Renal haemodynamic response to amino acids infusion in an experimental porcine model of septic shock.

BACKGROUND:Acute kidney injury (AKI) is common in sepsis. Treatments allowing maintenance of renal blood flow (RBF) could help to prevent AKI associated with renal hypoperfusion. Amino acids (AA) have been associated with an increase of RBF and glomerular filtration rate (GFR) in several species. The aim of this study was to evaluate the effects of an AA infusion on RBF and GFR in a porcine model of septic shock. METHODS:A total of 17 piglets were randomly assigned into three groups: Sham (Sham, n = 5), sepsis without AA (S-NAA, n = 6), sepsis treated with AA (S-AA, n = 6). Piglets preparation included the placement of ultrasonic transit time flow probes around left renal artery for continuous RBF measurement; ureteral catheters for GFR and urine output evaluation; pulmonary artery catheter for cardiac output (CO) and pulmonary arterial pressure measurements. Mean arterial pressure (MAP) and renal vascular resistance (RVR) were also determined. Septic shock was induced with a live Pseudomonas aeruginosa infusion. Crystalloids, colloids and epinephrine infusion were used to maintain and restore MAP > 60 mmHg and CO > 80% from baseline. RESULTS:Renal haemodynamic did not change significantly in the Sham group, whereas RBF increased slightly in the S-NAA group. Conversely, a significant increase in RVR and a decrease in RBF and GFR were observed in the S-AA group. AA infusion was associated with a higher requirement of epinephrine [340.0 (141.2; 542.5) mg vs. 32.5 (3.8; 65.0) mg in the S-NAA group P = 0.044]. CONCLUSION:An infusion of amino acids impaired renal haemodynamics in this experimental model of septic shock.