Evaluation of Maternal S100B Protein and Arterial Blood Gas Exchange During Spinal Anesthesia for Cesarean Delivery

Abstract

Background: Cesarean section is the most common surgery in the obstetrics department, and an incision is made in the abdomen and uterus of a pregnant woman to deliver the baby and the placenta. In recent years, the rate of cesarean delivery has been increasing worldwide. In the years 2015-2019, out of 11020-12813 mothers gave birth in the NCMCH, 3147-3355 mothers gave birth by cesarean section, and the rate of cesarean section is 26-29.5%. Elevated S100B levels in biological fluids are thus regarded as a biomarker of pathological conditions, including perinatal brain distress, acute brain injury, brain tumors, neuroinflammatory/neurodegenerative disorders, psychiatric disorders. It is interesting to investigate the effects of cesarean spinal anesthesia on maternal arterial blood gas exchange and brain injury biomarker S100B levels. Aim: To evaluate the effects of spinal anesthesia during cesarean section on maternal arterial blood gas exchange and brain injury biomarker S100B levels Materials and Methods: The parturient women who undergo C-section in ObGyn Hospital of The National Center of the Maternal and Child Health of Mongolia from January 2022 to June 2022 recruited in this study according to the inclusion and exclusion criteria. The 50 parturient women enrolled in this study. This study was approved by the Ethics Committee of The National Center of the Maternal and Child Health of Mongolia; Ethics Committee of Mongolian National University of Medical Sciences. Maternal blood samples collected from a.radialis via Arterial line. The blood gas analysis performed 3 times (before anesthesia, after delivery, at the end of surgery) using the blood gas analyzer. The concentration of S100B protein in the blood serum is determined by the enzyme-linked antibody reaction (ELISA) using the German DRG® S100B (Human) ELISA (EIA-4555) album. Results: Before surgery, mothers arterial S100B was 276±93 ng/L, after surgery was 275±135 ng/L. There was no significant difference in S100B levels before and after C-section under spinal anesthesia (p=0.86) and no correlation between age and the concentrations of S100B protein in blood (r=0.03, p=0.83). At the end of operation, the following ions increased to Cl105.1±1.88 (p<0.05), Ca2+ 1.25±0.3 mmol/l, Na+ 138.8±0.7 mmol/l, Osm 275±1.9 mOsm/kg. After caesarean section, maternal arterial blood pH significantly decreased (p=0.01), while PCO2 and Cllevels significantly increased (p<0.05). Conclusion: Serum S100b levels didn’t increase in maternal arterial blood during spinal anesthesia for C-section. There was no significant change in maternal arterial blood pH during spinal anesthesia, but altered other ion levels, possibly related to fluid management. More clinical trials in the future are needed to confirm the sensitivity and specificity of S100β to detect possible anesthesia-mediated harmful effects to the developing brain.