A comparison of outcomes of out-of-hospital cardiac arrest with non-cardiac etiology between emergency departments with low- and high-resuscitation case volume

Nationwide population-based study of poisoning-induced out-of-hospital cardiac arrest in South Korea

OBJECTIVE

To evaluate the characteristics of poisoning-induced out-of-hospital cardiac arrest (pOHCA) and the factors influencing survival to discharge and good neurological outcomes using a nationwide, population-based database.

DESIGN

Nationwide, retrospective, population-based cohort study.

SETTING AND PARTICIPANTS

This study included adult patients who had experienced pOHCA and those who had not (non-pOHCA patients) in South Korea from January 2008 to December 2018.

OUTCOME MEASURES

The primary outcome was survival to discharge, and the secondary outcome was a good neurological outcome.

METHODS

The basic characteristics of pOHCA and non-pOHCA patients were analysed by descriptive analysis. Logistic regression analysis was conducted for related variables, including pOHCA.

RESULTS

A total of 173 190 patients were included, and 3582 patients (2.1%) were in the pOHCA group. Some of the pOHCA patients were young (58.2±17.8 vs 69.0±15.5, p<0.001), a few of their cardiac arrests were witnessed (12.8% vs 45.1%, p<0.001), a few were resuscitated by bystanders (8.2% vs 14.8%, p<0.001) and they had low shockable rhythm rates (1.2% vs 8.8%, p<0.001). They showed significantly lower survival to discharge and poorer neurological outcomes than non-pOHCA patients (survival to discharge, 3.7% vs 6.2%, p<0.001; good neurological outcomes, 1.3% vs 3.2%, p<0.001). There were no significant differences between pOHCA and non-pOHCA patients in terms of the adjusted ORs for survival to discharge (adjusted OR 0.608; 95% CI 0.86 to 1.27) and good neurological outcomes (adjusted OR 1.03; 95% CI 0.73 to 1.42).

CONCLUSION

This study shows that apparent aetiology of OHCA caused by poison, did not influence survival to discharge and good neurological outcomes. Furthermore, pOHCA occurs in younger patients and has fewer witnesses and shockable rhythms. pOHCA did not influence survival to discharge and good neurological outcomes. Also, pesticides and gases were the most frequent substances causing pOHCA in South Korea.

Direct Transport to Cardiac Arrest Center and Survival Outcomes after Out-of-Hospital Cardiac Arrest by Urbanization Level

Current guidelines for post-resuscitation care recommend regionalized care at a cardiac arrest center (CAC). Our objectives were to evaluate the effect of direct transport to a CAC on survival outcomes of out-of-hospital cardiac arrests (OHCAs), and to assess interaction effects between CAC and urbanization levels. Adult EMS-treated OHCAs with presumed cardiac etiology between 2015 and 2019 were enrolled. The main exposure was the hospital where OHCA patients were transported by EMS (CAC or non-CAC). The outcomes were good neurological recovery and survival to discharge. Multivariable logistic regression analyses were conducted. Interaction analysis between the urbanization level of the location of arrest (metropolitan or urban/rural area) and the exposure variable was performed. Among the 95,931 study population, 23,292 (24.3%) OHCA patients were transported directly to CACs. Patients in the CAC group had significantly higher likelihood of good neurological recovery and survival to discharge than the non-CAC group (both p < 0.01, aORs (95% CIs): 1.75 (1.63–1.89) and 1.70 (1.60–1.80), respectively). There were interaction effects between CAC and the urbanization level for good neurological recovery and survival to discharge. Direct transport to CAC was associated with significantly better clinical outcomes compared to non-CAC, and the findings were strengthened in OHCAs occurring in nonmetropolitan areas.

Mild therapeutic hypothermia improves neurological outcomes in a rat model of cardiac arrest

Cardiac arrest (CA) is the leading cause of death in humans. Research has shown that mild therapeutic hypothermia (MTH) can reduce neurological sequelae and mortality after CA. Nevertheless, the mechanism remains unclear. This study aimed to determine whether MTH promotes neurogenesis, attenuates neuronal damage, and inhibits apoptosis of neurons in rats after CA. Sprague-Dawley rats were divided into the normothermia and mild hypothermia groups. The rats in the normothermia and hypothermia groups were exposed to 2 h of normothermia (36-37℃) and hypothermia (32-33℃), respectively, immediately after resuscitation from 5 min of asphyxial CA. Corresponding control groups not subjected to CA were included. On days 1-6, 5-bromodeoxyuridine (BrdU) 100 mg/kg/day was administered intraperitoneally. The animals were euthanized 1 week after CA. Compared with the normothermia group, the hypothermia group showed a significant increase in the number of doublecortin (DCX) immune-positive cells in the subgranular zone of the hippocampus 1 week after CA. Neurogenesis was assessed using double immunofluorescent labeling of BrdU with neuronal-specific nuclear protein (NeuN)/DCX. There was no marked change in the number of newborn mature (BrdU+-NeuN+) neurons, though there was a significant increase in the number of newborn immature (BrdU+-DCX+) neurons in the hypothermia than in the normothermia group 1 week after CA. Neuronal injury and apoptosis in the CA1 region of the hippocampus, assessed using NeuN immunofluorescence and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, were significantly reduced in the hypothermia group 1 week after CA. Moreover, mild hypothermia increased the expression of cold-shock protein RNA-binding motif protein 3 (RBM3) in the early stage (24 h/48 h) after CA. These results suggested that mild hypothermia promotes generation of neuronal cells, reduces neuronal injury, and inhibits apoptosis of neurons, which may be related to RBM3 expression.

Factors Predisposing to Survival After Resuscitation for Sudden Cardiac Arrest

BACKGROUND

In the POST SCD study, the authors autopsied all World Health Organization (WHO)-defined sudden cardiac deaths (SCDs) and found that only 56% had an arrhythmic cause; resuscitated sudden cardiac arrests (SCAs) were excluded because they did not die suddenly. They hypothesized that causes underlying resuscitated SCAs would be similarly heterogeneous.

OBJECTIVES

The aim of this study was to determine the causes and outcomes of resuscitated SCAs.

METHODS

The authors identified all out-of-hospital cardiac arrests (OHCAs) from February 1, 2011, to January 1, 2015, of patients aged 18 to 90 years in San Francisco County. Resuscitated SCAs were OHCAs surviving to hospitalization and meeting WHO criteria for suddenness. Underlying cause was determined by comprehensive record review.

RESULTS

The authors identified 734 OHCAs over 48 months; 239 met SCA criteria, 133 (55.6%) were resuscitated to hospitalization, and 47 (19.7%) survived to discharge. Arrhythmic causes accounted for significantly more resuscitated SCAs overall (92 of 133, 69.1%), particularly among survivors (43 of 47, 91.5%), than WHO-defined SCDs in POST SCD (293 of 525, 55.8%; p < 0.004 for both). Among resuscitated SCAs, arrhythmic cause, ventricular tachycardia/fibrillation initial rhythm, and white race were independent predictors of survival. None of the resuscitated SCAs due to neurologic causes survived.

