Effect of different position on inferior vena cava dimensions and its influence on hemodynamics during cesarean section under combined spinal-epidural anesthesia: A randomized controlled trial.

OBJECTIVE

The purpose of our study was to investigate the effect of the 15° left operating table tilt on the inferior vena cava (IVC) and the hemodynamics of full-term pregnant women, and to evaluate the efficacy of inferior vena cava collapse index (IVCCI) in predicting hypotension.

METHODS

All parturients planning to perform cesarean section (CS) were randomly divided into supine group and 15° group. Their parameters of IVC were measured by ultrasound and then calculated the IVCCI. Systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate (HR) in two positions were recorded from baseline to fetal delivery.

RESULTS

The IVCCI in the 15° group was significantly lower when compared with that in the supine group (20.40 [18.84-21.60] vs. 21.82 [20.16-22.79] %, p = 0.012). The incidence of hypotension was observed statistically lower in the 15° group than the supine group (27.5% vs. 50%, p = 0.039). Best cut-off value was 21.69% and area under the receiver operating characteristic (ROC) curve of IVCCI in supine position to predict hypotension was 0.93. Best cut-off value was 21.78% and area under the ROC curve of IVCCI in supine position to predict hypotension was 0.80.

CONCLUSIONS

The 15° left operating table tilt can relieve the extent of compression of IVC and reduce the incidence of hypotension. IVCCI can predict the occurrence of hypotension.