The effects of dopamine on central hemodynamics and myocardial metabolism in experimental propoxyphene-induced shock.

Abstract

The hemodynamic and cardiometabolic effects of dopamine were evaluated in propoxyphene-induced circulatory shock in eight pentobarbital anesthetized pigs. Circulatory shock was induced by an infusion of propoxyphene chloride 15 mg . min-1 i.v. At shock, i.e. CI less than or equal to 2.0 l . min-1 . m-2 and/or MAP less than or equal to 60 mmHg, dopamine was infused at 10, 20, 40, 80 and 160 micrograms . kg-1 . min-1 with an interval between increments of 8 min. After 30 min at 160 micrograms . kg-1 . min-1, the infusion rate was reversibly decreased. The propoxyphene infusion of 15 mg . min-1 was continued throughout the study. Dopamine improved the circulation in seven animals; one animal died in refractory shock during dopamine infusion. Dopamine infusion at shock level resulted in an increase of the following variables (% of baseline value): MAP (69%), HR (109%), CI (138%) and SVI (129%). Normalisation was seen in MRAP (120%) and in MPAOP (100%). A profound decrease in systemic vascular resistance was unchanged. Increases were seen in left and right ventricular stroke work index, to 88% and 176% of baseline, respectively. Left ventricular dP/dt increased (170%). In the coronary circulation myocardial blood flow increased (133%) as did myocardial oxygen consumption (65%) concomitant with a decrease in myocardial oxygen uptake (41%), but coronary vascular resistance progressively decreased (38%). The myocardial propoxyphene extraction changed from +54% to -86% during peak dopamine infusion. In conclusion, dopamine reversed cardiac failure in propoxyphene overdose by a marked positive inotropic stimulation restoring contractility. A marked positive chronotropic stimulation maintained a sufficient cardiac index and a normal blood pressure in spite of a profound vasodilatation which was unresponsive to dopamine.

• Authors: J Strøm, S Häggmark, H Nyhman, S Reiz, P S Madsen, H Angelo, M Bredgaard Sørensen
• Journal: Acta anaesthesiologica Scandinavica (Acta Anaesthesiol Scand) Vol. 29 Issue 6 Pg. 643-50 (Aug 1985) ISSN: 0001-5172 [Print] England
• PMID: 4061011 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Dextropropoxyphene
• Dopamine

Topics

• Animals
• Coronary Circulation (drug effects)
• Dextropropoxyphene (blood, toxicity)
• Dopamine (pharmacology)
• Electrocardiography
• Hemodynamics (drug effects)
• Myocardium (metabolism)
• Oxygen Consumption (drug effects)
• Shock (chemically induced, physiopathology)