Serum S-100 protein levels after pediatric cardiac operations: a possible new marker for postperfusion cerebral injury

Utility of Brain Injury Biomarkers in Children With Congenital Heart Disease Undergoing Cardiac Surgery

BACKGROUND

Congenital heart disease (CHD) affects roughly 40,000 children annually. Despite advancements, children undergoing surgery for CHD are at an increased risk for adverse neurological outcomes. At present, there is no gold standard for the diagnosis of cerebral injury during the perioperative period.

OBJECTIVE

To determine the utility of brain injury biomarkers in children undergoing cardiac surgery.

METHODS

We searched PUBMED, EMBASE, LILACS, EBSCO, ClinicalTrials.gov, Cochrane Databases, and OVID interface to search MEDLINE through July 2021 and assessed the literature following the snowball method. The search terms used were "congenital heart disease," "cardiopulmonary bypass," "biomarkers," "diagnosis," "prognosis," and "children." No language or publication date restrictions were used. Papers studying inflammatory and imaging biomarkers were excluded. The risk of bias, strengths, and limitations of the study were reported. Study was registered in PROSPERO ID: CRD42021258385.

RESULTS

A total of 1449 articles were retrieved, and 27 were included. Eight neurological biomarkers were examined. Outcomes assessed included prognosis of poor neurological outcome, mortality, readmission, and diagnosis of brain injury. Results from these studies support that significant perioperative elevations in brain injury biomarkers in cerebrospinal fluid and serum, including S100B, GFAP, NSE, and activin A, may be diagnostic of real-time brain injury and serve as an independent predictor of adverse neurological outcomes in patients with CHD undergoing cardiopulmonary bypass.

CONCLUSIONS

There are limited homogeneous data in the field, limiting the generalizability and comparability of the results. Further large-scale longitudinal studies addressing neurological biomarkers in children undergoing CHD corrective surgery are required to support the routine use of neuronal biomarkers in this population.

Serum Markers of Brain Injury in Pediatric Patients with Congenital Heart Defects Undergoing Cardiac Surgery: Diagnostic and Prognostic Role

Introduction: The objectives of this study were to assess the role of neuromarkers like glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF), protein S100 (pS100), and neuron-specific enolase (NSE) as diagnostic markers of acute brain injury and also as prognostic markers for short-term neurodevelopmental impairment. Methods: Pediatric patients with congenital heart defects (CHDs) undergoing elective cardiac surgery were included. Neurodevelopmental functioning was assessed preoperatively and 4-6 months postoperatively using the Denver Developmental Screening Test II. Blood samples were collected preoperatively and postoperatively. During surgery, regional cerebral tissue oxygen saturation was monitored using near-infrared spectroscopy (NIRS). Results: Forty-two patients were enrolled and dichotomized into cyanotic and non-cyanotic groups based on peripheric oxygen saturation. Nineteen patients (65.5%) had abnormal developmental scores in the non-cyanotic group and eleven (84.6%) in the cyanotic group. A good diagnostic model was observed between NIRS values and GFAP in the cyanotic CHD group (AUC = 0.7). A good predicting model was observed with GFAP and developmental scores in the cyanotic CHD group (AUC = 0.667). A correlation was found between NSE and developmental quotient scores (r = 0.09, p = 0.046). Conclusions: From all four neuromarkers studied, only GFAP was demonstrated to be a good diagnostic and prognostic factor in cyanotic CHD patients. NSE had only prognostic value.

Study on collateral circulation level and prognosis of acute ischemic stroke by 4D CTA-CTP integrated technology and serum S100B

OBJECTIVE

To evaluate the cerebral collateral circulation in patients with acute ischemic stroke (AIS) by Four-dimensional CT angiography-CT perfusion (4D CTA-CTP)-integrated technology, and to explore the feasibility of predicting the prognosis of patients with AIS by using cerebral collateral circulation and serum S100B protein concentration.

METHODS

Thirty-two patients with anterior circulation AIS who underwent 4D CTA-CTP were retrospectively analysed. The level of cerebral collateral circulation was assessed by multi-phase CT angiography (mCTA) scores and regional leptomeningeal collateral (rLMC) scores. Combined with serum S100B protein concentration, multivariate binary logistic regression was used to explore the indicators that can independently predict the prognosis of AIS neurological function.

RESULTS

Univariate analysis showed that the baseline National Institutes of Health stroke scale score, rLMC score, and mCTA score were correlated with the neurological prognosis of patients with AIS; multivariate analysis showed that mCTA cerebral collateral circulation score was the only indicator that could independently predict the neurological prognosis of AIS patients (OR = 0.065, P = 0.030). The baseline serum S100B protein concentration could not independently predict the neurological prognosis of AIS patients.

CONCLUSION

mCTA cerebral collateral circulation scores can independently predict the neurological prognosis of patients with AIS. For the assessment of neurological prognosis of AIS patients, the cerebral collateral circulation phase score is better than the regional score.

S100B and its relation to cerebral oxygenation in neonates and infants undergoing surgery for congenital heart disease

OBJECTIVES

Neonates and infants undergoing surgery for congenital heart disease are at risk for developmental impairment. Hypoxic-ischemic brain injury might be one contributing factor. We aimed to investigate the perioperative release of the astrocyte protein S100B and its relation to cerebral oxygenation.

METHODS

Serum S100B was measured before and 0, 12, 24, and 48 hours after surgery. Cerebral oxygen saturation was derived by near-infrared spectroscopy. S100B reference values based on preoperative samples; concentrations above the 75th percentile were defined as elevated. Patients with elevated S100B at 24 or 48 hours were compared to cases with S100B in the normal range. Neonates (≤28 days) and infants (>28 and ≤365 days) were analyzed separately due to age-dependent release of S100B.

RESULTS

Seventy-four patients underwent 94 surgical procedures (neonates, n = 38; infants, n = 56). S100B concentrations were higher in neonates before and after surgery at all time points (P ≤ .015). Highest values were noticed immediately after surgery. Postoperative S100B was elevated after 15 (40.5%) surgeries in neonates. There was no difference in pre-, intra-, or postoperative cerebral oxygenation. In infants, postoperative S100B was elevated after 23 (41.8%) procedures. Preoperative cerebral oxygen saturations tended to be lower (53 ± 12% vs 59 ± 12%, P = .069) and arterial-cerebral oxygen saturation difference was higher (35 ± 11% vs 28 ± 11%, P = .018) in infants with elevated postoperative S100B. In the early postoperative course, cerebral oxygen saturation was lower (54 ± 13% vs 63 ± 12%, P = .011) and arterial-cerebral oxygen saturation difference was wider (38 ± 11% vs 30 ± 10%, P = .008). Cerebral oxygen saturation was also lower for the entire postoperative course (62 ± 18% vs 67 ± 9%, P = .047).

CONCLUSIONS

Postoperative S100B was elevated in about 40% of neonates and infants undergoing cardiac surgery. Infants with elevated postoperative S100B had impaired perioperative cerebral tissue oxygenation. No relation between S100B and cerebral oxygenation could be demonstrated in neonates.

Serum Neuronal Biomarkers in Neonates With Congenital Heart Disease Undergoing Cardiac Surgery

BACKGROUND

Newborns with congenital heart disease have associated brain damage that affects short-and long-term neurodevelopment. Several neuronal biomarkers exist that could predict brain damage. We investigated the pattern of neuron-specific enolase (NSE) and s100B levels after cardiopulmonary bypass surgery in neonates with congenital heart disease.

METHODS

We completed a prospective observational study of neonates with congenital heart disease who were undergoing cardiopulmonary bypass surgery. NSE and s100B levels were measured from serum samples obtained preoperatively, immediately postoperatively, and once daily on postoperative days one to seven. Cranial ultrasounds were obtained preoperatively and postoperatively and findings were scored using an internally developed scoring system.

RESULTS

Eighteen neonates were included. Immediate postoperative and peak levels of both NSE (58.0 [21.6] and 68.1 [55.7] μg/L) and s100B (0.14 [0.3] and 0.14 [0.3] μg/L) were significantly increased when compared with preoperative levels (34.0 [21.6] μg/L; P < 0.01 and 0.08 [0.1] μg/L; P < 0.02). By postoperative day seven, NSE and s100B levels were lower than preoperative levels: NSE (18 [5.7]; P = 0.09) and s100B (0.03 [0.05]; P < 0.01). Postoperative s100B levels were negatively correlated with age at surgery and positively correlated with circulatory arrest time. Although there was no significant correlation between either NSE or s100B levels and intensive care unit length of stay, hospital length of stay, and pediatric cerebral performance category score, there was a negative correlation between postoperative levels of NSE and ventriculomegaly.

