Continuous Versus Intermittent Loop Diuretics Infusion Dosing in Acute Heart Failure: Effects on Renal Function, Outcome and BNP Levels

Patients were eligible if they were admitted with a primary diagnosis of ADHF, randomized within 12 h after hospital presentation, and with evidence of volume overload (pulmonary congestion) on a chest X-ray study and had BNP levels >100 pg/ml. Patients also displayed mild to moderate renal dysfunction with creatinine values up to 1.4 mg/dl. Some patients were supported with non invasive ventilation before randomization. Once the initial 12 h dose was determined, patients were randomized using a 1:1 ratio using a computer-generated scheme to receive the furosemide dose either divided into a twice-daily bolus injection or in a continuous infusion (mixed as a 1:1 ratio in 5 % dextrose in water) for a time period ranging from 72 to 120 h. The randomization was casual, and the physicians did not previously know the assigned arm. The dose escalation and subsequent titration of furosemide was guided by clinical response in terms of urine output volume and body weight reduction .Before randomization, renal function parameters and BNP levels were measured in all patients. Subsequent titration of the furosemide dosage was at the discretion of the attending physician, but was guided by a dose-escalation algorithm based on the treatment response (weight loss and urine output volume), symptom improvement, changes in renal function, electrolyte balance, and chest radiography. The specific doses of furosemide and the use of additional agents to manage ADHF (dopamine, IV vasodilators, hypertonic saline infusion) were decided based upon blood pressure measurements, renal function evaluation and diuresis response. Supplementary treatment was left to the discretion of the treating physician. The duration of infusion was continued for up to 72 h, at 48 h the physicians had the possibility to adjust diuretic dose administration on the basis of the clinical response. After 72 h the treatment could be stopped or continued for an additional 36-48 h depending on the patient's condition and diuresis response. Acute kidney injury (AKI) was defined following the RIFLE criteria.

Abbreviations:

(AKI) Acute kidney injury (ADHF) Acute decompensated heart failure (BNP) B-type natriuretic peptide (CHD) Coronary heart disease (cIV) Continuous infusion (iIV) Intermittent infusione (eGFR)Estimated glomerular filtration rate (Hb) Hemoglobin (HF) Heart failure (Hct) Hematocrit (LVEF) Left ventricular ejection fraction (RBC) Red blood cells