Serum neuron-specific enolase as early predictor of outcome after cardiac arrest

A locally optimised machine learning approach to early prognostication of long-term neurological outcomes after out-of-hospital cardiac arrest

Background

Out-of-hospital cardiac arrest (OHCA) represents a major burden for society and health care, with an average incidence in adults of 67 to 170 cases per 100,000 person-years in Europe and in-hospital survival rates of less than 10%. Patients and practitioners would benefit from a prognostication tool for long-term good neurological outcomes.

Objective

We aim to develop a machine learning (ML) pipeline on a local database to classify patients according to their neurological outcomes and identify prognostic features.

Methods

We collected clinical and biological data consecutively from 595 patients who presented OHCA and were routed to a single regional cardiac arrest centre in the south of France. We applied recursive feature elimination and ML analyses to identify the main features associated with a good neurological outcome, defined as a Cerebral Performance Category score less than or equal to 2 at six months post-OHCA.

Results

We identified 12 variables 24 h after admission, capable of predicting a six-month good neurological outcome. The best model (extreme gradient boosting) achieved an AUC of 0.96 and an accuracy of 0.92 in the test cohort.

Conclusion

We demonstrated that it is possible to build accurate, locally optimised prediction and prognostication scores using datasets of limited size and breadth. We proposed and shared a generic machine-learning pipeline which allows external teams to replicate the approach locally.

Longitudinal serum neurofilament light kinetics in post-anoxic encephalopathy

Serum neurofilament light (sNfL) is a promising marker of outcome after cardiac arrest, but its kinetics are unclear. We prospectively measured sNfL concentrations in 62 patients at 0, 1, 3, 5, 7 and 10 days after cardiac arrest. Survivors and non-survivors had similar sNfL at admission (14.2 [8.6-21.9] vs. 22.5 [14.2-46.9] pg/mL) but largely different at 24 h (16.4 [10.2-293] vs. 464.3 [151.8-1658.2], respectively). The AUC for sNfL concentrations predicting death was above 0.95 from Day 1 to 10 (highest on Day 3). Late sNfL measurements may exert prognostic value, especially when early samples are unavailable or prognosis remains unclear.

Effect of Hemolysis Regarding the Characterization and Prognostic Relevance of Neuron Specific Enolase (NSE) after Cardiopulmonary Resuscitation with Extracorporeal Circulation (eCPR)

BACKGROUND

Hemolysis, a common adverse event associated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO), may affect neuron-specific enolase (NSE) levels and potentially confound its prognostic value in predicting neurological outcomes in resuscitated patients without return of spontaneous circulation (ROSC) that require extracorporeal cardiopulmonary resuscitation (eCPR). Therefore, a better understanding of the relationship between hemolysis and NSE levels could help to improve the accuracy of NSE as a prognostic marker in this patient population.

METHODS

We retrospectively analyzed the records of patients who received a VA-ECMO for eCPR between 2004 and 2021 and were treated in the medical intensive care unit (ICU) of the University Hospital Jena. The outcome was measured clinically by using the Cerebral Performance Category Scale (CPC) four weeks after eCPR. The serum concentration of NSE (baseline until 96 h) was analyzed by enzyme-linked immunosorbent assay (ELISA). To evaluate the ability of individual NSE measurements to discriminate, receiver operating characteristic (ROC) curves were calculated. Serum-free hemoglobin (fHb, baseline until 96 h) served as a marker for identifying a confounding effect of parallel hemolysis.

RESULTS

190 patients were included in our study. A total of 86.8% died within 4 weeks after ICU admission or remained unconscious (CPC 3-5), and 13.2% survived with a residual mild to moderate neurological deficit (CPC 1-2). Starting 24h after CPR, NSE was significantly lower and continued to decrease in patients with CPC 1-2 compared to the group with an unfavorable outcome of CPC 3-5. In addition, when evaluating on the basis of receiver operating characteristic curves (ROC), relevant and stable area under the curve (AUC) values for NSE could be calculated (48 h: 0.85 // 72 h: 0.84 // 96 h: 0.80; p < 0.01), and on the basis of a binary logistic regression model, relevant odds ratios for the NSE values were found even after adjusting for fHb regarding the prediction of an unfavorable outcome of CPC 3-5. The respective adjusted AUCs of the combined predictive probabilities were significant (48 h: 0.79 // 72 h: 0.76 // 96 h: 0.72; p ≤ 0.05).

CONCLUSIONS

Our study confirms NSE as a reliable prognostic marker for poor neurological outcomes in resuscitated patients receiving VA-ECMO therapy. Furthermore, our results demonstrate that potential hemolysis during VA-ECMO does not significantly impact NSE's prognostic value. These findings are crucial for clinical decision making and prognostic assessment in this patient population.

Early prognostic impact of serum sodium level among out-of-hospital cardiac arrest patients: a nationwide multicentre observational study in Japan (the JAAM-OHCA registry)

Dysnatremia is an electrolytic disorder commonly associated with mortality in various diseases. However, little is known about dysnatremia in out-of-hospital cardiac arrest (OHCA) cases. Here, we investigated the association between serum sodium level on hospital arrival and neurological outcomes after OHCA. This nationwide hospital-based observational study (The Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry) enrolled patients with OHCA between 2014 and 2017. We included adult patients aged ≥ 18 years with non-traumatic OHCA who achieved return of spontaneous circulation (ROSC) and whose serum sodium level on hospital arrival was available. Based on the serum sodium level, patients were divided into three levels: hyponatremia (Na < 135 mEq/L), normal sodium level (Na ≥ 135 or ≤ 145 mEq/L), and hypernatremia (Na > 145 mEq/L). The primary outcome was 1-month survival with favourable neurological outcomes. Altogether, 34 754 patients with OHCA were documented, and 5160 patients with non-traumatic OHCA and who achieved ROSC were eligible for our analyses. The proportion of favourable neurological outcomes was highest in patients with normal sodium levels at 17.6% (677/3854), followed by patients with hyponatremia at 8.2% (57/696) and patients with hypernatremia at 5.7% (35/610). Moreover, hyponatremia and hypernatremia were associated with a decreased probability of favourable neurological outcomes compared with normal sodium level (vs. hyponatremia, adjusted odds ratio [AOR] 0.97, 95% confidence interval [CI] 0.95-0.99; vs. hypernatremia, AOR 0.96, 95% CI 0.94-0.98). Hypo- and hypernatremia on hospital arrival were associated with a decreased probability of favourable neurological outcomes in patients with non-traumatic OHCA who achieved ROSC.

Brain Natriuretic Peptide as a Marker of Adverse Neurological Outcomes Among Survivors of Cardiac Arrest

BACKGROUND

Neurological prognosis after cardiac arrest remains ill-defined. Plasma brain natriuretic peptide (BNP) may relate to poor neurological prognosis in brain-injury patients, though it has not been well studied in survivors of cardiac arrest.

METHODS

We performed a retrospective review and examined the association of BNP with mortality and neurological outcomes at discharge in a cohort of cardiac arrest survivors enrolled from January 2012 to December 2016 at the Wake Forest Baptist Hospital, in North Carolina. Cerebral performance category (CPC) and modified Rankin scales were calculated from the chart based on neurological evaluation performed at the time of discharge. The cohort was subdivided into quartiles based on their BNP levels after which multivariable adjusted logistic regression models were applied to assess for an association between BNP and poor neurological outcomes as defined by a CPC of 3 to 4 and a modified Rankin scale of 4 to 5.

