Ultrasound assessment of central venous pressure: A systematic review and meta-analysis
Abstract Background Ultrasound is increasingly relied upon to estimate central venous pressure (CVP) in the echocardiography lab and using point-of-care systems in the intensive care unit and the emergency department. However, there is uncertainty regarding the diagnostic accuracy of ultrasound-based parameters as reported in diverse studies.Methods A systematic review was performed by searching MEDLINE, EMBASE, and the Cochrane Database for studies evaluating ultrasound-based indicators of filling pressures in relation to catheterization-based CVP. Studies were screened for predefined inclusion criteria and rated for quality by duplicate observers. Standardized correlation coefficients for each ultrasound-based indicator were meta-analyzed using a random effects model.Results 3949 articles were screened and 64 met the criteria for inclusion. Inferior vena cava (IVC) diameter was assessed in 34 study measures and the pooled standardized correlation with invasive CVP was 0.74 (95% CI 0.63 to 0.84). IVC collapsibility was assessed in 20 study measures and the pooled standardized correlation with invasive CVP was -0.57 (95% CI -0.70 to -0.44). Tricuspid E/Ep was assessed in 6 study measures and the pooled standardized correlation with invasive CVP was 0.59 (95% CI 0.26 to 0.93). IVC parameters but not E/Ep remained correlated with CVP in mechanically ventilated patients, including cardiac surgery patients. Results were similar in studies featuring non-traditional users and cardiac specialists.Conclusions Echocardiographic IVC diameter, collapsibility, and tricuspid E/Ep ratio are significantly correlated with invasive CVP, albeit with important heterogeneity between studies. Most of these indicators are equally valid when applied in ventilated patients and by non-traditional users.