The Use of End-Tidal CO₂ and Integrated Pulmonary Index to Predict Postspinal Hypotension in Cesarean Section

Early diagnosis and treatment of postspinal hypotension (PSH) in obstetric anaesthesia reduces the risk of maternofetal complications. In this study, the effect of EtCO₂ and the integrated pulmonary index (IPI) in predicting PSH was investigated. Patients scheduled for cesarean section under spinal anaesthesia were included. The Capnostream 35 respiratory monitor (Medtronic, Inc., Dublin, Ireland) was used for EtCO₂ and IPI. PSH developed in 52 (63.4%) of the 82 patients. EtCO₂ and IPI values decreased significantly compared with baseline values in patients who developed PSH. There were statistically significant differences in EtCO₂ (p = 0.001) and the IPI change (p = 0.045) in patients who developed PSH compared with those who did not. It was found that the EtCO₂ difference had an independent effect on predicting PSH (p < 0.05), whereas the IPI difference did not (p > 0.05). One unit decrease in EtCO₂ from the baseline increased the risk of PSH by 3.3 times. ROC curve analysis showed that the magnitude of change in EtCO₂ was diagnostic for predicting PSH (AUC: 0.90 (0.83-0.97; p < 0.001)). IPI showed no predictive value for postspinal hypotension in cesarean section. However, EtCO₂ monitoring, which is non-invasive and real-time monitoring, can be used to predict postspinal hypotension.