Low dose of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis: evidence for an impaired cardiopulmonary baroreflex function
Abstract
High doses of nitroglycerin may decrease portal pressure in patients with cirrhosis with untoward effects such as arterial hypotension and a decrease in systemic O2 uptake. In the present study, low doses of nitroglycerin (7 to 15 micrograms per min, i.v.) were administered in 11 patients with cirrhosis in order to unload cardiopulmonary baroreceptor--one of the possible mechanisms by which nitroglycerin may improve splanchnic hemodynamics--and moreover to avoid deleterious systemic effects. Nitroglycerin significantly decreased right atrial pressure (-35%) and pulmonary wedged pressure (-27%) with significant increase in plasma norepinephrine concentration (+23%), which indicated that cardiopulmonary baroreceptor unloading was achieved. Changes in systemic hemodynamics were slight, although significant, with a decrease in arterial pressure (-8%) and an increase in heart rate (+8%); this indicates a minimal effect on high-pressure baroreflexes. In contrast, no significant change was observed in hepatic venous pressure gradient, hepatic blood flow and azygos blood flow. However, the fraction of cardiac output reaching the azygos system significantly increased by 18%. Plasma renin activity did not change significantly. Moreover, ...Continue Reading
References
Treatment of portal hypertension with isosorbide dinitrate alone and in combination with vasopressin
Citations
Reduced baroreflex sensitivity and pulmonary dysfunction in alcoholic cirrhosis: effect of hyperoxia
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