Assessment of Fluid Responsiveness via Central Venous Ultrasound Measurement: A Network Meta-Analysis

Background: Ultrasonographic assessment of the diameters of various veins and their indices are among the most applied diagnostic tools for evaluating fluid responsiveness in clinical practice. Despite their widespread use, there is no definitive answer on which is preferable. Our study aimed to investigate the diagnostic accuracy of different venous diameters and their indices to assess fluid responsiveness. Methods: We conducted a systematic review and network meta-analysis, analyzing prospective studies evaluating the diagnostic accuracy of venous diameters (inferior vena cava [IVC], internal jugular vein [IJV], superior vena cava, and subclavian vena) and their indices for fluid responsiveness. Electronic databases were searched from inception until March 2024; this search was supplemented by snowballing methods. The risk of bias was evaluated with QUADAS-2, and evidence certainty was assessed using the GRADE approach. Nine prospective cohort studies (560 patients) were included. Results: The network meta-analysis revealed that the ΔCaval index exhibited a significant performance advantage over other "venous" test parameters. The caval index significantly outperformed IJV min/max and IVCmax. IJV index and IVCmin significantly outperformed IJVmin/max. The caval index was comparable to the IJV index. The caval index was comparable during mechanical ventilation and spontaneous breathing. Conclusions: In this meta-analysis, the ΔCaval index test showed higher diagnostic accuracy for fluid responsiveness compared with other venous tests. Caval and jugular indices displayed similar accuracy, and caval indices were consistent under mechanical ventilation and spontaneous breathing. Indices generally outperformed absolute values, except for IVCmin, which equaled the caval index in efficacy. This study was registered on the International Platform for Registered Protocols for Systematic Reviews and Meta-Analyses: INPLASY202430104.