Effects of furosemide and slow‐release furosemide on thoracic fluid volumes

Abstract

Summary:Transthoracic electrical impedance (TEI) was used to assess the relative effectiveness of a 60 mg sustained-release furosemide preparation (FR) and a 40 mg standard furosemide tablet (F), in reducing the fluid content in the thoracic cavity. A double-blind crossover study was performed, in which 12 men with a history of one or more myocardial infarctions and mild left heart failure treated with 40 mg furosemide once daily participated. The trial, lasting 28 days, was divided into two 14-day periods. Each participant received one active drug and one placebo preparation daily, the same regimen being maintained for 14 days, when the active substances were switched. TEI, body weight, serum potassium, sodium, creatinine, and urate were measured immediately prior to the start of the study, after 14 days, and at the end of the study. TEI was measured at frequencies of 1 and 100 kHz with a constant current of 100 PA, during a period of one hour following an intravenous injection of 40 mg furosemide, when the urine volumes were measured also. TEI and urine production after the furosemide injections were similar irrespective of the drug preparation. No evidence of treatment period interaction was seen. No significant differences were demonstrated in body weight and blood chemistry during the trial. These results suggest clinical equipotency of the two preparations in mild left heart failure.

Analysis of Consistency of Transthoracic Bioimpedance Measurements Acquired with Dry Carbon Black PDMS Electrodes, Adhesive Electrodes, and Wet Textile Electrodes

“…More recent studies found that the aorta contributed to only about 1% of the total impedance measurement, the skeletal muscle represented the highest contribution (>50%), and the measure was highly sensitive to changes in impedance in the upper thorax [ 33 , 34 ]. Despite the limitations and the additional components that were captured by the TBI, it had clinical importance, as the intra-patient directional changes in the impedance were indicative of directional changes in the thoracic fluid [ 35 ].…”

Transthoracic electrical bioimpedance: A means of filling the void?

“…There is some evidence that, apart from using the variable impedance signal to measure cardiac output, the baseline signal can be used to measure the thoracic fluid content, a measure of a patient's total volume state 85 . This signal has been used to follow changes in thoracic fluid content during diuretic therapy 86,87 and for titrating fluid shifts during haemodialysis 88 . However, the presence of too much fluid in the chest can cause so low a baseline impedance signal ( Z 0 < 15 Ω) that it interferes with accuracy 43,89 .…”

Utility of Impedance Cardiography for the Identification of Short-Term Risk of Clinical Decompensation in Stable Patients With Chronic Heart Failure

“…Although one study suggested that knowledge of ICG parameters can alter a physician's treatment plans (24), and others have suggested that ICG parameters improve when patients receive effective drugs for heart failure (25,26), it is not clear whether ICG-directed modifications improve clinical outcomes beyond that expected if physicians responded appropriately to clinical signals in the absence of ICG data. In the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) (27), the use of in-hospital invasive hemodynamic measurements to titrate treatment failed to alter long-term outcomes, but such assessments were not repeated during the period of follow-up.…”