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Effects of dopamine and dobutamine on the distribution of pulmonary blood flow during lobar ventilation hypoxia and lobar collapse in dogs
Author(s) -
McFARLANE P. A.,
MORTIMER A. J.,
RYDER W. A.,
MADGWICK R. G.,
GARDAZ JP.,
HARRISON B. J.,
SYKES M. K.
Publication year - 1985
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1985.tb00144.x
Subject(s) - hypoxia (environmental) , blood flow , medicine , anesthesia , hypoxic pulmonary vasoconstriction , cardiology , vasoconstriction , chemistry , oxygen , organic chemistry
. Hypoxic pulmonary vasoconstriction was induced in the left lower lobe of fifteen dogs by ventilating the lobe with 7% O 2 or by absorption collapse, and the distribution of flow between the lobe and the remainder of the lung was measured with electromagnetic flow probes. The lobar to total blood flow ratio was reduced by lobar ventilation hyoxia and decreased further during lobar collapse. In seven dogs, an infusion of 20 μg kg ‐1 min ‐1 of dopamine produced an increase in total blood flow, an increase in pulmonary artery pressure ( P lt; 0·01), and an increase in lobar to total flow ratio ( P lt; 0·05) during both hypoxic states. There was a significant fall in arterial P O 2 ( P < 0·01) during ventilation hypoxia. Similar changes in total and lobar to total flow ratio ( P < 0·01) were observed in eight dogs given 20 μg kg ‐1 min ‐1 of dobutamine, but there were no changes in pulmonary artery pressure. The greater increase in total flow (+111%) resulted in a marked increase in mixed venous P O 2 and no significant changes in arterial P O 2 in this group of dogs. It is concluded that both drugs produce an increase in lobar to total blood flow ratio and shunt fraction, but that the mechanisms causing the redistribution of flow may differ.