ACCURACY OF THE TRANSVERSE DIAMETER OF RIGHT COMMON FEMORAL VEIN BY ULTRASOUND IN THE SUPINE POSITION FOR PREDICTING POST-SPINAL HYPOTENSION DURING CESAREAN DELIVERY

Abstract

Objective: To validate the accuracy of ultrasound measurements of the transverse diameter of the right common femoral vein (RCFV) in the supine position for predicting post-surgical hypotension (PSH) in women undergoing scheduled C-sections with spinal anesthesia.

Study design: Cross-sectional validation study.

Place and duration of the study: Department of Anesthesia, Jinnah Hospital, Lahore, from 01 August 2024 till 31 January 2025.

Methodology: 200 multiparous women aged 20-40 years scheduled for elective C-section with spinal anesthesia were enrolled in this study. The researchers collected patient demographics, body mass index and parity on a structured data form before conducting pre-operative ultrasound measurement of the RCFV at approximately 15 minutes prior to initiation of anesthesia. Intra-operative monitoring will be conducted to determine hypotension as defined as blood pressure < 20% from baseline. Statistical evaluation was done with the use of SPSS v.27 using t-test, and chi-square tests.

Results: In total, 69.0% (n=138) of the 200 subjects undergoing surgery experienced an intraoperative period of PR (i.e. intraoperative hypotension). The mean RCFV diameter in the hypotensive subjects was significantly greater than that of non-hypotensive subjects (12.97 ± 0.63 vs. 12.31 ± 0.78 respectively; p < 0.001). Ultrasound measurement of RCFV diameter had a sensitivity of 92.0%, PPV of 83.6% and NPV of 77.1%.

Conclusion: The transverse diameter of RCFV is a reliable predictor of PSH in patients undergoing cesarean delivery, when the RCFV diameter is > 12.2 mm, the patient is at increased risk for post-spinal hypotension.