4-fold association with survival to hospital discharge. None of these associations substantively increased with age. Conclusion: The major OHCA predictors of survival were initial shockable cardiac rhythm, being male, lower EMS response time, and access to prehospital defibrillation. These findings indicate a need for increased public awareness and more education.

Brochoscopic Airway Clearance Therapy vs. Conventional Sputum Aspiration: The Future of Flexible Brochoscopes in Intensive Care Units?

(1) Background: The aim of our study is to investigate the effectiveness of bronchoscopic airway clearance therapy (B-ACT) on severe pneumonia (SP) patients with invasive mechanical ventilation (IMV) in the intensive care unit (ICU). (2) Methods: Our study retrospectively enrolled 49 patients with sputum aspiration and 99 patients with B-ACT, and the latter were divided into the ≤once every 3 days group (n = 50) and >once every 3 days group (n = 49). (3) Results: We found most laboratory blood results were significantly improved in the B-ACT group as compared with those in sputum aspiration group (p < 0.05). Patients in the B-ACT group and those in ≤once every 3 days group also had significantly better survival to hospital discharge than those in their counterpart groups (Logrank p < 0.001). In patients with cardiopulmonary diseases or positive cultures for bacteria, the B-ACT group and those in the ≤once every 3 days group had significantly better survival outcomes to discharge than those in their counterpart groups (Logrank p < 0.001). B-ACT and the average frequency of ≤once every 3 days had significantly better impact on survival outcomes than their counterpart groups (HR: 0.444, 95% CI: 0.238-0.829, p = 0.011; HR: 0.285, 95% CI: 0163-0.498, p < 0.001). (4) Conclusions: In the future, flexible bronchoscopes may paly an important role in ACT for SP patients with IMV.

Do cardiopulmonary resuscitation real-time audiovisual feedback devices improve patient outcomes? A systematic review and meta-analysis.

BACKGROUND: Cardiac arrest is a leading cause of mortality in America and has increased in the incidence of cases over the last several years. Cardiopulmonary resuscitation (CPR) increases survival outcomes in cases of cardiac arrest; however, healthcare workers often do not perform CPR within recommended guidelines. Real-time audiovisual feedback (RTAVF) devices improve the quality of CPR performed. This systematic review and meta-analysis aims to compare the effect of RTAVF-assisted CPR with conventional CPR and to evaluate whether the use of these devices improved outcomes in both in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients. AIM: To identify the effect of RTAVF-assisted CPR on patient outcomes and CPR quality with in- and OHCA. METHODS: We searched PubMed, SCOPUS, the Cochrane Library, and EMBASE from inception to July 27, 2020, for studies comparing patient outcomes and/or CPR quality metrics between RTAVF-assisted CPR and conventional CPR in cases of IHCA or OHCA. The primary outcomes of interest were return of spontaneous circulation (ROSC) and survival to hospital discharge (SHD), with secondary outcomes of chest compression rate and chest compression depth. The methodological quality of the included studies was assessed using the Newcastle-Ottawa scale and Cochrane Collaboration's "risk of bias" tool. Data was analyzed using R statistical software 4.2.0. results were statistically significant if P < 0.05. RESULTS: Thirteen studies (n = 17600) were included. Patients were on average 69 ± 17.5 years old, with 7022 (39.8%) female patients. Overall pooled ROSC in patients in this study was 37% (95% confidence interval = 23%-54%). RTAVF-assisted CPR significantly improved ROSC, both overall [risk ratio (RR) 1.17 (1.001-1.362); P = 0.048] and in cases of IHCA [RR 1.36 (1.06-1.80); P = 0.002]. There was no significant improvement in ROSC for OHCA (RR 1.04; 0.91-1.19; P = 0.47). No significant effect was seen in SHD [RR 1.04 (0.91-1.19); P = 0.47] or chest compression rate [standardized mean difference (SMD) -2.1; (-4.6-0.5)]; P = 0.09]. A significant improvement was seen in chest compression depth [SMD 1.6; (0.02-3.1); P = 0.047]. CONCLUSION: RTAVF-assisted CPR increases ROSC in cases of IHCA and chest compression depth but has no significant effect on ROSC in cases of OHCA, SHD, or chest compression rate.