CONCLUSIONS

NSE and s100B levels increase after bypass surgery and return below preoperative baseline levels by postoperative day seven. The levels of s100B were positively correlated with circulatory arrest time and negatively correlated with age at time of surgery. This finding may be supportive of pre-existing prenatal brain injury that could be enhanced by longer surgical times but also of some brain protection effect associated with longer wait until surgery.

Investigation of factors relating to neuropsychological change following cardiac surgery

Background. An analysis of neuropsychological impairment following cardiopulmonary bypass was performed in 55 patients undergoing elective coronary artery bypass grafting. Methods. Neurocognitive function was measured preoperatively using the MicroCog: Assessment of Cognitive Functioning computer-based testing tool. Testing was repeated in the postoperative period immediately prior to discharge from hospital. Analysis of significant score decline was performed using the standardised regression-based technique. A patient was classified as overall impaired when ≥20% of test scores were significantly impaired. The proposed marker of neurological damage S-100β was also used. Prothrombin Fragment 1+2 (F1+2) was measured as a marker of thrombin development to test the hypothesis that excessive haemostatic activation may lead to thromboembolic damage to the brain. Results and Conclusions. 32.7% of patients were classified as significantly impaired. No relationship was detected between F1+2 and any neuropsychological test score; however, the study was limited due to small sample size. F1+2 levels were higher in patients undergoing prolonged bypass times. Neuropsychological decline was significantly correlated with patient age, suggesting a degree of caution is warranted when operating on an elderly cohort. An unexpected relationship was detected between higher heparin concentrations and increased risk of neuropsychological impairment; however, this requires re-evaluation. Perfusion (2007) 22, 27—33.

Elevated preoperative serum asymmetrical dimethylarginine (ADMA) is associated with poor outcomes after pediatric cardiac surgery

PURPOSE

Asymmetrical dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase, is elevated in vascular pathologies such as hypertension and chronic kidney disease. Children undergoing cardiac surgery are at high risk of poor hemodynamic and renal outcomes secondary to cardiopulmonary bypass (CPB). This study tested the hypothesis that elevated preoperative ADMA levels are associated with overall worse clinical outcomes after pediatric CPB.

METHODS

This was a prospective, observational study of 100 patients aged from 2 weeks to 18 years who underwent cardiac surgery involving CPB. Serum ADMA levels were obtained preoperatively and on postoperative days zero through four. Clinical outcomes measured included acute kidney injury (AKI) by pRIFLE criteria, low cardiac output syndrome (LCOS), length of mechanical ventilation, hospital and ICU length of stay, unplanned reoperation, and mortality.

RESULTS

The 29 patients with an elevated preoperative ADMA were more likely to have prolonged mechanical ventilation, increased ICU and hospital length of stay, unplanned reoperation, and LCOS than those with a normal preoperative level. ADMA levels inversely correlated with estimated glomerular filtration rate (eGFR), but did not differ between patients with and without AKI after CPB. Preoperative ADMA levels correlated with hospital length of stay (r(s) = 0.289), ICU length of stay (r(s) = 0.308), and length of mechanical ventilation (r(s) = 0.402); [all p < 0.05]. ADMA levels before surgery had good predictive power for prolonged mechanical ventilation (AUC-ROC 0.809; 95 % CI 0.704, 0.914; p < 0.001).

CONCLUSIONS

Patients with elevated ADMA before surgery were more likely to have prolonged mechanical ventilation, develop LCOS, require an extended length of stay, and require reoperation. ADMA levels inversely correlated with eGFR, but did not predict AKI. Preoperative serum ADMA appears to identify pediatric cardiac surgery patients at risk of poor postoperative outcomes following CPB.

Ability of S100B to predict severity and cranial CT results in children with TBI

OBJECTIVES

To evaluate the ability of S100B to predict severity of TBI and abnormal cranial CT results for children with TBI.

METHODS

This is a secondary analysis of a previously established cohort of consecutive patients presenting to the emergency department with TBI limited to children <19 years of age, who arrived within 6 hours of injury, received a cranial CT scan and consented to blood drawn for S100B.

RESULTS

A total of 109 children were included in this cohort. The mean S100B levels were higher in children with moderate/severe TBI as compared to children with mild TBI based GCS score (0.281 µg L(-1), 95%CI = 0.101, 0.461 vs 0.053, 95%CI = 0.010, 0.095). S100B levels were significantly elevated in children following TBI with abnormal cranial CT as compared to children with a normal cranial CT (0.210 µg L(-1), SD = 0.313 vs 0.036 µg L(-1), SD = 0.046, p = 0.03). Area under the curve for S100B was also significant (0.72, 95%CI = 0.58, 0.86) for prediction of abnormal cranial CT for children with TBI. S100B did not predict abnormal cranial CT for children following TBI with a GCS of 15 (AUC = 0.53, 95%CI = 0.36, 0.71).

CONCLUSIONS

For children following TBI, S100B appears to predict severity of TBI; however, it may not be clinically useful as an independent screening test to select children with mild TBI who need a cranial CT.

Ketamine as a neuroprotective and anti-inflammatory agent in children undergoing surgery on cardiopulmonary bypass: a pilot randomized, double-blind, placebo-controlled trial

OBJECTIVE

Infants are potentially more susceptible to cell death mediated via glutamate excitotoxicity attributed to cardiopulmonary bypass. We hypothesized that ketamine, via N-methyl D-aspartate receptor blockade and anti-inflammatory effects, would reduce central nervous system injury during cardiopulmonary bypass.

METHODS

We randomized 24 infants, without chromosomal abnormalities, to receive ketamine (2 mg/kg, n = 13) or placebo (saline, n = 11) before cardiopulmonary bypass for repair of ventricular septal defects. Plasma markers of inflammation and central nervous system injury were compared at the end of surgery, and 6, 24, and 48 hrs after surgery. Magnetic resonance imaging and spectroscopy before cardiopulmonary bypass and at the time of hospital discharge were performed in a subset of cases and controls (n = 5 in each group). Cerebral hemodynamics were monitored postoperatively using near-infrared spectroscopy, and neurodevelopmental outcomes were assessed using Bayley Scales of Infant Development-II before and 2-3 wks after surgery.

RESULTS

Statistically significant differences were noted in preoperative inspired oxygen levels, intraoperative cooling and postoperative temperature, respiratory rate, platelet count, and bicarbonate levels. The peak concentration of C-reactive protein was lower in cases compared to controls at 24 hrs (p = .048) and 48 hrs (p = .001). No significant differences were noted in the expression of various cytokines, chemokines, S100, and neuron-specific enolase between the cases and controls. Magnetic resonance imaging with spectroscopy studies showed that ketamine administration led to a significant decrease in choline and glutamate plus glutamine/creatine in frontal white matter. No statistically significant differences occurred between pre- and postoperative Bayley Scales of Infant Development-II scores.

CONCLUSIONS

We did not find any evidence for neuroprotection or neurotoxicity in our pilot study. A large, adequately powered randomized control trial is needed to discern the central nervous system effect of ketamine on the developing brain. brain.

TRIAL REGISTRATION

The trial is registered at www.ClinicalTrials.gov, NCT00556361.

Comparison of S100B and NSE between cardiac surgery and interventional therapy for children

This study aimed to compare the release of S100B and NSE between cardiac surgery and interventional therapy for children and to investigate whether S100B serum concentration correlates with cardiopulmonary bypass in children. For this study, 40 children with congenital heart disease were selected and assigned to two groups: group A (20 children undergoing surgical therapy) and group B (20 children undergoing interventional therapy). In group A, blood samples were drawn 10 min after the induction of anesthesia, immediately after aortic cross-clamping, immediately at the end of cardiopulmonary bypass (CPB), immediately at the end of the operation, then 6 and 24 h after the operation. In group B, blood samples were drawn 10 min after the induction of anesthesia, immediately at the end of the procedure, then 6 and 24 h after the procedure. In group A, S100B plasma levels during the perioperative period and 6 h after the operation were higher than the preoperative level (p < 0.05). The NSE plasma concentrations at the termination of CPB and postoperatively were higher than the preoperative level (p < 0.05). Significant correlation was found between the peak value of S100B at the termination of CPB and the durations of both CPB and aortic cross-clamping. In group B, the differences in S100B and NSE between the post- and preoperative levels were not statistically significant (p > 0.05). The perioperative cerebral impairment indirectly evaluated by the release of NSE and S100B protein is greater in children undergoing CPB than in children undergoing interventional therapy. The release of S100B had a strong correlation with the durations of CPB and aortic cross-clamping in children.

