Biochemical markers (NSE, S-100, IL-8) as predictors of neurological outcome in patients after cardiac arrest and return of spontaneous circulation

Mitochondrial transplantation following cardiopulmonary resuscitation improves neurological function in rats by inducing M2-type MG/MΦ polarization

AIM

Explore the effects of mitochondrial transplantation (MT) after cardiopulmonary resuscitation (CPR) on the polarization of microglia/macrophages (MG/MΦ) and neurological function.

METHODS

Seventy-five Sprague-Dawley rats were randomly divided into five groups: sham, normal saline (NS), vehicle, mitochondria (Mito), and non-functional mitochondria (N-Mito) group. Rats in sham group underwent surgical procedures without cardiac arrest, while the other four groups underwent cardiac arrest and CPR, and then received NS, respiration buffer, mitochondrial suspension or non-functional mitochondria, immediately after the restoration of spontaneous circulation (ROSC). The number of mitochondria in the hippocampus, the morphology and structure of mitochondria in MG/MΦ, the phenotype of MG/MΦ, and hippocampal tissue injury, neuroinflammation, and neuronal apoptosis were detected on days 1 and 3 after ROSC. Neurodeficit score (NDS) was performed on days 1, 3, 7, 15 and 30 after ROSC.

RESULTS

Compared with other groups, the number of mitochondria in the hippocampus was increased, and the morphology and structure of mitochondria in MG/MΦ were significantly improved in the Mito group. Our results show higher expression of M2-type markers in MG/MΦ and decreased hippocampal tissue damage in the Mito group. Levels of NSE and S100β in serum, and TNF-α, IL-6 in the hippocampus were decreased, while the levels of TGF-β and IL-10 were increased in the Mito group. Apoptosis rate of neurons in the Mito group was decreased and the NDS of the Mito group was higher than the other groups.

CONCLUSIONS

Exogenous MT can improve neurological function after CPR by promoting the polarization of MG/MΦ to M2-type cells, and this could be a potential method for brain protection after CPR.

Neuron-Specific Enolase-What Are We Measuring?

Since the discovery of the neuron-specific protein by Moore and McGregor in 1965, tens of thousands of studies have investigated the basic and applied significance of neuron-specific enolase (NSE). This promising biomarker, according to many researchers, has not found widespread use in clinical practice, particularly in acute cerebrovascular accidents. Moreover, the several studies refuting the usefulness of serum NSE measurement in critically ill patients leads us to consider the reasons for such contradictory conclusions. In this article, we have analyzed the main directions in the study of NSE and expressed our perspective on the reasons for the contradictory results and the difficulties in implementing the results of these studies in clinical practice. In our opinion, the method of the enzyme-linked immunosorbent assay (ELISA) used in the majority of the studies is inappropriate for the evaluation of NSE as a marker of central nervous system damage, because it does not allow for the differentiation of heterodimers of enolases and the assessment of the enzymatic activity of this group of enzymatic proteins. Therefore, the methodological approach for the evaluation of NSE (γγ-enolase) as a biomarker needs to be elaborated and improved. Furthermore, the specificity of the applied research methods and the appropriateness of the continued use of the term "neuron-specific enolase" must be addressed.

Distribution of Nerve Fibers in Abdominal Wall Endometriosis and Their Clinical Significance

Objective

This study aimed to explore the distribution of nerve fibers in abdominal wall endometriosis (AWE) and discern their association with pain.

Methods

A retrospective case-control study was conducted. The cases comprised 30 patients diagnosed with AWE, while the control group consisted of 17 patients who had undergone laparotomy without any history of endometriosis. We analyzed clinical characteristics and examined the innervation patterns in samples using stains for S-100, neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), neurofilament (NF), and substance P (SP) antibodies.

Results

There was a notable increase in the density of S-100, NSE and PGP9.5 immunoreactive nerve fibers and a higher proportion of SP positivity in AWE lesions compared to standard abdominal wall scars (p < 0.05). However, there were no significant differences in the density or proportion of NF-immunoreactive nerve fibers between the cases and the controls. Moreover, no statistically significant correlation was observed between the density of S-100, NSE, PGP9.5, NF, or SP-positive nerve fibers and pain scores.

Conclusion

This study demonstrated an increased immunoreactive nerve fiber density located in AWE lesions compared to normal abdominal wall scars. Further high-quality studies are needed to investigate the mechanisms responsible for pain in women with endometriosis.

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Prognostic predictors in patients with cardiopulmonary arrest: A novel equation for evaluating the 30-day mortality

BACKGROUND

Early prediction of outcomes after cardiopulmonary arrest (CPA) is important for considering the best support. Our purpose was to evaluate predictors of the 30-day mortality in patients with CPA after return of spontaneous circulation (ROSC) and to assess an equation for calculating the 30-day mortality using clinical parameters.

METHODS

We retrospectively analyzed the data of 194 consecutive patients with CPA and ROSC in a derivation study (2015-2022). We compared clinical parameters between the survived (n = 78) and dead (n = 116) patients. We derived an equation for estimated probability of death based on clinical parameters, using multivariate logistic regression analysis. The reliability of the equation was validated in 80 additional patients with CPA.

RESULTS

The 30-day mortality was associated with sex, witnessed cardiac arrest, bystander cardiopulmonary resuscitation (CPR), CPA due to acute myocardial infarction, pupil diameter, Glasgow Coma Scale score (GCS), presence of light reflex, arterial or venous pH, lactate levels, initial ventricular fibrillation (VF), CPA time, and age. The derived logistic regression equation was as follows: Estimated probability of death = 1 / (1 + e-x), x = (0.25 × bystander CPR) + (0.44 × pupil diameter) - (0.14 × GCS) + (0.09 × lactate) - (1.87 × initial VF) + (0.07 × CPA time) + (0.05 × age) - 7.03. The cut-off value for estimated probability of death calculated by this equation was 54.5 %, yielding a sensitivity, specificity, and accuracy of 86.2 %, 80.8 %, and 84.5 %, respectively. In the validation model, these values were 81.8 %, 85.7 %, and 82.5 %, respectively.

