Sustained improvement in functional capacity after removal of body fluid with isolated ultrafiltration in chronic cardiac insufficiency: failure of furosemide to provide the same result.
OBJECTIVE
This study was designed to investigate whether a subclinical accumulation of fluid in the lung interstitium associated with moderate congestive heart failure interferes with the patient's functional capacity, and whether furosemide treatment can promote reabsorption of the excessive fluid.


BACKGROUND
In patients with moderate congestive heart failure, pulmonary overhydration may be detected by chest roentgenography even if therapy is optimized to keep the urinary output normal and to prevent weight gain and dependent edema formation. Removal of the overhydration may help define its significance.


METHODS
Patients, whose regimens of digoxin, oral furosemide, and angiotensin-converting enzyme (ACE) inhibitor therapy were kept constant, were randomly allocated to receive ultrafiltration (8 cases) or an intravenous bolus of supplemental furosemide (mean dose: 248 mg; 8 cases). The amount of body fluid removed with each method approximated 1600 mL. Functional performance was assessed with cardiopulmonary exercise tests.


RESULTS
Soon after fluid withdrawal by either method, the filling pressures of the two ventricles and body weight were reduced and plasma renin activity, norepinephrine, and aldosterone were augmented. After furosemide administration, hormone levels remained elevated for the next 4 days, and during this period, patients had positive water metabolism, recovery of the elevated ventricular filling pressures, and re-occurrence of lung congestion with no improvement in functional capacity. After ultrafiltration, levels of renin, norepinephrine, and aldosterone fell to below control values within the first 48 hours and water metabolism was equilibrated at a new set point (less fluid intake and diuresis without weight gain). The favorable circulatory and ventilatory adjustments consequent to the reabsorption of lung water improved the functional capacity of these patients. That may also have restored the lung's ability to clear norepinephrine, thus restraining its facilitation of renin release. The improvement continued 3 months after the procedure.


CONCLUSIONS
In patients with congestive heart failure the set point of fluid balance is altered in spite of oral furosemide therapy; supplemental intravenous furosemide does not shift the set point, at least not when combined with ACE inhibition. Excessive, although asymptomatic, lung water limits the functional capacity of the patient.
Agostoni
P
P
Instituto di Cardiologia dell'Università degli Studi, Fondazione I Monzino, Istituto G. Sisini, Milan, Italy.
Marenzi
G
G
Lauri
G
G
Perego
G
G
Schianni
M
M
Sganzerla
P
P
Guazzi
M D
MD
D000368:Aged; D002908:Chronic Disease; D005080:Exercise Test; D005260:Female; D005665:Furosemide / Q000008:administration & dosage / Q000627:therapeutic use*; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011654:Pulmonary Edema / Q000209:etiology / Q000503:physiopathology*; D012129:Respiratory Function Tests; D013997:Time Factors; D016896:Treatment Outcome; D014462:Ultrafiltration
D005665:Furosemide