RESULTS

Of the 657 patients included in the study, 254 patients survived until discharge. Among these, poor neurological status was observed in 101 (39.8%) patients that had a CPC score of 3 to 4 and 97 patients (38.2%) that had a modified Rankin scale of 4 to 5. Mean BNP levels were higher in patients with poor neurological status compared to those with good neurological status at discharge (P = .03 for CPC 3-4 and P = .02 for modified Rankin score 4-5). BNP levels however, did not vary significantly between patients that survived and those that expired (P = .22). BNP did emerge as a significant discriminator between patients with severe neurological disability at discharge when compared to those without. The area under the curve for BNP predicting a modified Rankin score of 4 to 5 was 0.800 (95% confidence interval [CI] 0.756-0.844, P < .001) and for predicting CPC 3 to 4 was 0.797 (95% CI 0.756-0.838, P < .001). BNP was able to significantly improve the net reclassification index and integrated discriminatory increment (P < .05). BNP was not associated with long-term all-cause mortality (P > .05).

CONCLUSIONS

In survivors of either inpatient or out-of-hospital cardiac arrest, increased BNP levels measured at the time of arrest predicted severe neurological disability at discharge. We did not observe an independent association between BNP levels and long-term all-cause mortality. BNP may be a useful biomarker for predicting adverse neurological outcomes in survivors of cardiac arrest.

Serum neuron-specific enolase measurement for neuro-prognostication post out-of-hospital cardiac arrest: Determination of the optimum testing strategy in routine clinical use

Background

Measurement of serum neuron-specific enolase (NSE) for neuro-prognostication post out-of-hospital cardiac arrest (OHCA) is recommended by international guidelines. There is, however, a lack of consensus regarding the cut-offs and time points to use. In addition, NSE is particularly susceptible to haemolysis interference. This study aimed to define the optimum NSE testing strategy to support the intensive care unit (ICU).

Methods

Patients admitted to ICU post-OHCA over 16 months had NSE measured. The outcome was survival to ICU discharge. NSE at 0 h, 24 h, 48 h, 72 h and change in NSE (ΔNSE) were assessed for prognostic accuracy using receiver operator characteristic curve analysis. The magnitude of haemolysis interference was quantified by spiking haemolysate into paired serum.

Results

There is a consistent linear increase in NSE with increasing haemolysis, independent of baseline NSE concentration. A haemolysis index acceptance threshold was defined as 20. There were 142 patients, and 82 survived to ICU discharge. The NSE parameter with best predictive performance was ΔNSE at 48 h, which had an area under the receiver operator characteristic curve of 0.91. A cut-off of >0 μg/L at this time point had sensitivity of 80% and specificity of 97% for predicting death on ICU. When patients who died of non-neurological causes were removed, the sensitivity increased to 91%.

Conclusions

Application of a stringent haemolysis interference threshold and measurement of NSE at two time points enabled us to achieve excellent discrimination. Increasing NSE over the first 48 h, suggestive of an ongoing reperfusion injury to the brain, is a strong predictor of poor outcome.

Serum neurofilament light chain as a prognostic marker in postanoxic encephalopathy

Functional outcome in patients with postanoxic encephalopathy after cardiac arrest (CA) often remains unclear, and there is a strong need of new prognostication measures. We aimed at investigating serum neurofilament light (NfL) chain concentration in patients with a postanoxic encephalopathy after CA and its prognostic potential. Serum samples were prospectively collected at different time points after CA in consecutive patients admitted to the intensive care unit (ICU) of Ticino Cardiocentre (Lugano, Switzerland) between June 2017 and March 2018. Serum NfL concentration was measured using a single molecule array (SIMOA) assay. The association of NfL levels with time to return of spontaneous circulation (ROSC), serum neuronal specific enolase (NSE) concentration, time between CA and sample collection, electroencephalogram (EEG) pattern and clinical outcome (death status at one month) were explored. Fourteen patients experiencing 15 CAs were included in the study (median age = 58 (57-68) years, 8 males). Median serum NfL concentration was 1027.0 (25.5-6033.7) pg/ml. There were positive associations between serum NfL and time to ROSC (rho = 0.60, p < 0.0001), NSE concentration (rho = 0.76, p < 0.0001), and severity of brain damage as estimated by EEG, with the highest concentrations measured in patients with suppressed electrical activity (14,954.0 [9006.0-25,364.0] pg/ml). Neurofilament light concentration remained high in samples collected up to 17 days after CA. Median NfL levels were higher among dead than alive patients at one month (6401.7 [3768.5-15,573.3] vs 25.5 [25.2-75.4] pg/ml). High NfL levels performed better than NSE in predicting death status at one month (NfL area under the curve (AUC) = 0.98, 95% confidence interval (CI) = 0.94-1.00; NSE AUC = 0.80, 95% CI = 0.67-0.94). These results support the potential inclusion of serum NfL in the battery of prognostication measures to be used in patients with postanoxic encephalopathy in ICU settings. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

Management of Out-of-Hospital Cardiac Arrest Complicating Acute Coronary Syndromes

PURPOSE OF THE REVIEW

Out-of-hospital cardiac arrest (OHCA) complicating acute coronary syndromes (ACS) continues to carry a high rate of morbidity and mortality despite significant advances in EMS and interventional cardiology services. In this review, we discuss an evidence-based approach to the initial care and management of patients with OHCA complicating ACS from the pre-hospital response and initial resuscitation strategy, to advanced therapies such as coronary angiography, targeted-temperature management, neuro-prognostication, and care of the post-arrest patient.

RECENT FINDINGS

Early recognition of cardiac arrest and prompt initiation of bystander CPR are the most important factors associated with improved survival. A comprehensive and coordinated approach to in-hospital management, including PCI, targeted temperature management, critical care, and hemodynamic support represents a significant critical link in the chain of survival. OHCA complicated by ACS continues to be one of the most challenging disease states facing healthcare practitioners and maintains a high mortality rate despite substantial advancements in healthcare delivery. A comprehensive approach to in-hospital management and further exploration of novel interventions, including ECMO, may yield opportunities to optimize care and improve outcomes for cardiac arrest patients.

Serum potassium level on hospital arrival and survival after out-of-hospital cardiac arrest: The CRITICAL study in Osaka, Japan

BACKGROUND

Little is known about the association between serum potassium level on hospital arrival and neurological outcome after out-of-hospital cardiac arrest (OHCA). We investigated whether the serum potassium level on hospital arrival had prognostic indications for patients with OHCA.

METHODS

This prospective, multicenter observational study conducted in Osaka, Japan (CRITICAL study) enrolled consecutive patients with OHCA transported to 14 participating institutions from 2012 to 2016. We included adult patients aged ⩾18 years with OHCA of cardiac origin who achieved return of spontaneous circulation and whose serum potassium level on hospital arrival was available. Based on the serum potassium level, patients were divided into four quartiles: Q1 (K ⩽3.8 mEq/L), Q2 (3.8< K⩽4.5 mEq/L), Q3 (4.5< K⩽5.6 mEq/L) and Q4 (K >5.6 mEq/L). The primary outcome was one-month survival with favorable neurological outcome, defined as cerebral performance category scale 1 or 2.

RESULTS

A total of 9822 patients were registered, and 1516 of these were eligible for analyses. The highest proportion of favorable neurological outcome was 44.8% (189/422) in Q1 group, followed by 30.3% (103/340), 11.7% (44/375) and 4.5% (17/379) in the Q2, Q3 and Q4 groups, respectively (p<0.001). In the multivariable analysis, the proportion of favorable neurological outcome decreased as the serum potassium level increased (p<0.001).