CONCLUSIONS

The 30-day mortality may be calculated after ROSC in patients with CPA using simple clinical parameters. This equation may facilitate further best support for patients with CPA.

Lactate to Albumin Ratio for Predicting Clinical Outcomes after In-Hospital Cardiac Arrest

In-hospital cardiac arrest (IHCA) is associated with high mortality and poor neurological outcomes. Our objective was to assess whether the lactate-to-albumin ratio (LAR) can predict the outcomes in patients after IHCA. We retrospectively screened 75,987 hospitalised patients at a university hospital between 2015 and 2019. The primary endpoint was survival at 30-days. Neurological outcomes were assessed at 30 days using the cerebral performance category scale. 244 patients with IHCA and return of spontaneous circulation (ROSC) were included in this study and divided into quartiles of LAR. Overall, there were no differences in key baseline characteristics or rates of pre-existing comorbidities among the LAR quartiles. Patients with higher LAR had poorer survival after IHCA compared to patients with lower LAR: Q1, 70.4% of the patients; Q2, 50.8% of the patients; Q3, 26.2% of the patients; Q4, 6.6% of the patients (p = 0.001). Across increasing quartiles, the probability of a favourable neurological outcome in patients with ROSC after IHCA decreased: Q1: 49.2% of the patients; Q2: 32.8% of the patients; Q3: 14.7% of the patients; Q4: 3.2% of the patients (p = 0.001). The AUCs for predicting 30-days survival using the LAR were higher as compared to using a single measurement of lactate or albumin. The prognostic performance of LAR was superior to that of a single measurement of lactate or albumin for predicting survival after IHCA.

S100B in maternal circulation of pregnancies complicated by FGR and brain sparing

OBJECTIVE

To determine whether the presence of brain sparing in fetal growth restricted (FGR) fetuses involves elevation of the cerebral injury biomarker S100B in maternal circulation.

METHODS

We included 63 women with suspected small for gestational age (SGA) fetuses between 24 and 35 +6/7 weeks of gestation. Maternal plasma angiogenic factors measurements and sonographic evaluation were performed at recruitment. Next, we subdivided our SGA cohort into three groups: SGA fetuses, FGR fetuses without brain-sparing, and FGR fetuses with brain-sparing (FGR-BS). Serum S100B concentration was calculated as S100B µg/L, S100B MoM, and the ratio S100B/ estimated fetal weight (EFW). We also report one case of S100B concentration surge in maternal serum following the diagnosis of fetal intraventricular hemorrhage (IVH).

RESULTS

The FGR-BS group had higher maternal S100B µg/L (p < 0.01, p < 0.05, respectively), S100B MoM (p < 0.001, p < 0.001, respectively), and S100B/EFW (p < 0.001, p < 0.01, respectively), compared to the SGA and FGR groups. In the case report, maternal serum S100B concentrations were 0.0346 µg/L before, and 0.0874 µg/L after IVH occurrence.

CONCLUSIONS

S100B concentration in maternal serum increased in pregnancies complicated by FGR and brain sparing. These results may substantiate in-utero cerebral injury and may explain the adverse neurocognitive outcomes reported for this group.

Can brain natriuretic peptide, S100b, and interleukin-6 prognosticate the neurological consequences in Egyptian patients presented with supratentorial intracerebral hemorrhage?

Background:

Biomarkers in supratentorial intracerebral hemorrhage (SICH) enhance the prognosis of the disease. This study aimed to assess the prognosticative grade of S100 calcium-binding protein B (S100B), interleukin-6 (IL-6), and the pro-brain natriuretic peptide (pro-BNP) in SICH outcome prediction.

Methods:

Blood samples of 50 SICH patients were analyzed for the biomarkers. The patients were classified into two groups with and without intraventricular hemorrhage (IVH). The following scales including Glasgow Coma Score (GCS), the Barthel index (BI), intracerebral hemorrhage (ICH) score, ICH volume, National Institutes of Health Stroke Scale (NIHSS), Modified Rankin Score (mRS), and length of stay were used to evaluate the severity.

Results:

The severity scores (NIHSS, GCS, BI, mRI) were significantly higher in SICH patients with IVH versus SICH patients without IVH (P = 0.002, 0.008, 0.001, and 0.03, respectively). Serum levels for a pro-BNP and S100b are significantly higher in SICH patients with IVH versus SICH patients without IVH (P = 0.02 and 0.027, respectively). Multivariate correlations between demographic (age), biomarkers panel (IL-6, S100b, and proBNP), and clinical and severity scores (ICH score, ICH volume, length of hospital stay [LOS], BI, mRS, GCS, and NIHSSS) in all studied patients showed a highly significant correlation between ICH score and pro-BNP (P = 0.04). There was a highly significant correlation between LOS and IL-6 (P = 0.003).

Conclusion:

Pro-BNP, IL-6, and S100b are greatly associated with the presence of IVH that, in turn, correlated well with poor clinical outcome measures.

Macrophage-specific protein perforin-2 is associated with poor neurological recovery and reduced survival after sudden cardiac arrest

BACKGROUND

Biomarkers involved in inflammation and stress response were implicated in patients who were successfully resuscitated from out of hospital cardiac arrest (sR-OHCA). Here we report that macrophage-expressed gene, perforin-2, an evolutionarily conserved protein with membrane attack domain, is associated with poor neurological outcomes and mortality after sR-OHCA.

OBJECTIVES

To examine the association between circulating perforin-2 protein measured within 6-h of sR-OHCA, mortality and neurological outcomes.

