Validation of a Novel Monitoring System to Measure Contrast Volume Use during Invasive Angiography

BACKGROUND: Multiple studies have demonstrated the relationship between contrast volume (CV) and the risk of acute kidney injury (AKI). Quantification of total CV is often estimated and therefore may be inaccurate. We describe validation of a novel contrast monitoring system (CMS) (Osprey Medical), which is designed to detect and display injection by injection and total CV use on a monitor system in real time. METHODS: Thirty patients undergoing a coronary or peripheral angiogram were included. Ten patients underwent procedures using the CMS only and 20 underwent procedures using both the CMS and the AVERT Plus contrast modulation system (Osprey Medical). Total CV used during these cases was measured using direct measurement via a graduated cylinder (CV_DM). This was compared with the CMS-reported CV and with the operator's assessment of CV (CV_PE) used during the case. Intraclass correlation coefficient (ICC) and Pearson correlation coefficient (PCC) were used for analysis and the results displayed using Bland-Altman plots. RESULTS: Twenty-one cases were diagnostic and 9 were interventional. The ICC/PCC (confidence interval [CI]) for the comparison of CV_DM to CMS and CV_PE were 0.96/0.97 [CI, 0.94-0.99] and 0.89/0.90 [CI, 0.80-0.95], respectively, with a P=.01 for difference between the correlations. The average absolute difference between the CV_DM and CMS readout and the CV_PE was 12.0 ± 13.7 mL and 22.8 ± 15.3 mL, respectively; P=.01. CONCLUSIONS: The CMS was accurate when compared with the direct measurement of CV used. This accuracy was superior to physician estimation of CV.