Measuring outcome after cardiac arrest: construct validity of Cerebral Performance Category

Extracorporeal Membrane Oxygenation Pathway for Management of Refractory Cardiac Arrest: a Retrospective Study From a National Center of Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Cardiac arrest remains a critical condition with high mortality and catastrophic neurological impact. Extracorporeal cardiopulmonary resuscitation (ECPR) has been introduced as an adjunct in cardiopulmonary resuscitation modalities. However, survival with good neurological outcomes remains a major concern. This study aims to explore our early experience with ECPR and identify the factors associated with survival in patients presenting with refractory cardiac arrest.

METHODS

This is a retrospective cohort study analyzing 6-year data from a tertiary center, the country reference for ECPR. This study was conducted at a national center of ECPR. Participants of this study were adult patients who experienced witnessed refractory cardiopulmonary arrest and were supported by ECPR. ECPR was performed for eligible patients as per the local service protocols.

RESULTS

Data from 87 patients were analyzed; of this cohort, 62/87 patients presented with in-hospital cardiac arrest (IHCA) and 25/87 presented with out-of-hospital cardiac arrest (OHCA). Overall survival to decannulation and hospital discharge rates were 26.4% and 25.3%, respectively. Among survivors (n = 22), 19 presented with IHCA (30.6%), while only 3 survivors presented with OHCA (12%). A total of 15/87 (17%) patients were alive at 6-month follow-up. All survivors had good neurological function assessed as Cerebral Performance Category 1 or 2. Multivariate logistic regression to predict survival to hospital discharge showed that IHCA was the only independent predictor (odds ratio: 5.8, P = 0.042); however, this positive association disappeared after adjusting for the first left ventricular ejection fraction after resuscitation.

CONCLUSIONS

In this study, the use of ECPR for IHCA was associated with a higher survival to discharge compared to OHCA. This study demonstrated a comparable survival rate to other established centers, particularly for IHCA. Neurological outcomes were comparable in both IHCA and OHCA survivors. However, large multicenter studies are warranted for better understanding and improving the outcomes.

Long term functioning with poor neurologic outcome after cardiac arrest

AIM

Around six percent of comatose patients after cardiac arrest have a Cerebral Performance Categories score of three (CPC3) at six months after the arrest, classified as severe neurological disability. There is limited knowledge regarding the likelihood of further recovery in the cognitive, emotional, and quality of life domains. We aimed to estimate the probability of recovery towards independency.

METHODS

From a prospective Registry on comatose cardiac arrest patients admitted between 2013 and 2017 in two Dutch hospitals, we included patients with a CPC3 at six months after cardiac arrest. We followed patients up to November 2023. The primary outcome measure was the CPC score at time of follow up. Secondary outcomes were scores on questionnaires on cognition, mood, and quality of life according to the minimal dataset of acquired brain injury.

RESULTS

In our cohort of 667 patients, 29 (4.3%) had a CPC3 score at six months (median age 68 years, 83% male). At a median time of eight years after cardiac arrest, sixteen patients had died. Twelve of thirteen alive patients still had a CPC3 score (92%) and one a CPC2 (8%). Seven patients agreed with further interviewing, one showed independency in activities of daily living (14%). Six patients (86%) reported limitations due to physical and one (14%) due to emotional problems. All had severe cognitive impairment. Six (86%) missed cognitive rehabilitation.

CONCLUSION

Our study shows that while the probability of recovery towards independence for patients with severe neurological disability at six months after cardiac arrest is limited, most long-term survivors are satisfied with their quality of life.

Neurological outcomes in traffic accidents: A propensity score matching analysis of medical and non-medical origin cases of out-of-hospital cardiac arrest

AIM

This study aimed to comprehensively compare the characteristics of out-of-hospital cardiac arrest (OHCA) with medical and non-medical origins attributed to traffic accidents and explore the potential association between the cases with a medical origin and neurologically favorable outcomes.

METHODS

In this retrospective nationwide population-based study, baseline data were collected between January 2018 and December 2020. We analyzed 5091 OHCA associated with traffic accidents on the road scene. Only those encounters involving treatment or transport by prehospital emergency medical technicians were included. The characteristics of OHCA incidents and their outcomes were analyzed by categorizing patients into "medical origin" and "non-medical origin" groups.

RESULTS

Medical-origin cases exhibited several distinct characteristics, including higher frequencies of occurrence during the daytime (79.3% [706/890] vs. 68.9% [2895/4201], p < 0.001), a higher prevalence among male (77.8% [692/890] vs. 68.3% [2871/4201], p < 0.001) and younger patients (median [25-75%]: 63 years [42-77] vs. 66 years [50-76], p = 0.003), a higher proportion of shockable initial rhythms(10.5% [93/890] vs. 1.1% [45/4201], p < 0.001), an increased number of cases requiring advanced airway management (33.8% [301/890] vs. 28.5% [1199/4201], p = 0.002) and adrenaline administration by emergency medical teams (26.9% [239/890] vs. 21.7% [910/4201], p < 0.001), and shorter transport times (55.3% [492/890] vs. 60.9% [2558/4201], p = 0.002) compared to non-medical-origin cases. However, medical-origin cases also had lower witness rates (42.8% [381/890] vs. 27.2% [1142/4201], p < 0.001) and were less likely to be transported to higher-level hospitals (55.3% [492/890] vs. 60.9% [2558/4201], p = 0.002). Propensity score matching analysis identified factors associated with favorable neurological outcomes in medical-origin traffic accidents. The adjusted odds ratios were as follows: 8.46 (3.47-20.61) for cases with shockable initial rhythms, 2.36 (1.01-5.52) for cases involving traffic accidents due to medical origin, and 0.09 (0.01-0.67) for cases where advanced airway management was provided.

CONCLUSION

In this retrospective study, the occurrence of OHCAs of medical origin involving traffic accidents were associated with favorable neurological outcomes. These cases more frequently demonstrated favorable factors for survival compared to those classified as of non-medical origin. The findings have important implications for public health and EMS professionals, they will guide future research aimed at optimizing prehospital care strategies and improving survival rates for similar cases.