METHODS

We prospectively enrolled 144 sR-OHCA patients from 4 different tertiary care centers. We measured perforin-2 and other conventional clinical biomarkers and compared between survivors vs. non-survivors. The neurological outcomes were dichotomized as poor or good according to the cereberal performance score.

RESULTS

At the end of the hospital stay, 45% of the patients had died and 46% had poor neurological outcomes. Serum perforin-2 levels were significantly higher in patients with poor neurological recovery, compared to the ones with good neurological recovery (ng/mL, 13.7 ± 45.9 vs. 1.2 ± 7.0, p = 0.01). There were no differences in other routinely measured biomarkers and left ventricular ejection fraction. On multivariate logistic regression, elevated perforin-2 (OR: 12.78, 95% CI: 1.0-17.8, p = 0.02), comatose on presentation (OR: 27.82, 95% CI: 0.2-19.5, p = 0.02) and non-shockable rhythm (OR: 17.04, 95% CI: 0.7-15.7, p = 0.01) were the significant predictors of poor neurological outcome.

CONCLUSIONS

This study reports a novel macrophage-expressed circulating biomarker perforin-2 to be strongly associated with reduced survival and poor neurological outcomes in sR-OHCA. These data can guide clinicians to prognosticate survival and neurological outcomes in sR-OHCA, and also form the basis for future therapeutic approaches.

Usefulness of F2-isoprostanes in early prognostication after cardiac arrest: a topical review of the literature and meta-analysis of preclinical data

Prognostication after cardiac arrest (CA) represents a challenging issue, and several biomarkers have been proposed in the attempt to predict outcome. Among these, F2-isoprostanes stand out as potential biomarkers for early prognostication, providing information on the magnitude of global oxidative injury after return of spontaneous circulation (ROSC). We performed a topical review searching PubMed and Scopus databases to identify studies evaluating the modifications of F2-isoprostanes in the early period after CA, and a meta-analysis of studies providing curves of F2-isoprostanes plasma levels seeking to describe the biomarker's kinetics after CA. Evidence suggests that plasma levels of F2-isoprostanes increase in the early post-resuscitation period and seem well correlated with the burden of ischaemia-reperfusion injury. Our meta-analysis shows a possible increase as early as 5 minutes after ROSC, which persists at 2 hours and is attenuated at 4 hours. Clinical studies are warranted to evaluate the utility of this biomarker for prognostication purposes in CA survivors.

Standards for Studies of Neurological Prognostication in Comatose Survivors of Cardiac Arrest: A Scientific Statement From the American Heart Association

Significant improvements have been achieved in cardiac arrest resuscitation and postarrest resuscitation care, but mortality remains high. Most of the poor outcomes and deaths of cardiac arrest survivors have been attributed to widespread brain injury. This brain injury, commonly manifested as a comatose state, is a marker of poor outcome and a major basis for unfavorable neurological prognostication. Accurate prognostication is important to avoid pursuing futile treatments when poor outcome is inevitable but also to avoid an inappropriate withdrawal of life-sustaining treatment in patients who may otherwise have a chance of achieving meaningful neurological recovery. Inaccurate neurological prognostication leading to withdrawal of life-sustaining treatment and deaths may significantly bias clinical studies, leading to failure in detecting the true study outcomes. The American Heart Association Emergency Cardiovascular Care Science Subcommittee organized a writing group composed of adult and pediatric experts from neurology, cardiology, emergency medicine, intensive care medicine, and nursing to review existing neurological prognostication studies, the practice of neurological prognostication, and withdrawal of life-sustaining treatment. The writing group determined that the overall quality of existing neurological prognostication studies is low. As a consequence, the degree of confidence in the predictors and the subsequent outcomes is also low. Therefore, the writing group suggests that neurological prognostication parameters need to be approached as index tests based on relevant neurological functions that are directly related to the functional outcome and contribute to the quality of life of cardiac arrest survivors. Suggestions to improve the quality of adult and pediatric neurological prognostication studies are provided.

Improved Outcome in an Animal Model of Prolonged Cardiac Arrest Through Pulsatile High Pressure Controlled Automated Reperfusion of the Whole Body

The reperfusion period after extracorporeal cardiopulmonary resuscitation has been recognized as a key player in improving the outcome after cardiac arrest (CA). Our aim was to evaluate the effects of high mean arterial pressure (MAP) and pulsatile flow during controlled automated reperfusion of the whole body. Following 20 min of normothermic CA, high MAP, and pulsatile blood flow (pulsatile group, n = 10) or low MAP and nonpulsatile flow (nonpulsatile group, n = 6) controlled automated reperfusion of the whole body was commenced through the femoral vessels of German landrace pigs for 60 min. Afterwards, animals were observed for eight days. Blood samples were analyzed throughout the experiment and a species-specific neurologic disability score (NDS) was used for neurologic evaluation. In the pulsatile group, nine animals finished the study protocol, while no animal survived postoperative day four in the nonpulsatile group. NDS were significantly better at any given time in the pulsatile group and reached overall satisfactory outcome values. In addition, blood analyses revealed lower levels of lactate in the pulsatile group compared to the nonpulsatile group. This study demonstrates superior survival and neurologic outcome when using pulsatile high pressure automated reperfusion following 20 min of normothermic CA compared to nonpulsatile flow and low MAP. This study strongly supports regulating the reperfusion period after prolonged periods of CA.

