Post–Cardiac Arrest Mortality Is Declining

Cardiac arrest risk standardization using administrative data compared to registry data

BACKGROUND

Methods for comparing hospitals regarding cardiac arrest (CA) outcomes, vital for improving resuscitation performance, rely on data collected by cardiac arrest registries. However, most CA patients are treated at hospitals that do not participate in such registries. This study aimed to determine whether CA risk standardization modeling based on administrative data could perform as well as that based on registry data.

METHODS AND RESULTS

Two risk standardization logistic regression models were developed using 2453 patients treated from 2000-2015 at three hospitals in an academic health system. Registry and administrative data were accessed for all patients. The outcome was death at hospital discharge. The registry model was considered the "gold standard" with which to compare the administrative model, using metrics including comparing areas under the curve, calibration curves, and Bland-Altman plots. The administrative risk standardization model had a c-statistic of 0.891 (95% CI: 0.876-0.905) compared to a registry c-statistic of 0.907 (95% CI: 0.895-0.919). When limited to only non-modifiable factors, the administrative model had a c-statistic of 0.818 (95% CI: 0.799-0.838) compared to a registry c-statistic of 0.810 (95% CI: 0.788-0.831). All models were well-calibrated. There was no significant difference between c-statistics of the models, providing evidence that valid risk standardization can be performed using administrative data.

CONCLUSIONS

Risk standardization using administrative data performs comparably to standardization using registry data. This methodology represents a new tool that can enable opportunities to compare hospital performance in specific hospital systems or across the entire US in terms of survival after CA.

Regional Variation in Outcomes of Hospitalized Patients Having Out-of-Hospital Cardiac Arrest

The aim of this study was to investigate patient outcomes after hospitalization for out-of-hospital cardiac arrest in the United States. We used the 2002 to 2013 Nationwide Inpatient Sample database to identify adults ≥18 years with an International Classification of Diseases, Ninth Revision, Clinical Modification, principal diagnosis code of cardiorespiratory arrest (427.5) or ventricular fibrillation (VF) (427.41). In 4 predefined federal geographic regions: Northeast, Midwest, South, and West, means and proportions of survival, survival stratified by initial rhythm, hospital charges, and cost were estimated. Multiple linear and logistic regression models were conducted. Of the 154,177 patients with out-of-hospital cardiac arrest hospitalized in the United States, 25,873 (16.8%) were in the Northeast, 38,296 (24.8%) in the Midwest, 57,305 (37.2%) in the South, and 32,703 (21.2%) in the West. Variability in survival was noted in VF arrests; compared with the Northeast, survival was higher in the Midwest and South (adjusted odds ratio [AOR] 1.16, 95% confidence interval [CI] 1.02 to 1.32 and AOR 1.24, 95% CI 1.09 to 1.40, respectively), with no difference detected in the West (AOR 0.93, 95% CI 0.82 to 1.06). No variability in survival was noted after non-VF arrests (p >0.05). Hospital charges rose significantly across all regions of the United States (p-trend < 0.001) and were higher in the West compared with the Northeast (hospital charges >$109,000/admission, AOR 1.76; 95% CI 1.50 to 2.06). In conclusion, nationwide, we observed significant regional variability in survival of hospitalized patients after out of hospital VF cardiac arrest, no survival variability after non-VF arrests, and a steady increase in hospital charges.

Favorable Neurocognitive Outcome with Low Tidal Volume Ventilation after Cardiac Arrest

RATIONALE

Neurocognitive outcome after out-of-hospital cardiac arrest (OHCA) is often poor, even when initial resuscitation succeeds. Lower tidal volumes (Vts) attenuate extrapulmonary organ injury in other disease states and are neuroprotective in preclinical models of critical illness.

OBJECTIVE

To evaluate the association between Vt and neurocognitive outcome after OHCA.

METHODS

We performed a propensity-adjusted analysis of a two-center retrospective cohort of patients experiencing OHCA who received mechanical ventilation for at least the first 48 hours of hospitalization. Vt was calculated as the time-weighted average over the first 48 hours, in milliliters per kilogram of predicted body weight (PBW). The primary endpoint was favorable neurocognitive outcome (cerebral performance category of 1 or 2) at discharge.

MEASUREMENTS AND MAIN RESULTS

Of 256 included patients, 38% received time-weighted average Vt greater than 8 ml/kg PBW during the first 48 hours. Lower Vt was independently associated with favorable neurocognitive outcome in propensity-adjusted analysis (odds ratio, 1.61; 95% confidence interval [CI], 1.13-2.28 per 1-ml/kg PBW decrease in Vt; P = 0.008). This finding was robust to several sensitivity analyses. Lower Vt also was associated with more ventilator-free days (β = 1.78; 95% CI, 0.39-3.16 per 1-ml/kg PBW decrease; P = 0.012) and shock-free days (β = 1.31; 95% CI, 0.10-2.51; P = 0.034). Vt was not associated with hypercapnia (P = 1.00). Although the propensity score incorporated several biologically relevant covariates, only height, weight, and admitting hospital were independent predictors of Vt less than or equal to 8 ml/kg PBW.

CONCLUSIONS

Lower Vt after OHCA is independently associated with favorable neurocognitive outcome, more ventilator-free days, and more shock-free days. These findings suggest a role for low-Vt ventilation after cardiac arrest.

Variations in survival after cardiac arrest among academic medical center-affiliated hospitals

Background

Variation exists in cardiac arrest (CA) survival among institutions. We sought to determine institutional-level characteristics of academic medical centers (AMCs) associated with CA survival.

Methods

We examined discharge data from AMCs participating with Vizient clinical database–resource manager. We identified cases using ICD-9 diagnosis code 427.5 (CA) or procedure code 99.60 (CPR). We estimated hospital-specific risk-standardized survival rates (RSSRs) using mixed effects logistic regression, adjusting for individual mortality risk. Institutional and community characteristics of AMCs with higher than average survival were compared with those with lower survival.

Results

We analyzed data on 3,686,296 discharges in 2012, of which 33,700 (0.91%) included a CA diagnosis. Overall survival was 42.3% (95% CI 41.8–42.9) with median institutional RSSR of 42.6% (IQR 35.7–51.0; Min-Max 19.4–101.6). We identified 28 AMCs with above average survival (median RSSR 61.8%) and 20 AMCs with below average survival (median RSSR 26.8%). Compared to AMCs with below average survival, those with high CA survival had higher CA volume (median 262 vs.119 discharges, p = 0.002), total beds (722 vs. 452, p = 0.02), and annual surgical volume (24,939 vs. 13,109, p<0.001), more likely to offer cardiac catheterization (100% vs. 72%, p = 0.007) or cardiac surgery (93% vs. 61%, p = 0.02) and cared for catchment areas with higher household income ($61,922 vs. $49,104, p = 0.004) and lower poverty rates (14.6% vs. 17.3%, p = 0.03).

