Neuroapoptosis in newborns with respiratory acidosis at birth.

BACKGROUND: S100B protein is one of the most accurate biomarkers for diagnosis of neuroapoptosis and brain damage. The aim was to evaluate the lactate concentration and acid-base balance (pH, pCO2, pO2, HCO3c and BEb) in umbilical cord blood to predict high risk of neuroapoptosis and analyze the relationship between the levels of these biomarkers and umbilical cord blood S100B protein concentration at birth. METHODS: Apparently healthy newborns were included. S100B protein and blood gas test (lactate and acid-base balance) were determined in umbilical cord blood at birth. Newborns were classified into two groups: with and without high risk of neuroapoptosis. Newborns with high umbilical cord blood S100B protein concentration were considered newborns at high risk of neuroapoptosis. RESULTS: Sixty-one newborns were included, 12 had high risk of neuroapoptosis and 49 did not. S100B protein concentration correlate directly with pCO2 levels (Rho: 0.286, p = .0321) and lactate concentration (Rho: 0.278, p = .0315); and indirectly with pH (Rho: -0.332, p = .01). The analysis of the ROC curves yielded significant curves for pH and pCO2 to predict high risk of neuroapoptosis, pH optimal cutoff value was 7.19 (sensitivity: 50%, specificity: 83.7%, AUC: 0.708); and pCO2 optimal cutoff value was 60 mmHg (sensitivity: 30%, specificity: 85.4%, AUC: 0.705). CONCLUSIONS: Respiratory acidosis is associated to high concentrations of S100B protein in umbilical cord blood at birth. Umbilical cord blood pH and pCO2 may be useful in differentiating newborns at high risk of neuroapoptosis. Umbilical cord blood gas test may be valuable as risk indicator for neuroapoptosis at birth.

Neuroprotective effect of sevoflurane in general anaesthesia. / Efecto neuroprotector del sevoflurano en anestesia general.

INTRODUCTION AND OBJECTIVE: The aim of this study was to evaluate the brain damage caused by inhaled sevoflurane, by determining the concentration of serum S100B protein before and after the exposure to this drug as the only anaesthetic agent. PATIENTS AND METHOD: Paediatric patients undergoing general anaesthesia for the conduct of a nuclear magnetic resonance were included in the study. A venous blood sample was taken from each patient before (basal sample) and after (post-exposure sample) administering the general anaesthesia. The concentration of serum S100B protein was determined in the basal (S100Bb) and post-exposure sample (S100Bp). RESULTS: A total of 72 patients were included in the study, with a mean patient age of 2 to 13 years (median=6), 28 males and 44 females. S100Bp values (median=66.5ng/L) were significantly lower (P=.0059) than those of S100Bb (median=84.0ng/L). The median of the difference between S100Bp and S100Bb was -11.0ng/L. CONCLUSIONS: Inhaled sevoflurane at low doses causes a decrease of serum S100B protein levels, hence, this drug could have a neuroprotective effect in the central nervous system.

[Brain damage after general anesthesia]. / Daño cerebral postanestesia general.

BACKGROUND AND OBJECTIVE: S100B protein is a serum marker of cerebral damage. The objective was to evaluate the brain damage caused by general anaesthesia, by determining the concentration of serum S100B protein before and after of general anaesthesia. PATIENTS AND METHOD: Patients with chronic adenotonsillar hypertrophy and indications for tonsillectomy were included. A venous blood sample was taken from the patients before general anaesthesia (basal sample). The patients were anaesthetised using the following intravenous anaesthetic drugs: midazolam, fentanyl and propofol; and inhaled sevoflurane. A second venous blood sample (postoperative sample) was taken from patients after the surgery, in the operating room. The concentration of serum S100B protein was determined in the basal sample (S100Bb) and postoperative sample (S100Bp) by immunoassay electro-chemiluminescence in MODULAR E-170 (Roche Diagnostics). RESULTS: Seventy-six patients were included, 46 males and 30 females, aged between 3 to 14 (median 5 years). In all the patients, serum S100B protein levels increased after general anaesthesia. The values of S100Bp (median 164.0 ng/L) were significantly higher than the values of S100Bb (median 94.5 ng/L). The median of the difference between S100Bp and S100Bb was 58.0 ng/L. There were statistically significant differences between S100Bb and S100Bp using the Wilcoxon test (P<.0001). CONCLUSIONS: The concentration of serum S100B protein increased significantly after general anaesthesia. This indicates that general anaesthesia may cause brain damage.