Protective effects of nicorandil against cerebral injury in a swine cardiac arrest model

The present study investigated the effects of nicorandil on cerebral injury following cardiopulmonary resuscitation (CPR) in a swine model of cardiac arrest. CPR was performed on swine following 4 min induced ventricular fibrillation. Surviving animals were randomly divided into 3 groups: A nicorandil group (n=8), a control group (n=8) and a sham group (n=4). The sham group underwent the same surgical procedure to imitate cardiac arrest, but ventricular fibrillation was not induced. When the earliest observable return of spontaneous circulation (ROSC) was detected, the nicorandil and control groups received injections of nicorandil and saline, respectively. Swine serum was collected at baseline and 5 min, 0.5, 3 and 6 h following ROSC. Serum levels of neuron-specific enolase (NSE), S100β, tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) were measured using ELISA. Animals were euthanized and brain tissue samples were collected and assessed using light and electron microscopy 6 h following ROSC. The expression of aquaporin-4 (AQP-4) in the brain tissue was measured using western blotting. Malondialdehyde (MDA) and glutathione (GSH) levels in the brain tissue were determined using thiobarbituric acid and thiobenzoic acid colorimetric methods, respectively. Serum NSE and S100β were significantly higher in the nicorandil and control groups following CPR, compared with baseline (P<0.05). Additionally, NSE and S100β levels were significantly lower in the nicorandil group compared with the control (P<0.05). Pathological examinations and electron microscopy indicated that nicorandil reduced brain tissue damage. TNF-α and IL-6 levels were significantly decreased in the nicorandil group compared with the control group (P<0.05). Furthermore, AQP-4 expression in brain tissue 6 h following ROSC was significantly lower in the nicorandil group compared with the control group (P<0.05). MDA and GSH levels in swine brain tissue decreased and increased, respectively, in the nicorandil group compared with the control group (P<0.05). The results of the present study demonstrate that nicorandil exerts a protective effect against brain injury following cardiac arrest by reducing oxidative damage, inflammatory responses and brain edema post-ROSC.

Preserved brain morphology after controlled automated reperfusion of the whole body following normothermic circulatory arrest time of up to 20 minutes

OBJECTIVES

Clinical outcomes following cardiac arrest (CA) and resuscitation remain a cause for concern. The use of Controlled Automated Reperfusion of the whoLe body (CARL) confers superior neurological outcome even after extended periods of CA. We aimed at investigating clinical outcome and brain morphology preservation when employing CARL following CA periods of 20 min.

METHODS

Twenty-eight pigs were allocated to four extracorporeal circulation treatment strategies; seven others served as magnetic resonance imaging (MRI) controls. In prompt cardiopulmonary resuscitation (CPR; n = 6), induced circulatory arrest was followed immediately by open cardiac massage of 15 min, thereafter by CARL for 60 min. In delayed CPR (n = 6), induced CA was maintained for 15 min, after that open cardiac massage of 10 min duration was performed prior to extracorporeal CPR (ECPR) of 60 min. Induced CA times of 15 min in the ECPR 15' group (n = 6) and CA of 20 min in the CARL 20' group (n = 10) were followed by ECPR of 60 min and CARL of 60 min, respectively, without prior CPR. Daily neurological deficit scoring (NDS) up to the seventh day, markers of cellular injury [alanine transaminase (ALT), aspartate transaminase (AST) and neuron-specific enolase (NSE)] and brain MRI were performed.

RESULTS

100% survival and normal NDSs were achieved in all animals in the prompt CPR and ECPR 15' groups. In CARL 20', nine animals survived. In contrast, only one animal in the delayed CPR group survived; three animals died within 24 h with a further two dying on Days 4 and 5, respectively. All markers of cellular injury were elevated in the delayed CPR group, ALT [38 (20.3) to 206 U/l (158.2); P = 0.0095], AST [26 (18.8) to 97 U/l (1965.8); P = 0.0095] and NSE [0.45 (0.25) to 7.95 µg/l (24.03); P = 0.0095]. In the ECPR 15' group, only NSE [0.45 (0.15) to 1.20 µg/l (2.40); P = 0.0065] remained elevated. In the CARL 20' group, differences in ALT [36 (10) to 53 U/l (20); P = 0.0005] and NSE [0.50 (0.40) to 1.5 µg/l (0.40); P < 0.0001] values were evident. T₂-weighted MR images of the cerebellum [454 (28) to 495 mm²/s (55); U = 11; P = 0.0311], caudate nucleus [400 (59) to 467 mm²/s (42); U = 9; P = 0.0156], lentiform nucleus [377 (89) to 416 mm²/s (55); U = 11; P = 0.0311] and hippocampus [421 (109) to 511 mm²/s (58); U = 9; P = 0.0164] in the CARL 20' group showed higher signal intensities compared with controls. In delayed CPR, corresponding regions of interest on early apparent diffusion coefficient images showed a restricted diffusion.

CONCLUSIONS

In our experimental animal model of CA, CARL results in satisfactory survival at CA periods of 20 min despite detected enzyme and morphological changes. These changes did not translate to clinical neurological deficits.

Effect of Tempol on Cerebral Resuscitation Caused by Asphyxia-Induced Cardiac Arrest

BACKGROUND

This study was conducted to investigate the effect and mechanism of the nitrogen oxide 4-hydroxy- 2,2,6,6-tetramethylpiperidine (Tempol) on cerebral resuscitation caused by asphyxia-induced cardiac arrest.

METHODS

Airway occlusion-induced asphyxia at the end of expiration was used to establish the rat cerebral ischaemia-hypoxia injury model. A total of 90 adult male Sprague-Dawley rats were randomly divided into the three groups. The Tempol and conventional cardiopulmonary resuscitation (CPR) groups were further divided into four subgroups according to different time points.

RESULTS

After cerebral ischaemia, independent heart rate following asphyxia appeared earlier, and the success rate of primary recovery and the neurological function score of rats were higher in the Tempol group than in the conventional CPR group. The serum neuron-specific enolase (NSE) levels in the Tempol and conventional CPR groups were significantly higher within 6 to 48 h than that in the blank control group. The serum NSE level was significantly lower in the Tempol group than the conventional CPR group.

CONCLUSIONS

After global cerebral ischaemia-hypoxia, the antioxidant Tempol improved cerebral resuscitation by reducing oxidative stress injuries and post-CPR cerebral damage. The NSE level can be used as an early detection index in the diagnosis of global cerebral ischaemia-hypoxia injuries.