CONCLUSIONS

High serum potassium level was significantly and dose-dependently associated with poor neurological outcome. Serum potassium on hospital arrival would be one of the effective prognostic indications for OHCA achieving return of spontaneous circulation.

Lipidomics Detection of Brain Cardiolipins in Plasma Is Associated With Outcome After Cardiac Arrest

OBJECTIVES

Brain mitochondrial dysfunction limits neurologic recovery after cardiac arrest. Brain polyunsaturated cardiolipins, mitochondria-unique and functionally essential phospholipids, have unprecedented diversification. Since brain cardiolipins are not present in plasma normally, we hypothesized their appearance would correlate with brain injury severity early after cardiac arrest and return of spontaneous circulation.

DESIGN

Observational case-control study.

SETTING

Two medical centers within one city.

PARTICIPANTS (SUBJECTS)

We enrolled 41 adult cardiac arrest patients in whom blood could be obtained within 6 hours of resuscitation. Two subjects were excluded following outlier analysis. Ten healthy subjects were controls. Sprague-Dawley rats were used in asphyxial cardiac arrest studies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We developed a high-resolution liquid chromatography/mass spectrometry method and determined cardiolipins speciation in human brain, heart, and plasma within 6 hours of (return of spontaneous circulation) from 39 patients with cardiac arrest, 5 with myocardial infarction, and 10 healthy controls. Cerebral score was derived from brain-specific cardiolipins identified in plasma of patients with varying neurologic injury and outcome. Using a rat model of cardiac arrest, cardiolipins were quantified in plasma, brain, and heart. Human brain exhibited a highly diverse cardiolipinome compared with heart that allowed the identification of brain-specific cardiolipins. Nine of 26 brain-specific cardiolipins were detected in plasma and correlated with brain injury. The cerebral score correlated with early neurologic injury and predicted discharge neurologic/functional outcome. Cardiolipin (70:5) emerged as a potential point-of-care marker predicting injury severity and outcome. In rat cardiac arrest, a significant reduction in hippocampal cardiolipins corresponded to their release from the brain into systemic circulation. Cerebral score was significantly increased in 10 minutes versus 5 minutes no-flow cardiac arrest and naïve controls.

CONCLUSIONS

Brain-specific cardiolipins accumulate in plasma early after return of spontaneous circulation and proportional to neurologic injury representing a promising novel biomarker.

Outcome prediction with serial neuron-specific enolase and machine learning in anoxic-ischaemic disorders of consciousness

BACKGROUND

The continuation of life-sustaining therapy in critical care patients with anoxic-ischemic disorders of consciousness (AI-DOC) depends on prognostic tests such as serum neuron-specific enolase (NSE) concentration levels.

OBJECTIVES

To apply predictive models using machine learning methods to examine, one year after onset, the prognostic power of serial measurements of NSE in patients with AI-DOC. To compare the discriminative accuracy of this method to both standard single-day, absolute, and difference-between-days, relative NSE levels.

METHODS

Classification algorithms were implemented and K-nearest neighbours (KNN) imputation was used to avoid complete case elimination of patients with missing NSE values. Non-imputed measurements from Day 0 to Day 6 were used for single day and difference-between-days.

RESULTS

The naive Bayes classifier on imputed serial NSE measurements returned an AUC of (0.81±0.07) for n=126 patients (100 poor outcome). This was greater than logistic regression (0.73±0.08) and all other classifiers. Naive Bayes gave a specificity and sensitivity of 96% and 49%, respectively, for an (uncalibrated) probability decision threshold of 90%. The maximum AUC for a single day was Day 3 (0.75) for a subset of n=79 (61 poor outcome) patients, and for differences between Day 1 and Day 4 (0.81) for a subset of n=46 (39 poor outcome) patients.

CONCLUSION

Imputation avoided the elimination of patients with missing data and naive Bayes outperformed all other classifiers. Machine learning algorithms could detect automatically discriminatory features and the overall predictive power increased from standard methods due to the larger data set.

CODE AVAILABILITY

Data analysis code is available under GNU at: https://github.com/emilymuller1991/outcome_prediction_nse.

[Relationship between body temperature, neuron-specific enolase, and clinical course in patients after out-of-hospital cardiac arrest]

BACKGROUND

According to ILCOR (International Liaison Committee on Resuscitation) recommendations (released in 2003), use of therapeutic hypothermia is recommended for unconscious adult patients who have survived a cardiac arrest regardless of the initial monitored cardiac rhythm. Thereby, the treatment goal is to achieve and maintain a body temperature of 32-34 °C for a period of 12-24 h. According to the October 2015 recommendations of the European Resuscitation Council (ERC), targeted temperature management (TTM) remains part of treatment, but, as an option, it is advised that the targeted body temperature be 36 °C rather than 32-34 °C.

PATIENT POPULATION AND METHODS

For a non-randomized retrospective observational study, a total of 149 patients were treated with cardiopulmonary resuscitation (CPR) between May 1999 and September 2009. For the first 4 days after CPR, data associated with demography, resuscitation, therapy (temperature course, neuron-specific enolase [NSE]) and clinical-neurological development (Glasgow Outcome Scale [GOS]) were collected. In the study, patients receiving mild hyperthermia were compared with those who did not receive hypothermia.

RESULTS

Of the 149 patients included, 90 were treated with mild hypothermia (as decided by the attending physician), while 59 received no hypothermia therapy. Assessment reveals that mild hypothermia positively influences clinical-neurological progression, but not survival. On day three and four, patients with an unfavorable neurological progression exhibited significantly increased serum levels of NSE (day 4: 108.7 ± 137.3 ng/ml versus 25.5 ± 15.4 ng/ml). Patients receiving hypothermia showed lower average NSE levels compared with persons not receiving hypothermia. Furthermore, during the first 4 days, their NSE values tended to increase slower (NSE value at day 4: 55.9 ± 64.9 ng/ml versus 129.9 ± 174.9 ng/ml). The best cut-off-value for an unfavorable neurological result was 74.2 ng/ml at day four (specificity 100%, sensitivity 48.6%). For the group of patients who received hypothermia, the best cut-off-value was 74.2 ng/ml at day four (specificity 100%, sensitivity 40.9%), and, for the comparison group, best cut-off-value was 25.5 ng/ml at day three (specificity 100%, sensitivity 88.2%).

CONCLUSION

After out-of-hospital resuscitation, there is a trend for improved clinical-neurological progression with mild hypothermia but it does not influence the prognostic significance of serum NSE. After assessment of available data, it is not possible to recommend uniform cut-off values for patients who received mild therapeutic hypothermia and for those who did not receive hypothermia treatment.

Neurologic and cognitive outcomes associated with the clinical use of xenon: a systematic review and meta-analysis of randomized-controlled trials

BACKGROUND

Xenon has been shown to have positive neurologic effects in various pre-clinical models. This study systematically reviewed the randomized-controlled trials (RCTs) investigating neurologic and cognitive outcomes associated with the clinical use of xenon.

METHODS

We searched PubMed, CENTRAL, EMBASE, CINAHL, elibrary.ru (for Russian studies), Google Scholar (for Russian studies), and Wanfang (for Chinese studies) for appropriate RCTs comparing neurologic or cognitive outcomes after clinical use of xenon with control treatment or with other anesthetic agents.