A simple scoring rule to predict survival to discharge after out of hospital cardiac arrest at the time of ED arrival.

BACKGROUND: It is important to be able to predict the chance of survival to hospital discharge upon ED arrival in order to determine whether to continue or terminate resuscitation efforts after out of hospital cardiac arrest. This study was conducted to develop and validate a simple scoring rule that could predict survival to hospital discharge at the time of ED arrival. METHODS: This was a multicenter retrospective cohort study based on a nationwide registry (Korean Cardiac Arrest Research Consortium) of out of hospital cardiac arrest (OHCA). The study included adult OHCA patients older than 18 years old, who visited one of 33 tertiary hospitals in South Korea from September 1st, 2015 to June 30th, 2020. Among 12,321 screened, 5471 patients were deemed suitable for analysis after exclusion. Pre-hospital ROSC, pre-hospital witness, shockable rhythm, initial pH, and age were selected as the independent variables. The dependent variable was set to be the survival to hospital discharge. Multivariable logistic regression (LR) was performed, and the beta-coefficients were rounded to the nearest integer to formulate the scoring rule. Several machine learning algorithms including the random forest classifier (RF), support vector machine (SVM), and K-nearest neighbor classifier (K-NN) were also trained via 5-fold cross-validation over a pre-specified grid, and validated on the test data. The prediction performances and the calibration curves of each model were obtained. Pre-processing of the registry was done using R, model training & optimization using Python. RESULTS: A total of 5471 patients were included in the analysis. The AUROC of the scoring rule over the test data was 0.7620 (0.7311-0.7929). The AUROCs of the machine learning classifiers (LR, SVM, k-NN, RF) were 0.8126 (0.7748-0.8505), 0.7920 (0.7512-0.8329), 0.6783 (0.6236-0.7329), and 0.7879 (0.7465-0.8294), respectively. CONCLUSION: A simple scoring rule consisting of five, binary variables could aid in the prediction of the survival to hospital discharge at the time of ED arrival, showing comparable results to conventional machine learning classifiers.

Successful resuscitation and neurological monitoring of a dog with out-of-hospital cardiopulmonary arrest due to pentobarbital overdose.

OBJECTIVE: To describe the clinical signs, electroencephalographic (EEG) findings, treatment, and outcome in a dog after successful resuscitation from out-of-hospital cardiopulmonary arrest (OHCA) induced by pentobarbital intoxication. CASE SUMMARY: A 10-year-old, male intact Jack Russell Terrier was referred for management of refractory status epilepticus and presented dead on arrival. After 7 minutes of cardiopulmonary resuscitation, return of spontaneous circulation was achieved, but the dog remained comatose, apneic, and lacked brainstem reflexes on neurological examination 6 hours following resuscitation. Magnetic resonance imaging showed polioencephalomalacia consistent with prolonged epileptiform activity, and EEG was initially concerning for electrocerebral inactivity. Following supportive care that included short-term mechanical ventilation, the dog made a full recovery and was discharged from the hospital alive 7 days postresuscitation. It was later revealed that the dog had been administered an unknown amount of pentobarbital during transportation, which likely contributed to the OHCA, clinical, and EEG findings. NEW INFORMATION PROVIDED: This is the first report to describe the full recovery and hospital discharge of a dog suffering OHCA and the first description of EEG findings in a clinical veterinary patient following cardiopulmonary arrest and successful resuscitation. Factors likely contributing to successful patient outcome and potential benefits and limitations of EEG in monitoring postcardiac arrest patients are discussed.

Management of Out-of-Hospital Cardiac Arrest during COVID-19: A Tale of Two Cities.

