To Estimate the Maternal Cerebral Near Infrared Spectroscopy Values and Fetal Umbilical Cord Arterial Blood pH Values in Patients Undergoing Elective LSCS Under Spinal Anaesthesia in a Tertiary Care Hospital and to Study the Correlation Between Them

Background: Near infrared spectroscopy (NIRS) monitoring in the parturient have shown fall in its readings post spinal anaesthesia. Aims and Objectives: This study was planned to estimate the maternal cerebral NIRS values in elective LSCS patients under spinal anaesthesia as well as to correlate it with the fetal umbilical cord blood pH values. Secondary objectives include to correlate changes in hemodynamics with the changes in NIRS value post spinal anaesthesia. Methodology: A total of 85 parturient undergoing elective lower segment caesarean section were included. Subarachnoid block with 2.2ml of 0.5% bupivacaine heavy was administered in the sitting position and then the patient was made supine. NIRS electrodes both left and right were attached on the forehead and a baseline recording was done followed by recording every 1 min till 10 min by the time the cord was clamped and the baby was delivered, followed by the cord blood collected from the umbilical artery for the pH assessment. The NIRS recording continued till 30 min along with the routine hemodynamic monitoring, heart rate(HR), systolic blood pressure(SBP), diastolic blood pressure(DBP). Results: There was an initial drop in the NIRS score from minute 1 of observation to minute 5 on left side (59.09 ± 0.709 to 55.03 ± 0.929) and right side (58.13 ± 0.769 to 53.86 ± 0.765) respectively which was statistically significant (p < .001). Subsequently, there was a significant rise from 5min to 10minute. Mean NIRS value had a weak to moderate correlation with the mean SBP, DBP and HR. The mean fetal pH recorded in our study was 7.34+/-0.02 which correlated poorly with the NIRS values. Conclusion: Maternal NIRS values definitely fall significantly following spinal anaesthesia over first 5 minutes with subsequent improvement but the correlation between the maternal NIRS values with fetal pH of umbilical artery could not be established.