Background and aims: In cesarean section (CS) with spinal anesthesia, pregnancy- specific complications can suddenly affect maternal brain circulation. The aim of our study is to measure the changes in maternal cerebral blood flow (CBF) and cerebral oxygenation (CBO) using Near-infrared spectroscopy (NIRS) and to evaluate the difference between planned and emergency operation.
Methods: Fifty-one patients undergoing CS were monitored using NIRS (NIRO-200NX, Hamamatsu Photonics) between July 1, 2018 and September 30, 2018 and divided into two groups; planned CS, group P (n=34) and emergency CS, group E (n=17). We measured CBF (estimated from total- Hb) and CBO (estimated from tissue oxygen index (TOI)) changes using NIRS. Hyperbaric 0.5% bupivacaine was used for spinal anesthesia. Data was taken from the following five time points; before spinal anesthesia (1), from injection of bupivacaine (2) and at 10 (3), 20 (4) and 30 (5) minutes after injection. Data were calculated using unpaired t-test, Mann-Whitney U test, Fisher’s exact test, repeated-measures ANOVA and Turkey-Klamer multiple comparison test.
Results: Changes in SAP (Systolic arterial pressure), HR, total-Hb, and TOI with time in each group are shown in Fig.1. SAP, total- Hb and TOI significantly decreased after spinal anesthesia in both groups. SAPs were significantly higher in the emergency group but this did not correspond to a similar difference in total-Hb and TOI. 
Conclusion: There was no significant difference in the change of maternal CBF and CBO after spinal anesthesia between planned and emergency cesarean section although SAP was significantly higher in the emergency CS group.

3 - The clinical efficacy of near-infrared spectroscopy in cesarean section during spinal anesthesia; a comparison of planned and emergency surgery