Variations in the impact of the COVID-19 pandemic on out-of-hospital cardiac arrest (OHCA) have been reported. We aimed to, using population-based registries, compare community response, Emergency Medical Services (EMS) interventions and outcomes of adult, EMS-treated, non-traumatic OHCA in Singapore and metropolitan Atlanta, before and during the pandemic. Associations of OHCA characteristics, pre-hospital interventions and pandemic with survival to hospital discharge were analyzed using logistic regression. There were 2084 cases during the pandemic (17 weeks from the first confirmed COVID-19 case) and 1900 in the pre-pandemic period (corresponding weeks in 2019). Compared to Atlanta, OHCAs in Singapore were older, received more bystander interventions (cardiopulmonary resuscitation (CPR): 65.0% vs. 41.4%; automated external defibrillator application: 28.6% vs. 10.1%), yet had lower survival (5.6% vs. 8.1%). Compared to the pre-pandemic period, OHCAs in Singapore and Atlanta occurred more at home (adjusted odds ratio (aOR) 2.05 and 2.03, respectively) and were transported less to hospitals (aOR 0.59 and 0.36, respectively) during the pandemic. Singapore reported more witnessed OHCAs (aOR 1.96) yet less bystander CPR (aOR 0.81) during pandemic, but not Atlanta (p < 0.05). The impact of COVID-19 on OHCA outcomes did not differ between cities. Changes in OHCA characteristics and management during the pandemic, and differences between Singapore and Atlanta were likely the result of systemic and sociocultural factors.

Elevated prehospital point-of-care glucose is associated with worse neurologic outcome after out-of-hospital cardiac arrest.

OBJECTIVES: Hyperglycemia is associated with poor outcomes in critically-ill patients. This has implications for prognostication of patients with out-of-hospital cardiac arrest (OHCA) and for post-resuscitation care. We assessed the association of hyperglycemia, on field point-of-care (POC) testing, with survival and neurologic outcome in patients with return of spontaneous circulation (ROSC) after OHCA. METHODS: This was a retrospective analysis of data in a regional cardiac care system from April 2011 through December 2017 of adult patients with OHCA and ROSC who had a field POC glucose. Patients were excluded if they were hypoglycemic (glucose <60 mg/dl) or received empiric dextrose. We compared hyperglycemic (glucose >250 mg/dL) with euglycemic (glucose 60-250 mg/dL) patients. Primary outcome was survival to hospital discharge (SHD). Secondary outcome was survival with good neurologic outcome (cerebral performance category 1 or 2 at discharge). We determined the adjusted odds ratios (AORs) for SHD and survival with good neurologic outcome. RESULTS: Of 9008 patients with OHCA and ROSC, 6995 patients were included; 1941 (28%) were hyperglycemic and 5054 (72%) were euglycemic. Hyperglycemic patients were more likely to be female, of non-White race, and have an initial non-shockable rhythm compared to euglycemic patients (p < 0.0001 for all). Hyperglycemic patients were less likely to have SHD compared to euglycemic survivors, 24.4% vs 32.9%, risk difference (RD) -8.5% (95 %CI -10.8%, -6.2%), p < 0.0001. Hyperglycemic survivors were also less likely to have good neurologic outcome compared to euglycemic survivors, 57.0% vs 64.6%, RD -7.6% (95 %CI -12.9%, -2.4%), p = 0.004. The AOR for SHD was 0.72 (95 %CI 0.62, 0.85), p < 0.0001 and for good neurologic outcome, 0.70 (95 %CI 0.57, 0.86), p = 0.0005. CONCLUSION: In patients with OHCA, hyperglycemia on field POC glucose was associated with lower survival and worse neurologic outcome.

Survival to hospital discharge and neurological outcomes with targeted temperature management after in-hospital cardiac arrest: a systematic review and meta-analysis.