Conclusion

Using discharge data from Vizient, we showed AMCs with higher CA and surgical case volume, cardiac catheterization and cardiac surgery facilities, and catchment areas with higher socioeconomic status had higher risk-standardized CA survival.

Clinical neurophysiology for neurological prognostication of comatose patients after cardiac arrest

•

A multimodal prognostic approach is recommended after cardiac arrest.

•

EEG (background and, reactivity, repetitive epileptiform features) and SSEP are core assessments.

•

Some outlook into long-latency evoked potentials is offered.

Early prognostication of outcome in comatose patients after cardiac arrest represents a daunting task for clinicians, also considering the nowadays commonly used targeted temperature management with sedation in the first 24–48 h. A multimodal approach is currently recommended, in order to minimize the risks of false-positive prediction of poor outcome, including clinical examination off sedation, EEG (background characterization and reactivity, occurrence of repetitive epileptiform features), and early-latency SSEP responses represent the core assessments in this setting; they may be complemented by biochemical markers and neuroimaging.

This paper, which relies on a recent comprehensive review, focuses on an updated review of EEG and SSEP, and also offers some outlook into long-latency evoked potentials, which seem promising in clinical use.

Recent developments in the management of patients resuscitated from cardiac arrest

Cardiac arrest is the leading cause of death in Europe and the United States. Many patients who are initially resuscitated die in the hospital, and hospital survivors often have substantial neurologic dysfunction. Most cardiac arrests are caused by coronary artery disease; patients with coronary artery disease likely benefit from early coronary angiography and intervention. After resuscitation, cardiac arrest patients remain critically ill and frequently suffer cardiogenic shock and multiorgan failure. Early cardiopulmonary stabilization is important to prevent worsening organ injury. To achieve best patient outcomes, comprehensive critical care management is needed, with primary goals of stabilizing hemodynamics and preventing progressive brain injury. Targeted temperature management is frequently recommended for comatose survivors of cardiac arrest to mitigate the neurologic injury that drives outcomes. Accurate neurologic assessment is central to managing care of cardiac arrest survivors and should combine physical examination with objective neurologic testing, with the caveat that delaying neurologic prognosis is essential to avoid premature withdrawal of supportive care. A combination of clinical findings and diagnostic results should be used to estimate the likelihood of functional recovery. This review focuses on recent advances in care and specific cardiac intensive care strategies that may improve morbidity and mortality for patients after cardiac arrest.

Incidence and Survival After In-Hospital Cardiopulmonary Resuscitation in Nonelderly Adults

Background—

Survival trends after in-hospital cardiopulmonary resuscitation (ICPR) for cardiac arrest in nonelderly adults is not well known. Influence of cardiopulmonary resuscitation guidelines on nationwide survival after ICPR is yet to be well elucidated.

Methods and Results—

We examined survival trends and factors associated with survival after ICPR in nonelderly adults aged 18 to 64 years, using Healthcare Utilization Project Nationwide Inpatient Sample Database from 2007 through 2012 in the United States. Furthermore, we studied the impact of 2010 American Heart Association cardiopulmonary resuscitation guidelines on survival. We identified 235 959 patients who underwent ICPR after cardiac arrest. Overall, 30.4% patients survived to hospital discharge. Survival improved from 27.4% in 2007 to 32.8% in 2012 ( P trend <0.001). Shockable arrest rhythms were noted in 23.3% of patients. Incidence of ICPR increased from 1.81 per 1000 hospitalizations in 2007 to 2.37 per 1000 hospitalizations in 2012 ( P trend <0.001). There was no statistically significant change in survival trends before and after 2010 cardiopulmonary resuscitation guidelines. Female sex and shockable rhythms were associated with higher adjusted odds of survival, whereas black race, lack of health insurance, age, and weekend admission were associated with lower adjusted odds of survival.

Conclusions—

Among nonelderly adults, survival after ICPR improved significantly from 2007 through 2012, with an overall survival rate of 30.4%. Incidence of ICPR increased significantly during the study period. There was no statistically significant change in survival before and after 2010 cardiopulmonary resuscitation guidelines. Female sex and black race were associated with higher and lower odds of survival, respectively.

Pathophysiology and the Monitoring Methods for Cardiac Arrest Associated Brain Injury

Cardiac arrest (CA) is a well-known cause of global brain ischemia. After CA and subsequent loss of consciousness, oxygen tension starts to decline and leads to a series of cellular changes that will lead to cellular death, if not reversed immediately, with brain edema as a result. The electroencephalographic activity starts to change as well. Although increased intracranial pressure (ICP) is not a direct result of cardiac arrest, it can still occur due to hypoxic-ischemic encephalopathy induced changes in brain tissue, and is a measure of brain edema after CA and ischemic brain injury. In this review, we will discuss the pathophysiology of brain edema after CA, some available techniques, and methods to monitor brain oxygen, electroencephalography (EEG), ICP (intracranial pressure), and microdialysis on its measurement of cerebral metabolism and its usefulness both in clinical practice and possible basic science research in development. With this review, we hope to gain knowledge of the more personalized information about patient status and specifics of their brain injury, and thus facilitating the physicians’ decision making in terms of which treatments to pursue.

The rate of brain death and organ donation in patients resuscitated from cardiac arrest: a systematic review and meta-analysis

BACKGROUND

The occurrence of brain death in patients with hypoxic-ischaemic brain injury after resuscitation from cardiac arrest creates opportunities for organ donation. However, its prevalence is currently unknown.

METHODS

Systematic review. MEDLINE via PubMed, ISI Web of Science and the Cochrane Database of Systematic Reviews were searched for eligible studies (2002-2016). The prevalence of brain death in adult patients resuscitated from cardiac arrest and the rate of organ donation among brain dead patients were summarised using a random effect model with double-arcsine transformation. The quality of evidence (QOE) was evaluated according to the GRADE guidelines.

RESULTS

26 studies [16 on conventional cardiopulmonary resuscitation (c-CPR), 10 on extracorporeal CPR (e-CPR)] included a total of 23,388 patients, 1830 of whom developed brain death at a mean time of 3.2 ± 0.4 days after recovery of circulation. The overall prevalence of brain death among patients who died before hospital discharge was 12.6 [10.2-15.2] %. Prevalence was significantly higher in e-CPR vs. c-CPR patients (27.9 [19.7-36.6] vs. 8.3 [6.5-10.4] %; p < 0.0001). The overall rate of organ donation among brain dead patients was 41.8 [20.2-51.0] % (9/26 studies, 1264 patients; range 0-100 %). The QOE was very low for both outcomes.