RESULTS

Seventeen RCTs met the inclusion criteria. Two studies investigated the effects of xenon plus therapeutic hypothermia to treat neonatal asphyxia or out-of-hospital cardiac arrest. Compared with therapeutic hypothermia alone, xenon and therapeutic hypothermia reduced cerebral white matter abnormalities after cardiac arrest but had no effect on neurocognitive outcome and mortality. Xenon had no added value when used to treat neonatal asphyxia. Thirteen RCTs compared neurocognitive effects of xenon with other anesthetic agents in surgical patients. While xenon may be associated with improved short-term (< three hours) cognitive outcome, no medium-term (six hours to three months) advantage was observed, and longer-term data are lacking. No differences in biochemical (S-100β, neuron-specific enolase) and neuropsychologic (attentional performance) outcomes were found with xenon compared with other anesthetic drugs. Finally, two studies suggest that brief, intermittent administration of sub-anesthetic doses of xenon to patients during the acute phase of substance withdrawal may improve neurocognitive outcomes.

CONCLUSIONS

Despite promising pre-clinical results, the evidence for positive clinical neurologic and cognitive outcomes associated with xenon administration is modest. Nevertheless, there is some evidence to suggest that xenon may be associated with better neurologic outcomes compared with the standard of care therapy in certain specific clinical situations. More clinical trials are needed to determine any potential benefit linked to xenon administration.

Elevated Serum Glial Fibrillary Acidic Protein (GFAP) is Associated with Poor Functional Outcome After Cardiopulmonary Resuscitation

BACKGROUND

The neurological prognosis of patients after cardiopulmonary resuscitation (CPR) is difficult to assess. GFAP is an astrocytic intermediate filament protein released into bloodstream in case of cell death. We performed a prospective study aiming to compare the predictive potential of GFAP after resuscitation to the more widely used biomarker neuron-specific enolase (NSE).

METHODS

One hundred patients were included at 48 h (tolerance interval ±12 h) after cardiac arrest. A serum sample was collected immediately after study inclusion. We determined serum levels of GFAP and NSE by means of immunoassays. Primary outcome was the modified Glasgow outcome scale at 4 weeks. Values below four were considered as a poor functional outcome.

RESULTS

Median GFAP levels in poor outcome (n = 61) and good outcome (n = 39) patients were 0.03 μg/L (interquartile range 0.01-0.07 μg/L) and 0.02 μg/L (0.01-0.03 μg/L; p = 0.014), respectively. GFAP revealed a sensitivity of 60.7% and a specificity of 66.7% to predict a poor functional outcome. All patients having a GFAP level >0.08 µg/L had a poor functional outcome. For NSE, sensitivity was 44.3% and specificity was 100.0% for predicting a poor outcome. Multivariate regression analysis revealed GFAP, NSE, and the Karnofsky index to be independent predictors of outcome.

CONCLUSIONS

The release patterns of GFAP and NSE after CPR show differences. GFAP levels above 0.08 µg/L were associated with a poor outcome in all cases, and patients with strongly elevated values (>3 µg/L) consistently had severe brain damage on brain imaging. Both biomarkers independently contribute to outcome prediction after CPR.

Biochemical changes in the injured brain

Brain metabolism is an energy intensive phenomenon involving a wide spectrum of chemical intermediaries. Various injury states have a detrimental effect on the biochemical processes involved in the homeostatic and electrophysiological properties of the brain. The biochemical markers of brain injury are a recent addition in the armamentarium of neuro-clinicians and are being increasingly used in the routine management of neuro-pathological entities such as traumatic brain injury, stroke, subarachnoid haemorrhage and intracranial space occupying lesions. These markers are increasingly being used in assessing severity as well as in predicting the prognostic course of neuro-pathological lesions. S-100 protein, neuron specific enolase, creatinine phosphokinase isoenzyme BB and myelin basic protein are some of the biochemical markers which have been proven to have prognostic and clinical value in the brain injury. While S-100, glial fibrillary acidic protein and ubiquitin C terminal hydrolase are early biomarkers of neuronal injury and have the potential to aid in clinical decision-making in the initial management of patients presenting with an acute neuronal crisis, the other biomarkers are of value in predicting long-term complications and prognosis in such patients. In recent times cerebral microdialysis has established itself as a novel way of monitoring brain tissue biochemical metabolites such as glucose, lactate, pyruvate, glutamate and glycerol while small non-coding RNAs have presented themselves as potential markers of brain injury for future.

Global cerebral ischemia due to circulatory arrest: insights into cellular pathophysiology and diagnostic modalities

Circulatory arrest (CA) remains a major unresolved public health problem in the United States; the annual incidence of which is ~0.50 to 0.55 per 1000 population. Despite seminal advances in therapeutic approaches over the past several decades, brain injury continues to be the leading cause of morbidity and mortality after CA. In brief, CA typically results in global cerebral ischemia leading to delayed neuronal death in the hippocampal pyramidal cells as well as in the cortical layers. The dynamic changes occurring in neurons after CA are still unclear, and predicting these neurological changes in the brain still remains a difficult issue. It is hypothesized that the "no-flow" period produces a cytotoxic cascade of membrane depolarization, Ca²⁺ ion influx, glutamate release, acidosis, and resultant activation of lipases, nucleases, and proteases. Furthermore, during reperfusion injury, neuronal death occurs due to the generation of free radicals by interfering with the mitochondrial respiratory chain. The efficacy of many pharmacological agents for CA patients has often been disappointing, reflecting our incomplete understanding of this enigmatic disease. The primary obstacles to the development of a neuroprotective therapy in CA include uncertainties with regard to the precise cause(s) of neuronal dysfunction and what to target. In this review, we summarize our knowledge of the pathophysiology as well as specific cellular changes in brain after CA and revisit the most important neurofunctional, neuroimaging techniques, and serum biomarkers as potent predictors of neurologic outcome in CA patients.

Neuron specific enolase: a promising therapeutic target in acute spinal cord injury

Enolase is a multifunctional protein, which is expressed abundantly in the cytosol. Upon stimulatory signals, enolase can traffic to cell surface and contribute to different pathologies including injury, autoimmunity, infection, inflammation, and cancer. Cell-surface expression of enolase is often detected on activated macrophages, microglia/macrophages, microglia, and astrocytes, promoting extracellular matrix degradation, production of pro-inflammatory cytokines/chemokines, and invasion of inflammatory cells in the sites of injury and inflammation. Inflammatory stimulation also induces translocation of enolase from the cytosolic pool to the cell surface where it can act as a plasminogen receptor and promote extracellular matrix degradation and tissue damage. Spinal cord injury (SCI) is a devastating debilitating condition characterized by progressive pathological changes including complex and evolving molecular cascades, and insights into the role of enolase in multiple inflammatory events have not yet been fully elucidated. Neuronal damage following SCI is associated with an elevation of neuron specific enolase (NSE), which is also known to play a role in the pathogenesis of hypoxic-ischemic brain injury. Thus, NSE is now considered as a biomarker in ischemic brain damage, and it has recently been suggested to be a biomarker in traumatic brain injury (TBI), stroke and anoxic encephalopathy after cardiac arrest and acute SCI as well. This review article gives an overview of the current basic research and clinical studies on the role of multifunctional enolase in neurotrauma, with a special emphasis on NSE in acute SCI.

Fibroblast growth factor 23 (FGF-23) is an early predictor of mortality in patients with cardiac arrest

BACKGROUND

Post-cardiac arrest management has seen significant advances with profound improvements in survival and neurologic outcome. However, early prognostication after return of spontaneous circulation remains most challenging. Biomarkers have evolved as helpful tools in identifying patients who are at increased risk of adverse outcome. While fibroblast growth factor 23 (FGF-23) has recently emerged as a promising predictor of mortality in patients with cardiogenic shock, its role in risk stratification in post-resuscitation management remains unresolved.