BACKGROUND: Multiple randomized controlled trials have shown that targeted temperature management (TTM) has favorable effects in out-of-hospital cardiac arrest. However, the benefit of TTM in patients with in-hospital cardiac arrest (IHCA) remains to be verified. METHODS: The PubMed, Cochrane Library, and EMBASE databases were searched for clinical studies with the primary outcomes of survival to hospital discharge and neurological outcomes. Neurological outcomes were evaluated by the categorical scale of cerebral function (CPC); a score of 1-2 points was considered neurologically good, and a score of 3-5 points was considered a poor outcome. Revman 5.3 and Stata 14 software with the random effects model were used for analysis. P<0.05 was considered statistically significant. RESULTS: Six retrospective controlled studies with a total of 14,607 patients (TTM group: 1,845, control group: 12,762) were included and analyzed. There were no statistically significant differences between the two groups in survival to hospital discharge [odds ratio (OR) =1.02, 95% CI: 0.77-1.35, P=0.89, I2=47%] or favorable neurological outcomes (OR =1.06, 95% CI: 0.56-2.02, P=0.85, I2=79%). After excluding patients with non-shockable initial rhythms, TTM did not show any significant improvement in survival to hospital discharge. Subgroup analysis was performed according to the sample size. No significant improvement was observed between the two groups in terms of survival to hospital discharge or neurological outcome. DISCUSSION: In this meta-analysis, the effects of TTM on discharge survival and neurological prognosis were evaluated by studying the results of IHCA in 14,607 patients. We found that the TTM did not improve survival and neurological function in discharged patients. Our results showed that the sample size discrepancy had a large effect on the heterogeneity; to address this, subgroup analyses were performed according to the different sample sizes. However, TTM treatment in different sample size subgroups showed no significant effect on survival to hospital discharge. Moreover, in the large sample size subgroup, therapeutic hypothermia was associated with increased unfavorable neurological outcome compared with no hypothermia.

Survival to hospital discharge is equivalent to 30-day survival as a primary survival outcome for out-of-hospital cardiac arrest studies.

AIM: The 2015 Utstein guidelines stated that 30-day survival could be used as an alternative to survival to hospital discharge (STHD) as the primary survival outcome in out-of-hospital cardiac arrest (OHCA) studies. We sought to ascertain the equivalence (concordance) of these two survival outcome measures. METHODS: We conducted a population-based retrospective cohort study of OHCA patients who were attended by St John Western Australia (SJ-WA) paramedics in Perth, WA between 1999 and 2018. OHCA patients were included if they received either an attempted resuscitation by SJ-WA or bystander defibrillation; were a resident of WA; and were transported to a hospital emergency department (ED). STHD was determined through hospital record review and 30-day survival via the WA Death Registry and cemetery registration data. RESULTS: The study cohort comprised a total of 7953 OHCA patients, predominantly male (70%), with a median (IQR) age of 63 (46-77 years), a presumed cardiac arrest aetiology (78.9%), and the majority occurred in a private residence (66.8%). Survival rates were identical for STHD and 30-day survival, with both being (13.78%, 95% CI: 13.02-14.54%) (p = 0.99). The overall concordance between the two survival rates was 99.6%. There were only 30 (0.4%) discordant cases in total: 15 cases with STHD-yes but 30-day survival-no; and 15 cases with STHD-no but 30-day survival-yes. CONCLUSION: We found that STHD and 30-day survival were equivalent survival metrics in our OHCA Registry. However, given potential differences in health systems, we suggest that 30-day survival is likely to enable more reliable comparisons across jurisdictions.

Survival of pediatric patients after cardiopulmonary resuscitation for in-hospital cardiac arrest: a systematic review and meta-analysis.

BACKGROUND: In-hospital cardiac arrest is a major public health issue. It is a serious condition; most probably end up with death within a few minutes even with corrective measures. However, cardiopulmonary resuscitation is expected to increase the probability of survival and prevent neurological disabilities in patients with cardiac arrest. Having a pooled prevalence of survival to hospital discharge after cardiopulmonary resuscitation is vital to develop strategies targeted to increase probability of survival among patients with cardiac arrest. Therefore, this systematic review and meta-analysis was aimed to assess the pooled prevalence of survival to hospital discharge among pediatric patients who underwent cardiopulmonary resuscitation for in-hospital cardiac arrest. METHODS: PubMed, Google Scholar, and Cochrane review databases were searched. To have current (five-year) evidence, only studies published in 2016 to 2020 were included. The weighted inverse variance random-effects model at 95%CI was used to estimate the pooled prevalence of survival. Heterogeneity assessment, test of publication bias, and subgroup analyses were also employed accordingly. RESULTS: Twenty-five articles with a total sample size of 28,479 children were included in the final analysis. The pooled prevalence of survival to hospital discharge was found to be 46% (95% CI = 43.0-50.0%; I2 = 96.7%; p < 0.001). Based on subgroup analysis by "continent" and "income level", lowest prevalence of pooled survival was observed in Asia (six studies; pooled survival =36.0% with 95% CI = 19.01-52.15%; I2 = 97.4%; p < 0.001) and in low and middle income countries (six studies, pooled survival = 34.0% with 95% CI = 17.0-51.0%, I2 = 97.67%, p < 0.001) respectively. CONCLUSION: Although there was an extremely high heterogeneity among reported results (I2 = 96.7%), in this meta-analysis more than half of pediatric patients (54%) who underwent cardiopulmonary resuscitation for in-hospital cardiac arrest did not survived to hospital discharge. Therefore, developing further strategies and encouraging researches might be crucial.

