Does low dose dopamine attenuate the decrease of renal function in the treatment of patients under controlled mechanical ventilation with positive end expiratory pressure?

Abstract

Controlled mechanical ventilation (CMV) with positive and expiratory pressure (PEEP) is often used to improve the pulmonary gas exchange in patients with acute respiratory distress syndrome. However, this ventilatory technique may induce hemodynamic and hormonal changes which may lead to vital organ dysfunction, such as oliguria. Low dose dopamine, acting as a dopaminergic receptor agonist, may improve vital organ perfusions, i.e. renal, mesenteric and coronary perfusions. The purpose of this current study was to evaluate the effects of low dose dopamine on renal function and hemodynamic change during controlled mechanical ventilation with PEEP. The study was performed on 10 patients treated with PEEP in the surgical intensive care unit. Starting with 0 cmH2O of PEEP and adding 4 cmH2O of PEEP at 4-hour intervals until it reached 12 cmH2O of PEEP, dopamine, 2 ug/kg/min, was selectively, administered, intravenously during the last two hours of each four hour intervals. Following each procedure, hemodynamic parameters, urine output, creatinine clearance and fractional excretion of sodium were measured. The cardiac index and mean arterial pressure had both decreased, but the mean pulmonary arterial pressure was increased at 12 cmH2O of PEEP compared with 0 cmH2O of PEEP in both groups with and without low dose dopamine. The main result of this study was that low dose dopamine attenuated the decrease of the cardiac index, urine output and creatinine clearance induced by mechanical ventilation with PEEP at 12 cmH2O.

Mechanical Ventilation and Lung–Kidney Interactions

“…Several small trials have shown that fluid administration and the use of vasoactive drugs (dopamine at 5 g/kg per min or fenoldopam) may improve renal function (24,26,27), but results are not consistently positive (for example, no benefit of dopamine at 2 g/kg per min) (28). It is unlikely that approaches focused solely on the hemodynamic and neurohormonal mechanisms of ALI-induced AKI will be clinically effective in preventing or treating this multifactorial problem, and the development of optimal interventional strategies will require more research into the molecular and cellular mechanisms involved (29).…”

Mechanical Ventilation and the Kidney

“…Several small trials have shown that fluid administration and the use of vasoactive drugs (dopamine at 5 g/kg/min or fenoldopam) may improve renal function [44,81,82] , but results are not consistently positive (for example, there was no benefit of dopamine at 2 g/ kg/min) [83] . It is unlikely that approaches focused solely on the hemodynamic and neurohormonal mechanisms of ALI-induced AKI will be clinically effective in preventing or treating this multifactorial problem, and the development of optimal interventional strategies will require more research into the molecular and cellular mechanisms involved [84] .…”

Controversy: Is there a "renal dose" dopamine?

“…Earlier studies in animals have shown the natruretic and diuretic effects of dopamine. Whether or not this effect is a direct effect of dopamine on the kidneys or secondary to changes in hemodynamics has been debated for many years (2,6,7).…”