METHODS

This study included 90 patients who had been resuscitated and transferred to the ICU of the University Hospital Heidelberg. Survivors and non-survivors were retrospectively analyzed for known prognostic biomarkers as well as FGF-23 serum levels 24h and 72 h post cardiac arrest (CA).

RESULTS

FGF-23 levels were significantly elevated in non-survivors compared to survivors. ROC analysis of FGF-23 levels at 24h and 72 h post CA yielded an AUC of 0.759 and 0.726, respectively, for prediction of overall survival after 6 months. FGF-23 levels remained as significant prognosticators after adjusting for age, renal function, and initial cardiac rhythm. FGF-23 levels did not show significant differences in patient outcome after stratification for cardiac origin of CA or left ventricular dysfunction. Furthermore, FGF-23 levels were moderately predictive of poor neurologic outcome in ROC analysis on day 1 and day 3 post CA with an AUC of 0.738 and 0.687, respectively.

CONCLUSION

This study demonstrates elevated FGF-23 serum levels to be potentially helpful in prediction of mortality and poor neurological outcome as early as 24h post cardiac arrest.

Neuron specific enolase and Glasgow motor score remain useful tools for assessing neurological prognosis after out-of-hospital cardiac arrest treated with therapeutic hypothermia

AIM OF THE STUDY

Identifying clinical, electrophysiological and biological predictors for 6-month neurological outcome in survivors at day 3 after cardiac arrest (CA) treated with therapeutic hypothermia (TH).

METHODS

We conducted a retrospective cohort study of adults comatose after out-of hospital CA treated with TH. All data were collected from medical charts and laboratory files.

RESULTS

Between January 2010 and March 2013, among the 130 analysed CA survivors, 27 (21%) had a good neurological outcome at 6 months and 103 (79%) had a poor neurological outcome, including 98 deaths. The Glasgow coma score motor response (GCS-M), pupillary reflexes and Neuron Specific Enolase (NSE) were the three best predictors of neurological outcome (P<0.0001). The area under the Receiver Operating Characteristic curve for NSE was 0.92 [0.84-0.99].

CONCLUSION

NSE values, GCS-M scores and pupillary reflexes are the best predictors of poor 6-month outcome after out-of-hospital CA treated with TH. Of these, NSE values have the best-isolated prognostic performance when above 28.8μg/L.

Neurologic aspects of cardiac emergencies

In this review, cardiac arrest is discussed, with a focus on neuroprognostication and the emerging data, with regard to identifying more accurate predictors of neurologic outcomes in the era of therapeutic hypothermia. Topics discussed include recent controversies with regard to targeted temperature management in comatose survivors of cardiac arrest; neurologic complications associated with surgical disease and procedures, namely aortic dissection, infective endocarditis, left ventricular assist devices, and coronary artery bypass grafting; and the cause, pathogenesis, and management of neurogenic stunned myocardium.

Ability of neuron-specific enolase to predict survival to hospital discharge after successful cardiopulmonary resuscitation

Background:

Accurate prediction of survival to hospital discharge in patients who achieve return of spontaneous circulation after cardiopulmonary resuscitation (CPR) has significant ethical and socioeconomic implications. We investigated the prognostic performance of serum neuron-specific enolase (NSE), a biochemical marker of ischemic brain injury, after successful CPR.

Methods:

In-hospital or out-of-hospital patients with nontraumatic normothermic cardiac arrest who achieved return of spontaneous circulation (ROSC) following at least 5 minutes of CPR were eligible. Neuron-specific enolase levels were assessed immediately, 6 hours, 12 hours and 2 days after ROSC. Subjects were followed to death or hospital discharge.

Results:

Seventeen patients (7 men, 10 women) were enrolled during a 1-year period. Median (range) NSE levels in survivors and non-survivors respectively were as follows: immediately after ROSC: 14.0 μg/L (9.1–51.4 μg/L) versus 25.9 μg/L (10.2–57.5 μg/L); 6 hours after ROSC: 15.2 μg/L (9.7–30.8 μg/L) versus 25.6 μg/L (12.7–38.2 μg/L); 12 hours after ROSC: 14.0 μg/L (8.6–32.4 μg/L) versus 28.5 μg/L (11.0–50.7 μg/L); and 48 hours after ROSC: 13.1 μg/L (7.8–29.5 μg/L) versus 52.0 μg/L (29.1–254.0 μg/L). Non-survivors had significantly higher NSE levels 48 hours after ROSC than surivors (p = 0.04) and showed a trend toward higher values during the entire time course following ROSC. An NSE concentration of &gt;30 μg/L 48 hours after ROSC predicted death with a high specificity (100%: 95% confidence interval [CI] 85%–100%), and a level of 29 μg/L or less at 48 hours predicted survival with a high specificity (100%: 95% CI 83%–100%).

Conclusions:

Serum NSE levels may have clinical utility for the prediction of survival to hospital discharge in patients after ROSC following CPR over 5 minutes in duration. This study is small, and our results are limited by wide confidence intervals. Further research on ability of NSE to facilitate prediction and clinical decision-making after cardiac arrest is warranted.

Serum neuron specific enolase - impact of storage and measuring method

Background

Neuron specific enolase (NSE) is a recognized biomarker for assessment of neurological outcome after cardiac arrest, but its reliability has been questioned. Our aim was to investigate what influence storage of samples and choice of measuring methods may have on levels of NSE in peripheral blood.

Methods

Two serum samples were drawn simultaneously from 51 hypothermia treated cardiac arrest patients. One sample (original sample) was analysed when collected, using the Diasorin-method (LIAISON®NSE, LNSE). The other sample was frozen, stored at −70°C (stored sample), and reanalysed in the same laboratory 4–7 years later using both the Diasorin method and a Roche-method (NSE Cobas e601, CNSE). In addition, a comparison of the two methods was performed on 29 fresh samples.

Results

The paired NSE results in original and stored samples were not significantly different, using the LNSE-method. The two methods produced significantly different results (p < 0.0001) on the paired, stored samples, with the CNSE method yielding higher values than the LNSE-method in 96% of samples. The CNSE method resulted in 36% higher values on average. In the method comparison on fresh samples, the CNSE-method generated on average 15% higher values compared to the LNSE-method, and the difference between the paired results was significant (p < 0.0001).

Conclusion

The CNSE method generated consistently higher NSE-values than the LNSE method and this difference was more pronounced when frozen samples were analysed. Tolerability for prolonged freezing was acceptable.

Association between oxidative stress index and post-CPR early mortality in cardiac arrest patients: A prospective observational study

Objective:

Cardiopulmonary resuscitation (CPR) is a series of lifesaving actions that improve the chance of survival following cardiac arrest (CA). Many clinical and laboratory parameters, such as the presence of asystole, out-of-hospital CPR, and duration of cardiac arrest, are associated with failed CPR in patients with CA. Asystole is a state of no cardiac electrical activity, along with the absence of contractions of the myocardium and absence of cardiac output. Oxidative stress index (OSI), which is the ratio of total oxidative status to total antioxidant status, increases by ischemia-reperfusion injury. We investigated whether OSI levels in patients with CA could predict early mortality after CPR.

Methods:

This study has a prospective observational cohort design. Five patients with a history of cancer, four patients who developed hemolysis in their blood, six patients who were transferred to our hospital from other hospitals, and six patients in whom blood samples for OSI could not be stored properly were excluded. Finally, a total of 90 in-hospital or out-of-hospital CA patients and 40 age- and sex-matched healthy volunteers as the control group were evaluated prospectively. The patients were classified according to the CPR response into a successful group (n=46) and a failed group (n=44). Comparisons between groups were performed using one-way ANOVA with post hoc analysis by Tukey’s HSD or independent samples t-test and the Kruskal-Wallis tests or Mann-Whitney U test for normally and abnormally distributed data, respectively. Also, we used chi-square test, Spearman’s correlation test, univariate and multible logistic regression analyses, and receiver operator characteristic curve analysis.

