Non-invasive Assessment of Intravascular Volume Status for Postoperative Patients: The Correlation Between the Internal Jugular Vein/Common Carotid Artery Cross-Sectional Area Ratio and the Inferior Vena Cava Diameter

Background: This study aimed to assess the correlation between the internal jugular vein/common carotid artery (IJV/CCA) cross-sectional area (CSA) ratio and the inferior vena cava (IVC) diameter as non-invasive techniques for the assessment of intravascular volume. Methods: The study samples included 35 adult patients of both sexes (age range: 20 - 60 years) according to the criteria of the American Society of Anaesthesiology (ASA) physical status II - III, who were admitted to the surgical intensive care unit (SICU) after major surgeries for the assessment of intravascular volume status. Results: There was a positive correlation between the IJV/CCA CSA ratio and the IVC maximum and minimum diameter before and after fluid infusion (r = 0.923, P < 0.001 and r = 0.390, P = 0.021, respectively) and between the IJV/CCA CSA ratio at inspiration and the IVC minimum diameter before and after fluid infusion (r = 0.605, P < 0.001 and r = 0.496, P < 0.001, respectively). The sensitivity and specificity analysis of the IJV/CCA CSA during inspiration after fluid correction to predict a central venous pressure (CVP) of 8 - 12 cmH2O showed that at a ratio of 2.56, the highest sensitivity was 56.5%, and the specificity was 83.3%; at a ratio of 2.58, the highest sensitivity was 65.2% and the specificity was 75%. During expiration, specificity after fluid correction was 56.62%; at a ratio of 2.62, the highest sensitivity was 52.2%, and the specificity was 67%; and at a ratio of 2.65, the sensitivity was 56.5%, and the specificity was 50%. Conclusions: The assessment of the IJV/CCA CSA ratio alongside ultrasonography could be a non-invasive tool for the evaluation of intravascular volume status in spontaneously breathing adult patients after major surgeries.

Vascular ultrasound

Vascular ultrasound is accurate in the diagnosis of abdominal aortic aneurysm (AAA) and deep vein thrombosis (DVT) at or above the knee. B-mode ultrasound usually suffices to make or refute these diagnoses, although sometimes Doppler ultrasound is required. Vascular ultrasound can also assist in the diagnosis of aortic dissection, although it cannot be used to rule out dissection. Finally, vascular ultrasound is also used to image the inferior vena cava (IVC) to assist in the estimation of intravascular volume status in the shocked patient, usually in conjunction with a shock protocol.