Association of Frailty and Cardiopulmonary Resuscitation Outcomes in Older U.S. Veterans

Objectives: Determine the association between frailty and immediate survival of cardiopulmonary resuscitation (CPR) in older Veterans. Secondary outcomes: compare in-hospital mortality, duration of resuscitation efforts, hospital and intensive care unit (ICU) length of stay, neurologic outcomes, and discharge disposition between frail and non-frail Veterans. Methods: Retrospective cohort study including Veterans 50 years and older, who were "Full Code" and had in-hospital cardiac arrest between 7/1/2017 and 6/30/2020, at the Miami VAMC. Frailty Index for the VA (VA-FI) was used to determine frailty status. Immediate Survival was determined by return of spontaneous circulation (ROSC) and in-hospital mortality was determined by all-cause mortality. We compared outcomes between frail and non-frail Veterans using chi-square test. After adjusting for age, gender, race, and previous hospitalizations, we used multivariate binomial logistic regression with 95% confidence intervals to analyze the relationship between immediate survival and frailty, and in-hospital mortality and frailty. Results: 91% Veterans were non-Hispanic, 49% Caucasian, 96% male, mean age 70.7 ± 8.5 years, 73% frail and 27% non-frail. Seventy-six (65.5%) Veterans had ROSC, without difference by frailty status (P = .891). There was no difference based on frailty status of in-hospital mortality, discharge disposition, or neurologic outcomes. Frail and non-frail Veterans had resuscitation efforts lasting the same amount of time. Conclusions and Implications: CPR outcomes were not different depending on frailty status in our Veteran population. With these results, we cannot use frailty - as measured by the VA-FI - as a prognosticator of CPR outcomes in Veterans.

Optimal duration and timing of basic-life-support-only intervention for patients with out-of-hospital cardiac arrest

To elucidate the relationship between the interval from cardiopulmonary resuscitation initiation to return of spontaneous circulation (ROSC) and neurologically favourable 1-month survival in order to determine the appropriate duration of basic life support (BLS) without advanced interventions. This population-based cohort study included patients aged ≥ 18 years with 9132 out-of-hospital cardiac arrest of presumed cardiac origin who were bystander-witnessed and had achieved ROSC between 2018 and 2020. Patients were classified into two groups based on the resuscitation methods as the "BLS-only" and the "BLS with administered epinephrine (BLS-AE)" groups. Receiver operating characteristic (ROC) curve analysis indicated that administering BLS for 9 min yielded the best neurologically outcome for patients with a shockable rhythm [sensitivity, 0.42; specificity, 0.27; area under the ROC curve (AUC), 0.60] in the BLS-only group. Contrastingly, for patients with a non-shockable rhythm, performing BLS for 6 min yielded the best neurologically outcome (sensitivity, 0.65; specificity, 0.43; AUC, 0.63). After propensity score matching, multivariate analysis revealed that BLS-only resuscitation [6.44 (5.34-7.77)] was associated with neurologically favourable 1-month survival. This retrospective study revealed that BLS-only intervention had a significant impact in the initial minutes following CPR initiation. Nevertheless, its effectiveness markedly declined thereafter. The optimal duration for effective BLS-only intervention varied depending on the patient's initial rhythm. Consequently, advanced interventions should be administered within the first few minutes to counteract the diminishing effectiveness of BLS-only intervention.

Coma Prognostication After Acute Brain Injury: A Review

Importance

Among the most impactful neurologic assessments is that of neuroprognostication, defined here as the prediction of neurologic recovery from disorders of consciousness caused by severe, acute brain injury. Across a range of brain injury etiologies, these determinations often dictate whether life-sustaining treatment is continued or withdrawn; thus, they have major implications for morbidity, mortality, and health care costs. Neuroprognostication relies on a diverse array of tests, including behavioral, radiologic, physiological, and serologic markers, that evaluate the brain's functional and structural integrity.

Observations

Prognostic markers, such as the neurologic examination, electroencephalography, and conventional computed tomography and magnetic resonance imaging (MRI), have been foundational in assessing a patient's current level of consciousness and capacity for recovery. Emerging techniques, such as functional MRI, diffusion MRI, and advanced forms of electroencephalography, provide new ways of evaluating the brain, leading to evolving schemes for characterizing neurologic function and novel methods for predicting recovery.

Conclusions and Relevance

Neuroprognostic markers are rapidly evolving as new ways of assessing the brain's structural and functional integrity after brain injury are discovered. Many of these techniques remain in development, and further research is needed to optimize their prognostic utility. However, even as such efforts are underway, a series of promising findings coupled with the imperfect predictive value of conventional prognostic markers and the high stakes of these assessments have prompted clinical guidelines to endorse emerging techniques for neuroprognostication. Thus, clinicians have been thrust into an uncertain predicament in which emerging techniques are not yet perfected but too promising to ignore. This review illustrates the current, and likely future, landscapes of prognostic markers. No matter how much prognostic markers evolve and improve, these assessments must be approached with humility and individualized to reflect each patient's values.

An exploratory study of dialectical behaviour therapy for emotional dysregulation and challenging behaviours after acquired brain injury

BACKGROUND

Challenging behaviours and emotional dysregulation are common sequelae of acquired brain injury (ABI), but treatment remain underdeveloped. Dialectical behaviour therapy is an evidence-based therapy for emotional dysregulation.

OBJECTIVE

To explore the feasibility and preliminary efficacy of dialectical behaviour therapy for ABI.

METHODS

An exploratory longitudinal study that compared thirty adults with brain injury presenting persistent emotion dysregulation or challenging behaviours. Control group received a personalized multidisciplinary program only (n = 13). The dialectical behaviour therapy group received five months of emotion regulation skills learning as an add-on (n = 17). Preliminary efficacy was measured on Difficulties in Emotion Regulation Scale-16 and Quality of Life after Brain Injury total score and emotion subscore.

RESULTS

Fourteen participants completed the dialectical behaviour therapy. This study provided preliminary evidence for the feasibility and acceptability of dialectical behaviour therapy. Repeated measures revealed improvement on the Difficulties in Emotion Regulation Scale-16 (-7.6 [-17.3; 1.7]; Pr = 0.95) and on the Quality Of Life emotion subscore (13.5 [-3.8; 30.9]; Pr = 0.94).