CONCLUSIONS

In this 4-year countywide study of OHCAs, only one-third were sudden, of which one-half were resuscitated to hospitalization and 1 in 5 survived to discharge. Arrhythmic cause predicted survival and nearly one-half of nonsurvivors had nonarrhythmic causes, suggesting that SCA survivors are not equivalent to SCDs. Early identification of nonarrhythmic SCAs, such as neurologic emergencies, may be a target to improve OHCA survival.

Association between case volume of ambulance stations and clinical outcomes of out-of-hospital cardiac arrest: A nationwide multilevel analysis

OBJECTIVES

The case volume effects of ambulance stations on the survival of out-of-hospital cardiac arrest (OHCA) patients are uncertain. This study was conducted to evaluate the association between the case volume of ambulance stations and clinical outcomes in OHCAs by the number of emergency medical services (EMS) providers at the scene.

METHODS

Adult cardiac EMS-treated OHCAs between 2015 and 2018 were enrolled. The main exposure was the annual OHCA case volumes of 204 ambulance stations in Korea, which were categorized into three groups; low-volume (<100), moderate-volume (100-159) and high-volume (≥160). The primary and secondary outcomes were good neurological recovery and survival to discharge. Multilevel multivariable logistic regression analysis was conducted to calculate adjusted odds ratios (AORs). Interaction analysis between the number of EMS providers at the scene and the exposure variable was performed.

RESULTS

A total of 92,534 patients were enrolled. OHCAs in the low-volume group tended to be arrest in a public place or a non-metropolitan area, less prehospital administration of an advanced airway and intravenous management. Significant differences were found the main analysis: AORs (95% CIs) compared to the low-volume group were 1.15 (1.03-1.29) and 1.14 (1.03-1.27) in the high-volume and moderate-volume groups for good neurological recovery and 1.19 (1.07-1.33) and 1.14 (1.04-1.25) in the high-volume and moderate-volume groups for survival to discharge. Significant interaction effects between the number of EMS providers at the scene and case volume on clinical outcomes were found.

CONCLUSION

OHCA case volumes of ambulance stations are associated with clinical outcomes after cardiac arrest.

Association between Cardiac Arrest Time and Favorable Neurological Outcomes in Witnessed Out-of-Hospital Cardiac Arrest Patients Treated with Targeted Temperature Management

BACKGROUND

Patients who achieve a return of spontaneous circulation (ROSC) with prolonged cardiac arrest have been recognized to have a poor prognosis. This might lead to reluctance in the provision of post-resuscitation care. Hence, we evaluated the impact of cardiac arrest time on neurologic outcomes in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

This cross-sectional study used a hospital-based nationwide registry of OHCAs in Korea between 2012 and 2016. All witnessed OHCA patients aged ≥ 15 years and treated with targeted temperature management were included. We collected the time from collapse to sustained ROSC, which was defined as the downtime. The primary outcome was a favorable neurological outcome at hospital discharge. A multiple logistic regression analysis was conducted to determine independent factors for primary outcome in patients with downtime > 30 minutes.

RESULTS

Overall, neurologically favorable outcome rates were 30.5% in 1,963 patients. When the downtime was stratified into categories of 0-10, 11-20, 21-30, 31-40, 41-50, 51-60, and > 60 minutes according to 10-minute intervals, neurologically favorable outcome rates were 58.2%, 52.3%, 37.3%, 24.6%, 14.1%, 17.4%, and 16.7%, respectively (P < 0.001). In patients with downtime > 30 minutes, age 51-70 years (odds ratio [OR], 5.35; 95% confidence interval [CI], 2.50-11.49), age ≤ 50 years (OR, 13.16; 95% CI, 6.06-28.57), shockable rhythm (OR, 3.92; 95% CI, 2.71-5.68), bystander resuscitation (OR, 1.80; 95% CI, 1.27-2.55), cardiac cause (OR, 3.50; 95% CI, 1.69-7.25), percutaneous coronary intervention (OR, 1.82; 95% CI, 1.18-2.81), and downtime ≤ 40 minutes (OR, 2.02; 95% CI, 1.42-2.88) were associated with favorable neurological outcomes.

CONCLUSION

In patients with prolonged downtime, predicting favorable neurologic outcome may be multifactorial. The cutoff value for downtime is not the only determining factor to provide post-resuscitation care.

Outcomes of paediatric out-of-hospital cardiac arrest according to hospital characteristic defined by the annual number of paediatric patients with invasive mechanical ventilation: A nationwide study in Japan

AIM

We examined whether outcomes of paediatric out-of-hospital cardiac arrest (OHCA) are associated with a hospital characteristic defined by the annual number of invasive mechanical ventilation cases, suggesting hospitals' experience in caring for severely ill paediatric patients.

METHOD

We analysed the Japanese Diagnosis Procedure Combination database from 2010 to 2017. We identified children (<18 years) with OHCA and post-resuscitation intensive care (defined as invasive mechanical ventilation and/or catecholamine infusion). Hospitals were divided into four groups by mean annual number of paediatric cases involving invasive mechanical ventilation. The primary outcome was in-hospital mortality, and the secondary outcome was unfavourable outcomes (death or medical care dependency at discharge). Multivariable logistic regression analyses were conducted to examine the relationship between hospitals' experience and outcomes.

RESULTS

We included 2540 paediatric OHCA patients from 385 institutions. Overall in-hospital mortality was 62.4%, with rates of 69.6%, 61.3%, 61.8%, and 57.0% in hospitals with low (≤48 cases/year), low-intermediate (48-110), high-intermediate (110-164), and high (>164) experience levels (P < .001), respectively. Compared to hospitals with low experience, adjusted odds ratios (95% confidence interval) for hospitals with low-intermediate, high-intermediate, and high experience were as follows: primary outcome: 0.64 (0.40-1.01), 0.67 (0.42-1.05), and 0.46 (0.31-0.70), respectively; secondary outcome: 0.93 (0.55-1.57), 0.95 (0.63-1.43), and 0.67 (0.46-0.96), respectively.

CONCLUSION

Japanese hospitals with higher experience in caring for severely ill paediatric patients showed lower mortality for paediatric OHCA. This fact should be considered by the Emergency Medical Systems when deciding transport strategy.

Comparison of Quantitative Characteristics of Early Post-resuscitation EEG Between Asphyxial and Ventricular Fibrillation Cardiac Arrest in Rats

BACKGROUND

Quantitative electroencephalogram (EEG) analysis has shown promising results in studying brain injury and functional recovery after cardiac arrest (CA). However, whether the quantitative characteristics of EEG, as potential indicators of neurological prognosis, are influenced by CA causes is unknown. The purpose of this study was designed to compare the quantitative characteristics of early post-resuscitation EEG between asphyxial CA (ACA) and ventricular fibrillation CA (VFCA) in rats.

METHODS

Thirty-two Sprague-Dawley rats of both sexes were randomized into either ACA or VFCA group. Cardiopulmonary resuscitation was initiated after 5-min untreated CA. Characteristics of early post-resuscitation EEG were compared, and the relationships between quantitative EEG features and neurological outcomes were investigated.

