Prediction of intraoperative arterial hypotension associated with the spinal anesthesia. Prospective observational study

Background: 90% of C-sections are supported by spinal anesthesia, which is complicated by arterial hypotension in 60%-80% of cases. The perfusion index seems to be a significant prognostic tool for arterial hypotension. Objective: Тo confirm the value of perfusion index in predicting arterial hypotension associated with the spinal anesthesia. Materials and methods: The study included 105 female patients who underwent С-section under spinal anesthesia. A decrease in mean arterial pressure by ≤ 20% was considered as arterial hypotension. Baseline perfusion index was assessed with a pulse oximeter. Results: 68 patients (64.8%) developed arterial hypotension in the intraoperative period. In 37 (35.2%) parturient women there were no significant changes in blood pressure. A cut-off threshold of 3.1 with 75% sensitivity and 75% specificity was obtained with the ROC analysis. Arterial hypotension developed in 29.4% (n = 15) of parturient women with a perfusion index < 3.1 and in 72.2% (n = 39) of parturient women with a perfusion index > 3.1. Conclusions: We can use the perfusion index threshold of 3.1 to identify parturient women with an increased risk of arterial hypotension associated with the spinal anesthesia for C-section. The arterial hypotension rate is significantly higher in women with an initial perfusion index > 3.1 compared with those with an initial perfusion index < 3.1.