Inferior vena cava diameter change after intravenous furosemide in patients diagnosed with acute decompensated heart failure.

PURPOSE: Measurement of the inferior vena cava (IVC) diameters may improve decision-making for patients hospitalized with acute decompensated heart failure. Nevertheless, little is known about how the IVC is affected by loop diuretics. We sought to determine if bolus infusions of intravenous furosemide affect IVC diameters measured by hand-carried ultrasonography. METHODS: We conducted a prospective cohort study at a public teaching hospital from September 2009 through June 2010. Physician investigators performed IVC ultrasonography on a convenience sample of 70 hospitalized adults who were prescribed intravenous furosemide for the diagnosis of acute decompensated heart failure. RESULTS: Participants' median baseline IVC diameter was 2.38 cm (interquartile range, 1.91-2.55 cm). At 1-2 hours after furosemide, IVC diameters decreased an average of 0.21 cm (95% CI, 0.13-0.29 cm) and remained significantly below baseline at 2-3 hours after furosemide by an average of 0.15 cm (95% CI, 0.07-0.22 cm). CONCLUSIONS: IVC diameters of adults diagnosed with acute decompensated heart failure become measurably smaller after single doses of intravenous furosemide. Whether this represents a true change in volume status has not been studied.