Acute Hemodynamic Effects of Nebulised Furosemide in Stable Heart Failure

Purpose: Dyspnoea is a common and burdensome symptom in heart failure (HF). Nebulised furosemide has been proposed as a novel therapeutic for relieving dyspnoea. This mode of administration is potentially useful in community based settings. However, to date mechanisms of action are unclear. This study sought to measure the acute hemodynamic effects of nebulised furosemide in patients with stable, advanced HF. Methods: In this randomised, double blind, placebo controlled trial, participants undergoing scheduled, right heart catheterisation were randomized to receive either 40mg (4mls) of nebulised furosemide or 4mls of normal saline. Following baseline pulmonary pressure measurement and inhalation of the study medication, subjects’ pulmonary pressures were recorded every 15 minutes for one hour. The volume of urine in the bladder was measured at baseline and at 60 minutes using ultrasound methods. Results: There were no significant differences in the hemodynamic weighted average time course data of the subjects in either group over the study period. Weighted average pulmonary capillary wedge pressure after 60 minutes in the furosemide group was 22.5 ± 6.5 mmHg (n=14) compared to the placebo group's 24.0 ± 7.3 mmHg (n=18), p=0.55. No other significant differences were observed in hemodynamic parameters between the two groups. This dose of nebulised furosemide was sufficient to produce a significant change in the median volume of urine in the bladder at 60 minutes 186 ml (124.5 to 247.5) (n=8) compared to placebo 76 ml (21.5 to 130.5) ml (n=13), p = 0.02. Conclusions: This study showed that 40mg of nebulised furosemide had no significant effect on the hemodynamic parameters of the participants. Despite this, this dose was able to produce a diuretic effect in these subjects after one hour. Inhalation of furosemide may provide a novel method for drug delivery and requires further investigation.