CONCLUSIONS

In patients with hypoxic-ischaemic brain injury following CPR, more than 10 % of deaths were due to brain death. More than 40 % of brain-dead patients could donate organs. Patients who are unconscious after resuscitation from cardiac arrest, especially when resuscitated using e-CPR, should be carefully screened for signs of brain death.

EEG power as a biomarker to predict the outcome after cardiac arrest and cardiopulmonary resuscitation induced global ischemia

AIMS

Cardiac arrest (CA) is a major cause of mortality and survivors often develop neurologic deficits. The objective of this study was to determine the effect of CA and cardiopulmonary resuscitation (CPR) in mice on the EEG and neurologic outcomes, and identify biomarkers that can prognosticate poor outcomes.

MAIN METHODS

Video-EEG records were obtained at various periods following CA-CPR and examined manually to determine the presence of spikes and sharp-waves, and seizures. EEG power was calculated using a fast Fourier transform (FFT) algorithm.

KEY FINDINGS

Fifty percent mice died within 72h following CA and successful CPR. Universal suppression of the background EEG was observed in all mice following CA-CPR, however, a more severe and sustained reduction in EEG power occurred in the mice that did not survive beyond 72h than those that survived until sacrificed. Spikes and sharp wave activity appeared in the cortex and hippocampus of all mice, but only one out of eight mice developed a purely electrographic seizure in the acute period after CA-CPR. Interestingly, none of the mice that died experienced any acute seizures. At 10days after the CA-CPR, 25% of the mice developed spontaneous convulsive and nonconvulsive seizures that remained restricted to the hippocampus. The frequency of nonconvulsive seizures was higher than that of convulsive seizures.

SIGNIFICANCE

A strong association between changes in EEG power and mortality following CA-CPR were observed in our study. Therefore, we suggest that the EEG power can be used to prognosticate mortality following CA-CPR induced global ischemia.

EEG as an Indicator of Cerebral Functioning in Postanoxic Coma

Postanoxic coma after cardiac arrest is one of the most serious acute cerebral conditions and a frequent cause of admission to critical care units. Given substantial improvement of outcome over the recent years, a reliable and timely assessment of clinical evolution and prognosis is essential in this context, but may be challenging. In addition to the classic neurologic examination, EEG is increasingly emerging as an important tool to assess cerebral functions noninvasively. Although targeted temperature management and related sedation may delay clinical assessment, EEG provides accurate prognostic information in the early phase of coma. Here, the most frequently encountered EEG patterns in postanoxic coma are summarized and their relations with outcome prediction are discussed. This article also addresses the influence of targeted temperature management on brain signals and the implication of the evolution of EEG patterns over time. Finally, the article ends with a view of the future prospects for EEG in postanoxic management and prognostication.

Implementation of a Screening Program for Patients at Risk for Posttraumatic Stress Disorder

INTRODUCTION

Implantable cardioverter defibrillator (ICD) recipients who suffer from posttraumatic stress disorder (PTSD) are known to be associated with significant cardiac-specific mortality. Clinical observations suggest that PTSD is frequently undetected in ICD recipients followed up at electrophysiology (EP) outpatient clinics. Early recognition of PTSD is important to reduce the risk of serious manifestations on patient outcomes.

METHODS

All ICD recipients aged 19 years or older at the Washington University School of Medicine (WASHU) EP clinic, a large urban EP clinic, were invited to participate in the project. An informed consent letter with an attached primary care: posttraumatic stress disorder (PC: PTSD) survey was offered to the participants who met the inclusion criteria. Those who completed the survey were included in the project. Individuals with positive survey result were offered a referral to mental health services. Comparisons between PTSD and non-PTSD patients were done using a two-sample t-test for continuous variables. Using Fisher’s exact test, PTSD prevalence was compared to the study by Ladwig et al in which prevalence was determined as the proportion of patients with positive findings of PTSD (n = 38/147). All analyses were conducted using SAS v9.4. The proportion of patients having PTSD was determined and an exact 95% confidence interval was evaluated based on the binomial distribution.

RESULTS

Using a convenience sample, 50 ICD recipients (33 males and 17 females) were enrolled. The project had a 30-day outcome period. Nine (18%) of the 50 participants had positive PC: PTSD findings and all these nine participants were referred to a mental health specialist. The current project demonstrated an 18% (9/50) PTSD prevalence rate when compared to a 26% (38/147) prevalence rate in the study by Ladwig et al (P = 0.34). Although this project did not demonstrate 20% PTSD prevalence rate, as hypothesized, the 18% PTSD prevalence rate is consistent with previous research.

CONCLUSION

The prevalence of PTSD noted in the current project is consistent with previous research and validates underrecognition of PTSD in ICD patients. Offering a referral to all ICD recipients at EP clinic visits with a positive PC: PTSD screening to a mental health specialist is an important step in reducing the risk of serious manifestations on patient outcomes.

Changes in Therapeutic Hypothermia and Coronary Intervention Provision and In-Hospital Mortality of Patients With Out-of-Hospital Cardiac Arrest: A Nationwide Database Study

OBJECTIVES

To evaluate the change in provision of therapeutic hypothermia and coronary intervention (postresuscitation care) over time and to clarify the association between these provisions and in-hospital mortality in patients with out-of-hospital cardiac arrest.

DESIGN

A nationwide retrospective cohort study using multiple propensity score analyses.

SETTING

Japanese Diagnosis Procedure Combination inpatient database.

PATIENTS

Adult patients with cardiogenic out-of-hospital cardiac arrest related to ventricular fibrillation were identified from July to December in 2008-2012 (385 hospitals; n = 3,413).

MEASUREMENTS AND MAIN RESULTS

We evaluated the proportion of patients receiving postresuscitation care and all-cause mortality at 30 days after out-of-hospital cardiac arrest. The proportion of postresuscitation care provision increased significantly over the study period (Mantel-Haenszel trend test, p < 0.001). The overall 30-day mortality was 52.0% (1,774/3,413), and the crude 30-day mortality decreased significantly during the study period (p = 0.006). Logistic regression analysis showed significant associations between the fiscal years 2011 and 2012 and 30-day mortality (2011: odds ratio, 0.75; 95% CI, 0.57-0.98 and 2012: odds ratio, 0.61; 95% CI, 0.47-0.81). Multiple propensity score analysis incorporating postresuscitation care showed that 30-day mortality was significantly associated with postresuscitation care, and the significant associations between 30-day mortality and the years 2011 and 2012 were no longer observed (2011: odds ratio, 1.05; 95% CI, 0.82-1.3 and 2012: odds ratio, 0.95; 95% CI, 0.74-1.2).

CONCLUSIONS

The 30-day survival rate of adult patients with cardiogenic out-of-hospital cardiac arrest related to ventricular fibrillation improved significantly after 2010 in Japan. This improvement may be associated with an increase in postresuscitation care provision.