CONCLUSION

This study raises important questions regarding the type of patients who can benefit from this intervention, necessary adaptations of dialectical behaviour therapy and the way it can help post-traumatic growth and identity reconstruction after ABI.

Transcranial Doppler during the first week after cardiac arrest and association with 6-month outcomes

Background

Early prediction of outcomes in comatose patients after out-of-hospital cardiac arrest is challenging. Prognostication tools include clinical examination, biomarkers, and neuroradiological and neurophysiological tests. We studied the association between transcranial Doppler (TCD) and the outcome.

Methods

This was a pre-defined sub-study of the prospective observational Norwegian Cardiorespiratory Arrest Study. Patients underwent standardized post-resuscitation care, including target temperature management (TTM) to 33°C for 24 h. TCD was performed at days 1, 3, and 5-7. The primary endpoint was cerebral performance category (CPC) at 6 months, dichotomized into good (CPC 1-2) and poor (CPC 3-5) outcomes. We used linear mixed modeling time-series analysis.

Results

Of 139 TCD-examined patients, 81 (58%) had good outcomes. Peak systolic velocity in the middle cerebral artery (PSV) was low during TTM (Day 1) and elevated after rewarming (Day 3). Thereafter, it continued to rise in patients with poor, but normalized in patients with good, outcomes. At days 5-7, PSV was 1.0 m/s (95% CI 0.9; 1.0) in patients with good outcomes and 1.3 m/s (95% CI 1.1; 1.4) in patients with poor outcomes (p < 0.001).

Conclusion

Elevated PSV at days 5-7 indicated poor outcomes. Our findings suggest that serial TCD examinations during the first week after cardiorespiratory arrest may improve our understanding of serious brain injury.

Higher mean cerebral oxygen saturation shortly after extracorporeal cardiopulmonary resuscitation in patients who regain consciousness

INTRODUCTION

In cardiac arrest, cerebral ischemia and reperfusion injury mainly determine the neurological outcome. The aim of this study was to investigate the relation between the course of cerebral oxygenation and regain of consciousness in patients treated with extracorporeal cardiopulmonary resuscitation (ECPR). We hypothesized that rapid cerebral oxygenation increase causes unfavorable outcomes.

METHODS

This prospective observational study was conducted in three European hospitals. We included adult ECPR patients between October 2018 and March 2020, in whom cerebral regional oxygen saturation (rSO2 ) measurements were started minutes before ECPR initiation until 3 h after. The primary outcome was regain of consciousness, defined as following commands, analyzed using binary logistic regression.

RESULTS

The sample consisted of 26 ECPR patients (23% women, Agemean 46 years). We found no significant differences in rSO2 values at baseline (49.1% versus 49.3% for regain versus no regain of consciousness). Mean cerebral rSO2 values in the first 30 min after ECPR initiation were higher in patients who regained consciousness (38%) than in patients who did not regain consciousness (62%, odds ratio 1.23, 95% confidence interval 1.01-1.50).

CONCLUSION

Higher mean cerebral rSO2 values in the first 30 min after initiation of ECPR were found in patients who regained consciousness.

A randomized, double-blind trial comparing the effect of two blood pressure targets on global brain metabolism after out-of-hospital cardiac arrest

PURPOSE

This study aimed to assess the effect of different blood pressure levels on global cerebral metabolism in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA).

METHODS

In a double-blinded trial, we randomly assigned 60 comatose patients following OHCA to low (63 mmHg) or high (77 mmHg) mean arterial blood pressure (MAP). The trial was a sub-study in the Blood Pressure and Oxygenation Targets after Out-of-Hospital Cardiac Arrest-trial (BOX). Global cerebral metabolism utilizing jugular bulb microdialysis (JBM) and cerebral oxygenation (rSO₂) was monitored continuously for 96 h. The lactate-to-pyruvate (LP) ratio is a marker of cellular redox status and increases during deficient oxygen delivery (ischemia, hypoxia) and mitochondrial dysfunction. The primary outcome was to compare time-averaged means of cerebral energy metabolites between MAP groups during post-resuscitation care. Secondary outcomes included metabolic patterns of cerebral ischemia, rSO₂, plasma neuron-specific enolase level at 48 h and neurological outcome at hospital discharge (cerebral performance category).

RESULTS

We found a clear separation in MAP between the groups (15 mmHg, p < 0.001). Cerebral biochemical variables were not significantly different between MAP groups (LPR low MAP 19 (16-31) vs. high MAP 23 (16-33), p = 0.64). However, the LP ratio remained high (> 16) in both groups during the first 30 h. During the first 24 h, cerebral lactate > 2.5 mM, pyruvate levels > 110 µM, LP ratio > 30, and glycerol > 260 µM were highly predictive for poor neurological outcome and death with AUC 0.80. The median (IQR) rSO₂ during the first 48 h was 69.5% (62.0-75.0%) in the low MAP group and 69.0% (61.3-75.5%) in the high MAP group, p = 0.16.

CONCLUSIONS

Among comatose patients resuscitated from OHCA, targeting a higher MAP 180 min after ROSC did not significantly improve cerebral energy metabolism within 96 h of post-resuscitation care. Patients with a poor clinical outcome exhibited significantly worse biochemical patterns, probably illustrating that insufficient tissue oxygenation and recirculation during the initial hours after ROSC were essential factors determining neurological outcome.