Results:

OSI was 3.0±4.0, 5.6±4.3, and 8.7±3.8 in the control group, the successful CPR group, and the failed CPR group, respectively (p<0.001 for the 2 comparisons). OSI on admission, ischemia-modified albumin, presence of asystole, mean duration of cardiac arrest, out-of-hospital CPR, pH, and potassium and sodium levels were found to have prognostic significance in the univariate analysis. In the multivariate logistic regression model, OSI on admission (OR=1.325, p=0.003), ischemia-modified albumin (OR=1.008, p=0.005), presence of asystole (OR=13.576, p<0.001), and sodium level (OR=1.132, p=0.029) remained associated with an increased risk of early mortality. In addition, the optimal cut-off value of OSI to predict post-CPR mortality was measured as >6.02, with 84.1% sensitivity and 76.1% specificity.

Conclusion:

Elevated OSI levels can predict failed CPR in CA patients.

How to assess prognosis after cardiac arrest and therapeutic hypothermia

The prognosis of patients who are admitted in a comatose state following successful resuscitation after cardiac arrest remains uncertain. Although the introduction of therapeutic hypothermia (TH) and improvements in post-resuscitation care have significantly increased the number of patients who are discharged home with minimal brain damage, short-term assessment of neurological outcome remains a challenge. The need for early and accurate prognostic predictors is crucial, especially since sedation and TH may alter the neurological examination and delay the recovery of motor response for several days. The development of additional tools, including electrophysiological examinations (electroencephalography and somatosensory evoked potentials), neuroimaging and chemical biomarkers, may help to evaluate the extent of brain injury in these patients. Given the extensive literature existing on this topic and the confounding effects of TH on the strength of these tools in outcome prognostication after cardiac arrest, the aim of this narrative review is to provide a practical approach to post-anoxic brain injury when TH is used. We also discuss when and how these tools could be combined with the neurological examination in a multimodal approach to improve outcome prediction in this population.

Next generation biomarkers for brain injury

In perinatal medicine, there is an emerging interest on the potential usefulness of non-invasive brain biochemical monitoring in infants at risk for brain injury. To date, several biomarkers such as neuro-proteins, calcium binding proteins, oxidative stress markers, vasoactive agents, inflammatory mediators, have been investigated. Results showed that hypoxia insult, under different conditions, triggers a biochemical pathophysiological cascade of events leading to brain damage. In this setting, increased biomarkers concentrations in different biological fluids have been found to correlate with the occurrence of brain damage at short-long term both in preterm and term fetuses/newborns. However, before inclusion of any biomarker in guidelines, USA and European institutions have recently stated a panel of criteria that have to be fulfilled. Therefore, the present review offers an overview of the main biomarkers currently studied in perinatal medicine and their progresses according to institutions' criteria.

Assessment of serum S100B and neuron specific enolase levels to evaluate the neurotoxıc effects of organıc solvent exposure

OBJECTIVES

Long-term organic solvent exposure may cause toxic effects in central nervous system . Trichloroethylene (TCE) is known to be one of the neurotoxic chlorinated organic solvents. Trichloroacetic acid (TCA) is an oxidative pathway metabolite of TCE. S100B, a calcium-binding protein in glial cells, and neuron specific enolase (NSE) in neuron cytoplasma are protein markers of astrocyte and neuron damage, respectively.

MATERIALS AND METHODS

Clinical and laboratory assesments were performed in 25 participants with organic solvent exposure history. Control group included 25 healthy age and sex-matched individuals. Measurements of serum S100B and NSE were performed using Roche Cobas E 601 compatible kits and elechtrochemiluminescence immunoassay. The levels of TCA in urine were measured by the headspace GC technique, after methyl esterification by methanol.

RESULTS

Median value of urine TCA in solvent-exposed group was 12.30 mg/L with 10.20 mg/L and 35.00 mg/L minimum and maximum values, respectively. The difference between serum S100B levels of solvent-exposed group (0.064 μg/L) and control group (0.049 μg/L) was statistically significant (p < 0.05). Serum NSE levels of control group (15.61 ng/ml) were higher than solvent-exposed group (13.90 ng/ml) but difference was not statistically significant (p > 0.05).

CONCLUSIONS

Serum S100B levels were found to be higher in solvent-exposed group when compared with control group. NSE levels were comparable between two groups. Increased Serum S100B levels in organic solvent exposure may indicate a preventive response to neuronal damage caused by reactive oxygen species (ROS) produced through oxidative metabolic pathways of organic solvents.

Prognosis in severe brain injury

BACKGROUND

The prediction of neurologic outcome is a fundamental concern in the resuscitation of patients with severe brain injury.

OBJECTIVE

To provide an evidence-based update on neurologic prognosis following traumatic brain injury and hypoxic-ischemic encephalopathy after cardiac arrest.

DATA SOURCE

Search of the PubMed database and manual review of bibliographies from selected articles to identify original data relating to prognostic methods and outcome prediction models in patients with neurologic trauma or hypoxic-ischemic encephalopathy.

DATA SYNTHESIS AND CONCLUSION

Articles were scrutinized regarding study design, population evaluated, interventions, outcomes, and limitations. Outcome prediction in severe brain injury is reliant on features of the neurologic examination, anatomical and physiological changes identified with CT and MRI, abnormalities detected with electroencephalography and evoked potentials, and physiological and biochemical derangements at both the brain and systemic levels. Use of such information in univariable association studies generally lacks specificity in classifying neurologic outcome. Furthermore, the accuracy of established prognostic classifiers may be affected by the introduction of outcome-modifying interventions, such as therapeutic hypothermia following cardiac arrest. Although greater specificity may be achieved with scoring systems derived from multivariable models, they generally fail to predict outcome with sufficient accuracy to be meaningful at the single patient level. Discriminative models which integrate knowledge of genetic determinants and biologic processes governing both injury and repair and account for the effects of resuscitative and rehabilitative care are needed.

Biomarkers as predictors of outcome after cardiac arrest

Cardiac arrest (CA) is a major health and economic problem. Management of patients resuscitated from CA is challenging for clinicians, and the mortality rate of those who achieve return of spontaneous circulation remains high. Hypoxic brain injury, cardiovascular abnormalities and systemic ischemia/reperfusion response characterize the so-called 'postcardiac arrest syndrome', which could lead to multiple organ failure and poor outcome after CA. The magnitude of these disorders differs in individual patients, mainly based on the cause and duration of CA and on the severity of the ischemic episode. Prognostication of outcome after CA is of importance because it could help physicians on triage decisions and readdress the overall management. A number of factors are thought to influence the prognosis of patients after CA, but due to the heterogeneity of CA population and scenarios no single factor has been identified as a reliable predictor of outcome and the timing and optimal approach to prognostication is still controversial. Biomarkers represent a growing area of interest in this field, as they may provide clinicians with early information on the severity of organ dysfunction to make a decision on clinical strategies and prognosticate outcome. In this article, the authors will focus on cardiac, neurological and inflammatory biomarkers as potential predictors of outcome after CA.

Invasive versus non-invasive cooling after in- and out-of-hospital cardiac arrest: a randomized trial

INTRODUCTION

Mild induced hypothermia (MIH) is indicated for comatose survivors of sudden cardiac arrest (SCA) to improve clinical outcome. In this study, we compared the efficacy of two different cooling devices for temperature management in SCA survivors.

