[Improved kidney function with intravenous prostaglandin E1 in patients with terminal heart failure]

In end stage congestive heart failure activation of a series of compensatory mechanisms increase renal vascular resistance and impair renal function. Prostaglandin E1 is increasingly used in the treatment of severe heart failure for its vasodilating actions. In various experimental settings prostaglandin E analogues are known to improve renal function by modulating renal filtration pressure and redistribution of renal blood flow. However, prostaglandin E1 decreases systemic blood pressure and thus, also renal perfusion pressure, a fact by which renal function might be further compromized in heart failure patients. The aim of the study was to evaluate the effects of prostaglandin E1 on excretory renal function in patients with end stage heart failure and to prove the hypothesis, that the well known local actions of prostaglandins on renal microcirculation might outweigh the negative impact of an expected decrease in perfusion pressure. 25 patients with terminal congestive heart failure were investigated. 13 patients received prostaglandin E1 at a dose of 13.5 +/- 1.9 ng/kg/min in combination with constant rates of dopamine and dobutamine (group A), 12 patients received prostaglandin E1 at a dose of 10.3 +/- 1.7 ng/kg/min without catecholamines (group B). There was no significant difference in prostaglandin dosages between groups. Kidney function was assessed by measuring plasma creatinine and urea nitrogen, urinary output, creatinine clearance, osmotic and free water clearance at baseline and after 72 h of infusion therapy. Hemodynamic parameters were measured by using a balloon tipped pulmonary arterial catheter. Hemodynamic measurements during infusion showed a significant improvement in all patients. At the same time as expected mean arterial pressure decreased in both groups (p < 0.001). Nevertheless, in both groups a significant increase of creatinine clearance during infusion was observed (in group A from 45 ml/min to 78 ml/min., p < 0.05, in group B from 59 ml/min to 105 ml/min., p < 0.001). Creatinine clearance in group B (without catecholamines) reached higher levels than group A (p < 0.05). Urinary volumes did not change during infusion therapy, whereas free water clearance significantly decreased, as an indication of an improvement of renal concentrations ability. We conclude, that in patients with end stage heart failure continuous infusion of prostaglandin E1 improves excretory kidney function. These findings suggest that the local effects of prostaglandin E1 on renal microcirculation can counterregulate the negative impact of prostaglandins on renal perfusion pressure.