Modification of termination of resuscitation rule with compression time interval in South Korea

This study aimed to validate the predictive performance of the termination of resuscitation (TOR) rule and examine the compression time interval (CTI) as a criterion for modifying the rule. This retrospective observational study analyzed adult out-of-hospital cardiac arrest (OHCA) patients attended by emergency medical service (EMS) providers in mixed urban-rural areas in Korea in 2020 and 2021. We evaluated the predictive performance of basic life support (BLS) and the Korean Cardiac Arrest Research Consortium (KoCARC) TOR rule using the false-positive rate (FPR) and positive predictive value (PPV). We modified the age cutoff criterion and examined the CTI as a new criterion. According to the TOR rule, 1827 OHCA patients were classified into two groups. The predictive performance of the BLS TOR rule had an FPR of 11.7% (95% confidence interval (CI): 5.9-17.5) and PPV of 98.4% (97.6-99.2) for mortality, and an FPR of 3.6% (0.0-7.8) and PPV of 78.6% (75.9-81.3) for poor neurological outcomes at hospital discharge. The predictive performance of the KoCARC TOR rule had an FPR of 5.0% (1.1-8.9) and PPV of 98.9% (98.0-99.8) for mortality, and an FPR of 3.7% (0.0-7.8) and PPV of 50.0% (45.7-54.3) for poor neurological outcomes at hospital discharge. The modified cutoff value for age was 68 years, with an area under the receiver operating characteristic curve over 0.7. In the group that met the BLS TOR rule, the cutoff of the CTI for death was not determined and was 21 min for poor neurological outcomes. In the group that met the KoCARC TOR rule, the cutoff of the CTI for death and poor neurological outcomes at the time of hospital discharge was 25 min and 21 min, respectively. The BLS TOR and KoCARC TOR rules showed inappropriate predictive performance for mortality and poor neurological outcomes. However, the predictive performance of the TOR rule could be supplemented by modifying the age criterion and adding the CTI criterion of the KoCARC.

Long Term Cognitive Function After Cardiac Arrest: A Mini-Review

Out-of-hospital cardiac arrest (OHCA) is a leading cause of mortality worldwide. With better pre- and inhospital treatment, including cardiopulmonary resuscitation (CPR) as an integrated part of public education and more public-access defibrillators available, OHCA survival has increased over the last decade. There are concerns, after successful resuscitation, of cerebral hypoxia and degrees of potential acquired brain injury with resulting poor cognitive functioning. Cognitive function is not routinely assessed in OHCA survivors, and there is a lack of consensus on screening methods for cognitive changes. This narrative mini-review, explores available evidence on hypoxic brain injury and long-term cognitive function in cardiac arrest survivors and highlights remaining knowledge deficits.

Neurological outcomes in adult drowning patients in China

BACKGROUND

Drowning is the third leading cause of unintentional death worldwide. The epidemiological characteristics of adult drownings are rarely reported.

OBJECTIVE

Investigate factors associated with neurological prognosis in adult drowning inpatients.

DESIGN

Multicenter medical record review.

SETTING

Tertiary health care institutions.

PATIENTS AND METHODS

We collected demographic and clinical data on patients who drowned but survived between September 2006 and January 2020. Neurological prognosis was compared in patients with and without cardiac arrest.

MAIN OUTCOME MEASURES

Neurological outcomes.

SAMPLE SIZE AND CHARACTERISTICS

142 patients with mean age of 50.6 (19.8) years, male/female ratio of 1.54:1.

RESULT

Forty-five patients (31.7%) received CPR, 90 patients (63.4%) experienced unconsciousness, and 59 patients (41.5%) received endotracheal intubation and mechanical ventilation. Multivariate logistic regression analysis showed that the initial blood lactic acid level (OR: 7.67, 95%CI: 1.23-47.82, P=.029) was associated with a poor neurological prognosis in patients without cardiac arrest. The incidence of ICU admission (OR: 16.604, 95%CI: 1.15-239.49, P=.039) was associated with a poor neurologic prognosis in patients with cardiac arrest.

CONCLUSIONS

For the drowning patients with cardiac arrest, ICU admission was associated with neurological function prognosis in these patients. Among the patients without cardiac arrest, the initial lactate value was associated with neurological function prognosis of these patients.

LIMITATIONS

Retrospective.

CONFLICT OF INTEREST

None.

Effect of Prehospital Epinephrine Use on Survival from Out-of-Hospital Cardiac Arrest and on Emergency Medical Services

This study was to identify the effect of epinephrine on the survival of out-of-hospital cardiac arrest (OHCA) patients and changes in prehospital emergency medical services (EMSs) after the introduction of prehospital epinephrine use by EMS providers. This was a retrospective observational study comparing two groups (epinephrine group and norepinephrine group). We used propensity score matching of the two groups and identified the association between outcome variables regarding survival and epinephrine use, controlling for confounding factors. The epinephrine group was 339 patients of a total 1943 study population. The survival-to-discharge rate and OR (95% CI) of the epinephrine group were 5.0% (p = 0.215) and 0.72 (0.43–1.21) in the total patient population and 4.7% (p = 0.699) and 1.15 (0.55–2.43) in the 1:1 propensity-matched population. The epinephrine group received more mechanical chest compression and had longer EMS response times and scene times than the norepinephrine group. Mechanical chest compression was a negative prognostic factor for survival to discharge and favorable neurological outcomes in the epinephrine group. The introduction of prehospital epinephrine use in OHCA patients yielded no evidence of improvement in survival to discharge and favorable neurological outcomes and adversely affected the practice of EMS providers, exacerbating the factors negatively associated with survival from OHCA.

Complement ratios C3bc/C3 and sC5b-9/C5 do not increase the sensitivity of detecting acute complement activation systemically

BACKGROUND

Complement activation plays an important pathogenic role in numerous diseases. The ratio between an activation product and its parent protein is suggested to be more sensitive to detect complement activation than the activation product itself. In the present study we explored whether the ratio between the activation product and the parent protein for C3 (C3bc/C3) and for C5 (sC5b-9/C5) increased the sensitivity to detect complement activation in acute clinical settings compared to the activation product alone.

MATERIALS AND METHODS

Samples from patients with acute heart failure following ST-elevated myocardial infarction (STEMI) and from patients with out-of-hospital cardiac arrest (OHCA) were used. C3, C3bc and C5, sC5b-9 were analysed in 629 and 672 patient samples, respectively. Healthy controls (n = 20) served to determine reference cut-off values for activation products and ratios, defined as two SD above the mean.