METHODS

Between April 2008 and August 2009, 80 patients after survived in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA) were included in this prospective, randomized, single center study. Hypothermia was induced after randomization by either invasive Coolgard(®) cooling or non-invasive ArcticSun(®) surface cooling at 33.0 °C core body temperature for 24 h followed by active rewarming. The primary endpoint was defined as the efficacy of both cooling systems, measured by neuron-specific enolase (NSE) levels as a surrogate parameter for brain damage. Secondary efficacy endpoints were the clinical and neurological outcome, time to start of cooling and reaching the target temperature, target temperature-maintenance and hypothermia-associated complications.

RESULTS

NSE at 72 h did not differ significantly between the 2 groups with 16.5 ng/ml, interquartile range 11.8-46.5 in surface-cooled patients versus 19.0 ng/ml, interquartile range 11.0-42.0 in invasive-cooled patients, p = 0.99. Neurological and clinical outcome was similar in both groups. Target temperature of 33.0 °C was maintained more stable in the invasive group (33.0 versus 32.7 °C, p < 0.001). Bleeding complications were more frequent with invasive cooling (n = 17 [43.6 %] versus n = 7 [17.9 %]; p = 0.03).

CONCLUSION

Invasive cooling has advantages with respect to temperature management over surface cooling; however, did not result in different outcome as measured by NSE release in SCA survivors. Bleeding complications were more frequently encountered by invasive cooling.

Assessing prognosis following cardiopulmonary resuscitation and therapeutic hypothermia-a critical discussion of recent studies

BACKGROUND

The prognosis of patients who are comatose after cardiopulmonary resuscitation (CPR) is poor but can be improved by mild therapeutic hypothermia. We studied the question whether the known, reliable indicators of a poor prognosis after CPR are also valid for patients treated with CPR and hypothermia.

METHODS

This review is based on a selective search of the PubMed database for recent articles on the assessment of prognosis in persons who are comatose after CPR and therapeutic hypothermia.

RESULTS

On the basis of 21 clinical trials, 4 of which yielded level I evidence, 9 level II evidence, and 8 level III evidence, the following were identified as reliable indicators of a poor prognosis: generalized myoclonus, bilateral absence of the pupillary light response or of the corneal reflex, bilateral absence of the cortical components of median nerve somatosensory evoked potentials, a burst-suppression or isoelectric EEG, continuous generalized epileptiform discharges, and an elevated serum concentration of neuron-specific enolase (with a higher cutoff value than for normothermic patients).

CONCLUSION

If the prognosis is poor, this should be thoroughly discussed with the patient's family, and the nature and extent of further intensive treatment should be reconsidered. The patient's wishes, if known, are paramount. Any decision to withhold care should be taken only if there are multiple concurrent indicators of a poor prognosis. If only one such indicator is present, or if the findings are inconsistent, such decisions should be postponed.

Modeling serum biomarkers S100 beta and neuron-specific enolase as predictors of outcome after out-of-hospital cardiac arrest: an aid to clinical decision making

OBJECTIVES

The aim of this study was to determine the added value of the serum biomarkers S100 and neuron-specific enolase to clinical characteristics for predicting outcome after out-of-hospital cardiac arrest.

BACKGROUND

Serum S100 beta (S100B) and neuron-specific enolase concentrations rise after brain injury.

METHODS

A prolective observational study was conducted among all adult survivors of nontraumatic out-of-hospital cardiac arrest admitted to 1 hospital (April 3, 2008 to April 3, 2011). Three blood samples (on arrival and on days 1 and 3) were drawn for biomarkers, contingent on survival. Follow-up continued until in-hospital death or discharge. Outcomes were defined as good (Cerebral Performance Category score 1 or 2) or poor (Cerebral performance category score 3 to 5).

RESULTS

A total of 195 patients were included (65.6% men, mean age 73 ± 16 years), with presenting rhythms of asystole in 61.5% and ventricular tachycardia or ventricular fibrillation in 24.1%. Only 43 patients (22.0%) survived to hospital discharge, 26 (13.3%) with good outcomes. Patients with good outcomes had significantly lower S100B levels at all time points and lower neuron-specific enolase levels on days 1 and 3 compared with those with poor outcomes. Independent predictors at admission of a good outcome were younger age, a presenting rhythm of ventricular tachycardia or ventricular fibrillation, and lower S100B level. Predictors on day 3 were younger age and lower day 3 S100B level. The area under the receiver-operating characteristic curve of the admission-day model was 0.932 with and 0.880 without biomarker data (p = 0.027 for the difference).

CONCLUSIONS

Risk stratification after out-of-hospital cardiac arrest using both clinical and biomarker data is feasible. The biomarkers, although adding an ostensibly modest 5.2% to the area under the receiver-operating characteristic curve, substantially reduced the level of uncertainty in decision making. Nevertheless, current biomarkers cannot replace societal considerations in determining acceptable levels of uncertainty. (Protein S100 Beta as a Predictor of Resuscitation Outcome; NCT00814814).

Prognostic values of blood ammonia and partial pressure of ammonia on hospital arrival in out-of-hospital cardiac arrests

PURPOSES

Outcome prediction for out-of-hospital cardiac arrest (OHCA) is of medical, ethical, and socioeconomic importance. We hypothesized that blood ammonia may reflect tissue hypoxia in OHCA patients and conducted this study to evaluate the prognostic value of ammonia for the return of spontaneous circulation (ROSC).

METHODS

This prospective, observational study was conducted in a tertiary university hospital between January 2008 and December 2008. The subjects consisted of OHCA patients who were sent to the emergency department (ED). The primary outcome was ROSC. The prognostic values were calculated for ammonia levels and the partial pressure of ammonia (pNH(3)), and the results were depicted as a receiver operating characteristics curve with an area under the curve.

RESULTS

Among 119 patients enrolled in this study, 28 patients (23.5%) achieved ROSC. Ammonia levels and pNH(3) in the non-ROSC group were significantly higher than those in the ROSC group (167.0 μmol/L vs 80.0 μmol/L, P < .05; 2.61 × 10(-5) vs 1.67 × 10(-5) mm Hg, P < .05, respectively). The predictive capacity of area under the curve for ammonia and pNH(3) for non-ROSC was 0.85 (95% confidence interval, 0.75-0.95) and 0.73 (95% confidence interval, 0.61-0.84), respectively. The multivariate analysis confirmed that ammonia and pNH(3) are independent predictors of non-ROSC. The prognostic value of ammonia was better than that of pNH(3). The cutoff level for ammonia of 84 μmol/L was 94.5% sensitive and 75.0% specific for predicting non-ROSC with a diagnostic accuracy of 89.9%.

CONCLUSIONS

Hyperammonemia on ED arrival is independently predictive of non-ROSC for OHCA patients. The findings may offer useful information for clinical management.

From clinical judgment to odds: a history of prognostication in anoxic-ischemic coma

Persistent coma from a major anoxic-ischemic injury to the brain may indicate there is less chance for full recovery. The tools of prognostication to assess comatose survivors of cardiopulmonary resuscitation have developed over several decades. Physicians would initially base their judgment on experience and data on outcome in these patients in the early years were merely on awakening not on disability. In the late 1970s, a large multicenter prospective study was performed on outcome in nontraumatic coma. The impetus for this study was the result of Plum and Jennet's collaboration. In 1981--for the first time--complex statistics were used to improve the accuracy of prognosis and became known as the "Levy algorithms." These early seminal studies shaped the prediction models and implied that clinical information alone could assist physicians in making a prediction. Later, probabilistic methods became more commonplace.

