Prediction of Hypotension During Neuraxial Anesthesia in Patients with Pregnancy-Induced Hypertension Through Subclavian Vein Collapsibility Index

Abstract

Objective: To explore and evaluate the predictive value of subclavian vein collapsibility index (SCV-CI) on hypotension during neuraxial anesthesia in patients with pregnancy-induced hypertension (PIH). Methods: Pregnant women with PIH who underwent elective cesarean section in our hospital from January to July 2021 were selected as the research subjects. Patients who experienced hypotension during anesthesia were included into the hypotension group, whereas patients who had a normal blood pressure during anesthesia were included in the normotensive group. The SCV-CI was then calculated for three respiratory cycles, the average value was taken as the base value, and the patient was monitored for another 20 minutes. The blood pressure, heart rate, blood oxygen saturation, and SCV-CI of the patients were measured, and the incidence of maternal nausea and vomiting and cord blood gas were recorded. Then, a correlation analysis was conducted on the relationship between subclavian vein collapsibility index and hypotension. A receiver operating characteristic curve was drawn to seek the threshold value of subclavian vein collapsibility index for post-anesthesia hypotension. Results: There was no significant difference in systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) between the two groups before anesthesia (P > 0.05). After anesthesia, the above indexes (SBP, 103.25 ± 12.48 mmHg; DBP, 58.94 ± 7.46 mmHg; and HR, 52.96 ± 6.48 beats/min) were significantly lower than those of the normal blood pressure group, and the difference was statistically significant (P < 0.05). In comparison, the SCV-CI in the hypotension group was 35.82 ± 4.93% greater than that in the normal blood pressure group (23.85 ± 5.27%), and the incidence of nausea and vomiting in the hypotension group (40.0%) was significantly higher than that in the normotensive group (10.53%), and the difference was statistically significant (P < 0.05). The area under the curve of SCV-CI prediction against hypotension in patients with PIH under neuraxial anesthesia was 0.825 (95% CI: 0.762–0.893, P < 0.001), the cut-off value was 25.68%, the predictive sensitivity was 92.68%, and the specificity was 81.24%. Conclusion: SCV-CI has a good predictive value for the occurrence of hypotension in patients with PIH during neuraxial anesthesia.