RESULTS

Compared with VFCA, serum level of S100B, neurological deficit score and brain histopathologic damage score were dramatically higher in the ACA group. Quantitative measures of EEG, including onset time of EEG burst, time to normal trace, burst suppression ratio, and information quantity, were significantly lower for CA caused by asphyxia and correlated with the 96-h neurological outcome and survival.

CONCLUSIONS

Characteristics of earlier post-resuscitation EEG differed between cardiac and respiratory causes. Quantitative measures of EEG not only predicted neurological outcome and survival, but also have the potential to stratify CA with different causes.

Prediction of good neurological recovery after out-of-hospital cardiac arrest: A machine learning analysis

BACKGROUND

This study aimed to train, validate and compare predictive models that use machine learning analysis for good neurological recovery in OHCA patients.

METHODS

Adult OHCA patients who had a presumed cardiac etiology and a sustained return of spontaneous circulation between 2013 and 2016 were analyzed; 80% of the individuals were analyzed for training and 20% were analyzed for validation. We developed using six machine learning algorithms: logistic regression (LR), extreme gradient boosting (XGB), support vector machine, random forest, elastic net (EN), and neural network. Variables that could be obtained within 24 hours of the emergency department visit were used. The area under the receiver operation curve (AUROC) was calculated to assess the discrimination. Calibration was assessed by the Hosmer-Lemeshow test. Reclassification was assessed by using the continuous net reclassification index (NRI).

RESULTS

A total of 19,860 OHCA patients were included in the analysis. Of the 15,888 patients in the training group, 2228 (14.0%) had a good neurological recovery; of the 3972 patients in the validation group, 577 (14.5%) had a good neurological recovery. The LR, XGB, and EN models showed the highest discrimination powers (AUROC (95% CI)) of 0.949 (0.941-0.957) for all), and all three models were well calibrated (Hosmer-Lemeshow test: p >0.05). The XGB model reclassified patients according to their true risk better than the LR model (NRI: 0.110), but the EN model reclassified patients worse than the LR model (NRI: -1.239).

CONCLUSION

The best performing machine learning algorithm was the XGB and LR algorithm.

The Effect of Transport Time Interval on Neurological Recovery after Out-of-Hospital Cardiac Arrest in Patients without a Prehospital Return of Spontaneous Circulation

BACKGROUND

Longer transport adversely affects outcomes in out-of-hospital cardiac arrest (OHCA) patients who do not return to spontaneous circulation (ROSC). The aim of this study was to determine the association between the transport time interval (TTI) and neurological outcomes in OHCA patients without ROSC.

METHODS

We analyzed adult OHCA patients with presumed cardiac etiology and without prehospital ROSC from 2012 to 2015. The study population was divided into 2 groups according to STI (short STI [1-5 minutes] and long STI [≥ 6 minutes]). The primary exposure was TTI, which was categorized as short (1-5 minutes), intermediate (6-10 minutes), or long (≥ 11 minutes). The primary outcome was a good neurological recovery at discharge. Multiple logistic regression analysis was used in each STI group.

RESULTS

Among 57,822 patients, 23,043 (40%), 20,985 (36%), and 13,794 (24%) were classified as short, intermediate, and long TTI group. A good neurological recovery occurred in 1.0%, 0.6%, and 0.3% of the patients in the short, intermediate and long TTI group, respectively. Among 12,652 patients with short STI, a good neurological recovery occurred in 2.2%, 1.0%, and 0.4% of the patients in the short, intermediate and long TTI group, respectively. Among 45,570 patients with long STI, a good neurological recovery occurred in 0.7%, 0.5%, and 0.3% of the patients in the short, intermediate and long TTI group, respectively. When short TTI was used as a reference, the adjusted odds ratios (AOR) of TTI for good neurological recovery was different between short STI group and long STI group (AOR [95% confidence interval, 0.46 [0.32-0.67] vs. 0.72 [0.59-0.89], respectively, for intermediate TTI and 0.31 [0.17-0.55] vs. 0.49 [0.37-0.65], respectively, for long TTI).

CONCLUSION

A longer TTI adversely affected the likelihood of a good neurological recovery in OHCA patients without prehospital ROSC. This negative effect was more prominent in short STI group.

Out-of-Hospital Cardiac Arrest Resuscitation Systems of Care: A Scientific Statement From the American Heart Association

The American Heart Association previously recommended implementation of cardiac resuscitation systems of care that consist of interconnected community, emergency medical services, and hospital efforts to measure and improve the process of care and outcome for patients with cardiac arrest. In addition, the American Heart Association proposed a national process to develop and implement evidence-based guidelines for cardiac resuscitation systems of care. Significant experience has been gained with implementing these systems, and new evidence has accumulated. This update describes recent advances in the science of cardiac resuscitation systems and evidence of their effectiveness, as well as recent progress in dissemination and implementation throughout the United States. Emphasis is placed on evidence published since the original recommendations (ie, including and since 2010).

Demographic, social, economic and geographic factors associated with long-term outcomes in a cohort of cardiac arrest survivors

BACKGROUND

Demographic, social, economic and geographic factors are associated with increased short-term mortality after cardiac arrest. We sought to determine if these factors are additionally associated with long-term outcome differences using a detailed clinical database linked to state-wide administrative data.

METHODS

We included cardiac arrest patients surviving to hospital discharge from five hospitals in the United States from 2005 to 2013, with follow-up through 2015. We obtained information on sex, race, arrest location, initial rhythm, median ZIP code income, post-arrest illness severity, cardiac catheterization, internal cardioverter-defibrillator insertion, rural residence and drive time from residence to the nearest acute care hospital. We used Cox proportional hazard models identify predictors of mortality.

RESULTS

We included 891 patients followed for 2081 patient-years. There were 340 deaths with median survival 6 years. In adjusted models we identified an interaction effect between median ZIP code income and cardiac catheterization. Among patients who had cardiac catheterization there was an attenuated benefit from cardiac catheterization at progressively lower neighborhood incomes (adjusted HR: 0.21 to 0.46 to 0.56). Residence more than 20 min from the nearest acute care hospital was associated with increased hazard of death (adjusted HR: 1.48; 95%CI: 1.35-1.62), after controlling for rural residence and residence in a Medically Underserved Area/Population. Female patients showed less benefit following ICD placement (male adjusted HR: 0.49; female adjusted HR: 0.66).

CONCLUSIONS

There are persistent long-term outcome differences in cardiac arrest survival based on sex, income, and geographic access acute care.

Combining early post-resuscitation EEG and HRV features improves the prognostic performance in cardiac arrest model of rats

OBJECTIVE

Early and reliable prediction of neurological outcome remains a challenge for comatose survivors of cardiac arrest (CA). The purpose of this study was to evaluate the predictive ability of EEG, heart rate variability (HRV) features and the combination of them for outcome prognostication in CA model of rats.

METHODS

Forty-eight male Sprague-Dawley rats were randomized into 6 groups (n=8 each) with different cause and duration of untreated arrest. Cardiopulmonary resuscitation was initiated after 5, 6 and 7min of ventricular fibrillation or 4, 6 and 8min of asphyxia. EEG and ECG were continuously recorded for 4h under normothermia after resuscitation. The relationships between features of early post-resuscitation EEG, HRV and 96-hour outcome were investigated. Prognostic performances were evaluated using the area under receiver operating characteristic curve (AUC).