Neuron-specific enolase and S-100B are associated with neurologic outcome after pediatric cardiac arrest

OBJECTIVE

To characterize the pattern of serum biochemical markers of central nervous system injury (neuron-specific enolase [NSE], S-100B, plasminogen activator inhibitor-1 [PAI-1]) after pediatric cardiac arrest and determine whether there is an association between biomarker concentrations and neurologic outcome.

DESIGN

Prospective, observational study.

SETTING

Urban, tertiary care children's hospital.

PATIENTS

Cardiac arrest survivors, n = 35.

INTERVENTIONS

Serial blood sampling, pediatric cerebral performance category, and standardized neurologic examination.

MEASUREMENTS AND MAIN RESULTS

Serial serum NSE and S-100B concentrations over 96 hrs and PAI-1 at 24 hrs were measured in children (age <18 yrs) who had return of spontaneous circulation following cardiac arrest. Neurologic outcome was prospectively categorized as poor if the change in pre- to postarrest pediatric cerebral performance category was > or =2. Biomarker concentrations were compared between outcome groups and between survival groups using longitudinal analysis correcting for multiple comparisons. Median levels (25th, 75th percentiles) are reported. Receiver operating characteristic analyses were performed at all time points. Biomarker concentrations showed statistically significant differences. Of the 35 patients, neurologic outcomes were poor in 19, with 15 deaths. Median NSE concentrations differed by outcome when measured at > or =48 hrs, and by survival at > or =24 hrs. S-100B concentrations were not significantly associated with neurologic outcome. S-100B levels were associated with survival outcome at > or =48 hrs. PAI-1 levels were not significantly associated with either neurologic or survival outcomes.

CONCLUSIONS

The timing, intensity, and duration of serum NSE and S-100B biomarker concentration patterns are associated with neurologic and survival outcomes following pediatric cardiac arrest. Serum NSE concentrations at > or =48 hrs are associated with neurologic outcome, whereas serum S-100B levels at > or =48 hrs are associated with survival. Prospective analysis of these markers may help to predict outcomes and guide postresuscitative therapies.

Factors associated with adverse neurodevelopmental outcomes in infants with congenital heart disease

OBJECTIVE

To review reported neurodevelopmental outcome data for patients with congenital heart disease, identify risk factors for adverse neurodevelopmental sequelae and summarize potential neuromonitoring strategies that have been described.

METHODS

A Medline search was performed utilizing combinations of the keywords congenital heart, cardiac, neurologic, neurodevelopment, neuromonitoring, quality of life, and outcome. All prospective and longitudinal follow-up studies of patients with congenital heart disease were included. Additionally, studies that examined neuroimaging, neuromonitoring, and clinical factors in relation to outcome were examined. Case reports and editorials were excluded. Additional references were retrieved from selected articles if the abstract described an evaluation of neurodevelopmental outcomes and/or predictors of outcome in patients with congenital heart disease.

RESULTS

Overall, patients with CHD have increased rates of neurodevelopmental impairments, although intelligence appears to be in the normal range. Preoperative risk stratification, intraoperative techniques, postoperative care, and neuromonitoring strategies may all contribute to ultimate long-term neurodevelopmental outcomes in patients with CHD postsurgical repair.

CONCLUSIONS

As advances in the medical and surgical management improves survival in patients with CHD, increasing knowledge about neurodevelopmental outcomes and the factors that affect them will provide for strategies to optimize long-term outcome in this high-risk population.

Surrogate markers for neurological outcome in children after deep hypothermic circulatory arrest

Improved survival for infants with congenital heart disease (CHD) has led to increased focus on the most significant morbidities that are neurodevelopmental. Neurologic injury in neurodevelopmental outcome may have many causes in children with complex CHD undergoing cardiopulmonary bypass and deep hypothermic circulatory arrest, including genetic syndromes, abnormal blood flow patterns, prenatal insults, and hemodynamic instability. Although gross neurological injury can be detected in the perinatal and postoperative period, more subtle injury may not be identified until much later. Disabilities in speech and language, motor skills, and attention deficit disorder are present by school age in up to 50% of the complex CHD population. It is imperative that the mechanisms of these injuries be identified to enable the application of neuroprotective interventions. To facilitate clinical investigation, evaluation of surrogate markers for these longer term "real" outcomes continues. Because some abnormalities may not be detected for years, the evaluation of a surrogate marker takes a long time. Thus, identification of surrogate markers is in its infancy. Serologic proteins, seizures, magnetic resonance findings, cerebral oxygenation, and the neurologic examination have all been studied. Continuing innovation in the use of magnetic resonance imaging techniques and the application of physiologic measures including near-infrared spectroscopy currently pose the greatest potential for advances. This article summarizes the state of the art and an admission about how far we have yet to travel as we strive to make the neurodevelopmental outcomes of patients with CHD comparable to their healthy peers.

NSE and S100 after hypoxia in the newborn pig

Perinatal asphyxia is an important cause of neonatal morbidity and mortality. There is the potential to halt cerebral damage if neural rescue strategies are applied within a short period of time after an insult. It is therefore important to be able to accurately identify neonates who may benefit from neural rescue therapies. Recent studies in asphyxiated neonates have correlated S100B and NSE with outcome; however, interpretation of these studies were difficult, as the timing of the measurements were not consistent. We measured NSE and S100 in 1-d-old piglets after a mild or severe hypoxic insult. Measurements were performed at 6-72 h after the insult and correlated with histologic outcome. There were no differences of the NSE or S100 concentrations between controls and the mild hypoxia group. After 24 h, there was a significant difference of NSE between the control/mild insult group and severe insult group. After 48 h, the S100 concentrations were significantly different between the control/mild insult group and the severe insult group. Both proteins showed good correlation at these time points with outcome as measured by histology score at 72 h. In conclusion, NSE and S100B measured in the serum of piglets after hypoxia increased significantly and correlated with outcome. This increase occurs too late to be used within the first 24 h but might be helpful for the clinician in determining the timing of an insult.

Serum S-100 β Protein During Coronary Artery Bypass Graft Surgery With or Without Cardiopulmonary Bypass

BACKGROUND

Brain damage is a serious complication of cardiac anesthesia. The purpose of this study was to detect brain damage at different surgical stages during coronary artery bypass graft with or without cardiopulmonary bypass.

METHODS

We conducted a prospective, longitudinal study to evaluate serum S-100 beta protein, an early marker of brain injury, in patients electively undergoing off-pump (n = 30) or traditional coronary artery bypass graft (n = 60). Blood was sampled immediately before anesthesia, before and after cardiopulmonary bypass, and on the day after surgery.

RESULTS

Serum S-100 beta protein was lowest immediately before induction of anesthesia and significantly increased before and after cardiopulmonary bypass, then declined by the first postoperative day in both groups. Peak values were highest in the traditional group directly after coronary artery bypass graft. On the day after surgery, S-100 beta protein levels were similar between groups, but were higher than baseline within each group. Significant increase in serum S-100 beta protein was also observed even before cardiopulmonary bypass in cardiopulmonary bypass patients, or before manipulation of the heart and aorta in off-pump patients. These reflect the possibility that brain damage may occur before major manipulation (cardiopulmonary bypass or manipulating heart and aorta). Moreover, S-100 beta levels did not return to normal on the day after the operation.

CONCLUSIONS

This prospective study has shown that serum S-100 beta protein was not only higher than baseline both after cardiopulmonary bypass and on the day after surgery in both groups of patients but it was also significantly increased before cardiopulmonary bypass or manipulation of the heart or aorta. These findings may have implications for anesthesiologic care during the total course of cardiac surgery.

