Diuretic Etficacy of High Dose Furosemide in Severe Heart Failure: Bolus Injection Versus Continuous Infusion

Objectives. The efficacy of high dose furosemide as a continuous infusion was compared with a bolus injection of equal dose in patients with severe heart failure. Background. The delivery rate of furosemide into the nephron has been proved to be a determinant of diuretic efficacy in healthy volunteers. Methods. In a randomized crossover study we compared the efficacy of a continuous infusion of high dose furosemide (mean daily dosage 690 mg, range 250 to 2,000) versus a single bolus injection of an equal dose in 20 patients with severe heart failure. The patients received an equal dosage, either as a single intravenous bolus injection or as an 8-h continuous infusion preceded by a loading dose (20% of total dosage). Results. Mean (-+SEM) daily urinary volume (infusion 2,860 240 ml, bolus 2,260 -+ 150 ml, p = 0.0005) and sodium excretion (infusion 210 -+ 40 mmol, bolus 150 -+ 20 mmol, p = 0.0045) were significantly higher after treatment with continuous infusion than with bolus injection, despite significantly lower urinary furosemide excretion (infusion 310 -+ 60 mg every 24 h, bolus 330 -+ 60 mg every 24 h, p = 0.0195). The maximal plasma furosemide concentration was significantly higher after bolus injection than during continuous infusion (infusion 24 -+ 5 pg/mi, bolus 95 +20 gg/ml, p < 0.0001). Short-term, completely reversible hearing loss was reported only after bolus injection in 5 patients. Conclusions. We conclude that in patients with severe heart failure, high dose furosemide administered as a continuous infusion is more efficacious than bolus injection and causes less ototoxic side effects. (JAm Coil Cardiol 1996;28:376-82)