KEY WORDS

Cerebral ischemia; Neuron-specific enolase; Rats; Tempol.

Serum Neutrophil Gelatinase-Associated Lipocalin Predicts Survival After Resuscitation From Cardiac Arrest

OBJECTIVES

In the first days after cardiac arrest, accurate prognostication is challenging. Serum biomarkers are a potentially attractive adjunct for prognostication and risk stratification. Our primary objective in this exploratory study was to identify novel early serum biomarkers that predict survival after cardiac arrest earlier than currently possible.

DESIGN

Prospective, observational study.

SETTING

A single academic medical center.

SUBJECTS

Adult subjects who sustained cardiac arrest with return of spontaneous circulation.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

We obtained blood samples from each subject at enrollment, 6, 12, 24, 48, and 72 hours after return of spontaneous circulation. We measured the serum levels of novel biomarkers, including neutrophil gelatinase-associated lipocalin, high-mobility group protein B1, intracellular cell adhesion molecule-1, and leptin, as well as previously characterized biomarkers, including neuron-specific enolase and S100B protein. Our primary outcome of interest was survival-to-hospital discharge. We compared biomarker concentrations at each time point between survivors and nonsurvivors and used logistic regression to test the unadjusted associations of baseline clinical characteristics and enrollment biomarker levels with survival. Finally, we constructed a series of adjusted models to explore the independent association of each enrollment biomarker level with survival. A total of 86 subjects were enrolled. Enrollment levels of high-mobility group protein B1, neutrophil gelatinase-associated lipocalin, and S100B were higher in nonsurvivors than survivors. Enrollment leptin, neuron-specific enolase, and intracellular cell adhesion molecule-1 levels did not differ between nonsurvivors and survivors. The discriminatory power of enrollment neutrophil gelatinase-associated lipocalin level was the greatest (c-statistic, 0.78 [95% CI, 0.66-0.90]) and remained stable across all time points. In our adjusted models, enrollment neutrophil gelatinase-associated lipocalin level was independently associated with survival even after controlling for the development of acute kidney injury, and its addition to clinical models improved overall predictive accuracy.

CONCLUSIONS

Serum neutrophil gelatinase-associated lipocalin levels are strongly predictive of survival-to-hospital discharge after cardiac arrest.

Serum neuron-specific enolase levels in preterm and term newborns and in infants 1-3 months of age

BACKGROUND

Elevated serum levels of neuron-specific enolase (NSE) was initially assumed to be specific to neuronal tumors (particularly neuroblastoma), but is now known to accompany nontumoral conditions and tumors other than neuroblastomas. There is a need to establish normal ranges for NSE, especially in early infancy. The aims of this study were to determine reference values for NSE in newborns and young infants and to assess whether NSE levels in early infancy (i.e., preterm infants and term infants) differ from the adult reference range for this enzyme.

METHODS

We enrolled 140 healthy babies, which included 40 preterm newborns (3-15 days old and born at 28-42 weeks gestation), 40 term newborns (< 1 month old and born at term), and 60 young infants 1-3 months old (n = 20 per subgroup of 1-, 2-, and 3-month-old infants). The determination of NSE levels was performed by the electrochemiluminescence immunoassay (ECLIA) method using the Elecysys 2010 device (Roche Diagnostics, Mannheim, Germany). The mean serum NSE levels for the preterm newborns was 21.83 ± 15.06 ng/mL [95% confidence interval (95%CI), 16.95-26.71 ng/mL]; term newborns, 18.06 ± 12.83 ng/mL (95%CI, 13.94-22.19 ng/mL); and young infants, 9.09 ± 4.38 ng/mL (95%CI, 7.96-10.23 ng/mL). The mean serum NSE level for infants 1-3 months old was within the ECLIA kit's normal range (4.7-18 ng/mL for adults), whereas the corresponding means for the preterm and term newborns were higher (p < 0.001, for both).

CONCLUSION

Our findings suggest that adult reference values should not be applied to the preterm and term age groups.

Development of a prompt model for predicting neurological outcomes in patients with return of spontaneous circulation from out-of-hospital cardiac arrest

Aim

Early prediction of the neurological outcomes of patients with out-of-hospital cardiac arrest is important to select the optimal clinical management. We hypothesized that clinical data recorded at the site of cardiopulmonary resuscitation would be clinically useful.

Methods

This retrospective cohort study included patients with return of spontaneous circulation after cardiopulmonary resuscitation who were admitted to our university hospital between January 2000 and November 2013 or two affiliated hospitals between January 2006 and November 2013. Clinical parameters recorded on arrival included age (A), arterial blood pH (B), time from cardiopulmonary resuscitation to return of spontaneous circulation (C), pupil diameter (D), and initial rhythm (E). Glasgow Outcome Scale was recorded at 6 months and a favorable neurological outcome was defined as a score of 4-5 on the Glasgow Outcome Scale. Multiple logistic regression analysis was carried out to derive a formula to predict neurological outcomes based on basic clinical parameters.

Results

The regression equation was derived using a teaching dataset (total, n = 477; favourable outcome, n = 55): EP = 1/(1 + e^-x ), where EP is the estimated probability of having a favorable outcome, and x = (-0.023 × A) + (3.296 × B) - (0.070 × C) - (1.006 × D) + (2.426 × E) - 19.489. The sensitivity, specificity, and accuracy were 80%, 92%, and 90%, respectively, for the validation dataset (total, n = 201; favourable outcome, n = 25).

Conclusion

The 6-month neurological outcomes can be predicted in patients resuscitated from out-of-hospital cardiac arrest using clinical parameters that can be easily recorded at the site of cardiopulmonary resuscitation.