Perioperative predictors of developmental outcome following cardiac surgery in infancy

At 1 year we assessed the neurodevelopmental outcomes in infants undergoing cardiac surgery, seeking to explore the predictive value of perioperative markers of cerebral injury. We prospectively enrolled 47 neurodevelopmentally normal infants prior to planned cardiac surgery. Postoperative monitoring consisted of 10-channel video synchronised, continuous electroencephalography from 6 to 30 h, Doppler assessment of cerebral blood flow in the anterior cerebral artery at 1, 2, 3 and 5 h, and measurement of serum S-100B at 0 and 24 h. Neurodevelopmental assessments were performed using the second edition of the Bayley Scale of Infant Development. Follow-up at 1 year was available on 35 infants. The mean age of these patients at surgery had been 57 +/- 15 days. We observed clinical seizures in 1 patient, with 3 other patients having electroencephalographic abnormalities. At follow-up of 1 year, neurodevelopmental scores were lower than preoperative scores, with mean mental scores changing from 103 +/- 5 to 94 +/- 13 (p = 0.001), and mean motor scores changing from 99 +/- 8 to 89 +/- 20 (p = 0.004). No association was found between electroencephalographic abnormalities, reduced cerebral blood flow, or elevation of serum S-100B levels and impaired neurodevelopmental outcome at 1 year. Infants with electroencephalographic abnormalities had elevation of the levels of S-100B in the serum (p = 0.02). At 1 year of follow-up, infants undergoing cardiac surgery demonstrated a reduction in the scores achieved using the second edition of the Bayley Scale of Infant Development. They require ongoing assessment of their progress. Electroencephalographic abnormalities, cerebral blood flow, or levels of S-100B in the serum were not useful perioperative markers for predicting a poor neurodevelopmental outcome in the clinical setting.

S-100beta protein--serum levels in children with brain neoplasms and its potential as a tumor marker

OBJECTIVE

To determine if serum S-100beta levels are elevated in children with brain neoplasms and if it can be used as a tumor marker for children with brain neoplasms.

DESIGN

Prospective cohort study.

SETTING

Urban, tertiary care, children's teaching hospital.

PATIENTS

136 healthy children and 27 children with brain neoplasms.

METHODS

Serum levels of S-100beta were measured in 136 healthy children to serve as controls and 27 children with brain neoplasms, who underwent biopsy or resection of the mass. Patients were then classified into astrocytoma or non-astrocytoma groups.

MEASUREMENTS AND MAIN RESULTS

The median serum S-100beta level for the control group was 0.27 mcg/l (range, 0.06-2.6 mcg/l), and for the brain neoplasm group was 0.2 mcg/l (range, 0.01-2.1 mcg/l), (p = 0.09). There were 13 children with astrocytomas and 14 with non-astrocytomas. The S-100beta levels for the astrocytoma group was 0.25 mcg/l (range, 0.05-1.1 mcg/l) and for the non-astrocytoma group 0.17 mcg/l (range, 0.01-2.1 mcg/l), (p = 0.47).

CONCLUSIONS

Serum S-100beta levels are not elevated in children with brain neoplasms compared to healthy children, nor are they elevated in children with astrocytomas compared to non-astrocytomas. The S-100beta protein does not appear to be useful as a serum tumor marker in children with brain neoplasms.

Delayed rises in serum S100B levels and adverse neurological outcome in infants and children undergoing cardiopulmonary bypass

BACKGROUND

The protein S100B is a marker of brain injury. Early after cardiopulmonary bypass (CPB), serum S100B levels are artefactually high. We investigated whether delayed (48 h) rise in S100B levels may have a role in detecting brain injury after CPB.

METHODS

Data from 43 children were analysed in this study. Samples were collected at preincision and 30 min, 24 and 48 h postbypass and then analysed by using a commercially available radioimmunoassay (Sangtec100). Charts were reviewed at 3-5 months for evidence of neurological injury.

RESULTS

S100B levels were high preoperatively in neonates and universally high immediately postbypass. In 36 children, samples were available for all time points. Compared with preoperative levels, rises occurred at both 24 and 48 h in three patients, only at 24 h in four patients and only at 48 h in three patients. Two patients had evidence of neurological injury. A rise at 48 h was associated with neurological injury (odds ratio 33.9, P < 0.03, 95% CI 1.39-827). There was no association between neurological injury and S100B levels at 24 h. Both the patients with neurological injury had rises at 48 h that were significantly higher than patients with rises at 48 h without injury.

CONCLUSIONS

The results of this study suggest that monitoring S100B levels in the late postoperative period may still have a role in detecting neurological injury after cardiac surgery in children. Consistent with previous observations, S100B is high preoperatively in neonates and early postbypass in all patients.

Over-expression of S100B protein in children with cerebral palsy or delayed development

S100B protein plays a role in promoting the maturation of a variety of neurons in many different CNS regions. Behavioral dysfunction in S100B over-expressed transgenic mice and the chronic elevation of S100B in Down's syndrome and in schizophrenia suggest that S100B over-expression is related to abnormal brain function. Therefore, we believed that the over-expression of S100B protein might be implicated in developmental brain dysfunction. The purpose of this study was to evaluate the serum S100B protein levels in patients with developmental brain dysfunction, such as cerebral palsy and delayed development, and to determine the clinical relevance of serum S100B protein in these patients. The mean values of serum S100B protein were significantly increased in both conditions. Patients with cerebral palsy had a S100B protein level of 3455.8 +/- 5004.6 ng/L and those with delayed development of 2557.0 +/- 2321.0 ng/L, compared with a normal control level of 583.8 +/- 483.0 ng/L (P < 0.05). The over-expression of S100B (defined as the normal mean plus three standard deviations) was found in 47.1% of the total patient group (delayed development (47.5%) and cerebral palsy (47.0%)). The frequency of over-expression was not significantly related to clinical diagnosis, disease severity or to brain MRI findings. However, patients who had periventricular leukomalacia by brain MRI showed a wide range and very high levels of S100B exceeding 10,000 ng/L in some cases. These findings suggest that the pathogenesis implied by the over-expression of S100B protein during brain development may play a role in developmental brain dysfunction.

S100 protein in serum as a prognostic marker for cerebral injury in term newborn infants with hypoxic ischemic encephalopathy

The astroglial protein S100 is an established biochemical marker for CNS injury in the adult. The aim was to investigate whether S100 in serum is a prognostic marker of cerebral injury in term newborn infants with hypoxic ischemic encephalopathy (HIE) after perinatal asphyxia. Serum S100 was measured on postnatal days 1-4 in 62 term infants with birth asphyxia. The infants were classified for HIE and had follow-up for at least 18 mo. Infants with moderate and severe HIE had significantly higher S100 levels on postnatal day 1 (p = 0.031) and day 2 (p = 0.008) than infants with mild or no HIE. The levels of S100 decreased on days 2 and 3 in all infants with HIE. The median S100 level on postnatal day 1 was higher in nine infants who died neonatally and in 10 infants who developed cerebral palsy (CP), compared with 43 infants with no signs of impairment at follow up, 14.0 (0.5-60.0) microg/L, 20.7 (0.2-64.0) microg/L and 5.5 (0.7-120.0) microg/L, respectively. A level of S100 above 12 microg/L the first day of life was significantly more frequent in infants who died or developed CP than in infants with no impairment at follow up (p = 0.02). Increased S100 levels were significantly inversely correlated with perinatal pH in the infants and associated with abnormal CTG at admission to the labor ward. Early determination of serum S100 may reflect the extent of brain damage in infants with HIE after asphyxia.

A pilot study of evaluation of cerebral function by S100? protein and near-infrared spectroscopy during cold and warm cardiopulmonary bypass in infants and children undergoing open-heart surgery

Cerebral injury in children undergoing cardiopulmonary bypass (CPB) remains a major source of morbidity. The effect of cardiopulmonary bypass temperature on cerebral function in terms of serum S100beta protein level and cerebral oxygenation monitored by near infrared spectroscopy (NIRO-300) in children is not known. In this study, 18 children undergoing open-heart surgery at the Hospital for Sick Children in London were equally assigned by minimisation to warm (35 +/- 1 degrees C) or cold (25 +/- 1 degrees C) CPB. Changes in S100beta protein and cerebral oxygenation were studied in both groups. S100beta protein serum level increased significantly after CPB in both groups. There was no significant difference in serum S100beta protein concentrations between the two groups. However, cerebral oxygenation in terms of tissue oxygen index (TOI) was significantly impaired during rewarming from cold CPB. Five patients were desaturated (TOI < 50%) during rewarming in the cold bypass group compared to two in the warm patients. This study supports the use of warm CPB in children undergoing open-heart surgery, although further studies recruiting more patients are warranted.

Early postoperative prediction of cerebral damage after pediatric cardiac surgery

BACKGROUND

Cerebral damage is a serious complication of pediatric cardiac surgery. Early prediction of actual risk can be useful in counseling of parents, and in early diagnosis and rehabilitation therapy. Also, if all children at risk could be identified therapeutic strategies to limit perioperative cerebral damage might be developed. The aim of this study is to create a mathematical model to predict risk of neurologic sequelae within 24 hours after surgery using simple and readily available clinical measurements.