RESULTS

Increased C3bc/C3- and sC5b-9/C5 ratios were vastly dependent on C3bc and sC5b-9. Thus, 99.5 % and 98.1 % of the increased C3bc/C3- and sC5b-9/C5 ratios were solely dependent on increased C3bc and sC5b-9, respectively. Significantly decreased C3 and C5 caused increased ratios in only 3/600 (0.5 %) and 4/319 (1.3 %) samples, respectively. Strong correlations between C3bc and C3bc/C3-ratio and between sC5b-9 and sC5b-9/C5-ratio were found in the STEMI- (r = 0.926 and r = 0.786, respectively) and the OHCA-population (r = 0.908 and r = 0.843, respectively; p < 0.0001 for all). Importantly, sC5b-9 identified worse outcome groups better than sC5b-9/C5-ratio.

CONCLUSION

C3bc and sC5b-9 were sensitive markers of complement activation. The ratios of C3bc/C3 and sC5b-9/C5 did not improve detection of complement activation systemically.

Neuron-Specific Enolase (NSE) Predicts Long-Term Mortality in Adult Patients after Cardiac Arrest: Results from a Prospective Trial

Background: We investigated whether Neuron-specific enolase (NSE) serum concentration predicts long-term mortality and poor neurological outcome in adult cardiac arrest patients. Methods: Within this prospective observational study, we included consecutive adult patients admitted to the intensive care unit (ICU) after cardiac arrest. NSE was measured upon ICU admission and on days 1, 2, 3, 5 and 7. Results: Of 403 patients, 176 (43.7%) survived. Median follow-up duration was 43.7 months (IQR 14.3 to 63.0 months). NSE levels on day 3 were increased more than threefold in non-survivors compared to survivors (median NSE (ng/mL) 19.8 (IQR 15.7 to 27.8) vs. 72.6 (IQR 26 to 194)) and showed the highest prognostic performance for mortality compared to other days of measurement, with an AUC of 0.81 and an adjusted hazard ratio of 1.55 (95% CI 1.41 to 1.71, p < 0.001). Subgroup analysis showed an excellent sensitivity and negative predictive value of 100% of NSE in patients <54 years of age. Conclusion: NSE measured three days after cardiac arrest is associated with long-term mortality and neurological outcome and may provide prognostic information that improves clinical decision making. Particularly in the subgroup of younger patients (<54 years), NSE showed excellent negative predictive value.

The Comparison of Emergency Medical Service Responses to and Outcomes of Out-of-hospital Cardiac Arrest before and during the COVID-19 Pandemic in an Area of Korea

BACKGROUND

Since the declaration of the coronavirus disease 2019 (COVID-19) pandemic, COVID-19 has affected the responses of emergency medical service (EMS) systems to cases of out-of-hospital cardiac arrest (OHCA). The purpose of this study was to identify the impact of the COVID-19 pandemic on EMS responses to and outcomes of adult OHCA in an area of South Korea.

METHODS

This was a retrospective observational study of adult OHCA patients attended by EMS providers comparing the EMS responses to and outcomes of adult OHCA during the COVID-19 pandemic to those during the pre-COVID-19 period. Propensity score matching was used to compare the survival rates, and logistic regression analysis was used to assess the impact of the COVID-19 pandemic on the survival of OHCA patients.

RESULTS

A total of 891 patients in the pre-COVID-19 group and 1,063 patients in the COVID-19 group were included in the final analysis. During the COVID-19 period, the EMS call time was shifted to a later time period (16:00-24:00, P < 0.001), and the presence of an initial shockable rhythm was increased (pre-COVID-19 vs. COVID-19, 7.97% vs. 11.95%, P = 0.004). The number of tracheal intubations decreased (5.27% vs. 1.22%, P < 0.001), and the use of mechanical chest compression devices (30.53% vs. 44.59%, P < 0.001) and EMS response time (median [quartile 1-quartile 3], 7 [5-10] vs. 8 [6-11], P < 0.001) increased. After propensity score matching, the survival at admission rate (22.52% vs. 18.24%, P = 0.025), survival to discharge rate (7.77% vs. 5.52%, P = 0.056), and favorable neurological outcome (5.97% vs. 3.49%, P < 0.001) decreased. In the propensity score matching analysis of the impact of COVID-19, odds ratios of 0.768 (95% confidence interval [CI], 0.592-0.995) for survival at admission and 0.693 (95% CI, 0.446-1.077) for survival to discharge were found.

CONCLUSION

During the COVID-19 period, there were significant changes in the EMS responses to OHCA. These changes are considered to be partly due to social distancing measures. As a result, the proportion of patients with an initial shockable rhythm in the COVID-19 period was greater than that in the pre-COVID-19 period, but the final survival rate and favorable neurological outcome were lower.

Neurological outcomes associated with prehospital advanced airway management in patients with out-of-hospital cardiac arrest due to foreign body airway obstruction

OBJECTIVES

Several studies have examined the association between advanced airway management (AAM) and survival for arrest that is non-shockable, noncardiac in origin, or due to suffocation; however, the efficacy of prehospital AAM compared with no AAM following foreign body removal by emergency medical services (EMS) has not been examined. We aimed to compare neurological outcomes in patients after out-of-hospital cardiac arrest (OHCA) due to foreign body airway obstruction (FBAO) managed with and without AAM after foreign body removal.

METHODS

This retrospective observational cohort study used all emergency transportation data of Japan and the All-Japan Utstein Registry. We included patients with OHCA aged ≥18 years undergoing resuscitation and removal of airway foreign bodies by EMS from January 2015 to December 2017. The exposure of interest was prehospital AAM by EMS after foreign body removal, and the primary outcome was a favorable neurological outcome at hospital discharge (i.e., a cerebral performance category of 1-2).

RESULTS

Overall, 329,098 adults had OHCAs and 23,060 had foreign bodies removed from their airways; 3681 adult patients met our eligibility criteria and were divided as: AAM (2045) and non-AAM (1636) groups. Propensity score matching resulted in 1210 matched pairs with balanced baseline characteristics between the groups. The rate of favorable neurological outcome was significantly lower in the AAM group than in the non-AAM group (OR 0.34, 95% CI 0.19-0.62). However, survival was not significantly different between the two groups (OR 1.08, 95% CI 0.84-1.37).

CONCLUSIONS

We have not demonstrated the benefit of AAM for patients with OHCA due to FBAO. Further study will be required to confirm the efficacy of AAM for those patients.