RESULTS

All of the animals were successfully resuscitated and 27 of them survived to 96h. Weighted-permutation entropy (WPE) and normalized high frequency (nHF) outperformed other EEG and HRV features for the prediction of survival. The AUC of WPE was markedly higher than that of nHF (0.892 vs. 0.759, p<0.001). The AUC was 0.954 when WPE and nHF were combined using a logistic regression model, which was significantly higher than the individual EEG (p=0.018) and HRV (p<0.001) features.

CONCLUSIONS

Earlier post-resuscitation HRV provided prognostic information complementary to quantitative EEG in the CA model of rats. The combination of EEG and HRV features leads to improving performance of outcome prognostication compared to either EEG or HRV based features alone.

Poisoning-induced Out-of-Hospital Cardiac Arrest and Outcomes according to Poison Agent

It is unclear whether specific agent groups are associated with outcomes in cases of poisoning-induced out-of-hospital cardiac arrest (P-OHCA). The study population comprised cases of confirmed P-OHCA drawn from the national out-of-hospital cardiac arrest (OHCA) registry (2008-2013). Exposures were categorized into five groups according to the International Classification of Disease, 10th version: group 1, prescribed drugs; group 2, vapors and gases; group 3, pesticides; group 4, alcohol and organic solvents; and group 5, other poisons. The outcome was survival to discharge and good neurological recovery. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated to test the association between specific groups and outcomes. A total of 2,083 patients were analyzed; group 1 (10.3%), group 2 (23.6%), group 3 (52.9%), group 4 (1.4%), and group 5 (13.2%). The survival to discharge and good neurological recovery rates were 3.3%/1.3% for all patients, 10.3%/5.6% (group 1), 6.9%/3.4% (group 2), 2.4%/0.4% (group 3), 2.2%/1.0% (group 4), and 3.3%/2.4% (group 5) (all P < 0.001). The aORs (95% CIs) of groups 2-5 compared with group 1 for survival to discharge were 0.47 (0.09-2.51), 0.34 (0.17-0.68), 0.33 (0.14-0.77), and 0.31 (0.13-0.77), respectively. The odds ratios (95% CIs) for good neurological recovery were significant only in group 1, the pesticides group (0.07 [0.02-0.26]) and were not significant in the other groups. P-OHCA outcomes differed significantly among the poisoning agent groups. The pesticides group showed the worst outcomes, followed by the group of vapors or gases.

Prehospital Supraglottic Airway Was Associated With Good Neurologic Outcome in Cardiac Arrest Victims Especially Those Who Received Prolonged Cardiopulmonary Resuscitation

OBJECTIVES

We performed this study to investigate the association of prehospital supraglottic airway (SGA) on neurologic outcome in cardiac arrest victims with adjustment of postresuscitation variables as well as prehospital and resuscitation variables.

METHODS

This study was a retrospective study based on a multicenter prospective cohort registry from December 2013 to April 2016. According to the 28-day cerebral performance categories (CPCs) scale, patients were divided into the good-outcome group (CPC 1-2) and the poor-outcome group (CPC 3-5). We compared the two groups with respect to demographic variables, prehospital and in-hospital resuscitation variables, and postresuscitation variables.

RESULTS

A total of 869 cardiac arrest victims who received in-progress cardiopulmonary resuscitation (CPR) were delivered to the emergency department of three hospitals, and 310 patients were admitted to the intensive care unit. The use of a prehospital SGA was independently associated with 28-day good neurologic outcome (odds ratio [OR] = 7.88; 95% confidence interval [CI] = 1.33-46.53; p = 0.023] when postresuscitation variables were adjusted, although there were no significant association with the acquisition of sustained return of spontaneous circulation (OR = 0.992; 95% CI = 0.591-1.666; p = 0.976). Furthermore, a prehospital SGA was significantly associated with good neurologic outcome, especially in patients who received prolonged CPR (low flow time > 15 minutes; OR = 3.41; 95% CI = 1.23-9.45; p = 0.018) rather than in patients with nonprolonged CPR (OR = 4.50; 95% CI = 0.75-27.13; p = 0.101).

CONCLUSIONS

When postresuscitation variables were adjusted, the prehospital SGA was independently associated with 28-day good neurologic outcome in cardiac arrest victims.

Education, exposure and experience of prehospital teams as quality indicators in regional trauma systems

OBJECTIVE

Indicators to measure the quality of trauma care may be instrumental in benchmarking and improving trauma systems. This retrospective, observational study investigated whether data on three indicators for competencies of Dutch trauma teams (i.e. education, exposure, experience; agreed upon during a prior Delphi procedure) can be retrieved from existing registrations. The validity and distinctive power of these indicators were explored by analysing available data in four regions.

METHODS

Data of all polytrauma patients treated by the Helicopter Emergency Medical Services were collected retrospectively over a 1-year period. During the Delphi procedure, a polytrauma patient was defined as one with a Glasgow Coma Scale of 9 or less or a Paediatric Coma Scale of 9 or less, together with a Revised Trauma Score of 10 or less. Information on education, exposure and experience of the Helicopter Emergency Medical Services physician and nurse were registered for each patient contact.

RESULTS

Data on 442 polytrauma patients could be retrieved. Of these, according to the Delphi consensus, 220 were treated by a fully competent team (i.e. both the physician and the nurse fulfilled the three indicators for competency) and 22 patients were treated by a team not fulfilling all three indicators for competency. Across the four regions, patients were treated by teams with significant differences in competencies (P=0.002).

CONCLUSION

The quality indicators of education, exposure and experience of prehospital physicians and nurses can be measured reliably, have a high level of usability and have distinctive power.

Hospital characteristics and favourable neurological outcome among patients with out-of-hospital cardiac arrest in Osaka, Japan

OBJECTIVE

To assess the association between favourable neurological outcome and hospital characteristics such as hospital volume and number of critical care centres (CCMCs) after out-of-hospital cardiac arrest (OHCA).

METHODS

This retrospective, population-based observational study conducted in Osaka Prefecture, Japan included adult patients with OHCA, aged ≥18 years who were transported to acute care hospitals between January 2005 and December 2012. We divided acute care hospitals into CCMCs or non-CCMCs, the latter of which were divided into the following three groups according to the annual average number of transported OHCA cases: low-volume (≤10 cases), middle-volume (11-39 cases), and high-volume (≥40 cases) groups. Random effects logistic regression models, with hospital treated as a random effect, were used to assess factors potentially associated with a favourable neurological outcome.

RESULTS

A total of 44,474 patients were eligible. The proportions of favourable neurological outcome from OHCA were 0.9% (31/3559) in the low-volume group, 1.2% (106/9171) in the middle-volume group, 1.6% (222/14,007) in the high-volume group, and 4.3% (766/17,737) in the CCMC group (P<0.001). In the multivariable analysis, transport to CCMCs was significantly associated with favourable neurological outcome, compared with transport to non-CCMCs (adjusted odds ratio 1.63; 95% confidence interval, 1.60-1.66). Among the non-CCMC group, there was no significant relationship between hospital volume and favourable neurological outcome.