METHODS

The hospital records of 534 children after cardiac surgery were reviewed. Variables examined were age at operation, diagnosis, use of cardiopulmonary bypass, arterial and central venous oxygen saturation, serum glucose, lactate and creatine kinase, mean arterial pressure, and body temperature. The endpoint for each study patient was the occurrence or lack of occurrence of seizures, movement or developmental disorders, cerebral hemorrhage, infarction, hydrocephalus, or marked cerebral atrophy. Univariate and multivariate regression analyses were used to evaluate the predictive power of the investigated factors as well as to create a predictive model.

RESULTS

In 6.26% of children symptoms of cerebral damage were found. Significant risk factors were age at surgery, more complex malformations, metabolic acidosis, and increased lactate (odds ratio: age, 0.882/yr [0.772-1.008]; complex malformations, 10.32 [1.32-80.28]; arterial pH more than 7.35 to 0.4 [0.18-0.89]; lactate -1.018 per mg/dL [1.006-1.03]).

CONCLUSIONS

It is possible to quantify the risk of appearance of symptoms of cerebral damage after cardiac surgery within 24 hours using simple and readily available clinical measurements.

Do S100beta protein level increases due to inflammation during cardiopulmonary bypass occur without any neurological deficit?

PURPOSE

S100beta protein level correlates with the duration of cardiopulmonary bypass (CPB) and aortic crossclamp times, but is different during pulsatile and nonpulsatile CPB. In this study, we investigated the time course of the release of S100beta protein during and after pulsatile and nonpulsatile CPB.

PATIENTS AND METHODS

This is a prospective study. Twenty patients had open-heart surgery with pulsatile flow and 20 with nonpulsatile flow. We compared complement proteins, interleukins, white blood cells and S100beta protein before the initiation of CPB, immediately prior to aortic crossclamping, following unclamping, and at postoperative 1st and 24th hours.

RESULTS

In the pulsatile CPB group following aortic unclamping, S100beta protein (p = 0.028) and C3a (p = 0.011) levels were significantly lower than those of the nonpulsatile group. In the pulsatile CPB group at postoperative first hour, C3a level (p = 0.018) and absolute neutrophil count (p = 0.034) were significantly lower than those of the nonpulsatile group. None of the patients developed a neurological deficit and all of the patients survived after the operation and were discharged from the hospital.

CONCLUSION

During CPB, serum S100beta protein level increases and this increase is higher in the nonpulsatile group. High serum level of S100beta protein is associated with increased levels of serum inflammatory mediators and systemic inflammatory response.

Detection of traumatic brain injury with magnetic resonance imaging and S-100B protein in children, despite normal computed tomography of the brain

OBJECTIVE

The objective of this study was to obtain data to further define the extent of traumatic brain injury by using S-100B protein and standard noncontrast magnetic resonance imaging with added fluid-attenuated inversion recovery (FLAIR) and gradient echo sequence in children with normal head computed tomography.

DESIGN

Pilot, single cohort, prospective, clinical diagnostic study.

SETTING

Pediatric intensive care and intermediate care unit in a tertiary care children's hospital.

PATIENTS

Children ages 5-18 yrs who sustained traumatic brain injury, had a negative computed tomography of the brain, and were admitted to hospital were eligible for enrollment.

INTERVENTIONS

Two blood samples were drawn for S-100B protein analysis: the first (t-1) as soon as possible or close to 6 hrs of injury and the second (t-2) close to 12 hrs from the time of injury. A magnetic resonance image of the brain was obtained within 96 hrs of injury.

MEASUREMENTS AND MAIN RESULTS

Seven of 17 patients (41%) had positive magnetic resonance image. Of the seven patients with positive magnetic resonance image, 100% (seven of seven) had a positive magnetic resonance image with FLAIR sequence, 85% (six of seven) with axial T2 sequence and 50% (three of six) with gradient echo sequence. There was no statistically significant difference in S-100B protein concentrations in patients with a positive magnetic resonance image (n = 7) and those with a negative magnetic resonance image (n = 10; p =.40 at t-1 and p =.13 at t-2). The concentration of S-100B protein was statistically significantly higher in patients with head and other bodily injury (n = 9) compared with isolated head injury (n = 6; p =.018 at t-1 and p =.025 at t-2). Patients with a positive magnetic resonance image had a lower Glasgow Coma Scale score and longer duration of hospital stay.

CONCLUSIONS

Magnetic resonance imaging seems to be a useful modality to better define the spectrum of brain injury in children with mild head trauma. The addition of S-100B protein measurement does not seem to be useful in this setting.

Effects of dexamethasone on clinical course, C-reactive protein, S100B protein and von Willebrand factor antigen after paediatric cardiac surgery

BACKGROUND

Anti-inflammatory treatment with glucocorticoids during cardiopulmonary bypass can reduce inflammatory mediator release, but the effects of glucocorticoid on outcome are controversial.

METHODS

We studied the effects of dexamethasone on clinical course, C-reactive protein, von Willebrand factor antigen (vWf:Ag) and S100B in a randomized masked study of children after open cardiac surgery. Twenty children weighing >10 kg received dexamethasone (1 mg kg(-1)) and 20 controls received saline after induction of anaesthesia. We measured vWf:Ag as a marker of endothelial activation, S100B as a marker of cerebral protein release and C-reactive protein as a marker of inflammatory activity. Oxygenation, body temperature, fluid balance, leucocyte and platelet counts, days in the intensive care unit (ICU) and days on mechanical ventilation were noted.

RESULTS

Dexamethasone decreased C-reactive protein concentration on the first postoperative day (P<0.05), but did not affect the release of vWf:Ag or S100B. There was no significant difference in oxygenation, body temperature, fluid balance, leucocyte and platelet counts, days in the ICU or days on mechanical ventilation between the placebo and dexamethasone-treated groups.

CONCLUSION

Administration of dexamethasone before cardiopulmonary bypass for paediatric cardiac surgery decreased the inflammatory response, but did not affect the immediate features after surgery or changes in vWf:Ag or S100B.

Serial measurement of serum S-100B protein as a marker of cerebral damage after cardiac surgery

BACKGROUND

We used serial measurements of serum S-100B protein to evaluate the time course of serum S-100B protein concentration after cardiovascular surgery and to determine the clinical relevance of its concentration and cerebral damage.

METHODS

We assessed neurologic function in 149 patients undergoing cardiovascular surgery with cardiopulmonary bypass. The patients were classified into three groups according to their early postoperative outcome: those without complications (group A), those having unconsciousness or convulsion or both but no hemiplegia (group B), and those having unconsciousness and hemiplegia either with or without convulsion (group C). Serum S-100B protein concentrations were measured with a commercially available immunoluminometric assay, Sangtec 100 LIA, at seven time-points: before cardiopulmonary bypass, at the end of cardiopulmonary bypass, and at 5, 12, 24, 48, and 72 hours after cardiopulmonary bypass.

RESULTS

At 5 hours after cardiopulmonary bypass, the S-100B values in groups B and C were significantly higher than the value in group A. Although the S-100B level decreased in group C during the first 5 hours after cardiopulmonary bypass, it increased thereafter (12 through 24 hours) and continued at a high level until the final measurement at 72 hours. At 12 hours after cardiopulmonary bypass, S-100B was significantly higher in group C than in group B. This late increase in S-100B was associated with radiologically detected abnormalities and cerebral damage.

CONCLUSIONS

Serial measurement of serum S-100B protein in the initial 12 hours after cardiopulmonary bypass can be used to predict early postoperative brain injury.

S100B in brain damage and neurodegeneration

S100B is a calcium-binding peptide produced mainly by astrocytes that exert paracrine and autocrine effects on neurons and glia. Some knowledge has been acquired from in vitro and in vivo animal experiments to understand S100B's roles in cellular energy metabolism, cytoskeleton modification, cell proliferation, and differentiation. Also, insights have been gained regarding the interaction between S100B and the cerebral immune system, and the regulation of S100B activity through serotonergic transmission. Secreted glial S100B exerts trophic or toxic effects depending on its concentration. At nanomolar concentrations, S100B stimulates neurite outgrowth and enhances survival of neurons during development. In contrast, micromolar levels of extracellular S100B in vitro stimulate the expression of proinflammatory cytokines and induce apoptosis. In animal studies, changes in the cerebral concentration of S100B cause behavioral disturbances and cognitive deficits. In humans, increased S100B has been detected with various clinical conditions. Brain trauma and ischemia is associated with increased S100B concentrations, probably due to the destruction of astrocytes. In neurodegenerative, inflammatory and psychiatric diseases, increased S100B levels may be caused by secreted S100B or release from damaged astrocytes. This review summarizes published findings on S100B regarding human brain damage and neurodegeneration. Findings from in vitro and in vivo animal experiments relevant for human neurodegenerative diseases and brain damage are reviewed together with the results of studies on traumatic, ischemic, and inflammatory brain damage as well as neurodegenerative and psychiatric disorders. Methodological problems are discussed and perspectives for future research are outlined.

