Acute haemodynamic effects of frusemide in patients with normal and raised left atrial pressures.

Abstract

Frusemide is a well-established diuretic (Vorburger, 1964;McKenzie, Fairley, and Baird, 1966;Kirkendall and Stein, 1968), and a mild hypotensive when given in a dosage of over 120 mg. daily (Davidov, Kakaviatos, and Finnerty, 1967). It is commonly used in the treatment of acute pulmonary oedema with beneficial results (Stason et al., 1966;Peltola, 1965;Biagi and Bapat, 1967 Though some work has been done-on the systemic haemodynamic effects of frusemide (International Furosemide Symposium, Bad Homburg, 1963), little or no information is available on its effect on left atrial pressure and pulmonary haemodynamics in patients either with normal or raised left atrial pressure. It was because of this paucity of information in association with its obvious clinical benefit in patients with acute pulmonary oedema that this study was instituted to investigate its haemodynamic effects in these 2 groups of patients. PATIENTS AND METHODSA total of 23 patients was studied, and for convenience the patients were divided into 2 groups. In the first group were 8 patients whose mean left atrial pressure was under 10 mm. Hg. In the second group 15 patients had mitral valve disease with a mean left atrial pressure above 10 mm. Hg, six of them had episodes of paroxysmal nocturnal dyspnoea, and all experienced dyspnoea on exertion.All patients had right heart catheterization and either Received May 9, 1969. * In receipt of a Research Award from the British Heart Foundation. 711 a brachial artery needle or retrograde aortic catheter inserted. In addition, those with valvular heart disease had left atrial catheterization performed using a modified Brockenbrough needle with a blunt-ended stylette. Cardiac outputs were measured by injecting indocyanine green dye (2-5 mg.) into the pulmonary artery with constant arterial withdrawal through a Gilford densitometer, and the dye curve was recorded on either a Sanborn photographic recorder or an ultraviolet recorder. Pressures in the pulmonary artery, brachial artery or central aorta, and the left atrium were measured at rest under mild sedation using a Sanborn pressure transducer (Model 267B) coupled to a Sanborn photographic recorder. The reference point for all pressure determinations was 5 cm. below the sternal angle and a simultaneous electrocardiogram was taken with all pressure measurements. One or two control cardiac outputs were determined and their average taken. Frusemide was injected directly into the pulmonary artery through the catheter in a dose of 40 mg. over a two-minute period, and the above parameters were measured 15 minutes and 45 minutes later.The following values were derived from the results: Cardiac output (ml./sec.) x 1332Central blood volume (ml.) = Appearance time of dye (sec.) x cardiac output (ml./sec.)Pressure-time index (mm. Hg sec./min.) = Ejection time (sec.) x mean ejection pressure (mm. Hg) x heart rate (beats/min.)

Decreased Pulmonary Transvascular Fluid Filtration in Awake Newborn Lambs after Intravenous Furosemide

“…Lal et al (1) found no significant change in Ppa or Pla after furosemide in human patients with an initial Pla less than 10 torr; when Pla was above 10 torr however, furosemide caused a significant decrease in Ppa and Pla. Decreases of Ppa and Pla were small and inconsistent in our base-line experiments, perhaps because these were normal lambs; the changes were more evident in lambs with pulmonary edema from circulatory overload.…”

“…Several investigators have attributed its benefits to reduced plasma volume and pulmonary vascular pressures that result from diuresis (1)(2)(3)(4). Others have suggested that patients with pulmonary edema derive rapid improvement from furosemide even before diuresis, because of an extrarenal site of action (5-7), possibly related to changes in pulmonary blood volume.…”

Effect of furosemide in canine low-pressure pulmonary edema.

“…Their effectiveness is attributable to the reduced filling pressure of the left heart and pulmonary capillaries, which results when central blood volume is reduced by diuresis and by the diuretic enhanced capacitance of the systemic venous bed (1)(2)(3)(4)(5)(6). Conceivably, such other mechaReceived for publication 11 May 1979 and in revised form 29 June 1979. 1494 nisms as increased plasma oncotic pressure or increased pulmonary lymph flow also reduce the pulmonary edema.…”

Comparison of the acute vascular effects of frusemide and bumetanide.

“…While bumetanide is known to produce increases in renal blood flow (Bollerup et al, 1974), the acute effects on left ventricular filling pressure and venous capacitance are less well defined and unlike other diuretics (Lal et al, 1969;Dikshit et al, 1973;Ramirez & Abelmann, 1968) bumetanide is associated with a decrease in total peripheral systemic resistance (Ziacchi et al, 1981).…”