Out-of-hospital cardiac arrest -optimal management

Out-of-hospital cardiac arrest (OHCA) has attracted increasing attention over the past years because outcomes have improved impressively lately. The changes for neurological intact outcomes has been poor but several areas have achieved improving survival rates after adjusting their cardiac arrest care. The pre-hospital management is certainly key and decides whether a cardiac arrest patient can be brought back into a spontaneous circulation. However, the whole chain of resuscitation including the in-hospital care have improved also. This review describes aetiologies of OHCA, risk and potential protective factors and recent advances in the pre-hospital and in-hospital management of these patients.

Detection of S100B in maternal blood before and after fetal death

BACKGROUND

S100B is a brain damage biomarker. When measured immediately after birth, it reflects neonatal brain damage following asphyxia. In this study, we used feticide as a novel model of fetal brain damage. We examined whether such damage is reflected by a rise in S100B in maternal blood before delivery.

METHODS

Eight pregnant women were recruited between January and July 2012. Maternal blood samples were drawn before and after feticide at predetermined time points (0, 15, 30, 60, 120, and 240 min). S100B, lactate dehydrogenase, creatine kinase, and creatinine concentrations were measured by standard human ELISA and chemical analyzer.

RESULTS

No significant difference was noted between S100B levels before and after feticide, neither in non-specific cell death markers (lactate dehydrogenase and creatine kinase), which remained within normal range. S100B ranged between 0.015-0.04 µg/L through all the predetermined time points.

CONCLUSION

No statistically significant differences were demonstrated in S100B levels before and after feticide.

Neuron-specific enolase serum levels predict severe neuronal injury after extracorporeal life support in resuscitation

OBJECTIVES

Extracorporeal life support (ECLS) is a rescue option in critically ill patients. Since fast available and appropriate for respiratory and circulatory failure, it is frequently applied in resuscitation scenarios. Neurological injury is a complication common in ECLS patients limiting outcome, particularly after resuscitation. In this study, the institutional ECLS database was used to correlate neuron-specific enolase (NSE) serum peak values with outcome of patients supported with venoarterial (VA) ECLS during cardiopulmonary resuscitation (CPR).

METHODS

From January 2011 to August 2012, 31 patients were provided with a VA ECLS during CPR (external cardiac massage). Serum NSE peaks were monitored and correlated with neurological outcome and hospital mortality. Patients were divided into two groups with mild-to-moderate and high NSE levels (cut-off value 100 μg/l).

RESULTS

High NSE levels were seen in 7 patients (mean 218 ± 155 μg/l) and mild-to-moderate levels in 24 patients (50 ± 23 μg/l, P = 0.0001). Duration of extracoporeal support was comparable in both groups (6.3 ± 7.5 vs 5.0 ± 4.5 days, P = n.s.). Patients with mild-to-moderate NSE levels were significantly older than those with high NSE levels (58 ± 16 vs 44 ± 15 years, P = 0.02). Six patients with high NSE levels (86%) developed severe neurological complications. Though 4 patients could be weaned from extracorporeal support, hospital mortality was 86% (6 patients). In contrast, patients with mild-to-moderate NSE levels had a hospital mortality of 46% (11 patients). Eighteen patients (75%) could be weaned from the device, and incidence of major neurological events was 29% (6 patients) only. Serum pH and lactate levels before ECLS implantation were significantly lower in patients with mild-to-moderate NSE values (pH: 7.23 ± 0.04 vs 6.93 ± 0.12, P = 0.039; lactate: 106 ± 11 vs 161 ± 16 mg/l, P = 0.023).

CONCLUSIONS

High NSE serum levels after ECLS correspond to poor neurological outcome and considerable mortality. Therefore, early neuroimaging is reasonable for determining therapeutic strategies in patients with high NSE peaks after resuscitation and extracorporeal support.

Use of the impedance threshold device improves survival rate and neurological outcome in a swine model of asphyxial cardiac arrest*

OBJECTIVE

To assess whether intermittent impedance of inspiratory gas exchange improves hemodynamic parameters, 48-hr survival, and neurologic outcome in a swine model of asphyxial cardiac arrest treated with active compression-decompression cardiopulmonary resuscitation.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Laboratory investigation.

SUBJECTS

Thirty healthy Landrace/Large-White piglets of both sexes, aged 10 to 15 wks, whose average weight was 19 ± 2 kg.

INTERVENTIONS

At approximately 7 mins following endotracheal tube clamping, ventricular fibrillation was induced and remained untreated for another 8 mins. Before initiation of cardiopulmonary resuscitation, animals were randomly assigned to either receive active compression-decompression cardiopulmonary resuscitation plus a sham impedance threshold device (control group, n = 15), or active compression-decompression cardiopulmonary resuscitation plus an active impedance threshold device (experimental group, n = 15). Electrical defibrillation was attempted every 2 mins until return of spontaneous circulation or asystole.

MEASUREMENTS AND MAIN RESULTS

Return of spontaneous circulation was observed in six (40%) animals treated with the sham valve and 14 (93.3%) animals treated with the active valve (p = .005, odds ratio 21.0, 95% confidence interval 2.16-204.6). Neuron-specific enolase and S-100 levels increased in the ensuing 4 hrs post resuscitation in both groups, but they were significantly elevated in animals treated with the sham valve (p < .01). At 48 hrs, neurologic alertness score was significantly better in animals treated with the active valve (79.1 ± 18.7 vs. 50 ± 10, p < .05) and was strongly negatively correlated with 1- and 4-hr postresuscitation neuron-specific enolase (r = -.86, p < .001 and r = -.87, p < .001, respectively) and S-100 (r = -.77, p < .001 and r = -0.8, p = .001) values.

CONCLUSIONS

In this model of asphyxial cardiac arrest, intermittent airway occlusion with the impedance threshold device during the decompression phase of active compression-decompression cardiopulmonary resuscitation significantly improved hemodynamic parameters, 24- and 48-hr survival, and neurologic outcome evaluated both with clinical and biochemical parameters (neuron-specific enolase, S-100).