CONCLUSIONS

In this population, transport of OHCA patients to CCMCs led to significantly higher one-month survival rates with favourable neurological outcome from OHCA, whereas no significant association was noted among the hospitals with different volumes.

Volume Matters: Improved Outcomes for Patients Presenting to High-Volume Emergency Departments with Atrial Flutter and Fibrillation

Objectives

Clinical familiarity plays a role in health outcomes; the relationship between emergency department (ED) volume and outcomes for atrial fibrillation and flutter (AFF) are not clear. We compared ED presentation outcomes for AFF between high (HV) and low volume (LV) EDs in Alberta, Canada.

Methods

45,372 AFF presentations for patients aged ≥ 35 years from all 104 EDs in Alberta during 1999 to 2011 using administrative health databases formed a retrospective cohort. EDs were grouped by annual AFF volume: 11 high (>100 presentations) or 93 low (≤100 presentations). Outcomes included hospital admission rate, return to ED for AFF within 30 and 90 days, and death within 30 and 90 days. Analyses included statistical tests and mixed effects modeling.

Results

Mean age at ED presentation was 69.8 years (52% male). HV ED presentations were associated with lower admissions (adjusted odds ratio [aOR] = 0.68, 95% confidence interval [CI] 0.64, 0.72; p-value [p]<0.001), ED returns at 90 (aOR = 0.81, 95% CI 0.73, 0.90; p<0.001) days, and a higher likelihood of specialist visits at 30 (aOR = 1.81, 95% CI 1.68, 1.94; p<0.001) and 90 (aOR = 1.82, 95% CI 1.76, 2.03; p<0.001) days. For admitted patients, there were fewer returns to HV EDs at 30 (aOR = 0.37, 95% CI 0.15, 0.87; p = 0.02) and 90 (aOR = 0.48, 95% CI 0.26, 0.89; p = 0.02) days after hospital discharge. There was no difference in death between the two groups.

Conclusions

AFF patients presenting to HV EDs experienced fewer admissions and AFF ED revisit and higher specialist referrals compared to LV EDs.

Dynamic prediction of patient outcomes during ongoing cardiopulmonary resuscitation

PURPOSE

The probability of the return of spontaneous circulation (ROSC) and subsequent favourable outcomes changes dynamically during advanced cardiac life support (ACLS). We sought to model these changes using time-to-event analysis in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

Adult (≥18 years old), non-traumatic OHCA patients without prehospital ROSC were included. Utstein variables and initial arterial blood gas measurements were used as predictors. The incidence rate of ROSC during the first 30min of ACLS in the emergency department (ED) was modelled using spline-based parametric survival analysis. Conditional probabilities of subsequent outcomes after ROSC (1-week and 1-month survival and 6-month neurologic recovery) were modelled using multivariable logistic regression. The ROSC and conditional probability models were then combined to estimate the likelihood of achieving ROSC and subsequent outcomes by providing k additional minutes of effort.

RESULTS

A total of 727 patients were analyzed. The incidence rate of ROSC increased rapidly until the 10th minute of ED ACLS, and it subsequently decreased. The conditional probabilities of subsequent outcomes after ROSC were also dependent on the duration of resuscitation with odds ratios for 1-week and 1-month survival and neurologic recovery of 0.93 (95% CI: 0.90-0.96, p<0.001), 0.93 (0.88-0.97, p=0.001) and 0.93 (0.87-0.99, p=0.031) per 1-min increase, respectively. Calibration testing of the combined models showed good correlation between mean predicted probability and actual prevalence.

CONCLUSIONS

The probability of ROSC and favourable subsequent outcomes changed according to a multiphasic pattern over the first 30min of ACLS, and modelling of the dynamic changes was feasible.

Epidemiology, Risk Factors, and Outcomes of Out-of-Hospital Cardiac Arrest Caused by Stroke: A Population-Based Study

Limited information is available regarding stroke-related out-of-hospital cardiac arrest (OHCA). We aimed to assess the clinical characteristics of stroke-related OHCA and to identify the factors associated with patient outcomes.We conducted a nationwide population-based study of adult OHCA patients in Japan from January 1, 2006 to December 31, 2009. We examined the epidemiology, risk factors, and outcomes of stroke-related OHCA compared with cardiogenic OHCA. The primary outcome was neurologically favorable survival.Of the 243,140 eligible patients, 18,682 (7.7%) were diagnosed with stroke-related OHCA. Compared to OHCA with a presumed cardiac etiology, stroke-related OHCA patients had a greater chance of prehospital return of spontaneous circulation (ROSC) (9.9% vs 5.9%, P < 0.0001) but a reduced chance of 1-month survival (3.6% vs 4.9%, P < 0.0001) or favorable neurological outcomes (1.2% vs 2.6%, P < 0.0001). After adjusting for a variety of confounding factors, the prehospital ROSC rates were higher (adjusted OR 2.47, 95% confidence interval [CI] 2.34-2.62), but the neurologically favorable survival rates were lower (adjusted OR 0.66, 95%CI 0.57-0.76), among the stroke-related OHCA patients. In stroke-related OHCA cases, having a younger age, witness, and shockable 1st documented rhythm were associated with improved outcomes. Men had more favorable neurological outcomes. Seasonal or circadian factors had no critical impact on favorable neurological outcomes. Prehospital advanced life support techniques (i.e., epinephrine administration or advanced airway management) were not associated with favorable neurological outcomes.Although stroke-related OHCA had lower 1-month survival rates and poorer neurological outcomes than cardiogenic OHCA, the rates were not considered to be medically futile. Characteristically, sex differences might impact neurologically favorable survival.

Sodium bicarbonate administration during ongoing resuscitation is associated with increased return of spontaneous circulation

PURPOSE

Sodium bicarbonate is frequently used for patients unresponsive to cardiopulmonary resuscitation (CPR). Its use may be associated with longer resuscitation duration as well as more severe metabolic acidosis. We applied a new analytical method based on a matched case-control study design to control for the potential confounders.

BASIC PROCEDURES

Out-of-hospital cardiac arrest patients resuscitated in an emergency department for at least 20 minutes, unless there was any return of spontaneous circulation (ROSC) within the time frame, were analyzed. Patients without ROSC for 20 minutes of CPR were matched to those with ROSC based on initial bicarbonate level categorized using cutoff points of 10, 15, 20, 25, and 30 mEq/L, and their observation durations were trimmed to match their pairs. The association between sodium bicarbonate and ROSC was examined using conditional logistic regression analysis.

MAIN FINDINGS

Two matched groups, one with ROSC and the other without (both n = 258), were generated. Sodium bicarbonate administration and its total cumulative dose were significantly associated with an increased ROSC, with odds ratios for ROSC of 1.86 (95% confidence interval [CI], 1.09-3.16; P = .022) and 1.18 (per 20 mEq; 95% CI, 1.04-1.33; P = .008), respectively. The positive associations remained unchanged after multivariable adjustment, with odds ratios for ROSC of 2.49 (95% CI, 1.33-4.65; P = .004) and 1.27 (95% CI, 1.11-1.47; P = .001), respectively.

