Role of cerebral oxygenation for prediction of hypotension after spinal anesthesia for caesarean section

To investigate the role of cerebral oxygen saturation (ScO₂) for prediction of hypotension after spinal anesthesia for caesarean section. Forty-five parturients undergoing elective caesarean section under spinal anesthesia were selected. Blood pressure, heart rate and pulse oxygen saturation before and after anesthesia were recorded, and the association between changes in ScO₂ before and after anesthesia with hypotension after spinal anesthesia was explored. Hypotension occurred in 32 parturients after spinal anesthesia. The decrease in ScO₂ after spinal anesthesia in parturients with hypotension was larger than in parturients without hypotension (P < 0.05). The duration from the intrathecal injection to 5 % decrease in ScO₂ was shorter than that from the intrathecal injection to the occurrence of hypotension (P < 0.05). The mean time from 5 % decrease in ScO₂ to hypotension was 38 s. The area under the receiver operation characteristic curve was 0.83 for decrease in ScO₂ for prediction of hypotension (P < 0.05), and the optimal threshold value was 4.5 %. The sensitivity, specificity, positive predictive value and negative predictive value of 4.5 % decrease in ScO₂ for prediction of hypotension were 0.75, 0.78, 0.92 and 0.47, respectively. The decrease in ScO₂ after spinal anesthesia is associated with hypotension after spinal anesthesia for cesarean section, and may be a clinically useful predictor.