S100B - a potential biomarker for early detection of neonatal brain damage following asphyxia

Birth asphyxia results in a significant percentage of neonatal morbidity and mortality. A key factor in the management of this complication is the early and accurate detection of brain damage following asphyxia. Currently, reliable tools for such diagnosis are absent. Extensive research has focused on biomarkers in an attempt to solve this matter. Recent data marked serum and urine elevation of the S100B protein as an established peripheral biomarker for detection of brain injury including traumatic head injuries and brain damage following cardiac arrest and stroke. In the past decade, a substantial number of studies illustrated the potential use of S100B testing in order to detect brain damage in asphyxiated newborns. This review summarizes the available data regarding the use of S100B as a biomarker of brain damage following birth asphyxia.

Time-dependent changes in serum biomarker levels after blast traumatic brain injury

Neuronal and glial proteins detected in the peripheral circulating blood after injury can reflect the extent of the damage caused by blast traumatic brain injury (bTBI). The temporal pattern of their serum levels can further predict the severity and outcome of the injury. As part of characterizing a large-animal model of bTBI, we determined the changes in the serum levels of S100B, neuron-specific enolase (NSE), myelin basic protein (MBP), and neurofilament heavy chain (NF-H). Blood samples were obtained prior to injury and at 6, 24, 72 h, and 2 weeks post-injury from animals with different severities of bTBI; protein levels were determined using reverse phase protein microarray (RPPM) technology. Serum levels of S100B, MBP, and NF-H, but not NSE, showed a time-dependent increase following injury. The detected changes in S100B and MBP levels showed no correlation with the severity of the injury. However, serum NF-H levels increased in a unique, rapid manner, peaking at 6 h post-injury only in animals exposed to severe blast with poor clinical and pathological outcomes. We conclude that the sudden increase in serum NF-H levels following bTBI may be a useful indicator of injury severity. If additional studies verify our findings, the observed early peak of serum NF-H levels can be developed into a useful diagnostic tool for predicting the extent of damage following bTBI.

Year in review 2009: Critical Care--cardiac arrest, trauma and disasters

During 2009, Critical Care published nine papers on various aspects of resuscitation, prehospital medicine, trauma care and disaster response. One article demonstrated that children as young as 9 years of age can learn cardiopulmonary resuscitation (CPR) effectively, although, depending on their size, some may have difficulty performing it. Another paper showed that while there was a trend toward mild therapeutic hypothermia reducing S-100 levels, there was no statistically significant change. Another predictor study also showed a strong link between acute kidney injury and neurologic outcome while another article described a program in which kidneys were harvested from cardiac arrest patients and showed an 89% graft survival rate. One experimental investigation indicated that when a pump-less interventional lung assist device is present, leaving the device open (unclamped) while performing CPR has no harmful effects on mean arterial pressures and it may have positive effects on blood oxygenation and CO2 clearance. One other study, conducted in the prehospital environment, found that end-tidal CO2 could be useful in diagnosing pulmonary embolism. Three articles addressed disaster medicine, the first of which described a triage system for use during pandemic influenza that demonstrated high reliability in delineating patients with a good chance of survival from those likely to die. The other two studies, both drawn from the 2008 Sichuan earthquake experience, showed success in treating crush injured patients in an on-site tent ICU and, in the second case, how the epidemiology of earthquake injuries and related factors predicted mortality.

Can early serum levels of S100B protein predict the prognosis of patients with out-of-hospital cardiac arrest?

OBJECTIVE

This study aims to know if the level of S100B protein at the initiation of cardiopulmonary resuscitation (CPR) and immediately after return of spontaneous circulation (ROSC) can predict clinical outcome.

MATERIALS AND METHODS

A prospective observational study from December 2004 to October 2006 was conducted in an urban tertiary hospital emergency department. Clinical demographics for out-of-hospital cardiac arrest patients were collected based on the Utstein style. Outcomes collected included ROSC for 20min, survival to admission, survival and Glasgow Outcome Scale (GOS) at 1 month. S100B protein was measured twice before starting CPR (first S100B) and immediately after ROSC (second S100B). We investigated the association between S100B protein levels and clinical outcomes using a multivariate logistic regression model.

RESULTS

A total of 151 patients were included (age: 60.2+/-16.8 years, male: 64.2%). Of these, 60 (39.7%) had ROSC and 46 (30.5%) survived to admission. After 1 month, 12 (8.0%) survived and only three patients showed good GOS (>/=4 points). The S100B levels were not different for ROSC, survival to admission and 1-month survival between survivors and non-survivors (p>0.05, first and second S100 B level). For the witnessed out-of-hospital cardiac arrest (OHCA) group (N=87), only the first S100B (1.22+/-0.85mugl(-1) vs. 3.91+/-4.25mugl(-1), p<0.001) showed significant difference for 1-month survival between survivors and non-survivors. The first S100B showed significant association with survival to emergency department (ED) but not 1-month survival (adjusted odds ratio (OR)=0.905, 95% confidence interval=0.821-0.998).

CONCLUSION

Higher levels of S100B at start of CPR were significantly associated with lower survival to admission, and not for 1-month survival.

S100B and brain natriuretic peptide predict functional neurological outcome after intracerebral haemorrhage

OBJECTIVE

To determine the predictive value of S100b and brain natriuretic peptide (BNP) in order to determine accurately and quickly a discharge prognosis after primary supratentorial intracerebral haemorrhage (ICH).

METHODS

After IRB approval and informed consent, blood samples were obtained and analysed from 28 adult patients consecutively admitted to the neuroscience intensive care unit with computed tomography-proven supratentorial ICH from June 2003 and December 2004 within the first 24 h after symptom onset for S100b and BNP. Functional outcomes on discharge were dichotomized to favourable (mRS < 3) or unfavourable.