S-100beta protein-serum levels in healthy children and its association with outcome in pediatric traumatic brain injury

OBJECTIVE

To describe normal serum levels of S-100beta in healthy children and determine whether serum S-100beta levels after traumatic brain injury are associated with outcome.

DESIGN

Prospective cohort study.

SETTING

Urban, tertiary care, children's teaching hospital.

PATIENTS

A total of 136 healthy children and 27 children with traumatic brain injury.

METHODS

Serum S-100beta levels were measured in 136 healthy children. A total of 27 children with traumatic brain injury had S-100beta levels collected within 12 hrs of injury. Other indices of severity of injury measured were admission Glasgow Coma Scale score, and Pediatric Risk of Mortality score at 24 hrs (PRISM 24). Outcome was measured by the Pediatric Cerebral Performance Category (PCPC) score at hospital discharge and 6 months postinjury or at death.

MEASUREMENTS AND MAIN RESULTS

S-100beta levels in healthy children had a mean of 0.3 microg/L (90% confidence interval, 0.03-1.47) and inversely correlated with age, (r = -.32, p <.001). In children with traumatic brain injury, 6-month postinjury outcome inversely correlated with Glasgow Coma Scale score (r = -.47, p =.01) and correlated with PRISM 24 score (r =.83, p <.001) and S-100beta levels (r =.75, p <.001). Six months postinjury, comparing good outcome (PCPC < or = 3, n = 20) vs. poor outcome (PCPC > or = 4, n = 7), median admission Glasgow Coma Scale scores were 8 (range, 3-15) and 3 (range, 3-7, p =.01), median PRISM 24 scores were 7 (range, 0-19) and 30 (range, 18-35, p <.001), and median S-100beta levels were 0.85 microg/L (range, 0.08-4.8 microg/L) and 3.6 microg/L (range, 1.4-20 microg/L, p <.001), respectively. A serum S-100beta level of > or =2.0 microg/L is associated with poor outcome, with a sensitivity of 86% and a specificity of 95%. The area under the receiver operating curve for S-100beta was 0.94 (+/-0.05).

CONCLUSIONS

Serum S-100beta levels in healthy children have a moderate inverse correlation with age. After traumatic brain injury in children, the acute assessment of serum S-100beta levels seems to be associated with outcome.

A glial-derived protein, S100B, in neonates and infants with congenital heart disease: evidence for preexisting neurologic injury

The glial-derived protein S100B is a serum marker of cerebral ischemia and correlates with negative neurological outcome after cardiopulmonary bypass (CPB) in adults. We sought to characterize the S100B release pattern before and after CPB in neonates and infants with congenital heart disease and correlate it with surgical mortality. Serum was collected before surgery and at 24 postoperative h from 109 neonates and infants with congenital heart disease. All patients had presurgical transthoracic echocardiograms and CPB with or without hypothermic circulatory arrest. S100B concentrations were determined using a two-site immunoluminometric assay (Sangtec 100). Thirty-day surgical mortality was observed. All neonates had significantly increased S100B concentrations before surgery that decreased by 24 postoperative h. Preoperative S100B concentrations in 32 neonates with hypoplastic left heart syndrome correlated inversely with the forward flow and size of the ascending aorta and postoperative mortality (r(2) = -0.63; P = 0.03). Among infants, increased pulmonary blood flow was associated with higher S100B levels before surgery than cyanosis. There was no correlation with postoperative S100B and time on CPB, hypothermic circulatory arrest, or 30-day surgical mortality. In conclusion, preoperative S100B concentrations correlate inversely with the size of the ascending aorta in hypoplastic left heart syndrome and may serve as a marker for preexisting brain injury and mortality.

IMPLICATIONS

Neonates with hypoplastic left heart syndrome and no forward flow in the ascending aorta may have brain injury at birth before heart surgery.

Clinical significance of serum S-100 beta protein level after pediatric cardiac surgery

OBJECTIVE

The serum S-100 beta protein level is a specific marker of damage to the central nerve system (CNS). We studied its significance in pediatric cardiac surgery as a possible marker of CNS damage.

METHODS

Subjects were 18 consecutive pediatric patients aged 12 days to 13 years (mean: 2.8 years) undergoing open-heart surgery. We measured the serum S-100 beta protein level using ELISA (SRL Co. Ltd., Tokyo) immediately after inducing anesthesia and immediately, 12 hours, and 24 hours after weaning from cardiopulmonary bypass (CPB).

RESULTS

None had postoperative neurological symptoms. The prebypass serum S-100 beta protein level showed a significant logarithmic correlation with patient age. All patients showed increased S-100 beta protein immediately after weaning from CPB, and multiple regression analysis showed that bypass time and cyanosis were significant factors in such as increase. Cyanosis was the only factor in increased S-100 beta protein levels 12 and 24 hours after weaning from CPB. The peak S-100 beta protein level showed a significant exponential correlation with bypass time.

CONCLUSION

Serum S-100 beta protein elevated immediately after weaning from CPB correlated with bypass time but not with neurological symptoms. Physiological changes other than substantial brain damage caused by CPB may increase the serum S-100 beta protein level. Prebypass data on neonates and infants showed serum S-100 beta protein increased without brain damage supporting this hypothesis.

Normothermic versus hypothermic cardiopulmonary bypass during repair of congenital heart disease

OBJECTIVE

To compare normothermic cardiopulmonary bypass (CPB) versus hypothermic CPB in pediatric patients undergoing repair of congenital heart disease with focus on biochemical markers for brain damage.

DESIGN

Prospective randomized interventional study.

SETTING

Postgraduate teaching hospital.

PARTICIPANTS

Twenty patients undergoing repair of congenital heart disease.

INTERVENTIONS

Patients were randomized to normothermic (36 degrees C) versus hypothermic (25 degrees C) CPB. Serum levels of neuron-specific enolase (NSE) and S-100beta protein were measured in all patients before surgery, immediately after CPB, and 12 and 24 hours after surgery. Blood loss and time for extubation of the trachea were recorded.

MEASUREMENTS AND MAIN RESULTS

Before operation, the S-100beta protein and NSE levels were similar in the 2 groups. The S-100beta protein serum level increased significantly after CPB in both groups, whereas no change was found in the NSE level. There was no difference in the change of NSE and S-100beta protein levels between normothermic and hypothermic CPB. Blood loss was significantly less after hypothermic CPB (25 mL/kg/24 h v 42 mL/kg/24 h). Time for extubation was similar.

CONCLUSION

No difference was found in the release of brain-specific proteins between normothermic and hypothermic CPB, but blood loss was higher after normothermic CPB.

The systemic inflammatory response after cardiac surgery with cardiopulmonary bypass in children

Paediatric cardiac surgery often requires cardiopulmonary bypass (CPB) during the surgical intervention. CPB is known to elicit a systemic inflammatory response with activation of the complement and coagulation systems, stimulation of cytokine production, cellular entrapment in organs, neutrophil activation with degranulation, platelet activation, and endothelial dysfunction. These changes are associated with a risk of postoperative organ dysfunction and increased morbidity and mortality in the postoperative period. Clinical studies have concentrated on measurement of inflammatory markers and mediators in peripheral blood, where the systemic inflammatory response in the paediatric cardiac patient seems to be different from the adult case. Looking at the organ level, experimental studies have the advantage of providing information contributing to a better understanding of the pathological events that may lead to the deteriorated organ function. This review focuses on the systemic inflammatory response after cardiac surgery with CPB in children and experimental CPB models.

S100beta correlates with neurologic complications after aortic operation using circulatory arrest

BACKGROUND

Astrocyte protein S100beta is a potential serum marker for neurologic injury. The goals of this study were to determine whether elevated serum S100beta correlates with neurologic complications in patients requiring hypothermic circulatory arrest (HCA) during thoracic aortic repair, and to determine the impact of retrograde cerebral perfusion (RCP) on S100beta release in this setting.

