Correlation Between Internal Jugular Vein Collapsibility Index and Inferior Vena Cava Collapsibility Index by Point-of-Care Ultrasound for Estimation of Central Venous Pressure

Background: Accurate assessment of central venous pressure (CVP) is essential for managing critically ill patients. Ultrasound-guided measurement of the internal jugular vein (IJV) and inferior vena cava (IVC) collapsibility index (CI) offers a non-invasive method for estimating CVP. This study aimed to correlate IVC and IJV collapsibility indices with invasively measured CVP. Objective: To assess the correlation between the internal jugular vein collapsibility index and IVC collapsibility index using point-of-care ultrasound (POCUS) for estimation of CVP. Methods: This cross-sectional study was conducted at the Department of Anesthesia, National Hospital Lahore, over a six-month period (26th July 2024 to 26th January 2025). A total of 61 ICU-admitted patients with an inserted CVP catheter were enrolled. IJV and IVC measurements were taken using bedside ultrasound, recording maximum and minimum diameters and cross-sectional areas (CSA) during respiratory cycles. Results: The mean age of patients was 64.62 ± 16.21 years, with a mean CVP of 13.66 ± 6.06 cm H₂O. The IJV collapsibility index at a cutoff of >10.2 cm² showed a sensitivity of 42.9%, specificity of 15.8%, and an overall accuracy of 34.4%, with a negative correlation of -0.641 with CVP. The IVC collapsibility index at a cutoff of >26.5 cm² showed 26.2% sensitivity, 36.8% specificity, and 29.5% overall accuracy, with a negative correlation of -0.570 with CVP. Conclusion: Both IVC and IJV collapsibility indices serve as beneficial non-invasive markers for assessing CVP. However, the IJV collapsibility index demonstrates a stronger correlation and may offer a more reliable prediction of CVP changes, serving as a valuable adjunct in fluid management for critically ill patients.