PRINCIPAL CONCLUSION

Sodium bicarbonate administration during CPR in emergency department was associated with increased ROSC.

Presumed Regional Incidence Rate of Out-of-Hospital Cardiac Arrest in Korea

The regional incidence rates of out-of-hospital cardiac arrest (OHCA) were traditionally calculated with the residential population as the denominator. The aim of this study was to estimate the true incidence rate of OHCA and to investigate characteristics of regions with overestimated and underestimated OHCA incidence rates. We used the national OHCA database from 2006 to 2010. The nighttime residential and daytime transient populations were investigated from the 2010 Census. The daytime population was calculated by adding the daytime influx of population to, and subtracting the daytime outflow from, the nighttime residential population. Conventional age-standardized incidence rates (CASRs) and daytime corrected age-standardized incidence rates (DASRs) for OHCA per 100,000 person-years were calculated in each county. A total of 97,291 OHCAs were eligible. The age-standardized incidence rates of OHCAs per 100,000 person-years were 34.6 (95% CI: 34.3-35.0) in the daytime and 24.8 (95% CI: 24.5-25.1) in the nighttime among males, and 14.9 (95% CI: 14.7-15.1) in the daytime, and 10.4 (95% CI: 10.2-10.6) in the nighttime among females. The difference between the CASR and DASR ranged from 35.4 to -11.6 in males and from 6.1 to -1.0 in females. Through the Bland-Altman plot analysis, we found the difference between the CASR and DASR increased as the average CASR and DASR increased as well as with the larger daytime transient population. The conventional incidence rate was overestimated in counties with many OHCA cases and in metropolitan cities with large daytime population influx and nighttime outflow, while it was underestimated in residential counties around metropolitan cities.

The Volume-Outcome Relationship in Critical Care: A Systematic Review and Meta-analysis

OBJECTIVE

The purpose of this study was to systematically review the research on volume and outcome relationships in critical care.

METHODS

From January 1, 2001, to April 30, 2014, MEDLINE and EMBASE were searched for studies assessing the relationship between admission volume and clinical outcomes in critical illness. Bibliographies were reviewed to identify other articles of interest, and experts were contacted about missing or unpublished studies. Of 127 studies reviewed, 46 met inclusion criteria, covering seven clinical conditions. Two investigators independently reviewed each article using a standardized form to abstract information on key study characteristics and results.

RESULTS

Overall, 29 of the studies (63%) reported a statistically significant association between higher admission volume and improved outcomes. The magnitude of the association (mortality OR between the lowest vs highest stratum of volume centers), as well as the thresholds used to characterize high volume, varied across clinical conditions. Critically ill patients with cardiovascular (n = 7, OR = 1.49 [1.11-2.00]), respiratory (n = 12, OR = 1.20 [1.04-1.38]), severe sepsis (n = 4, OR = 1.17 [1.03-1.33]), hepato-GI (n = 3, OR = 1.30 [1.08-1.78]), neurologic (n = 3, OR = 1.38 [1.22-1.57]), and postoperative admission diagnoses (n = 3, OR = 2.95 [1.05-8.30]) were more likely to benefit from admission to higher-volume centers compared with lower-volume centers. Studies that controlled for ICU or hospital organizational factors were less likely to find a significant volume-outcome relationship than studies that did not control for these factors.

CONCLUSIONS

Critically ill patients generally benefit from care in high-volume centers, with more substantial benefits in selected high-risk conditions. This relationship may in part be mediated by specific ICU and hospital organizational factors.

Epidemiological and Survival Trends of Pediatric Cardiac Arrests in Emergency Departments in Korea: A Cross-sectional, Nationwide Report

Cardiac arrest (CA) in children is associated with high mortality rates. In Korea, cohort studies regarding the outcomes of pediatric CAs are lacking, especially in emergency departments (EDs) or in-hospital settings. This study was conducted to examine the trends in epidemiology and survival outcomes in children with resuscitation-attempted CAs using data from a cross-sectional, national, ED-based clinical registry. We extracted cases in which cardiopulmonary resuscitation and/or manual defibrillation were performed according to treatment codes using the National Emergency Department Information System (NEDIS) from 2008 to 2012. The total number of ED visits registered in the NEDIS during the 5-yr evaluation period was 20,424,530; among these, there were 2,970 resuscitation-attempted CAs in children. The annual rates of pediatric CAs per 1,000 ED visits showed an upward trend from 2.81 in 2009 to 3.62 in 2012 (P for trend = 0.045). The median number of estimated pediatric CAs at each ED was 7.8 (25th to 75th percentile, 4 to 13) per year. The overall rates for admission survival and discharge survival were 35.2% and 12.8%, respectively. The survival outcome of adults increased substantially over the past 5 yr (11.8% in 2008, 11.7% in 2010, and 13.6% in 2012; P for trend = 0.001); however, the results for children did not improve (13.6% in 2008, 11.4% in 2010, and 13.7% in 2012; P for trend = 0.870). Conclusively, we found that the overall incidence of pediatric CAs in EDs increased substantially over the past 5 yr, but without significantly higher survival outcomes.

Epidemiology and outcomes of out-of-hospital cardiac arrest according to suicide mechanism: a nationwide observation study

Objective

Suicide remains a serious, preventable public health problem. This study aims to describe the epidemiological characteristics associated with various suicide methods and to investigate outcomes after suicide-associated sudden cardiac arrest (S-SCA), stratified by different suicide attempt methods.

Methods

An S-SCA database was constructed from ambulance run sheets and augmented by a review of hospital medical records from 2008 to 2010 in Korea. The cases with non-cardiac etiologies and suicide attempts were initially extracted. Suicide attempts were classified as hanging, poisoning, fall, and other. The primary end point was survival to discharge. Age- and sex-adjusted incidence rates were calculated for each suicide method. Adjusted odds ratios for outcome were calculated with adjustments for potential confounding variables.

Results

A total 5,743 patients were analyzed as S-SCAs. The most common method of suicide attempt was hanging (58.7%), followed by falls (17.6%), poisoning (17.5%), and others (5.8%). The survival to discharge rates were 2.1% (n=119) overall, 2.4% in hanging, 2.4% in poisoning and 0.5% in fall, respectively. The age- and sex-adjusted incidence rates (male/female) per million persons was 32.7 (35.8/29.7) in 2008, 41.8 (46.0/37.7) in 2009, and 43.0 (50.1/36.0) in 2010. Compared with hanging, adjusted odds ratios (95% confidence intervals) for survival to discharge was 1.05 (0.60 to 1.83) for poisoning and 0.08 (0.03 to 0.21) for falls.

Conclusion

In this nationwide S-SCA cohort study from 2008 to 2010, the standardized incidence rate increased annually. However, the rate of survival to discharge remains very low.

The risk factors and prognostic implication of acute pulmonary edema in resuscitated cardiac arrest patients

Objective

Pulmonary edema is frequently observed after a successful resuscitation in out-of-hospital cardiac arrest (OHCA) patients. Currently, its risk factors and prognostic implications are mostly unknown.