Bedside microdialysis for detection of early brain injury after out-of-hospital cardiac arrest

Bedside detection and early treatment of lasting cerebral ischemia may improve outcome after out-of-hospital cardiac arrest (OHCA). This feasibility study explores the possibilities to use microdialysis (MD) for continuous monitoring of cerebral energy metabolism by analyzing the draining cerebral venous blood. Eighteen comatose patients were continuously monitored with jugular bulb and radial artery (reference) MD following resuscitation. Median time from cardiac arrest to MD was 300 min (IQR 230–390) with median monitoring time 60 h (IQR 40–81). The lactate/pyruvate ratio in cerebral venous blood was increased during the first 20 h after OHCA, and significant differences in time-averaged mean MD metabolites between jugular venous and artery measurements, were documented (p < 0.02). In patients with unfavorable outcome (72%), cerebral venous lactate and pyruvate levels remained elevated during the study period. In conclusion, the study indicates that jugular bulb microdialysis (JBM) is feasible and safe. Biochemical signs of lasting ischemia and mitochondrial dysfunction are frequent and associated with unfavorable outcome. The technique may be used in comatose OHCA patients to monitor biochemical variables reflecting ongoing brain damage and support individualized treatment early after resuscitation.

Novel approaches to prediction in severe brain injury

PURPOSE OF REVIEW

Recovery after severe brain injury is variable and challenging to accurately predict at the individual patient level. This review highlights new developments in clinical prognostication with a special focus on the prediction of consciousness and increasing reliance on methods from data science.

RECENT FINDINGS

Recent research has leveraged serum biomarkers, quantitative electroencephalography, MRI, and physiological time-series to build models for recovery prediction. The analysis of high-resolution data and the integration of features from different modalities can be approached with efficient computational techniques.

SUMMARY

Advances in neurophysiology and neuroimaging, in combination with computational methods, represent a novel paradigm for prediction of consciousness and functional recovery after severe brain injury. Research is needed to produce reliable, patient-level predictions that could meaningfully impact clinical decision making.

Continuous vs Routine Electroencephalogram in Critically Ill Adults With Altered Consciousness and No Recent Seizure: A Multicenter Randomized Clinical Trial

Question

In patients with acute consciousness impairment and no recent seizures, does continuous electroencephalogram (cEEG) correlate with reduced mortality compared with repeated routine EEG (rEEG)?

Findings

In this pragmatic, multicenter randomized clinical trial analyzing 364 adults, cEEG translated into a higher rate of seizures/status epilepticus detection and antiseizure treatment modifications but did not improve mortality compared with rEEG.

Meaning

Pending larger studies, rEEG may represent a valid alternative to cEEG in centers with limited resources.

Importance

In critically ill patients with altered consciousness, continuous electroencephalogram (cEEG) improves seizure detection, but is resource-consuming compared with routine EEG (rEEG). It is also uncertain whether cEEG has an effect on outcome.

Objective

To assess whether cEEG is associated with reduced mortality compared with rEEG.

Design, Setting, and Participants

The pragmatic multicenter Continuous EEG Randomized Trial in Adults (CERTA) was conducted between 2017 and 2018, with follow-up of 6 months. Outcomes were assessed by interviewers blinded to interventions.The study took place at 4 tertiary hospitals in Switzerland (intensive and intermediate care units). Depending on investigators’ availability, we pragmatically recruited critically ill adults having Glasgow Coma Scale scores of 11 or less or Full Outline of Responsiveness score of 12 or less, without recent seizures or status epilepticus. They had cerebral (eg, brain trauma, cardiac arrest, hemorrhage, or stroke) or noncerebral conditions (eg, toxic-metabolic or unknown etiology), and EEG was requested as part of standard care. An independent physician provided emergency informed consent.

Interventions

Participants were randomized 1:1 to cEEG for 30 to 48 hours vs 2 rEEGs (20 minutes each), interpreted according to standardized American Clinical Neurophysiology Society guidelines.

Main Outcomes and Measures

Mortality at 6 months represented the primary outcome. Secondary outcomes included interictal and ictal features detection and change in therapy.

Results

We analyzed 364 patients (33% women; mean [SD] age, 63 [15] years). At 6 months, mortality was 89 of 182 in those with cEEG and 88 of 182 in those with rEEG (adjusted relative risk [RR], 1.02; 95% CI, 0.83-1.26; P = .85). Exploratory comparisons within subgroups stratifying patients according to age, premorbid disability, comorbidities on admission, deeper consciousness reduction, and underlying diagnoses revealed no significant effect modification. Continuous EEG was associated with increased detection of interictal features and seizures (adjusted RR, 1.26; 95% CI, 1.08-1.15; P = .004 and 3.37; 95% CI, 1.63-7.00; P = .001, respectively) and more frequent adaptations in antiseizure therapy (RR, 1.84; 95% CI, 1.12-3.00; P = .01).

Conclusions and Relevance

This pragmatic trial shows that in critically ill adults with impaired consciousness and no recent seizure, cEEG leads to increased seizure detection and modification of antiseizure treatment but is not related to improved outcome compared with repeated rEEG. Pending larger studies, rEEG may represent a valid alternative to cEEG in centers with limited resources.

Trial Registration

ClinicalTrials.gov Identifier: NCT03129438

An international, consensus-derived Core Outcome Set for Cardiac Arrest effectiveness trials: the COSCA initiative

PURPOSE OF REVIEW

Accurate and relevant assessment is essential to determining the impact of ill-health and the relative benefit of healthcare. This review details the recent development of a core outcome set for cardiac arrest effectiveness trials - the COSCA initiative.

RECENT FINDINGS

The reported heterogeneity in outcome assessment and a lack of outcome reporting guidance were key triggers for the development of the COSCA. The historical failure of existing research to adequately capture the perspective of survivors and their family members in defining survival is described. Working collaboratively with international stakeholders - including survivors, family members and advocates - as research partners and participants ensured that a range of perspectives were considered throughout all stages of COSCA development. Three core domains and methods of assessment were recommended: survival - at 30 days or hospital discharge; neurological function assessed at 30 days or hospital discharge with the modified Rankin Scale; and health-related quality of life assessed at 90 days (as a minimum) with one of three generic measures.

