Hemodynamic effects of dobutamine in an intact animal model

Effects of increasing infusion rates of dopamine, dobutamine, epinephrine, and phenylephrine in healthy anesthetized cats

“…23 In dogs, it is recognized that α-1 adrenergic receptor agonism does not normally have a positive inotropic effect at body temperatures considered normal 24 and that high doses of phenylephrine are needed in dogs to detect this effect. 25 In our study, pulmonary arterial pressure was significantly increased during administration of phenylephrine at an infusion rate of 0.5 μg/kg/min. This finding is similar to that in some people in which phenylephrine increased pul-monary vascular resistance more than norepinephrine at doses inducing a similar increase in systemic blood pressure.…”

Determinants of splanchnic blood flow

“…In experimental studies, alpha-adrenergic stimulation by dopamine, noradrenaline and adrenaline increase renal and visceral vascular resistance and reduce renal and visceral blood flow [61]. The effects of dobutamine depend on the balance between its alpha-mediated vasoconstriction and beta-mediated vasodilation [74]. Dopexamine with beta2and dopaminergic properties and without alphastimulation may have beneficial effects on splanchnic blood flow [41].…”

The effects of dobutamine and ephedrine on packed cell volume, total protein, heart rate, and blood pressure in anaesthetized horses

“…The administration of inotropic drugs, such as dobutamine or ephedrine, is one of the primary methods used to restore acceptable blood pressure in anaesthetized horses. The haemodynamic effects of dobutamine, a catecholamine with direct acting b 1 -, b 2 -, and a-adrenoceptor agonist activity (Ruffolo & Messick, 1985;Vernon et al, 1992), have been well characterized in the anaesthetized horse (Swanson et al, 1985). Dobutamine (2.5±5.0 mg/kg/min) increased oxygen delivery in ponies (Gasthuys et al, 1991) and horses (Dyson & Pascoe, 1990;Wertz et al, 1992) partly by increasing cardiac output and partly by increasing haemoglobin concentration.…”