Although frequently mentioned, the role of PEEP-induced decreases in renal blood flow seems to be less important than the decrease in renal perfusion pressure. Restoration of renal blood flow by volume expansion does not abolish the decrease in diuresis and natriuresis ( Farge ei a/ 1995).
A recent study of human renal allograft recipients showed that renal handling of water and sodium during ventilation with PEEP was dependent on perfusion pressure, despite denervation and renal blood flow stability. Animal work demonstrated that ventilation-independent rises in inferior vena caval and renal vein pressure increased water and sodium retention, and the addition of mechanical ventilation with PEEP enhanced this effect. This phenomenon, which may depend on increases in renal tissue pressure and local neurogenic-reflex-mediated changes, needs further elucidation.
Was this article helpful?