Increasing survival after admission to UK critical care units following cardiopulmonary resuscitation

Background

In recent years there have been many developments in post-resuscitation care. We have investigated trends in patient characteristics and outcome following admission to UK critical care units following cardiopulmonary resuscitation (CPR) for the period 2004–2014. Our hypothesis is that there has been a reduction in risk-adjusted mortality during this period.

Methods

We undertook a prospectively defined, retrospective analysis of the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme Database (CMPD) for the period 1 January 2004 to 31 December 2014. Admissions, mechanically ventilated in the first 24 hours in the critical care unit and admitted following CPR, defined as the delivery of chest compressions in the 24 hours before admission, were identified. Case mix, withdrawal, outcome and activity were described annually for all admissions identified as post-cardiac arrest admissions, and separately for out-of-hospital cardiac arrest and in-hospital cardiac arrest. To assess whether in-hospital mortality had improved over time, hierarchical multivariate logistic regression models were constructed, with in-hospital mortality as the dependent variable, year of admission as the main exposure variable and intensive care unit (ICU) as a random effect. All analyses were repeated using only the data from those ICUs contributing data throughout the study period.

Results

During the period 2004–2014 survivors of cardiac arrest accounted for an increasing proportion of mechanically ventilated admissions to ICUs in the ICNARC CMPD (9.0 % in 2004 increasing to 12.2 % in 2014). Risk-adjusted hospital mortality following admission to ICU after cardiac arrest has decreased significantly during this period (OR 0.96 per year). Over this time, the ICU length of stay and time to treatment withdrawal has increased significantly. Re-analysis including only those 116 ICUs contributing data throughout the study period confirmed all the results of the primary analysis.

Conclusions

Risk-adjusted hospital mortality following admission to ICU after cardiac arrest has decreased significantly during the period 2004–2014. Over the same period the ICU length of stay and time to treatment withdrawal has increased significantly.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1390-6) contains supplementary material, which is available to authorized users.

Improving Survival From Cardiac Arrest: A Review of Contemporary Practice and Challenges

Cardiac arrest is a common and lethal condition frequently encountered by emergency medicine providers. Resuscitation of persons after cardiac arrest remains challenging, and outcomes remain poor overall. Successful resuscitation hinges on timely, high-quality cardiopulmonary resuscitation. The optimal method of providing chest compressions and ventilator support during cardiac arrest remains uncertain. Prompt and effective defibrillation of ventricular arrhythmias is one of the few effective therapies available for treatment of cardiac arrest. Despite numerous studies during several decades, no specific drug delivered during cardiac arrest has been shown to improve neurologically intact survival after cardiac arrest. Extracorporeal circulation can rescue a minority of highly selected patients with refractory cardiac arrest. Current management of pulseless electrical activity is associated with poor outcomes, but it is hoped that a more targeted diagnostic approach based on electrocardiography and bedside cardiac ultrasonography may improve survival. The evolution of postresuscitation care appears to have improved cardiac arrest outcomes in patients who are successfully resuscitated. The initial approach to early stabilization includes standard measures, such as support of pulmonary function, hemodynamic stabilization, and rapid diagnostic assessment. Coronary angiography is often indicated because of the high frequency of unstable coronary artery disease in comatose survivors of cardiac arrest and should be performed early after resuscitation. Optimizing and standardizing our current approach to cardiac arrest resuscitation and postresuscitation care will be essential for developing strategies for improving survival after cardiac arrest.

Early-Onset Pneumonia in Non-Traumatic Out-of-Hospital Cardiac Arrest Patients with Special Focus on Prehospital Airway Management

Background

More than half of all non-traumatic out-of-hospital cardiac arrest (OHCA) patients die in the hospital. Early-onset pneumonia (EOP) has been described as one of the most common complications after successful cardiopulmonary resuscitation. However, the expanded use of alternative airway devices (AAD) might influence the incidence of EOP following OHCA.

Material/Methods

We analyzed data from all OHCA patients admitted to our hospital between 1 January 2008 and 31 December 2014. EOP was defined as proof of the presence of a pathogenic microorganism in samples of respiratory secretions within the first 5 days after hospital admission.

Results

There were 252 patients admitted: 155 men (61.5%) and 97 women (38.5%), with a mean age of 69.1±13.8 years. Of these, 164 patients (77.6%) were admitted with an endotracheal tube (ET) and 62 (27.4%) with an AAD. We found that 36 out of a total of 80 respiratory secretion samples (45.0%) contained pathogenic microorganisms, with Staphylococcus aureus as the most common bacteria. Neither bacterial detection (p=0.765) nor survival rates (p=0.538) differed between patients admitted with ET and those with AAD.

Conclusions

Irrespective of increasing use of AAD, the incidence of EOP remains high.

Neurological prognostication of outcome in patients in coma after cardiac arrest

Management of coma after cardiac arrest has improved during the past decade, allowing an increasing proportion of patients to survive, thus prognostication has become an integral part of post-resuscitation care. Neurologists are increasingly confronted with raised expectations of next of kin and the necessity to provide early predictions of long-term prognosis. During the past decade, as technology and clinical evidence have evolved, post-cardiac arrest prognostication has moved towards a multimodal paradigm combining clinical examination with additional methods, consisting of electrophysiology, blood biomarkers, and brain imaging, to optimise prognostic accuracy. Prognostication should never be based on a single indicator; although some variables have very low false positive rates for poor outcome, multimodal assessment provides resassurance about the reliability of a prognostic estimate by offering concordant evidence.

Association of early withdrawal of life-sustaining therapy for perceived neurological prognosis with mortality after cardiac arrest

BACKGROUND

Withdrawing life-sustaining therapy because of perceived poor neurological prognosis (WLST-N) is a common cause of hospital death after out-of-hospital cardiac arrest (OHCA). Although current guidelines recommend against WLST-N before 72h (WLST-N<72), this practice is common and may increase mortality. We sought to quantify these effects.

METHODS

In a secondary analysis of a multicenter OHCA trial, we evaluated survival to hospital discharge and survival with favorable functional status (modified Rankin Score ≤3) in adults alive >1h after hospital admission. Propensity score modeling the probability of exposure to WLST-N<72 based on pre-exposure covariates was used to match unexposed subjects with those exposed to WLST-N<72. We determined the probability of survival and functionally favorable survival in the unexposed matched cohort, fit adjusted logistic regression models to predict outcomes in this group, and then used these models to predict outcomes in the exposed cohort. Combining these findings with current epidemiologic statistics we estimated mortality nationally that is associated with WLST-N<72.