SUMMARY

The COSCA recommendation describes a small group of outcomes that should be reported as a minimum across large, randomized clinical effectiveness trials for cardiac arrest.

"Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA): Safety and efficacy of low-dose Iloprost, a prostacyclin analogue, in addition to standard therapy, as compared to standard therapy alone, in post-cardiac-arrest-syndrome patients."

OBJECTIVE

An increasingly recognized prognostic factor for out-of-hospital-cardiac-arrest (OHCA) patients is the ischemia-reperfusion injury after restored blood circulation. Endothelial injury is common in patients resuscitated from cardiac arrest and is associated with poor outcome. This study was designed to investigate if iloprost infusion, a prostacyclin analogue, reduces endothelial damage in OHCA patients.

METHODS

50 patients were randomized in a placebo controlled double-blinded trial and allocated 1:2 to 48-hours iloprost infusion, (1 ng/kg/min) or placebo (saline infusion). Endothelial biomarkers (soluble thrombomodulin (sTM), sE-selectin, syndecan-1, soluble vascular endothelial growth factor (sVEGF), vascular endothelial cadherine (VEcad), nucleosomes) and sympathoadrenal activation (epinephrine/norepinephrine) from baseline to 48 and 96-hours were evaluated.

RESULTS

Iloprost infusion did not influence endothelial biomarkers by the 48-hour endpoint. A rebound effect was observed with higher biomarker plasma values in the iloprost group (sTM p=0.02; Syndecan p=0.004; nucleosomes p<0.001; VEcad p<0.03) after 96-hours. There was a significant difference in 180-day mortality in favor of placebo. There was no difference regarding total adverse events between groups (p=0.73). Two patients were withdrawn in the iloprost group due to hypotension.

CONCLUSIONS

The administration of low-dose iloprost (1ng/kg/min) to OHCA patients did not significantly influence endothelial biomarkers as measured by the 48- hour endpoint. A rebound effect was however observed in the 96-hour statistical model, with increasing endothelial biomarker levels after cessation of the iloprost-infusion.

Activities of daily living among elderly persons with severe aortic stenosis

PURPOSE

To determine the level of limitations in activities of daily living (ADL) and instrumental ADL, and identify related factors to instrumental ADL among elderly persons with severe aortic stenosis (AS).

MATERIALS AND METHODS

We prospectively enrolled 112 consecutive elderly persons (mean age, 84.6 ± 4.4 y) with severe AS. We assessed ADL and instrumental ADL using the Barthel index (BI) and the Frenchay activities index (FAI), respectively. Cardiac, physical, cognitive and kidney functions, nutritional status, medical histories, and comorbidities were assessed. A multiple logistic analysis was developed to explore related factors to the FAI.

RESULTS

The medians (ranges) of BI and FAI were 100 (15-100) and 21 (0-38), respectively. The multiple logistic analysis revealed that a history of heart failure (sβ = -0.189), a history of cerebrovascular disease (sβ = -0.233), the short physical performance battery score ≤ 8 (sβ = -0.272), the mini-mental state examination score ≤ 23 (sβ = -0.168) were significantly related to the FAI (p < 0.05).

CONCLUSIONS

Physical frailty, a history of heart failure, cerebrovascular disease, and cognitive decline were independently related to declined instrumental ADL. IMPLICATIONS FOR REHABILIATION Activities of daily living was well-preserved among elderly persons with severe aortic stenosis. Instrumental activities of daily living varied among patients with aortic stenosis and was sometimes impaired. Physical frailty, a history of heart failure, and a history of cerebrovascular disease were independently associated with instrumental activities of daily living in elderly persons with severe aortic stenosis.

Design paper of the "Blood pressure targets in post-resuscitation care and bedside monitoring of cerebral energy state: a randomized clinical trial"

BACKGROUND

Neurological injuries remain the leading cause of death in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA). Adequate blood pressure is of paramount importance to optimize cerebral perfusion and to minimize secondary brain injury. Markers measuring global cerebral ischemia caused by cardiac arrest and consecutive resuscitation and reflecting the metabolic variations after successful resuscitation are needed to assist a more individualized post-resuscitation care. Currently, no technique is available for bedside evaluation of global cerebral energy state, and until now blood pressure targets have been based on limited clinical evidence. Recent experimental and clinical studies indicate that it might be possible to evaluate cerebral oxidative metabolism from measuring the lactate-to-pyruvate (LP) ratio of the draining venous blood. In this study, jugular bulb microdialysis and immediate bedside biochemical analysis are introduced as new diagnostic tools to evaluate the effect of higher mean arterial blood pressure on global cerebral metabolism and the degree of cellular damage after OHCA.

METHODS/DESIGN

This is a single-center, randomized, double-blinded, superiority trial. Sixty unconscious patients with sustained return of spontaneous circulation after OHCA will be randomly assigned in a one-to-one fashion to low (63 mm Hg) or high (77 mm Hg) mean arterial blood pressure target. The primary end-point will be a difference in mean LP ratio within 48 h between blood pressure groups. Secondary end-points are (1) association between LP ratio and all-cause intensive care unit (ICU) mortality and (2) association between LP ratio and survival to hospital discharge with poor neurological function.

DISCUSSION

Markers measuring cerebral ischemia caused by cardiac arrest and consecutive resuscitation and reflecting the metabolic changes after successful resuscitation are urgently needed to enable a more personalized post-resuscitation care and prognostication. Jugular bulb microdialysis may provide a reliable global estimate of cerebral metabolic state and can be implemented as an entirely new and less invasive diagnostic tool for ICU patients after OHCA and has implications for early prognosis and treatment.

TRIAL REGISTRATION

ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT03095742 ). Registered March 30, 2017.

How does the length of cardiopulmonary resuscitation affect brain damage in patients surviving cardiac arrest? A systematic review

BACKGROUND

Brain injury can occur after cardiac arrest due to the effects of ischaemia and reperfusion. In serious cases this can lead to permanent disability. This risk must be considered when making decisions about terminating resuscitation. There are very specific rules for termination of resuscitation in the prehospital setting however a similar rule for resuscitation in hospital does not exist. The aim of this review was to explore the effects of duration of cardiopulmonary resuscitation on neurological outcome in survivors of both in-hospital and out-of-hospital cardiac arrest achieving return of spontaneous circulation in hospital.