Serum S100B and neuron-specific enolase levels in normothermic and hypothermic infants after perinatal asphyxia

AIM

Serum S100B and neuron-specific enolase (NSE) levels are elevated after perinatal asphyxia, but the influence of hypothermia on these proteins has not been previously reported. The aim of this study was to evaluate the effect of systemic hypothermia on these protein levels after perinatal asphyxia, time course, and association with perinatal factors and neurodevelopmental outcome at 2 years of age.

METHODS

Serum S100B and NSE levels were measured at fixed time points in asphyxiated infants treated with standard intensive care on hypothermia (HT: n = 13) or normothermia (NT: n = 11).

RESULTS

Serum S100B and NSE levels were grossly elevated in both HT and NT groups. Compared with the values at 6 h of age, S100B values decreased over time in both groups (NT: p = 0.002, HT: p = 0.04). Serum S100B values were lower in HT infants compared with those in NT infants (p = 0.047 at 48 h). Serum S100B and NSE values were significantly higher in infants who died or developed severe neurological impairment (S100B, p < 0.05 at all time points; NSE, p = 0.036 at 24 h of age).

CONCLUSION

Both NSE and S100B levels are highly elevated following asphyxia. Serum S100B levels were lower in the HT group and strongly correlated with the neurodevelopmental outcome.

Clinical significance of serum biomarkers in pediatric solid mediastinal and abdominal tumors

Childhood cancer is the leading cause of death by disease among U.S. children between infancy and age 15. Despite successes in treating solid tumors such as Wilms tumor, disappointments in the outcomes of high-risk solid tumors like neuroblastoma have precipitated efforts towards the early and accurate detection of these malignancies. This review summarizes available solid tumor serum biomarkers with a special focus on mediastinal and abdominal cancers in children.

Serum neuron-specific enolase as predictor of outcome in comatose cardiac-arrest survivors: a prospective cohort study

BACKGROUND

The prediction of neurological outcome in comatose patients after cardiac arrest has major ethical and socioeconomic implications. The purpose of this study was to assess the capability of serum neuron-specific enolase (NSE), a biomarker of hypoxic brain damage, to predict death or vegetative state in comatose cardiac-arrest survivors.

METHODS

We conducted a prospective observational cohort study in one university hospital and one general hospital Intensive Care Unit (ICU). All consecutive patients who suffered cardiac arrest and were subsequently admitted from June 2007 to February 2009 were considered for inclusion in the study. Patients who died or awoke within the first 48 hours of admission were excluded from the analysis. Patients were followed for 3 months or until death after cardiopulmonary resuscitation. The Cerebral Performance Categories scale (CPC) was used as the outcome measure; a CPC of 4-5 was regarded as a poor outcome, and a CPC of 1-3 a good outcome. Measurement of serum NSE was performed at 24 h and at 72 h after the time of cardiac arrest using an enzyme immunoassay. Clinicians were blinded to NSE results.

RESULTS

Ninety-seven patients were included. All patients were actively supported during the first days following cardiac arrest. Sixty-five patients (67%) underwent cooling after resuscitation. At 3 months 72 (74%) patients had a poor outcome (CPC 4-5) and 25 (26%) a good outcome (CPC 1-3). The median and Interquartile Range [IQR] levels of NSE at 24 h and at 72 h were significantly higher in patients with poor outcomes: NSE at 24 h: 59.4 ng/mL [37-106] versus 28.8 ng/mL [18-41] (p < 0.0001); and NSE at 72 h: 129.5 ng/mL [40-247] versus 15.7 ng/mL [12-19] (p < 0.0001). The Receiver Operator Characteristics (ROC) curve for poor outcome for the highest observed NSE value for each patient determined a cut-off value for NSE of 97 ng/mL to predict a poor neurological outcome with a specificity of 100% [95% CI = 87-100] and a sensitivity of 49% [95% CI = 37-60]. However, an approach based on a combination of SSEPs, NSE and clinical-EEG tests allowed to increase the number of patients (63/72 (88%)) identified as having a poor outcome and for whom intensive treatment could be regarded as futile.

CONCLUSION

NSE levels measured early in the course of patient care for those who remained comatose after cardiac arrest were significantly higher in patients with outcomes of death or vegetative state. In addition, we provide a cut-off value for NSE (> 97 ng/mL) with 100% positive predictive value of poor outcome. Nevertheless, for decisions concerning the continuation of treatment in this setting, we emphasize that an approach based on a combination of SSEPs, NSE and clinical EEG would be more accurate for identifying patients with a poor neurological outcome.

Elevated S100B and neuron specific enolase levels in patients with migraine-without aura: evidence for neurodegeneration?

Although migraine has mainly been considered as a benign disease, there is cumulative evidence of silent changes in the brain, brainstem, or cerebellum and subtle subclinical cerebellar dysfunction. In this study, in order to investigate a possible neuronal and/or glial damage at the cellular level in migraine, we measured and compared serum levels of S100B which is a protein marker of glial damage or activation, and neuron specific enolase (NSE) which is a marker of neuronal damage, in migraine patients and control subjects. Serum levels of S100B and NSE were measured in blood samples from 41 patients with migraine-without aura taken during a migraine attack (ictal) and in the attack-free period between migraine attacks (interictal) and 35 age- and sex-matched controls. Patients with migraine-without aura had significantly higher ictal serum levels of S100B and NSE (P < 0.05, for both) than control subjects; whereas in the interictal phase, there was a significant increment only in S100B levels (P < 0.05) compared to controls. On the other hand, serum levels of S100B and NSE in ictal and interictal blood samples did not differ significantly. The findings of increased ictal serum S100B and NSE levels together with increased interictal levels of S100B suggested that migraine might be associated with glial and/or neuronal damage in the brain and a prolonged disruption of blood-brain barrier. Increased interictal serum levels of S100B might point out to an insidious and slow damaging process in migraine patients.

Mild therapeutic hypothermia alters neuron specific enolase as an outcome predictor after resuscitation: 97 prospective hypothermia patients compared to 133 historical non-hypothermia patients

INTRODUCTION

Neuron specific enolase (NSE) has been proven effective in predicting neurological outcome after cardiac arrest with a current cut off recommendation of 33 microg/l. However, most of the corresponding studies were conducted before the introduction of mild therapeutic hypothermia (MTH). Therefore we conducted a study investigating the association between NSE and neurological outcome in patients treated with MTH.

METHODS

In this prospective observational cohort study the data of patients after cardiac arrest receiving MTH (n = 97) were consecutively collected and compared with a retrospective non-hypothermia (NH) group (n = 133). Serum NSE was measured 72 hours after admission to ICU. Neurological outcome was classified according to the Pittsburgh cerebral performance category (CPC 1 to 5) at ICU discharge.

RESULTS

NSE serum levels were significantly lower under MTH compared to NH in univariate analysis. However, in a linear regression model NSE was affected significantly by time to return of spontaneous circulation (ROSC) and ventricular fibrillation rhythm but not by MTH. The model for neurological outcome identified NSE, NSE*MTH (interaction) as well as time to ROSC as significant predictors. Receiver Operating Characteristic (ROC) analysis revealed a higher cutoff value for unfavourable outcome (CPC 3 to 5) with a specificity of 100% in the hypothermia group (78.9 microg/l) compared to the NH group (26.9 microg/l).

CONCLUSIONS

Recommended cutoff levels for NSE 72 hours after ROSC do not reliably predict poor neurological outcome in cardiac arrest patients treated with MTH. Prospective multicentre trials are required to re-evaluate NSE cutoff values for the prediction of neurological outcome in patients treated with MTH.