Intravenous (IV) loop diuretics have been a key component in treating pulmonary edema since the 1960s and has a Class 1 recommendation in the 2021 guidelines for acute heart failure. However, no randomized clinical trials have investigated loop diuretics versus other interventions for acute heart failure, and clinical knowledge of the hemodynamic effects of furosemide is based in studies from the 1970s. In this study, we aim to assess the acute effect of furosemide on cardiac filling pressures and pulmonary congestion.

Hypothesis:

Administration of furosemide induces a hyperacute (within 30 minutes) lowering of cardiac filling pressures and pulmonary congestion before significant diuresis occurs.

Design:

A prospective, interventional study including 20 patients admitted due to a clinical diagnosis of acute heart failure with pulmonary congestion.

Intervention:

80 mg of furosemide is administered IV. Measurements include blood pressure, peripheral oxygen saturation, pulmonary fluid content by ReDS*, ultrasound examination of heart and lungs, and assessment of cardiac filling pressures with doppler and strain analysis. Measurements are repeated at several time points until 6 hours have passed.

Prospective observational study of the acute and subacute effects of furosemide in patients with acute heart failure.

After inclusion, 80 mg of furosemide is administered IV.

Measurements include blood pressure, peripheral oxygen saturation, pulmonary fluid content, ultrasound examination of heart and lungs, and assessment of cardiac filling pressures with doppler and strain analysis. Measurements are repeated at several time points until 6 hours have passed.

Inclusion Criteria:

1. Age ≥ 18 years
2. Clinical diagnosis of acute heart failure requiring hospitalization
3. Systolic blood pressure ≥100 mmHg
4. Oxygen saturation <94% or need of oxygen
5. Confirmed pulmonary congestion on x-ray or ReDS

Exclusion Criteria:

1. More than 40 mg iv furosemide within the last three hours before randomization, including prehospital administration
2. Ongoing ventricular taky- or brady-arrythmias or supraventricular arrhythmias with HR > 180 or < 40 bpm.
3. Known chronic obstructive lung disease
4. Pacemaker or ICD on the right side
5. Congenital heart malformations or intra-thoracic mass that would affect the right lung anatomy (e.g. dextrocardia, lung carcinoma)
6. Wounds, burns, healing tissue, skin infection or recent skin graft or flap where the sensors should be attached to the skin
7. Height less than 155 cm or higher than 200 cm
8. BMI of less than 18 or more than 38