RESULTS

BNP (a neurohormone) and S100b (a marker of glial activation) were found to be independently highly predictive of functional neurological outcome at the time of discharge as measured by the modified Rankin Score (BNP: p < 0.01, r = 0.46; S100b: p < 0.01, r = 0.42) and the Barthel Index (BNP: p < 0.01, r = 0.54; s100b: p < 0.01, r = 0.50). Although inclusion of either biomarker produced additive value when included with traditional clinical prognostic variables, such as the ICH score (Barthel index: p < 0.01, r = 0.66; mRS: p < 0.01, r = 0.96), little predictive power is added with inclusion of both biomarkers in a regression model for neurological outcome.

CONCLUSIONS

Serum S100b and BNP levels in the first 24 h after injury accurately predict neurological function at discharge after supratentorial ICH.

S-100B and neuron-specific enolase as predictors of neurological outcome in patients after cardiac arrest and return of spontaneous circulation: a systematic review

INTRODUCTION

Neurological prognostic factors after cardiopulmonary resuscitation (CPR) in patients with cardiac arrest (CA) as early and accurately as possible are urgently needed to determine therapeutic strategies after successful CPR. In particular, serum levels of protein neuron-specific enolase (NSE) and S-100B are considered promising candidates for neurological predictors, and many investigations on the clinical usefulness of these markers have been published. However, the design adopted varied from study to study, making a systematic literature review extremely difficult. The present review focuses on the following three respects for the study design: definitions of outcome, value of specificity and time points of blood sampling.

METHODS

A Medline search of literature published before August 2008 was performed using the following search terms: "NSE vs CA or CPR", "S100 vs CA or CPR". Publications examining the clinical usefulness of NSE or S-100B as a prognostic predictor in two outcome groups were reviewed. All publications met with inclusion criteria were classified into three groups with respect to the definitions of outcome; "dead or alive", "regained consciousness or remained comatose", and "return to independent daily life or not". The significance of differences between two outcome groups, cutoff values and predictive accuracy on each time points of blood sampling were investigated.

RESULTS

A total of 54 papers were retrieved by the initial text search, and 24 were finally selected. In the three classified groups, most of the studies showed the significance of differences and concluded these biomarkers were useful for neurological predictor. However, in view of blood sampling points, the significance was not always detected. Nevertheless, only five studies involved uniform application of a blood sampling schedule with sampling intervals specified based on a set starting point. Specificity was not always set to 100%, therefore it is difficult to indiscriminately assess the cut-off values and its predictive accuracy of these biomarkers in this meta analysis.

CONCLUSIONS

In such circumstances, the findings of the present study should aid future investigators in examining the clinical usefulness of these markers and determination of cut-off values.

Changes in S-100 protein serum levels in survivors of out-of-hospital cardiac arrest treated with mild therapeutic hypothermia: a prospective, observational study

Introduction

Knowledge about the influence of current neuroprotective interventions on prognostic markers after survival from cardiac arrest is lacking. This study aimed to investigate the effects of mild therapeutic hypothermia on the release of the astroglial protein S-100 after cardiopulmonary resuscitation (CPR) in survivors of out-of-hospital cardiac arrest.

Methods

This was a prospective, observational study performed during a two-year period, involving medical emergency services and five collaborating hospitals at the city of Aachen, Germany. Sixty-eight subjects were enrolled by the emergency physician on duty by taking blood samples after successful attempts at resuscitation with return of spontaneous circulation (ROSC), followed by samples at 6, 12, 24, 72 and 120 hours post ROSC by the appropriate intensive care unit staff. Depending on the decision of the attending physician, subjects were cooled down to 33°C (n = 37) for 24 hours or were held at 37°C (n = 31). Patients were tracked for estimating mortality and gross neurological outcome for 14 days.

Results

S-100 levels in patients not receiving mild therapeutic hypothermia (normothermia (NT)) showed equivalent numbers as compared with cooled patients (mild therapeutic hypothermia (MTH)) on baseline (NT = 1.38 μg/l versus MTH = 1.30 μg/l; P = 0.886). S-100 levels on baseline were significantly lower in patients with a good neurological outcome at 14 days after the event in comparison to their peers with adverse outcome (P = 0.014). Although the difference in S-100 levels of MTH patients with adverse or favourable neurological outcome reached statistical significance, it did not in NT patients.

Conclusions

Although the predictive power of S-100 levels were best on admission but not at later time points, MTH had no influence on S-100 serum levels in survivors of non-traumatic out-of-hospital cardiac arrest in the particular setting of this investigation.

Acute-phase reactants after paediatric cardiac arrest. Procalcitonin as marker of immediate outcome

Objective

Procalcitonin (PCT) and C reactive protein (CRP) have been used as infection parameters. PCT increase correlates with the infection's severity, course, and mortality. Post-cardiocirculatory arrest syndrome may be related to an early systemic inflammatory response, and may possibly be associated with an endotoxin tolerance. Our objective was to report the time profile of PCT and CRP levels after paediatric cardiac arrest and to assess if they could be use as markers of immediate survival.

Materials and methods

A retrospective observational study set in an eight-bed PICU of a university hospital was performed during a period of two years. Eleven children younger than 14 years were admitted in the PICU after a cardiac arrest. PCT and CRP plasma concentrations were measured within the first 12 and 24 hours of admission.

Results

In survivors, PCT values increased 12 hours after cardiac arrest without further increase between 12 and 24 hours. In non survivors, PCT values increased 12 hours after cardiac arrest with further increase between 12 and 24 hours. Median PCT values (range) at 24 hours after cardiac arrest were 22.7 ng/mL (0.2 – 41.0) in survivors vs. 205.5 ng/mL (116.6 – 600.0) in non survivors (p < 0.05). CRP levels were elevated in all patients, survivors and non-survivors, at 12 and 24 hours without differences between both groups.

Conclusion

Measurement of PCT during the first 24 hours after paediatric cardiac arrest could serve as marker of mortality.