METHODS

A systematic review was conducted. Five databases were searched in addition to hand searching the journals Resuscitation and Circulation and reference lists, quality of the selected studies was assessed and a narrative summary of the data presented. Studies reporting relevant outcomes were included if the participants were adults achieving return of spontaneous circulation in the hospital setting. Studies looking at additional interventions such as extracorporeal resuscitation and therapeutic hypothermia were not included. Case studies were excluded. The study period was from January 2010 to March 2016.

RESULTS

Seven cohort studies were included for review. Quality scores ranged from eight to 11 out of 12. Five of the studies found a significant association between shorter duration of resuscitation and favourable neurological outcome.

CONCLUSIONS

There is generally a better neurological outcome with a shorter duration of CPR in survivors of cardiac arrest however a cut-off beyond which resuscitation is likely to lead to unfavourable outcome could not be determined and is unlikely to exist. The findings of this review could be considered by clinicians making decisions about terminating resuscitation. This review has highlighted many gaps in the knowledge where future research is needed; a validated and reliable measure of neurological outcome following cardiac arrest, more focused research on the effects of duration on neurological outcome and further research into the factors leading to brain damage in cardiac arrest.

Early prognostic value of an Algorithm based on spectral Variables of Ventricular fibrillAtion from the EKG of patients with suddEn cardiac death: A multicentre observational study (AWAKE)

OBJECTIVE

Ventricular fibrillation (VF)-related sudden cardiac death (SCD) is a leading cause of mortality and morbidity. Current biological and imaging parameters show significant limitations on predicting cerebral performance at hospital admission. The AWAKE study (NCT03248557) is a multicentre observational study to validate a model based on spectral ECG analysis to early predict cerebral performance and survival in resuscitated comatose survivors.

METHODS

Data from VF ECG tracings of patients resuscitated from SCD will be collected using an electronic Case Report Form. Patients can be either comatose (Glasgow Coma Scale - GCS - ≤8) survivors undergoing temperature control after return of spontaneous circulation (RoSC), or those who regain consciousness (GCS=15) after RoSC; all admitted to Intensive Cardiac Care Units in 4 major university hospitals. VF tracings prior to the first direct current shock will be digitized and analyzed to derive spectral data and feed a predictive model to estimate favorable neurological performance (FNP). The results of the model will be compared to the actual prognosis.

RESULTS

The primary clinical outcome is FNP during hospitalization. Patients will be categorized into 4 subsets of neurological prognosis according to the risk score obtained from the predictive model. The secondary clinical outcomes are survival to hospital discharge, and FNP and survival after 6 months of follow-up. The model-derived categorisation will be also compared with clinical variables to assess model sensitivity, specificity, and accuracy.

CONCLUSIONS

A model based on spectral analysis of VF tracings is a promising tool to obtain early prognostic data after SCD.

COSCA (Core Outcome Set for Cardiac Arrest) in Adults: An Advisory Statement From the International Liaison Committee on Resuscitation

Cardiac arrest effectiveness trials have traditionally reported outcomes that focus on survival. A lack of consistency in outcome reporting between trials limits the opportunities to pool results for meta-analysis. The COSCA initiative (Core Outcome Set for Cardiac Arrest), a partnership between patients, their partners, clinicians, research scientists, and the International Liaison Committee on Resuscitation, sought to develop a consensus core outcome set for cardiac arrest for effectiveness trials. Core outcome sets are primarily intended for large, randomized clinical effectiveness trials (sometimes referred to as pragmatic trials or phase III/IV trials) rather than for pilot or efficacy studies. A systematic review of the literature combined with qualitative interviews among cardiac arrest survivors was used to generate a list of potential outcome domains. This list was prioritized through a Delphi process, which involved clinicians, patients, and their relatives/partners. An international advisory panel narrowed these down to 3 core domains by debate that led to consensus. The writing group refined recommendations for when these outcomes should be measured and further characterized relevant measurement tools. Consensus emerged that a core outcome set for reporting on effectiveness studies of cardiac arrest (COSCA) in adults should include survival, neurological function, and health-related quality of life. This should be reported as survival status and modified Rankin scale score at hospital discharge, at 30 days, or both. Health-related quality of life should be measured with ≥1 tools from Health Utilities Index version 3, Short-Form 36-Item Health Survey, and EuroQol 5D-5L at 90 days and at periodic intervals up to 1 year after cardiac arrest, if resources allow.

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.

Inter-rater reliability of post-arrest cerebral performance category (CPC) scores

PURPOSE

Cerebral Performance Category (CPC) scores are often an outcome measure for post-arrest neurologic function, collected worldwide to compare performance, evaluate therapies, and formulate recommendations. At most institutions, no formal training is offered in their determination, potentially leading to misclassification.

MATERIALS AND METHODS

We identified 171 patients at 2 hospitals between 5/10/2005 and 8/31/2012 with two CPC scores at hospital discharge recorded independently - in an in-house quality improvement database and as part of a national registry. Scores were abstracted retrospectively from the same electronic medical record by two separate non-clinical researchers. These scores were compared to assess inter-rater reliability and stratified based on whether the score was concordant or discordant among reviewers to determine factors related to discordance.

RESULTS

Thirty-nine CPC scores (22.8%) were discordant (kappa: 0.66), indicating substantial agreement. When dichotomized into "favorable" neurologic outcome (CPC 1-2)/"unfavorable" neurologic outcome (CPC 3-5), 20 (11.7%) scores were discordant (kappa: 0.70), also indicating substantial agreement. Patients discharged home (as opposed to nursing/other care facility) and patients with suspected cardiac etiology of arrest were statistically more likely to have concordant scores. For the quality improvement database, patients with discordant scores had a statistically higher median CPC score than those with concordant scores. The registry had statistically lower median CPC score (CPC 1) than the quality improvement database (CPC 2); p<0.01 for statistical significance.

CONCLUSIONS

CPC scores have substantial inter-rater reliability, which is reduced in patients who have worse outcomes, have a non-cardiac etiology of arrest, and are discharged to a location other than home.