RESULTS

Of 16,875 OHCA subjects, 4265 (25%) met inclusion criteria. WLST-N<72 occurred in one-third of subjects who died in-hospital. Adjusted analyses predicted that exposed subjects would have 26% survival and 16% functionally favorable survival if WLST-N<72 did not occur. Extrapolated nationally, WLST-N<72 may be associated with mortality in approximately 2300 Americans each year of whom nearly 1500 (64%) might have had functional recovery.

CONCLUSIONS

After OHCA, death following WLST-N<72 may be common and is potentially avoidable. Reducing WLST-N<72 has national public health implications and may afford an opportunity to decrease mortality after OHCA.

Cardiac arrest and therapeutic hypothermia

Therapeutic hypothermia for patients who remain comatose following resuscitation from a cardiac arrest improves both survival and neurologic outcomes. Although this therapy has been incorporated into the guidelines for routine post-resuscitation care and has been in clinical use for over a decade, significant questions and controversies remain. In this review, we discuss these questions in the context of the current evidence and provide a practical framework to help guide clinicians.

National Analysis of Short-Term Outcomes and Volume-Outcome Relationships for Transcatheter Aortic Valve Replacement in the Era of Commercialization

Objectives: We queried the 2012 National Inpatient Sample in order to (1) further describe the short-term outcomes for transcatheter aortic valve replacement (TAVR) and (2) characterize possible volume-outcome relationships and other prognostic factors for this procedure. Methods: Demographics and inhospital outcomes were tabulated for all patients, as were hospital characteristics and procedural-volume data for all centers at which patients underwent TAVR. Logistic regression analyses were performed to identify independent risk factors for mortality or morbidity. Results: 7,635 patients aged ≥18 years received TAVR during the study period; 84.5% (n = 6,450) underwent transfemoral TAVR and the rest were treated transapically. The median age was 83 years (IQR 77-88 years) and cardiovascular comorbidities were widespread. Overall inhospital mortality was 5.0% (n = 380), and 1.4% (n = 105) of the patients experienced a stroke. All-cause procedure-related morbidity was 24.7% (n = 1,885). Annual hospital TAVR volume did not predict inhospital mortality or morbidity (OR 1.00, 95% CI 0.99-1.00, p = 0.111 and OR 1.00, 95% CI 0.99-1.00, p = 0.947, respectively). Conclusions: Our analysis helps to confirm the short-term safety profile of TAVR and further demonstrates that inhospital outcomes have remained acceptable as this procedure has become commercialized.

Billing diagnoses do not accurately identify out-of-hospital cardiac arrest patients: An analysis of a regional healthcare system

BACKGROUND

International Classification of Diseases 9th Edition's Clinical Modification (ICD-9CM) codes are frequently used in health services research. We tested the operating characteristics of ICD-9CM codes for identifying out-of-hospital cardiac arrest (OHCA) subjects.

METHODS

We used ICD-9CM codes to generate an "administrative cohort" of subjects treated after possible OHCA at one of six emergency departments (EDs) between January 2010 and April 2014. We performed a structured chart review to determine proportion of this administrative cohort with actual OHCA (true positive rate for the ICD-9CM-based search method). The largest study site maintains a prospective registry of consecutive OHCA subjects, which we used to construct a "registry cohort". We used this cohort to calculate the sensitivity of the ICD-9CM-based search strategy at this site, and compared in-hospital mortality and discharge dispositions between the two cohorts using Chi-square tests.

RESULTS

ICD-9CM codes identified 2461 subjects that comprised the administrative cohort. Of these, the true positive rate for actual OHCA on chart review was 40%. ICD9-CM code sensitivity was 100% for subjects coded as dead on arrival and 19% for subjects coded as surviving to ED disposition. There were 609 OHCA subjects in the registry cohort and 268 subjects in the administrative cohort who presented to registry site. Only 26 subjects appeared in both cohorts. In-hospital mortality was significantly higher in the administrative cohort than the registry cohort (91% vs. 61%, p<0.001), and hospital discharge disposition of survivors was less favorable (p<0.001). Neither difference persisted after excluding subjects surviving <6h.

CONCLUSION

Compared to a prospective registry, ICD-9CM codes are an insensitive method to identify OHCA subjects. Moreover, ICD-9CM codes identify a biased sample of the OHCA population with higher mortality.

Age, sex, and hospital factors are associated with the duration of cardiopulmonary resuscitation in hospitalized patients who do not experience sustained return of spontaneous circulation

BACKGROUND

Variability in the duration of attempted in‐hospital cardiopulmonary resuscitation (CPR) is high, but the factors influencing termination of CPR efforts are unknown.

METHODS AND RESULTS

We examined the association between patient and hospital characteristics and CPR duration in 45 500 victims of in‐hospital cardiac arrest who did not experience return of spontaneous circulation (ROSC) and who were enrolled in the Get With the Guidelines registry between 2001 and 2010. In a secondary analysis, we performed analyses in 46 168 victims of in‐hospital cardiac arrest who experienced ROSC. We used ordered logistic regression to identify factors associated with CPR duration. Analyses were conducted by tertile of CPR duration (tertiles: ROSC group: 2 to 7, 8 to 17, and 18 to 120 minutes; no‐ROSC group: 2 to 16, 17 to 26, 27 to 120 minutes). In those without ROSC, younger age (aged 18 to 40 versus >65 years; odds ratio [OR] 1.81; 95% CI 1.69 to 1.95; P<0.001), female sex (OR 1.05; 95% CI 1.02 to 1.09; P=0.005), ventricular tachycardia or fibrillation (OR 1.50; 95% CI 1.42 to 1.58; P<0.001), and the need to place an invasive airway (OR 2.59; 95% CI 2.46 to 2.72; P<0.001) were associated with longer CPR duration. In those with ROSC, ventricular tachycardia or fibrillation (OR 0.89; 95% CI 0.85 to 0.93; P<0.001) and witnessed events (OR 0.87; 95% CI 0.82 to 0.91; P<0.001) were associated with shorter duration.

CONCLUSIONS

Age and sex were associated with attempted CPR duration in patients who do not experience ROSC after in‐hospital cardiac arrest but not in those who experience ROSC. Understanding the mechanism of these interactions may help explain variability in outcomes for in‐hospital cardiac arrest.

Changes in treatments and outcomes among elderly patients with out-of-hospital cardiac arrest between 2002 and 2012: A post hoc analysis of the SOS-KANTO 2002 and 2012

BACKGROUND

Little is known about recent changes in pre- and in-hospital treatments and outcomes for elderly patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We compared data collected for the SOS-KANTO study in 2002 and 2012. We included patients aged ≥65 years who experienced OHCA of cardiac aetiology. The primary endpoint was favourable neurological outcomes 1 month after cardiac arrest.

