The effects of mannitol on systemic and coronary hemodynamics in dogs
Takata, K.; Sakata, S.
Masui. Japanese Journal of Anesthesiology 34(7): 924-932
1985
ISSN/ISBN: 0021-4892 PMID: 3932705 Document Number: 264731
The effects of mannitol administration on systemic and coronary hemodynamics and myocardial O2 utilization were studied simultaneously, and the changes of the blood viscosity and plasma osmolality, which were induced by mannitol, were observed. A 20% mannitol solution was administered i.v. in doses of 5 ml/kg for 10 .apprx. 15 min to 20 mongrel dogs. Cardiac output, coronary blood flow, maximum left ventricular dp/dt [change in pressure/change in time] and left ventricular end-diastolic pressure increased significantly right after the administration of mannitol. Except for the left ventricular end-diastolic pressure, these parameters also increased significantly 15 min after the administration of mannitol. Mannitol had a direct positive inotropic action. The total peripheral vascular resistance and coronary vascular resistance decreased significantly right after the administration of mannitol. These significant decreases were accompanied by significant decreases in vascular hindrance (resistance/viscosity), and by a small but insignificant decrease in blood viscosity. The effects of mannitol on systemic and coronary hemodynamics resulted not only from the direct positive inotropic action, but also from the vasodilating effect of mannitol and the decrease of blood viscosity. Plasma osmolality significantly increased immediately after the administration of mannitol. The myocardial O2 availability increased significantly just after, as well as 15 min after the administration of mannitol, but myocardial O2 consumption only increased significantly right after the administration of mannitol and recovered to the control level 15 min after the administration of mannitol. Mannitol may be useful in improving cardiac function because it maintains myocardial O2 utilization, despite its positive inotropic action.