Methods

Adult OHCA patients with a presumed cardiac etiology who achieved sustained return of spontaneous circulation (ROSC) in emergency department were retrospectively analyzed. The patients were grouped according to the severity of consolidation on their initial chest X-ray (group I, no consolidation; group II, patchy consolidations; group III, consolidation involving an entire lobe; group IV, total white-out of any lung). The primary objective was to identify the risk factors of developing severe pulmonary edema (group III or IV). The secondary objective was to evaluate the association between long-term prognosis and the severity of pulmonary edema.

Results

One hundred and seven patients were included. Total duration of cardiopulmonary resuscitation (CPR) and initial pCO₂ level were both independent predictors of developing severe pulmonary edema with their odds ratio (OR) being 1.02 (95% confidence interval [CI], 1.00 to 1.04; per 1 minute) and 1.04 (95% CI, 1.01 to 1.07; per 1 mmHg), respectively. The long term prognosis was significantly poor in patients with severe pulmonary edema with a OR for good outcome (6-month cerebral performance category 1 or 2) being 0.22 (95% CI, 0.06 to 0.79) in group III and 0.16 (95% CI, 0.04 to 0.63) in group IV compared to group I.

Conclusion

The duration of CPR and initial pCO₂ level were both independent predictors for the development of severe pulmonary edema after resuscitation in emergency department. The severity of the pulmonary edema was significantly associated with long-term outcome.

Emergency medical services key performance measurement in Asian cities

Background

One of the key principles in the recommended standards is that emergency medical service (EMS) providers should continuously monitor the quality and safety of their services. This requires service providers to implement performance monitoring using appropriate and relevant measures including key performance indicators. In Asia, EMS systems are at different developmental phases and maturity. This will create difficultly in benchmarking or assessing the quality of EMS performance across the region. An attempt was made to compare the EMS performance index based on the structure, process, and outcome analysis.

Findings

The data was collected from the Pan-Asian Resuscitation Outcome Study (PAROS) data among few Asian cities, namely, Tokyo, Osaka, Singapore, Bangkok, Kuala Lumpur, Taipei, and Seoul. The parameters of inclusions were broadly divided into structure, process, and outcome measurements. The data was collected by the site investigators from each city and keyed into the electronic web-based data form which is secured strictly by username and passwords. Generally, there seems to be a more uniformity for EMS performance parameters among the more developed EMS systems. The major problem with the EMS agencies in the cities of developing countries like Bangkok and Kuala Lumpur is inadequate or unavailable data pertaining to EMS performance.

Conclusions

There is non-uniformity in the EMS performance measurement across the Asian cities. This creates difficulty for EMS performance index comparison and benchmarking. Hopefully, in the future, collaborative efforts such as the PAROS networking group will further enhance the standardization in EMS performance reporting across the region.

Resuscitation duration inequality by patient characteristics in emergency department out-of-hospital cardiac arrest: an observational study

Objective

Out-of-hospital cardiac arrest (OHCA) patients unresponsive to basic life support are frequently transferred to emergency departments (EDs) for further resuscitation. Although some survive with good neurologic outcomes, additional resuscitation in EDs is often futile. Without a dedicated termination of resuscitation (TOR) rule for ED resuscitation, the decision when to stop the resuscitation is up to emergency physicians. In this study, we assessed the association between patient characteristics and duration of resuscitation in EDs to understand how emergency physicians decide when to terminate cardiopulmonary resuscitation.

Methods

A retrospective analysis of the OHCA registry of a single ED was conducted. Adult (18 years or older) patients without any return of spontaneous circulation (ROSC) after unsuccessful ED advanced cardiac life support were included. The primary endpoint was duration of resuscitation attempts. Prehospital and demographic factors were assessed as independent variables. The relationship between these factors and duration of resuscitative attempts was analyzed with multivariable quantile regression.

Results

From January 2008 to August 2012, ED resuscitation was terminated without ROSC in 266 patients (53.5%). The duration of resuscitative attempts was significantly shorter if any of the currently recognized poor prognostic factors was present. Interestingly, controversial factors such as female sex and older age were significantly associated with shorter resuscitation duration, while factors definitively indicating poor prognosis, such as severe trauma and poor baseline neurological status, showed no significant association.

Conclusion

The results of this study suggest that physicians adjust the resuscitation duration according to their subjective prediction of futility despite the absence of evidence-based TOR guidelines.

Epidemiology and outcomes of in-hospital cardiac arrest in critically ill children across hospitals of varied center volume: a multi-center analysis

OBJECTIVE

To describe epidemiology and outcomes associated with cardiac arrest among critically ill children across hospitals of varying center volumes.

METHODS

Patients <18 years of age in the Virtual PICU Systems (VPS, LLC) Database (2009-2013) were included. Patients with both cardiac and non-cardiac diagnoses were included. Data on demographics, patient diagnosis, cardiac arrest, severity of illness and outcomes were collected. Hierarchical cluster analysis was performed to categorize all the participating centers into low, low-medium, high-medium, and high volume groups using the center volume characteristics (annual hospital discharges per center, annual extracorporeal membrane oxygenation per center, and annual mechanical ventilators per center). Multivariable models were used to evaluate association of center volume with incidence of cardiac arrest, and mortality after cardiac arrest, adjusting for patient and center characteristics.

RESULTS

Of 329,982 patients (108 centers), 2.2% (n=7390) patients had cardiac arrest with an associated mortality of 35% (n=2586). In multivariable models controlling for patient and center characteristics, center volume was not associated with either the incidence of cardiac arrest (OR: 1.00; 95% CI: 0.95-1.06; p=0.98), or mortality in those with cardiac arrest (OR: 0.93; 95% CI: 0.82-1.06; p=0.27). These associations were similar across cardiac and non-cardiac disease categories. Furthermore, we demonstrated that there was no correlation between incidence of cardiac arrest and mortality in those with cardiac arrest across different study hospitals in adjusted models.

CONCLUSIONS

Both incidence of cardiac arrest, and mortality in those with cardiac arrest vary substantially across hospitals. However, center volume is not associated with either of these outcomes, after adjusting for patient and center characteristics.

Global and regional differences in cerebral blood flow after asphyxial versus ventricular fibrillation cardiac arrest in rats using ASL-MRI