RESULTS

A total of 8,964 (2002 vs. 2012: 3,544 vs. 5,420) patients were eligible for the current analysis. The proportion of pre-hospital return of spontaneous circulation (ROSC) increased significantly (3.8 vs. 5.6%, p<0.001). Among patients achieving ROSC, the proportion of advanced in-hospital treatments (i.e., extracorporeal membrane oxygenation, therapeutic hypothermia, and/or percutaneous coronary angiogram/intervention) provided increased significantly in 2012 (1.2 vs. 5.5%, p<0.001; 2.6 vs. 15.1%, p<0.001; 4.9 vs. 16.5%, p<0.001; respectively). The proportion of favourable neurological outcomes at 1 month increased significantly in 2012 (1.6 vs. 2.7%, p=0.001). A logistic regression analysis that did not consider advanced in-hospital treatments showed a significantly higher rate of favourable neurological outcomes in the 2012 group than that in the 2002 group (OR, 2.2; 95% CI, 1.4-3.5). However, this difference was no longer observed in the second regression model that accounted for advanced in-hospital treatments (OR, 1.6; 95% CI, 0.9-2.9).

CONCLUSION

There was an increased proportion of aggressive treatment, both pre- and in-hospital, for elderly patients with cardiogenic OHCA in the Kanto area, Japan. Favourable neurological outcomes improved significantly over 10 years.

Therapeutic hypothermia post-cardiac arrest: a clinical nurse specialist initiative in Pakistan

PURPOSE

The purpose of this project was to assess the feasibility of an evidence-based therapeutic hypothermia protocol in adult post-cardiac arrest (CA) patients in a university hospital in Pakistan.

BACKGROUND

Cardiac arrest has a deleterious effect on neurological function, and survival is associated with significant morbidity. The International Liaison Committee of Cardiopulmonary Resuscitation and the American Heart Association recommend the use of mild hypothermia in post-CA victims to mitigate brain injury caused by anoxia. In Pakistan, the survival rate in CA victims is poor. At present, there are no hospitals in the country that use the evidence-based hypothermia intervention in adult post-CA victims.

DESCRIPTION

This pilot project of therapeutic hypothermia in adult post-CA patients was implemented in a university hospital in Pakistan by a clinical nurse specialist in collaboration with the cardiopulmonary resuscitation committee and the nursing leadership of the hospital. Various clinical nurse specialist competencies and roles were used to address the 3 spheres of influence: patient, nurses, and system, while executing an evidence-based hypothermia protocol. Process and outcome indicators were monitored to evaluate the effectiveness and feasibility of hypothermia intervention in this setting.

OUTCOME

The hypothermia protocol was successfully implemented in 3 adult post-CA patients using cost-effective measures. All 3 patients were extubated within 72 hours after CA, and 2 patients were discharged home with good neurological outcome.

CONCLUSION

Adoption of an evidence-based hypothermia protocol for adult CA patients is feasible in the intensive care setting of a university hospital in Pakistan.

IMPLICATIONS

The process used in the project can serve as a road map to other hospitals in resource-limited countries such as Pakistan that are motivated to improve post-CA outcomes. This experience reveals that advanced practice nurses can be instrumental in translation of evidence into practice in a healthcare system in Pakistan.

Survival of patients with spinal cord injury after cardiac arrest in Department of Veterans Affairs hospital: Pilot study

Survivability characteristics after cardiopulmonary resuscitation in the population with spinal cord injury (SCI) are unclear but may be useful for advanced care planning discussions with patients. Retrospective evaluation from records of all SCI patients over 10 yr at a Department of Veterans Affairs medical center who experienced in-hospital cardiac arrest was performed. Demographic data and other common measurements were recorded. Thirty-six male subjects were identified, and only two patients survived to discharge (5.5% survival rate), both of whom were admitted for nonacute issues and were asymptomatic shortly before the cardiac arrest. The mean age at the time of cardiopulmonary arrest was 62.4 yr, with a mean time from cardiac arrest to death of 3.02 d. No significant demographic parameters were identified. Overall, SCI likely portends worse outcome for acutely ill patients in the situation of a cardiac arrest. Conclusions are limited by sample size.

Prognostic Implications of Level-of-Care at Tertiary Heart Centers Compared With Other Hospitals After Resuscitation From Out-of-Hospital Cardiac Arrest

Background—

Studies have found higher survival rates after out-of-hospital cardiac arrest and admission to tertiary heart centers. The aim was to examine the level-of-care at tertiary centers compared with nontertiary hospitals and the association with outcome after out-of-hospital cardiac arrest.

Methods and Results—

Consecutive out-of-hospital cardiac arrest patients (n=1078) without ST-segment–elevation myocardial infarction admitted to tertiary centers (54%) and nontertiary hospitals (46%) were included (2002–2011). Patient charts were reviewed focusing on level-of-care and comorbidity. Survival to discharge differed significantly with 45% versus 24% of patients discharged alive ( P <0.001), and after adjustment for prognostic factors admissions to tertiary centers were still associated with lower 30-day mortality (hazard ratio, 0.78 [0.64–0.96; P =0.02]), independent of comorbidity. The adjusted odds of predefined markers of level-of-care were higher in tertiary centers: admission to intensive care unit (odds ratio [OR], 1.8 [95% confidence interval, 1.2–2.5]), temporary pacemaker (OR, 6.4 [2.2–19]), vasoactive agents (OR, 1.5 [1.1–2.1]), acute (<24 hours) and late coronary angiography (OR, 10 [5.3–22] and 3.8 [2.5–5.7]), neurophysiological examination (OR, 1.8 [1.3–2.6]), and brain computed tomography (OR, 1.9 [1.4–2.6]), whereas no difference in therapeutic hypothermia was noted. Patients at tertiary centers were more often consulted by a cardiologist (OR, 8.6 [5.0–15]), had an echocardiography (OR, 2.8 [2.1–3.7]), and survivors more often had implantable cardioverter defibrillator’s implanted (OR, 2.1 [1.2–3.6]).

Conclusions—

Admissions to tertiary centers were associated with significantly higher survival after out-of-hospital cardiac arrest in patients without ST-segment–elevation myocardial infarction in the Copenhagen area even after adjustment for prognostic factors including comorbidity. Level-of-care seems higher in tertiary centers both in the early phase, during the intensive care unit admission, and in the workup before discharge. The varying level-of-care may contribute to the survival difference; however, differences in comorbidity do not seem to matter significantly.

Changes in pre- and in-hospital management and outcomes for out-of-hospital cardiac arrest between 2002 and 2012 in Kanto, Japan: the SOS-KANTO 2012 Study

Aim

The current study compares pre- and in-hospital management and outcomes of out-of-hospital cardiac arrest cases between 2002 and 2012 in the Kanto region of Japan.

Methods

We compared the data collected for the SOS-KANTO study project in 2002 and 2012. We included adult patients (aged >18 years) who experienced bystander-witnessed out-of-hospital cardiac arrest of cardiac etiology. The outcomes were as follows: proportion of favorable neurological outcomes at 1 month, bystander cardiopulmonary resuscitation provision, and pre- and postresuscitation treatment administration.

