Treatment of canine permeability pulmonary edema: short-term effects of dobutamine, furosemide, and hydralazine.

The effects of treatment of oleic acid pulmonary edema with dobutamine, furosemide, and hydralazine on cardiopulmonary function in 24 dogs were investigated. Pulmonary capillary wedge pressure (PCWP) was adjusted to approximately 7 mm Hg; 45 min after oleic acid (0.08 ml/kg), dogs were randomly divided into a control group, in which PCWP was maintained at approximately 7 mm Hg, and into treatment groups as described above. Mean time-averaged PCWP was 2.3 mm Hg in dogs treated with dobutamine, 4.1 mm Hg with furosemide, and 4.4 mm Hg with hydralazine. Four hours of treatment with dobutamine and furosemide significantly (p less than .01) reduced accumulation of lung water compared with the control and hydralazine groups. Qs/Qt was lower (p less than .05) with dobutamine and furosemide compared with the other groups. In dogs given hydralazine, cardiac output (CO) and systemic vascular resistance (SVR) remained constant over the 4 hr treatment interval. In contrast, in all other groups, SVR increased and CO decreased (both p less than .05). The short-term pulmonary effects of the above drugs are probably explained by differences in PCWP and/or by regional pulmonary vascular effects.