The effect of intravenous furosemide on the Doppler waveform in normal kidneys

Duplex Doppler sonography is currently being evaluated in the differentiation of obstructive and nonobstructive hydronephrosis. It was thought that this method may be of use in the diagnosis and follow-up of pelviureteric junction obstruction, and that its sensitivity may be increased by the use of intravenous furosemide to raise the intrarenal pressure in obstructive cases. Before embarking on a formal study, a pilot study was initiated to determine the effect of furosemide on the Doppler waveform of the normal kidney. Intravenous furosemide had variable effects on peak systolic and end-diastolic velocities and little significant effect on resistive index but caused a constant and dramatic subjective increase in vascularity. Possible modes of action are discussed.