Results

Of 4,171 patients (1,982 in SOS-KANTO in 2002 and 2,189 in 2012), the proportion of those with favorable neurological outcomes at 1 month (4.8% versus 9.0%, P < 0.001), and bystander cardiopulmonary resuscitation rates increased significantly between 2002 and 2012 (24.5% versus 38.9%, P < 0.001). Although none were documented in 2002, 118 cases (5.4%) of layperson use of an automated external defibrillator were recorded in 2012. Relative to 2002, use of an i.v. line to provide fluid was more frequently attempted and carried out successfully by emergency medical service providers in 2012. Among cases in which return of spontaneous circulation was achieved, more postresuscitation treatment was provided in 2012 (13.3% versus 43.8%, P < 0.001) relative to that provided in 2002.

Conclusions

Proportions of bystander cardiopulmonary resuscitation, layperson use of automated external defibrillator, provision of prehospital adrenaline and postresuscitation treatment, and favorable neurological outcomes at 1 month increased significantly over 10 years in the Kanto region of Japan.

Post-Traumatic Stress Disorder among Cardiac Patients: Prevalence, Risk Factors, and Considerations for Assessment and Treatment

There is increasing awareness of the impact of post-traumatic stress disorder (PTSD) on physical health, particularly cardiovascular disease. We review the literature on the role of trauma in the development of cardiovascular risk factors and disease, aftermath of a cardiac event, and risk for recurrence in cardiac patients. We explore possible mechanisms to explain these relationships, as well as appropriate assessment and treatment strategies for this population. Our main conclusion is that screening and referral for appropriate treatments are important given the high prevalence rates of PTSD in cardiac populations and the associated impact on morbidity and mortality.

Enhancing approaches to therapeutic hypothermia in patients with sudden circulatory arrest

Cardiac arrest is common and causes substantial morbidity and mortality. Despite advances in prevention and resuscitation, most patients remain unconscious and survival remains poor. Therapeutic hypothermia (32-34 °C) has emerged as a potent neuroprotective modality following resuscitation. In early clinical trials, application of therapeutic hypothermia improved survival in patients with ventricular fibrillation (VF), which led to the recommended use of therapeutic hypothermia for patients resuscitated from VF. However, two recent clinical trials have challenged some assumptions. First, the use of paramedic-initiated rapid infusion of cold crystalloids as a mean to achieve faster cooling rates after resuscitation in patients with and without VF arrest did not improve survival. Second, once patients were admitted to the hospital, targeting their temperature to 33 versus 36 °C for 36 h (in addition to active hyperthermia prevention) after out-of-hospital cardiac arrest did not to change clinical outcomes, suggesting that 36 °C may represent the target temperature instead of temperatures of less than 34 °C.

Clinical outcome after a reactive hypothermic EEG following cardiac arrest

BACKGROUND

Reactive electroencephalography (EEG) background during therapeutic hypothermia (TH) is related to favorable prognosis after cardiac arrest (CA), but its predictive value is not 100 %. The aim of this study was to investigate outcome predictors after a first reactive EEG recorded during TH after CA.

METHODS

We studied a cohort of consecutive comatose adults admitted between February 2008 and November 2012, after successful resuscitation from CA, selecting patients with reactive EEG during TH. Outcome was assessed at three months, and categorized as survivors and non-survivors (no patient was in vegetative state). Demographics, clinical variables, EEG features, serum neuron-specific enolase (NSE) and procalcitonin, were compared using uni- and multivariable analyses.

RESULTS

A total of 290 patients were treated with TH after cardiac arrest; 146 had an EEG during TH, which proved reactive in 90 of them; 77 (86 %) survived and 13 (14 %) died (without recovery from coma). The group of non-survivors had a higher occurrence of discontinuous EEG (p = 0.006; multivariate analysis p = 0.026), and a higher serum NSE peak (p = 0.021; multivariate analysis p = 0.014); conversely, demographics, and other clinical variables including serum procalcitonin did not differ.

CONCLUSIONS

A discontinuous EEG and high serum NSE are associated with mortality after CA in patients with poor outcome despite a reactive hypothermic EEG. This suggests more severe cerebral damage, but not to higher extent of systemic disease.

Prolonged induced hypothermia in hemorrhagic shock is associated with decreased muscle metabolism: a nuclear magnetic resonance-based metabolomics study

Hemorrhagic shock is a leading cause of trauma-related death in war and is associated with significant alterations in metabolism. Using archived serum samples from a previous study, the purpose of this work was to identify metabolic changes associated with induced hypothermia in a porcine model of hemorrhagic shock. Twelve Yorkshire pigs underwent a standardized hemorrhagic shock and resuscitation protocol to simulate battlefield injury with prolonged evacuation to definitive care in cold environments. Animals were randomized to receive either hypothermic (33°C) or normothermic (39°C) limited resuscitation for 8 h, followed by standard resuscitation. Proton nuclear magnetic resonance spectroscopy was used to evaluate serum metabolites from these animals at intervals throughout the hypothermic resuscitation period. Animals in the hypothermic group had a significantly higher survival rate (P = 0.02) than normothermic animals. Using random forest analysis, a difference in metabolic response between hypothermic and normothermic animals was identified. Hypothermic resuscitation was characterized by decreased concentrations of several muscle-related metabolites including taurine, creatine, creatinine, and amino acids. This study suggests that a decrease in muscle metabolism as a result of induced hypothermia is associated with improved survival.

Early postresuscitation hypotension is associated with increased mortality following pediatric cardiac arrest

OBJECTIVE

To describe the association of systolic hypotension during the first 6 hours after successful resuscitation from pediatric cardiopulmonary arrest with in-hospital mortality.

DESIGN

Retrospective cohort study.

SETTING

Fifteen children's hospitals associated with the Pediatric Emergency Care Applied Research Network.

PATIENTS

Patients between 1 day and 18 years old who had a cardiopulmonary arrest, received chest compressions more than 1 minute, had a return of spontaneous circulation more than 20 minutes, and had a systolic blood pressure documented within 6 hours of arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three hundred eighty-three patients had complete data for analysis. Patients with a documented minimum systolic blood pressure less than fifth percentile for age and sex within the first 6 hours following return of spontaneous circulation were considered to have early postresuscitation hypotension. Two hundred fourteen patients (56%) had early postresuscitation hypotension. One hundred eighty-four patients (48%) died prior to hospital discharge. After controlling for patient and cardiopulmonary arrest characteristics, hypotension in the first 6 hours following return of spontaneous circulation was associated with a significantly increased odds of in-hospital mortality (adjusted odds ratio = 1.71; 95% CI, 1.02-2.89; p = 0.042) and odds of unfavorable outcome (adjusted odds ratio = 1.83; 95% CI, 1.06-3.19; p = 0.032).