The Outcomes of Targeted Temperature Management After Cardiac Arrest at Emergency Department: A Real-World Experience in a Developing Country.

Targeted temperature management (TTM) is indicated for comatose survivors of cardiac arrest to improve outcomes. However, the benefit of TTM was verified by rigid controlled clinical trials. This study aimed at evaluating its effects in real-world practices. A prospective observational study was done at the emergency department of tertiary care, Thammasat Hospital, from March 2012 until October 2015. We included all who did not obey verbal commands after being resuscitated from cardiac arrest regardless of initial cardiac rhythm. We excluded patients with traumatic arrest, uncontrolled bleeding, younger than 15 years old, and of poor neurological status (Glasgow coma scale below 14) before cardiac arrest. Primary and secondary outcomes were survival to hospital discharge and favorable neurological outcome (Cerebral Performance Categories 1 or 2 within 30 days). We used the logistic regression model to estimate the propensity score (PS) that will be used as a weight in the analysis. To analyze outcomes, the PS was introduced as a factor in the final logistic regression model in conjunction with other factors. A total of 192 cases, 61 and 131 patients, were enrolled in TTM and non-TTM groups, respectively. Characteristics believed to be related to initiation of TTM: gender, age, cardiac etiology, out-of-hospital cardiac arrest, witness arrest, collapse time, initial rhythm, received defibrillation, and advanced airway insertion, were included in multivariable analysis and estimated PS. After adjusted regression analysis with PS, the TTM group had a better result in survival to hospital discharge (34.43% vs. 12.21%; adjusted incidence risk ratio (IRR), 2.95; 95% confidence interval (CI), 1.49-5.84; p = 0.002). For neurological outcome, the TTM group had a higher number of favorable neurological outcomes (24.59% vs. 6.87%; IRR, 3.96; 95% CI, 1.67-9.36; p = 0.002). In real-world practices without a strictly controlled environment, TTM can improve survival and favorable neurological outcome in postcardiac arrest patients regardless of initial rhythm.

Association of presence and timing of invasive airway placement with outcomes after pediatric in-hospital cardiac arrest.

BACKGROUND: Little data exist regarding the association of presence of an invasive airway before cardiac arrest or early placement of an invasive airway after cardiac arrest with outcomes in children who experience in-hospital cardiac arrest. METHODS: We conducted a retrospective review of patients aged 1 day to 18 years who received cardiopulmonary resuscitation (CPR) for ≥ 1 min in any of the three intensive care units (ICUs) at a tertiary care, academic children's hospital between 2002 and 2010. Specific outcomes evaluated included survival to hospital discharge, return of spontaneous circulation (ROSC), 24-h survival, and good neurological status at hospital discharge. We fitted multivariable logistic regression models to evaluate the association between the presence of an invasive airway prior to cardiac arrest and timing of placement of an invasive airway with these outcomes. RESULTS: Three hundred and ninety-one patients were included. Of these, 197 (51%) patients were already tracheally intubated before the occurrence of cardiac arrest. Median time to intubation was 6 min [interquartile range (IQR): 2, 12] among the 194 patients tracheally intubated following cardiac arrest. We found lower survival to hospital discharge among patients intubated prior to cardiac arrest (intubated vs. non-intubated group, 43% vs. 61%, p < 0.001). After adjusting for patient and event characteristics, presence of an invasive airway prior to cardiac arrest was not associated with a significant improvement in survival to hospital discharge [odds ratio (OR): 0.70, 95% confidence interval (CI): 0.42-1.16, p = 0.17], or good neurological outcomes (OR: 0.60, 95% CI: 0.34-1.05, p = 0.07). Similarly, early placement of an invasive airway after cardiac arrest was also not associated with an improvement in survival to hospital discharge (OR: 1.05, 95% CI: 0.78-1.42, p = 0.73), or good neurological outcomes (OR: 1.08, 95% CI: 0.77-1.53, p = 0.65). CONCLUSIONS: Our study demonstrates that presence of an invasive airway prior to cardiac arrest or early placement of an invasive airway after cardiac arrest is not associated with an improvement in survival to hospital discharge or good neurological outcomes. Further study of the relationship between invasive airway management and survival following cardiac arrest is warranted.

