Reliability and consistency of point-of-care ultrasonography for inferior vena cava measurement: Visual versus automatic ultrasound systems

Abstract

PurposeWe aimed to study the concordance between the M-mode and the automatic measurement systems of the IVC. MethodsWe recruited five healthy volunteers. Two expert ultrasonographers (2 ED physicians), and four novices (2 ED physicians and 2 ED nurses) performed a manual (M-mode) and an automatic measurement of the maximum and minimum IVC diameter of each volunteer in the supine position. All examinations were blindly and consecutively performed using a GE VENUE ultrasound (GE Healthcare). The same measurement was then repeated in a second round. ResultsConcordance between the M-mode and automatic measurements in all US assessments was at least good [intraclass correlation coefficient (ICC) .786–.948; p<.001]. Intra-observer reliability was at least moderate in automatic system measures [ICC .614–.973], slightly better than in M-mode [ICC .483–.940], especially useful when performed by novice ultrasonographers. Inter-observer reliability was good for both methods [ICC .839–.919, p<.001]. The automatic measurement method was approximately 50% faster than the M-mode method (p=.001). ConclusionsIn this pilot study, the automatic measurement method was consistent with the M-mode measurement method, as performed by experts or novices. Both methods showed high intra-, inter-observer reliability, but the automatic system was significantly faster, which would allow us to implement this approach more effectively in our daily practice.