CONCLUSIONS

In the first 6 hours following successful resuscitation from pediatric cardiac arrest, systolic hypotension was documented in 56% and was associated with a higher rate of in-hospital mortality and worse hospital discharge neurologic outcomes.

Early bispectral index and sedation requirements during therapeutic hypothermia predict neurologic recovery following cardiac arrest

OBJECTIVES

To test the hypothesis that low bispectral index scores and low sedative requirements during therapeutic hypothermia predict poor neurologic outcome.

DESIGN

Observational study of a prospectively collected cohort.

SETTING

Cardiovascular ICU.

PATIENTS

One hundred sixty consecutive cardiac arrest patients treated with therapeutic hypothermia.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Eighty-four of the 141 subjects (60%) who survived hypothermia induction were discharged from the ICU with poor neurologic outcome, defined as a cerebral performance category score of 3, 4, or 5. These subjects had lower bispectral index (p < 0.001) and sedative requirements (p < 0.001) during hypothermia compared with the 57 subjects discharged with good outcome. Early prediction of neurologic recovery was best 7 hours after ICU admission, and median bispectral index scores at that time were 31 points lower in subjects discharged with poor outcome (11 [interquartile range, 4-29] vs 42 [37-49], p < 0.001). Median sedation requirements decreased by 17% (interquartile range, -50 to 0%) 7 hours after ICU admission in subjects with poor outcome but increased by 50% (interquartile range, 0-142%) in subjects with good outcome (p < 0.001). Each 10-point decrease in bispectral index was independently associated with a 59% increase in the odds of poor outcome (95% CI, 32-76%; p < 0.001). The model including bispectral index and sedative requirement correctly reclassified 15% of subjects from good to poor outcome and 1% of subjects from poor to good outcome. The model incorrectly reclassified 1% of subjects from poor to good outcome but did not incorrectly reclassify any from good to poor outcome.

CONCLUSIONS

Bispectral index scores and sedative requirements early in the course of therapeutic hypothermia improve the identification of patients who will not recover from brain anoxia. The ability to accurately predict nonrecovery after cardiac arrest could facilitate discussions with families, reduce patient suffering, and limit use of ICU resources in futile cases.

Hospital variation in survival trends for in-hospital cardiac arrest

Background

During the past decade, survival after in‐hospital cardiac arrest has improved markedly. It remains unknown whether the improvement in survival has occurred uniformly at all hospitals or was driven by large improvements at only a few hospitals.

Methods and Results

We identified 93 342 adults with an in‐hospital cardiac arrest at 231 hospitals in the Get With The Guidelines^®‐Resuscitation registry during 2000–2010. Using hierarchical regression models, we evaluated hospital‐level trends in survival to discharge. Mean age was 66 years, 59% were men, and 21% were black. Between 2000 and 2010, there was a significant decrease in age, prevalence of heart failure and myocardial infarction, and cardiac arrests due to shockable rhythms (P<0.001 for all) and an increase in prevalence of sepsis, respiratory insufficiency, renal insufficiency, intensive care unit location, and mechanical ventilation before arrest (P<0.001 for all). After adjustment for temporal trends in baseline characteristics, hospital rates of in‐hospital cardiac arrest survival improved by 7% per year (odds ratio [OR] 1.07, 95% CI 1.06 to 1.08, P<0.001). Improvement in survival varied markedly and ranged from 3% in the bottom hospital quartile to 11% in the top hospital quartile. Compared with minor teaching hospitals (OR 1.04, 95% CI 1.02 to 1.06), hospital rate of survival improvement was greater at major teaching (OR 1.08, 95% CI 1.06 to 1.10) and nonteaching hospitals (OR 1.07, 95% CI 1.05 to 1.09, P value for interaction=0.03).

Conclusion

Although in‐hospital cardiac arrest survival has improved during the past decade, the magnitude of improvement varied across hospitals. Future studies are needed to identify hospital processes that have led to the largest improvement in survival.

[Epidemiology, prognostic data of cardiac arrest in 2014]

Epidemiological data on the incidence, the survival and the prognostic factors of cardiac arrest (CA) are often heterogeneous. However, recent advances in methodology and research have improved the knowledge on that topic. The prognosis of victims CA depends on the initial patient's characteristics, the circumstances of the CA and the quality of the management. As a result, the subsequent outcome of these patients relies on the efficiency of the chain of survival: prompt alert, bystander cardiopulmonary resuscitation and early defibrillation, the advanced care life support provided by the emergency medical services and the integration of in-hospital care. Other parameters are also likely to influence the prognosis (such as the system of care or the environment) though their assessment remains incomplete. More important, factors potentially affecting the long-term outcome are currently very less investigated. Finally, despite the potential improvements in the management of these patients for some years now, the temporal trends of the overall survival appear fairly stable. The transition in the profile of patients could partly explain the absence of clear effect on survival.

Therapeutic hypothermia after in-hospital cardiac arrest: a critique

More than 210,000 in-hospital cardiac arrests occur annually in the United States. Use of moderate therapeutic hypothermia (TH) in comatose survivors after return of spontaneous circulation following out-of-hospital cardiac arrest (OOH-CA) caused by ventricular fibrillation or pulseless ventricular tachycardia is recommended strongly by many professional organizations and societies. The use of TH after cardiac arrest associated with nonshockable rhythms and after in-hospital cardiac arrest (IH-CA) is recommended to be considered by these same organizations and is being applied widely. The use in these latter circumstances is based on an extrapolation of the data supporting its use after out-of-hospital cardiac arrest associated with shockable rhythms. The purpose of this article is to review the limitations of existing data supporting these extended application of TH after cardiac arrest and to suggest approaches to this dilemma. The data supporting its use for OOH-CA appear to this author, and to some others, to be rather weak, and the data supporting the use of TH for IH-CA appear to be even weaker and to include no randomized controlled trials (RCTs) or supportive observational studies. The many reasons why TH might be expected to be less effective following IH-CA are reviewed. The degree of neurologic injury may be more severe in many of these cases and, thus, may not be responsive to TH as currently practiced following OOH-CA. The potential adverse consequences of the routine use of TH for IH-CA are listed and include complications associated with TH, interference with diagnostic and interventional therapy, and use of scarce personnel and financial resources. Most importantly, it inhibits the ability of researchers to conduct needed RCTs. The author believes that the proper method of providing TH in these cases needs to be better defined. Based on this analysis the author concludes that TH should not be used indiscriminantly following most cases of IH-CA, and instead clinicians should concentrate their efforts in conducting high-quality large RCTs or large-scale, well-designed prospective observation studies to determine its benefits and identify appropriate candidates.