To assess the prognosis of patients with return of spontaneous circulation after cardiac arrest by shock index and adjusted shock index / 中华急诊医学杂志

Objective To examine the usefulness of shock index (Sl) and adjusted shock index (corrected to temperature) (ASI) in predicting prognosis of patients with return of spontaneous circulation after cardiac arrest.Methods A prospective study,which data such as vital signs of the cases were collected by the Utstein template,was conducted in 111 of cases with return of spontaneous circulation after cardiac arrest to assess the value of SI and ASI for predicting their prognoses.Results There was no evidence to show difference between the cases with survival to hospital discharge and the ones who died about systolic blood pressure and heart rate (P ＞0.05).SI and ASI [(1.109 ±0.428) and (1.082 ±0.410)] of the group of death were higher significantly than the ones [(0.899 ± 0.303) and (0.844 ± 0.265)] of the group with survival to hospital discharge,P ＜ 0.05.The risk of death was elevated in the group with ASI ＞ 1.1,which odds ratio (5.4) higher than the ones of systolic blood prcssure ＜90 mm Hg (1.6)and ventricular rat ＞ 100 beat/min (3.1) significantly.The odds ratio of death with AS ＞ 1 was 2.8.Conclusions Shock index and adjusted shock index are easy to derive and conducive to predict effectively diseases prognosis such as survival to hospital discharge or death of patients with ROSC.

The efficacy of mild hypothermia for the treatment of patients successfully resuscitated from cardiac arrest: a meta-analysis / 中华急诊医学杂志

Objective To study the effectiveness and safety of therapeutic mild hypothermia in patients successfully resuscitated from cardiac arrest using a meta-analysis.Methods We searched the MEDLINE (1966-April 2012),OVID (1980 to April 2012),EMBASE (1980 to April 2012),Chinese bio-medical literature & retrieval system (CBM) (1978 to April 2012),Chinese medical current contents (CMCC) (1995 to April 2012),and Chinese medical academic conference (CMAC) (1994 to April 2012).Studies were included (1) the study design was a randomized controlled trial (RCT); (2) the study population included patients successfully resuscitated from cardiac arrest,and received either conventional post-resuscitation care with normothermia or mild hypothermia; (3) the study provided data about good neurologic outcome and survival till hospital discharge.Relative risk (RR) and 95％ corfidence interval (CI) were used to pool the effect.Results The study included four RCTs with a collected total of 417 patients successfully resuscitated from cardiac arrest.Compared to conventional post-resuscitation care with normothermia,patients in the hypothermia group were more likely to have good neurologic outcome (RR =1.43,95％ CI 1.14 ～ 1.80,P =0.002) and were more likely to survive till hospital discharge (RR =1.32,95％ CI 1.08 ～ 1.63,P =0.008).From all over the studies there was no significant difference in reported adverse events between the normothermia and hypothermia group (P ＞ 0.05).There did not exist heterogeneity and publication bias.Conclusions Therapeutic mild hypothermia improves neurologic outcome and survival in patients successfully resuscitated from cardiac arrest.