METHODS

Thirty-nine consecutive patients underwent thoracic aortic repairs during HCA; RCP was used in 25 patients. Serum S100beta was measured preoperatively, after cardiopulmonary bypass, and 24 hours postoperatively.

RESULTS

Neurologic complications occurred in 3 patients (8%). These patients had higher postbypass S100beta levels (7.17 +/- 1.01 microg/L) than those without neurologic complications (3.63 +/- 2.31 microg/L, p = 0.013). Patients with S100beta levels of 6.0 microg/L or more had a higher incidence of neurologic complications (3 of 7, 43%) compared with those who had levels less than 6.0 microg/L (0 of 30, p = 0.005). Retrograde cerebral perfusion did not affect S100beta release.

CONCLUSIONS

Serum S100beta levels of 6.0 microg/L or higher after HCA correlates with postoperative neurologic complications. Using serum S100beta as a marker for brain injury, RCP does not provide improved cerebral protection over HCA alone.

Early biochemical indicators of hypoxic-ischemic encephalopathy after birth asphyxia

Hypoxic-ischemic encephalopathy (HIE) after perinatal asphyxia is a condition in which serum concentrations of brain-specific biochemical markers may be elevated. Neuroprotective interventions in asphyxiated newborns require early indicators of brain damage to initiate therapy. We examined brain-specific creatine kinase (CK-BB), protein S-100, and neuron-specific enolase in cord blood and 2, 6, 12, and 24 h after birth in 29 asphyxiated and 20 control infants. At 2 h after birth, median (quartiles) serum CK-BB concentration was 10.0 U/L (6.0-13.0 U/L) in control infants, 16.0 U/L (13.0-23.5 U/L) in infants with no or mild HIE, and 46.5 U/L (21.4-83.0 U/L) in infants with moderate or severe HIE. Serum protein S-100 was 1.6 microg/L (1.4-2.5 microg/L) in control infants, 2.9 microg/L (1.8-4.7 microg/L) in asphyxiated infants with no or mild HIE, and 17.0 microg/L (3.2-34.1 microg/L) in infants with moderate or severe HIE 2 h after birth. No significant difference was detectable in serum neuron-specific enolase between infants with no or mild and moderate or severe HIE 2 and 6 h after birth. A combination of serum protein S-100 (cutoff value, 8.5 microg/L) and CK-BB (cutoff value, 18.8 U/L) 2 h after birth had the highest predictive value (83%) and specificity (95%) of predicting moderate and severe HIE. Cord blood pH (cutoff value, <6.9) and cord blood base deficit (cutoff value, >17 mM) increase the predictive values of protein S-100 and CK-BB. We conclude that elevated serum concentrations of protein S-100 and CK-BB reliably indicate moderate and severe HIE as early as 2 h after birth.

Brain-specific NSE and S-100 proteins in umbilical blood after normal delivery

BACKGROUND

To determine normal blood levels of brain-specific proteins S-100 and neuron specific enolase (NSE) in healthy newborns and their mothers following uncomplicated birth.

METHODS

Umbilical artery and vein blood and maternal venous blood was collected at 112 consecutive uncomplicated deliveries. Venous blood samples were taken from 18 of the neonates 3 days after birth. S-100 and NSE were analyzed quantitatively by double antibody immunoluminometric assay (Sangtec Medical AB, Sweden).

RESULTS

Compared with adults, healthy neonates had higher levels of both S-100 and NSE. For S-100, median levels (range) were 1.10 microg/l (0.38-5.50 microg/l and 0.98 microg/l (0.43-2.70 microg/l) in umbilical artery and vein, respectively. For NSE, median levels (range) in umbilical artery blood and vein were 27 microg/l (10-140 microg/l) and 10.75 microg/l (8.80->/=200 microg/l) respectively. The maternal venous blood levels of both S-100 and NSE were significantly lower than in their infants. At 3 days of life, neonatal venous levels of the proteins were still high: S-100, 0.48-9.70 microg/l; NSE, 17->/=200 microg/l. In contrast to adults, haemolysis affected the S-100 levels in umbilical blood significantly.

CONCLUSION

Concentrations of both S-100 and NSE in blood are greater in newborns after normal birth than in healthy adults. The higher levels in umbilical artery blood than in umbilical vein blood are consistent with a fetal origin of these proteins. High levels in venous blood at 3 days of life suggest that the high levels at birth are not related to the birth process but reflect a high activity of these proteins during fetal development.

Blood S-100 protein concentration in children undergoing cardiac surgery

OBJECTIVES

To investigate plasma levels of the betabeta isomer of S-100 protein and to assess the relationship between post-cardiopulmonary bypass (CPB) levels of this marker and a variety of perioperative and patient factors in children undergoing cardiac surgery.

DESIGN

Prospective study.

SETTING

University hospital.

PARTICIPANTS

Twenty-five children.

INTERVENTIONS

Blood samples (2 mL) for S-100 determinations were collected after the induction of anesthesia, 30 minutes after aortic cross-clamping, 1 hour after the termination of CPB, and 5 and 24 hours after the operation. Electroencephalogram activity was recorded, and neurologic examination was performed on all children 1 day before and 10 days after the operation. Lowest values of nasopharyngeal temperature, mean arterial pressure, arterial carbon dioxide tension (PaCO2), pH, and hematocrit during CPB were recorded.

MEASUREMENTS AND MAIN RESULTS

The overall change in S-100 during the study period was found to be statistically significant (p < 0.0001). Correlation between deltaS-100 and age (r = -0.45; p = 0.04), body surface area (r = -0.63; p = 0.002), nasopharyngeal temperature (r = -0.55; p = 0.01), and PaCO2 (r = -0.55; p = 0.009) was statistically significant in infants and children. Multivariate regression analysis indicated significant effects of PaCO2 and body surface area on deltaS-100 levels and area under the curve values.

CONCLUSION

In contrast to newborns, infants and older children showed prominent increases in S-100 protein concentration. Lack of pathologic electroencephalogram findings and neurologic signs in the postoperative period precludes the clinical use of S-100 protein concentration as a sensitive marker of cerebral injury.

Serum S-100beta protein predicts brain injury after hypothermic circulatory arrest in pigs

OBJECTIVE

Serum S-100beta protein is suggested to be a neurobiochemical marker of brain injury after cardiac and aortic arch surgery. The aim of the present study was to investigate the predictive value of S-100beta protein with respect to histopathological analysis of the brain after a prolonged period of hypothermic circulatory arrest (HCA).

METHODS

Eighteen pigs (21 to 31 kg) underwent a 75 min period of HCA at 20 degrees C. Serum concentrations of S-100beta were assayed in mixed venous blood before and 2, 4, 7 and 20 h after HCA. A semiquantitative post-mortem histopathological analysis scoring all main regions of the brain was carried out in every animal.

RESULTS

All animals were stable during and after cardiopulmonary bypass (CPB) and survived at least to the first postoperative day. Ten of the 18 animals survived 7 days after surgery and were electively sacrificed. Animals with severe histopathological injury showed higher serum S-100beta protein levels at every time point after HCA. The strongest correlation between the total histopathologic score and serum S-100beta levels was found at 7 h after HCA (tau = 0.422 and p = 0.023).

CONCLUSION

Serum S-100beta protein levels correlate with histopathological injury after a prolonged period of HCA in pigs. This finding supports the results of previous studies suggesting the potential accuracy of S-100beta in the prediction of brain injury after cardiac surgery.

Neuronal and astroglial injuries in patients undergoing coronary artery bypass grafting and aortic arch replacement during hypothermic cardiopulmonary bypass

More than 50% of patients suffer neuropsychologic impairment after cardiac surgery. We measured neuron-specific enolase (NSE) and S-100 protein (S-100) in patients' serum as putative markers of neuronal and astroglial cell injury, respectively. Group I (n = 13) underwent coronary artery bypass grafting (CABG) with mild hypothermic cardiopulmonary bypass (CPB); Group II (n = 6) underwent aortic arch replacement with deep hypothermic CPB; Group III (n = 8) underwent CABG under normothermia without CPB. During and after the operation, serum levels of NSE and S-100 were significantly increased only in Groups I and II (during CPB), NSE still being increased 12 h after surgery in Group II. This suggests that neuronal and astroglial cell injuries are more likely in patients undergoing CABG with mild hypothermic CPB or aortic arch replacement with deep hypothermic CPB than in those undergoing CABG under normothermia without CPB. However, these increases of NSE and S-100 failed to reflect clinical brain damage. Rather, an electroencephalogram, was only capable of detecting neurologic complications after surgery.

