Validation of a Novel Point-of-Care Ultrasound Method for Estimating Central Venous Pressure in Critically Ill...

To validate an ultrasound-based method for noninvasive estimation of central venous pressure (CVP) in critically ill patients and compare its performance with invasively measured CVP.

We conducted an analytical cross-sectional study in adults admitted to a general intensive care unit. Patients with a central venous catheter and CVP monitoring through an electronic transducer were included. Ultrasound-estimated CVP (CVPus) was calculated using the method described by Istrail et al, which combines right atrial depth and jugular venous distension height. Correlation, paired mean differences, Bland-Altman agreement, and discriminative performance for invasive CVP thresholds of ≥5 and ≥10 mmHg were assessed.

Seventy-five patients were included; CVPus was feasible in 70. Mean invasive CVP was 5.50 ± 3.80 mmHg; 53.3% of patients had CVP ≥5 mmHg and 21.3% had CVP ≥10 mmHg. CVPus showed a moderate positive correlation with invasive CVP (r = 0.61; p < .001). Mean invasive CVP and mean CVPus were 5.26 and 5.59 mmHg, respectively (p = .375). Bland-Altman analysis showed a mean bias of -0.33 mmHg, with 95% limits of agreement from -6.37 to 5.72 mmHg. The area under the ROC curve was 0.83 (95% CI, 0.68-0.99) for invasive CVP ≥10 mmHg and 0.81 (95% CI, 0.71-0.91) for invasive CVP ≥5 mmHg.

The Istrail et al ultrasound method showed favorable overall performance for noninvasive CVP estimation in critically ill patients. Its low mean bias and good discriminative ability support its use as a complementary bedside tool, although agreement with invasive measurement remains limited.