Objective: We evaluated electrical velocimetry, a noninvasive method for continuous cardiac output measurement, in very-low and low birth weight infants and the influence of patent ductus arteriosus (PDA) and ventilators on this method.
Study design: This prospective study compared 81 pairs of simultaneous cardiac output measurements by electrical velocimetry and transthoracic echocardiography in 28 patients. Data were compared by correlation, Bland-Altman analysis and two-way analysis of variance.
Results: The two methods exhibited a high correlation (r=0.859, P<0.0001). The bias (mean difference of the methods) and percent error (100 × 1.96 × s.d./mean cardiac output) were -6 ml min(-1) and 29.2%, respectively. PDA significantly affected the bias (P=0.0004), but ventilators did not (P=0.14). Hemodynamically significant PDA had a larger bias (-36 ml min(-1)) and higher percent error (38.6%).
Conclusions: Although influenced by PDA, electrical velocimetry was generally interchangeable with transthoracic echocardiography even using ventilators.