[Changes of renal hemodynamics in dogs with endotoxemic shock]

To explore the changes of renal hemodynamic in dogs with endotoxemic shock (ES) and their potential roles in acute kidney injury (AKI).

Canine endotoxic shock model was induced by an infusion of lipopolysaccharide of Escherichia coli through pulmonary artery catheter (PAC). Systemic hemodynamics and left renal blood flow (RBF) was monitored by PAC, pulse index continuous cardiac output (PiCCO) and ultrasonic blood flow meter. Blood and urine specimens were harvested timely for blood gas analysis, renal function tests and biochemical detection.

Hemodynamics: CO and RBF fluctuated widely but without any significance (P > 0.05). The values of mean arterial pressure (MAP), systemic vascular resistance (SVR), renal vascular resistance (RVR) and 2-hour urine volume significantly decreased (all P < 0.05) while extravascular lung water (EVLW) increased markedly (P < 0.05). Renal function: There was a drop in CCr, urine osmotic pressure and an elevation in SCr and NAG. RBF was correlated positively with CO (R(2) = 0.630, P = 0.001) .However, it had no correlation with MAP (R(2) = 0.009, P = 0.758) . CCr was correlated positively with MAP (R(2) = 0.415, P = 0.003) . However, it had no correlation with RBF or CO (P > 0.05 ). The auto-regulation curve of GFR had a shift to the right.

RBF is positively correlated with cardiac output in endotoxin shock. Renal pressure perfusion may decrease obviously without any noticeable change of renal flow perfusion. The shift of renal auto-regulation under pressure perfusion occurs at the early stage of septic shock.