IMPLICATIONS

Neuronal and astroglial cell injuries are likely to occur during coronary artery bypass grafting with mild hypothermic cardiopulmonary bypass (CPB) or aortic arch replacement with deep hypothermic CPB. Conversely, patients undergoing coronary artery bypass grafting without CPB under normothermic conditions may be less likely to suffer brain cell injury.

Off-pump coronary bypass operations significantly reduce S100 release: an indicator for less cerebral damage?

BACKGROUND

Cardiac operations using extracorporeal circulation bear a risk of cerebral complications. The aim of our study was to investigate if off-pump operations without heart-lung machines can reduce cerebral injury.

METHODS

S100, a protein specific for cerebral tissue, was used as a marker for cerebral impairment in 108 randomized patients undergoing coronary bypass operation: 67 patients (group A) were operated on with extracorporeal circulation and cardioplegic cardiac arrest, and 41 patients (group B) underwent off-pump beating heart revascularization. Both groups were similar regarding age, sex, ejection fraction, and number of anastomoses. S100 levels were measured from induction of anesthesia until 24 hours after the operation.

RESULTS

Data collection was 100% complete. There was no in-hospital death. Nonfatal myocardial infarctions occurred in 2 patients in group A, and 1 patient in group B required resternotomy for bleeding. There was no neurologic deficit in either group. S100 levels increased only slightly in the off-pump patients (group B), whereas in group A there was a sharp rise in S100 concentration during extracorporeal circulation, only returning to baseline 6 hours after the end of the operation. Peak S100 levels were four times higher in group A than in group B (2.1 microg/L versus 0.5 microg/L; p < 001).

CONCLUSIONS

The results of our study suggest that perioperative cerebral impairment is reduced in cardiac operations without the use of extracorporeal circulation. Further large-scale studies are needed to show whether this result is reflected by fewer neurologic deficits.

Serum S100 protein as a marker of cerebral damage during cardiac surgery

The identification of a serum marker to assist in the diagnosis of cerebral injury after cardiac surgery is potentially useful. S100 protein is an early marker of cerebral damage. It is released after cardiac surgery performed under cardiopulmonary bypass (CPB). Its level is correlated with the duration of CPB, deep circulatory arrest and aortic cross-clamping. Increased levels of S100 protein are correlated with the age of the patient and the number of microemboli, especially during aortic cannulation. Perioperative cerebral complications such as stroke, delayed awakening and confusion are associated with increased levels of S100 protein directly after bypass and from 15 to 48 h after it. In addition, increased levels of S100 protein are related to neuropsychological dysfunction after cardiac surgery. S100 protein has early and late release patterns after CPB; the early pattern may be due to sub-clinical brain injury. The late release pattern may be due to perioperative cerebral complications. Patients undergoing intracardiac operations combined with coronary artery bypass surgery are more susceptible to brain injury and have higher levels of S100 after CPB. Furthermore, adults and children undergoing deep circulatory arrest are more susceptible to brain injury, in terms of higher S100 protein release after CPB. Serum S100 protein levels are reduced after using arterial line filtration and covalent-bonded heparin to coat the inner surface of the CPB circuit.

Increased levels of S-100 protein after cardiac surgery with cardiopulmonary bypass and general surgery in children

The aim of this study was to evaluate changes in concentrations of the neurospecific protein S-100 in relation to cardiac surgery with cardiopulmonary bypass (CPB) and noncardiac general surgery in children below 3 years of age. Seventeen children underwent surgery for congenital heart disease and all survived without clinical signs of neurological complications. Samples for plasma concentrations of S-100 in these patients were taken on three occasions in connection with surgery: before the start of surgery, after CPB and finally 16-20 h after CPB. In the noncardiac group of 31 children, S-100 concentrations were measured on two occasions: before surgery and during surgery. In both groups, a significant increase in S-100 concentrations was observed during surgery, although the increase in the CPB group was significantly higher than in the noncardiac group. The CPB group included four children with Down's syndrome who had higher mean S-100 concentrations on all sampling occasions compared to the remaining patients. The peak S-100 concentrations after cardiac surgery were related to the duration of CPB, the time from the termination of CPB to the first post-CPB sample, as well as mean arterial pressure and cerebral arteriovenous lactate difference during rewarming. All the children studied (Down's patients excluded) had age-dependent plasma concentrations of S-100 measured before surgery. It can be concluded that CPB initiates a marked but transient release of S-100 into the systemic circulation during open heart surgery in children who are not developing clinical signs of neurological sequelae.

S-100 after correction of congenital heart defects in neonates: is it a reliable marker for cerebral damage?

BACKGROUND

Newborns undergoing cardiac operation may acquire some extent of neuronal damage. An early diagnosis is especially hard regarding neonates. In the past years, S-100 has been widely discussed as a marker revealing perioperative damage to the brain.

METHODS

Sequential blood samples from 33 neonates undergoing repair of congenital heart disease were taken perioperatively. Samples of 12 healthy neonates were taken at birth as a control group. The newborns were divided into four groups: cyanotic and acyanotic disease operated on in deep hypothermic circulatory arrest, operation without deep hypothermic cardiac arrest, and operation without extracorporeal circulation.

RESULTS

Even in healthy neonates, serum S-100 levels were at 10-fold values compared with adults. On admission, S-100 values in the operative groups were similar. During extracorporeal circulation, levels rose to a certain degree. Cyanotic newborns operated on in deep hypothermic cardiac arrest had significantly higher S-100 levels compared with acyanotic newborns also operated on in deep hypothermic cardiac arrest (p < 0.001). Two newborns who experienced seizures postoperatively had the highest absolute S-100 levels. One child with a poor neurologic outcome but no seizures did not have different values when compared with her group.

CONCLUSIONS

In this study, S-100 seemed to be a possible marker for a certain degree of neurologic deficit after cardiac operation in neonates, especially regarding postoperative seizures. The missing peaks of this protein in one newborn with poor neurologic outcome show that it is not possible to exclude damage to the brain with normal postoperative values. These results suggest that the mechanism of cerebral damage and S-100 release into the blood in neonates with a developing central nervous system and blood-brain barrier is not fully understood.

Is there a relationship between serum S-100beta protein and neuropsychologic dysfunction after cardiopulmonary bypass?

OBJECTIVES

Over the past decade, the glial protein S-100beta has been used to detect cerebral injury in a number of clinical settings including cardiac surgery. Previous investigations suggest that S-100beta is capable of identifying patients with cerebral dysfunction after cardiopulmonary bypass. Whether detection of elevated levels S-100beta reflects long-term cognitive impairment remains to be shown. The present study evaluated whether perioperative release of S-100beta after coronary artery operations with cardiopulmonary bypass could predict early or late neuropsychologic impairment.

METHODS

A total of 100 patients undergoing elective coronary bypass without a previous history of neurologic events were prospectively studied. To exclude noncerebral sources of S-100beta, we did not use cardiotomy suction or retransfusion of shed mediastinal blood. Serial perioperative measurements of S-100beta were performed with the use of a new sensitive immunoluminometric assay up to 8 hours after the operation. Patients underwent cognitive testing on a battery of 11 tests before the operation, before discharge from the hospital, and 3 months later.

RESULTS

No significant correlation was found between S-100beta release and neuropsychologic measures either 5 days or 3 months after the operation.

CONCLUSION

Despite using a sensitive immunoluminometric assay of S-100beta, we found no evidence to support the suggestion that early release of S-100beta may reflect long-term neurologic injury capable of producing cognitive impairment.

Early detection of neurologic injury and issues of rehabilitation after pediatric cardiac extracorporeal membrane oxygenation

Neurological impairment results in a significant population of children after extracorporeal membrane oxygenation (ECMO) for treatment of otherwise intractable circulatory failure. Pre-ECMO hypoxia/ischemia, reperfusion injury, and impaired cerebral perfusion during low output situations possibly aggravated by harmful effects of a pulsatile perfusion are discussed in terms of possible etiological reasons. To develop preventive strategies or to enable curative measure, early detection of neuronal injury seems mandatory. Electroencephalographic surveillance and/or monitoring of evoked potentials and monitoring of cerebral oxygenation by means of near infrared spectroscopy or jugular venous bulb oxygen saturation, as well as measurements of serum neuron specific enolase, S-100 protein, and brain type creatine kinase can be employed clinically. To improve functional outcome following neuronal injury, early rehabilitation seems essential to minimize the resulting effects on physical, cognitive, and emotional development.