Both ventricular fibrillation cardiac arrest (VFCA) and asphyxial cardiac arrest (ACA) are frequent causes of CA. However, only isolated reports compared cerebral blood flow (CBF) reperfusion patterns after different types of CA, and even fewer reports used methods that allow serial and regional assessment of CBF. We hypothesized that the reperfusion patterns of CBF will differ between individual types of experimental CA. In a prospective block-randomized study, fentanyl-anesthetized adult rats were subjected to 8min VFCA or ACA. Rats were then resuscitated with epinephrine, bicarbonate, manual chest compressions and mechanical ventilation. After the return of spontaneous circulation, CBF was then serially assessed via arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cortex, thalamus, hippocampus and amygdala/piriform complex over 1h resuscitation time (RT). Both ACA and VFCA produced significant temporal and regional differences in CBF. All regions in both models showed significant changes over time (p<0.01), with early hyperperfusion and delayed hypoperfusion. ACA resulted in early hyperperfusion in cortex and thalamus (both p<0.05 vs. amygdala/piriform complex). In contrast, VFCA induced early hyperperfusion only in cortex (p<0.05 vs. other regions). Hyperperfusion was prolonged after ACA, peaking at 7min RT (RT7; 199% vs. BL, Baseline, in cortex and 201% in thalamus, p<0.05), then returning close to BL at ∼RT15. In contrast, VFCA model induced mild hyperemia, peaking at RT7 (141% vs. BL in cortex). Both ACA and VFCA showed delayed hypoperfusion (ACA, ∼30% below BL in hippocampus and amygdala/piriform complex, p<0.05; VFCA, 34-41% below BL in hippocampus and amygdala/piriform complex, p<0.05). In conclusion, both ACA and VFCA in adult rats produced significant regional and temporal differences in CBF. In ACA, hyperperfusion was most pronounced in cortex and thalamus. In VFCA, the changes were more modest, with hyperperfusion seen only in cortex. Both insults resulted in delayed hypoperfusion in all regions. Both early hyperperfusion and delayed hypoperfusion may be important therapeutic targets. This study was approved by the University of Pittsburgh IACUC 1008816-1.

Improving code team performance and survival outcomes: implementation of pediatric resuscitation team training

OBJECTIVE

To determine whether implementation of Composite Resuscitation Team Training is associated with improvement in survival to discharge and code team performance after pediatric in-hospital cardiopulmonary arrest.

DESIGN, SETTING, AND SUBJECTS

We conducted a prospective observational study with historical controls at a 302-bed, quaternary care, academic children's hospital. Inpatients who experienced cardiopulmonary arrest between January 1, 2006, and December 31, 2009, were included in the control group (123 patients experienced 183 cardiopulmonary arrests) and between July 1, 2010, and June 30, 2011, were included in the intervention group (46 patients experienced 65 cardiopulmonary arrests).

INTERVENTION

Code team members were introduced to Composite Resuscitation Team Training and continued training throughout the intervention period (January 1, 2010-June 30, 2011). Training was integrated via in situ code blue simulations (n = 16). Simulations were videotaped and participants were debriefed for education and process improvement. Primary outcome was survival to discharge after cardiopulmonary arrest. Secondary outcome measures were 1) change in neurologic morbidity from admission to discharge, measured by Pediatric Cerebral Performance Category, and 2) code team adherence to resuscitation Standard Operating Performance variables.

MEASUREMENTS AND MAIN RESULTS

The intervention group was more likely to survive than the control group (60.9% vs 40.3%) (unadjusted odds ratio, 2.3 [95% CI, 1.15-4.60]) and had no significant change in neurologic morbidity (mean change in Pediatric Cerebral Performance Category 0.11 vs 0.27; p = 0.37). Code teams exposed to Composite Resuscitation Team Training were more likely than control group to adhere to resuscitation Standard Operating Performance (35.9% vs 20.8%) (unadjusted odds ratio, 2.14 [95% CI, 1.15-3.99]). After adjusting for adherence to Standard Operating Performance, survival remained improved in the intervention period (odds ratio, 2.13 [95% CI, 1.06-4.36]).

CONCLUSION

With implementation of Composite Resuscitation Team Training, survival to discharge after pediatric cardiopulmonary arrest improved, as did code team performance. Demonstration of improved survival after adjusting for code team adherence to resuscitation standards suggests that this may be a valuable resuscitation training program. Further studies are needed to determine causality and generalizability.

Etiology of out-of-hospital cardiac arrest diagnosed via detailed examinations including perimortem computed tomography

CONTEXT

The spectrum of the etiology of out-of-hospital cardiopulmonary arrest (OHCPA) has not been established. We have performed perimortem computed tomography (CT) during cardiopulmonary resuscitation.

AIMS

To clarify the incidence of non-cardiac etiology (NCE), actual distribution of the causes of OHCPA via perimortem CT and its usefulness.

SETTINGS AND DESIGN

Population-based observational case series study.

MATERIALS AND METHODS

We reviewed the medical records of 1846 consecutive OHCPA cases and divided them into two groups: 370 showing an obvious cause of OHCPA with NCE (trauma, neck hanging, terminal stage of malignancy, and gastrointestinal bleeding) and others.

RESULTS

Of a total OHCPA, perimortem CT was performed in 57.5% and 62.5% were finally diagnosed as NCE: Acute aortic dissection (AAD) 8.07%, pulmonary thrombo-embolization (PTE) 1.46%, hypoxia due to pneumonia 5.25%, asthma and acute worsening of chronic obstructive pulmonary disease 2.06%, cerebrovascular disorder (CVD) 4.48%, airway obstruction 7.64%, and submersion 5.63%. The rates of patients who survived to hospital discharge were 6-14% in patients with NCE. Out of the 1476 cases excluding obvious NCE of OHCPA, 66.3% underwent perimortem CT, 14.6% of cases without obvious NCE and 22.1% of cases with perimortem CT were confirmed as having some NCE.

CONCLUSIONS

Of the total OHCPA the incidences of NCE was 62.5%; the leading etiologies were AAD, airway obstruction, submersion, hypoxia and CVD. The rates of cases converted from cardiac etiology to NCE using perimortem CT were 14.6% of cases without an obvious NCE.

Prognostic performance of diffusion-weighted MRI combined with NSE in comatose cardiac arrest survivors treated with mild hypothermia

BACKGROUND

MRI-based prognostication of comatose cardiac arrest survivors has shown promising results. However, the technique has not been validated in patients treated with therapeutic hypothermia and it is unknown how it might add to NSE-based prognostication. We sought to evaluate the prognostic performance of regional apparent diffusion coefficient (ADC) in comatose out-of-hospital cardiac arrest (OHCA) patients treated with mild hypothermia and its added value to NSE-based prognostication.

METHODS

An OHCA registry was analyzed to identify OHCA patients older than 15 who were treated with therapeutic hypothermia and underwent brain MRI between 2008 and 2011. Quantitative measurement of regional ADCs was performed by a radiologist blinded to the clinical outcome.

RESULTS

Of the 43 eligible patients, 11 (18.6 %) achieved a good outcome (6-month CPC of 1 or 2). The regional ADC of the occipital cortex showed the highest discriminatory power with an area under the curve of receiver operating characteristic (AUROC) of 0.943 (95 % CI, 0.872-1.000) and predicted poor outcomes with a sensitivity of 90.6 % and a specificity of 100 %. The AUROC for NSE levels (48-h) was 0.911 (95 % CI, 0.801-1.000) which was significantly correlated with the regional ADC (Pearson's r = -0.674, p < .001). The ADC-based predictions identified an additional 5 (35.7 %) poor outcome patients out of 14 with 48-h NSE levels less than 78.9 ng/mL, which is the cutoff point suggested in a previous study. However, additional prognostic information was not provided when the 48-h NSE levels were >78.9 ng/mL.

CONCLUSIONS

Regional ADC-based prognostication was accurate in OHCA patients who were treated with mild hypothermia. However, it only provided additional prognostic information when the 48-h NSE levels indicated a good prognosis (48-h NSE <78.9 ng/mL).