Renal effects of low to moderate doses of dopamine in newborn piglets

Endotoxemia and the Effects of Dopamine on Renal Functions of Neonatal Piglets

“…Recently, the infusion of low-dose or 'renal dose' dopamine has been discouraged [4]. Controlled human studies have demonstrated that not only does dopamine not confer a nephroprotective effect [5] it may instead have a detrimental effect on renal function, as was also noted in animal studies [6][7][8]. We have also shown that in healthy neonatal animals 'low-dose' dopamine does not improve renal perfusion [7].…”

“…Nineteen piglets were sedated, anesthetized and intubated with catheters placed into the jugular vein, left ventricle and femoral artery of each animal as previously reported by us [7]. Body temperature was maintained between 37 and 39°C using a heating blanket and a suprapubic cystostomy was made to collect urine samples.…”

“…Mean arterial pressure and HR values were then averaged and plotted each hour. Cardiac output (CO), cardiac index (CI) and systemic vascular resistance (SVR) were assessed by injecting 15-Ìm diameter radio-labeled microspheres at baseline, 1 h and 3 h and by simultaneously drawing reference blood samples as previously described [7,9]. Arterial blood gas levels were monitored every 30 min (278 Blood Gas System; CIBA Corning, Medfield, Va., USA) and respiratory acidosis/alkalosis were corrected with ventilator adjustments.…”

“…Glomerular filtration rate (GFR) and clearance of p-amino hippuric acid (CPAH) were calculated by infusing iothalamate and p-amino hippuric acid and measuring their serum and urine levels [7,9]. Renal vascular resistance and GFR were calculated using standard formulae.…”

“…Controlled human studies have demonstrated that not only does dopamine not confer a nephroprotective effect [5] it may instead have a detrimental effect on renal function, as was also noted in animal studies [6][7][8]. We have also shown that in healthy neonatal animals 'low-dose' dopamine does not improve renal perfusion [7]. Although the use of dopamine for its direct action on the kidney may be falling out of favor, it could indirectly benefit the kidneys if its actions on the cardiovascular and endocrine systems lead to increased perfusion pressure and blood flow into the heart and kidneys.…”